Search

PurposesMethodsResultsConclusionsTo determine the relationship between carotid artery stenosis (CAS) and the development of open-angle glaucoma (OAG) in the Taiwanese population.This retrospective cohort study was conducted using Chang Gung Research Database. Cox-proportional hazards model was applied to calculate the hazard ratio for OAG between CAS and the control cohort.Among 19,590 CAS patients, 17,238 had mild CAS (<50%), 1,895 had moderate CAS (50–69%), and 457 had severe CAS (≥70%). The CAS cohort had a higher proportion of several comorbidities. After adjusting for comorbidities, no significant difference in OAG development was found between CAS and control cohorts. Matching for key comorbidities, no significant differences in OAG incidence were found between matched cohorts (P = .869). Subdividing the matched CAS cohort by stenosis severity: mild (<50%), moderate (50–69%), and severe (≥70%), a statistically significantly lower OAG risk was observed in patients with mild CAS stenosis (HR: 1.12, 95% CI = 1.03–1.21, P = .006). Kaplan-Meier analysis revealed reduced OAG incidence in CAS patients who underwent surgical intervention, compared to the control cohort (P <.001). Subgroup analysis revealed that patients in the mild CAS stenosis group, those who underwent surgical intervention exhibited a reduced OAG risk (HR: 0.29, 95% CI = 0.15–0.58, P = .001).No statistically significant differences in OAG risk were observed between patients with CAS and the control cohort. The severity of CAS appears to influence OAG risk, with surgical intervention potentially offering protective effects, particularly in patients with mild CAS stenosis (<50%), suggesting that enhanced ocular perfusion post-surgery may act as a protective factor against OAG development. [ABSTRACT FROM AUTHOR]

Purpose: To determine the correlation of Mean Ocular Perfusion Pressure (MOPP) with Mean Arterial Pressure (MAP) in primary open angle glaucoma (POAG)and normal tension glaucoma. Study Design: Cross sectional study. Place and Duration of Study: Khyber Teaching hospital, Peshawar from July, 2017 to December, 2019. Methods: A total of 375 patients with POAG were admitted in the hospital. Patients with variable blood pressure (BP) on admission or history of blood pressure or using anti-hypertensive drugs were selected. Patients with secondary Glaucoma, Primary Angle closure Glaucoma, patients with Diabetes mellitus and age below 40 years were excluded. Finally,200 patients were recruited by convenience sampling. Forty-eight hours monitoring of MAP and Intra ocular pressure (IOP) phasing were done. MAP, MOPP and peak IOP were charted. Results: MAP and MOPP variability was observed in 53% of patients with POAG. The Pearson co-relation coefficient for those patients in which intervention had yet not been done was -0.460 suggesting a moderate negative correlation between MOPP and IOP (p value <0.01). In IOP controlled patients, the coefficient was - 0.346 (p<0.01). The results showed a negative correlation between the two values in both data sets. The correlation co-efficient for MAP and IOP in both pre-admission and controlled IOP patients showed strong positive correlation (0.816 and 0.854 respectively for two tailed tests with 0.01 significance). Conclusion: MOPP, MAP and IOP are correlated and their determination is important in all Primary Open Angle Glaucoma particularly in Normal Tension Glaucoma. [ABSTRACT FROM AUTHOR]

Abstract Backgroud The aim of this study was to investigate the associations between fluctuation in blood pressure (BP), ocular perfusion pressure (OPP) and visual field (VF) progression in normal-tension glaucoma (NTG). Methods This prospective, longitudinal study included 44 patients with NTG. Only newly diagnosed NTG patients who had not been treated with a glaucoma medication were included. Patients were examined every year for 7 years. Intraocular pressure (IOP), heart rate (HR), systolic BP (SBP), diastolic BP (DBP), ocular perfusion pressure (OPP), and diastolic ocular perfusion pressure (DOPP) were measured at the same time. Ophthalmic examinations, including perimetry, were performed also. Initial VF were compared with follow-up data after 7 years. Results After 7 years of follow-up, 9 of the 44 patients showed VF progression. The standard deviation (SD) of SBP and OPP were significantly associated with VF progression (P = 0.007,

Backgroud: The aim of this study was to investigate the associations between fluctuation in blood pressure (BP), ocular perfusion pressure (OPP) and visual field (VF) progression in normal-tension glaucoma (NTG). Methods: This prospective, longitudinal study included 44 patients with NTG. Only newly diagnosed NTG patients who had not been treated with a glaucoma medication were included. Patients were examined every year for 7 years. Intraocular pressure (IOP), heart rate (HR), systolic BP (SBP), diastolic BP (DBP), ocular perfusion pressure (OPP), and diastolic ocular perfusion pressure (DOPP) were measured at the same time. Ophthalmic examinations, including perimetry, were performed also. Initial VF were compared with follow-up data after 7 years. Results: After 7 years of follow-up, 9 of the 44 patients showed VF progression. The standard deviation (SD) of SBP and OPP were significantly associated with VF progression (P = 0.007, < 0.001, respectively). Multiple regression analysis showed that VF progression was significantly associated with SD of OPP (odds ratio, OR = 2.012, 95% CI = 1.016–3.985; P = 0.045). Conclusions: Fluctuation in OPP was associated with VF progression in patients with NTG. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate diabetic retinopathy as a risk factor for open-angle glaucoma. Study Design: Case control study. Place and Duration of Study: Munawar Memorial Hospital Chakwal from December 2021 to April 2022. Methods: A sample of 206 eyes of 103 diabetic patients, 40 to 65 years of age and either gender were included in the study. The eyes were divided into two groups on the basis of presence and absence of diabetic retinopathy. Data included age, gender, visual acuity, intraocular pressure, type, and duration of diabetes mellitus. Fundus examination was carried out using a 90 Diopters lens. Diabetic retinopathy was graded according to the early treatment diabetic retinopathy scale (ETDRS). Primary open angle glaucoma was diagnosed on the basis of optic nerve head changes, defective visual field and raised intraocular pressure. Data was analyzed by IBM SPSS Statistics for Windows, Version 20.0. Results: Of 103 subjects, 52 subjects were male and 51 were female. Of the 206 eyes of 103 subjects, 100 eyes had no signs of diabetic retinopathy while 106 eyes had signs of diabetic retinopathy. Fifty six eyes had primary open angle glaucoma. Chi-square and a multivariate regression model were used for analysis. The odds ratio of diabetic retinopathy for primary open angle glaucoma was 1.50. Conclusion: In conclusion, Diabetic retinopathy was found to be a significant risk for developing primary open angle glaucoma in addition to other contributing factors like age, duration of diabetes mellitus, increased intraocular pressure, Ocular Perfusion pressure and cup disc ratio. [ABSTRACT FROM AUTHOR]

Purpose: To describe a case of non-arteritic ischemic optic neuropathy (NAION) secondary to Posner-Schlossman syndrome in a twenty-six-year-old female. Observations: A 26-year-old female presented with painful visual loss of the left eye, elevated intraocular pressure of 38 mmHg, and trace to 1+ anterior chamber cell. Diffuse optic disc edema in the left eye and a small cup-to-disc ratio of the right optic disc were evident. Magnetic resonance imaging was unremarkable. Conclusions and Importance: The patient was diagnosed with NAION secondary to Posner-Schlossman syndrome, an uncommon ocular entity that can significantly affect vision. Posner-Schlossman syndrome can cause a decrease in ocular perfusion pressure involving the optic nerve and can lead to ischemia, swelling, and infarction. NAION should be considered in the differential diagnosis of young patients with sudden development of optic disc swelling and increased intraocular pressure with normal magnetic resonance imaging findings.

Abstract Background Optical coherence tomography angiography (OCTA) is a novel technology that provides a noninvasive, dye-less method to visualize the blood vessels of the retina. In the present study, we investigate macular microvascular density and the correlation of ocular and demographic factors using OCTA in Posner-Schlossman syndrome (PSS) patients. Methods This is a prospective observational study. All PSS patients and age- and sex-matched healthy subjects underwent complete ophthalmologic examination, and RE, BCVA, IOP, CCT, AL, CMT, GCIPI, RNFL, C/D ratio were recorded. The whole-image vessel density (wiVD) and whole-image perfusion density (wiPD), three-circle (1 mm central ring, 3 mm inner ring, 6 mm outer ring), and four-quadrant segmental VD and PD were calculated. Results Seventeen PSS patients and 17 healthy subjects were enrolled in this study. The mean age was 42.65 ± 11.22 years in PSS patients and 42.71 ± 10.50 years in healthy controls. IOP, CCT, and C/D ratio were higher in PSS-attacked eyes, and BCVA, OPP and RNFL thickness was lower than those in the fellow eyes (p

Purpose: To investigate the change pattern of ocular perfusion pressure (OPP) and intra-ocular pressure (IOP) after short-term and long-term aerobic exercise.Methods: In this prospective, single-masked, randomized clinical trial, 123 patients with a primary open angle glaucoma that locally used prostaglandin analog alone were randomly divided into the exercise and control groups. In the short-term study, all individuals underwent a cycling exercise at moderate intensity (20% Wmax for 10 minutes) and high intensity (60% Wmax for 5 minutes). During the long-term study, the exercise group is characterized by regular jogging exercise lasting for 30 minutes during 6: 00-10: 00 in the morning for 3 months, with the exercise frequency of at least 20 times per month, and with the intensity reflected by the target heart rate. The control group is designed as a group with irregular exercise.Results: After short-term aerobic exercise, IOP significantly decreased, whereas the ocular perfusion pressure (OPP) significantly increased. The decreasing amplitude of IOP is related to the baseline of IOP, the intensity of exercise, gender, and so on. After 3 months of long-term exercise, the changes in the IOP level of the exercise group indicated a decreasing trend.Conclusion: The significant decrement of IOP and the increment of OPP suggest that aerobic exercise is beneficial for patients with primary open-angle glaucoma and appropriate aerobic exercise is appropriate in treating glaucoma patients.Trial registration: ChiCTR, ChiCTR-TRC-10001055. Registered one October 2010-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj = 8483. [ABSTRACT FROM AUTHOR]

Purpose: Impaired ocular blood flow is an important risk factor in the pathogenesis of open-angle glaucoma (OAG). Studies have reported that dorzolamide 2% may be effective in improving ocular blood flow (OBF) in OAG patients. The objective of this study was to determine the efficacy of dorzolamide 2% (DORZOX, Cipla Ltd.) in improving retrobulbar blood flow in an Indian setting.Methods: The study was conducted as an interventional pilot project in 24 healthy subjects and 19 OAG patients. Baseline OBF measurements were done for all glaucoma patients with color Doppler imaging (CDI). Baseline ocular perfusion pressure (OPP) was calculated for all participants. Glaucoma patients were given dorzolamide 2% thrice daily for 12 weeks. The primary efficacy endpoints were mean changes in the CDI parameters of the retrobulbar vessels and OPP posttreatment. The secondary endpoint was mean change in the intraocular pressure (IOP) and adverse events, if any.Results: In comparison to healthy subjects, glaucoma patients displayed significantly reduced baseline OPP (P = 0.002). Treatment with dorzolamide 2% for 12 weeks led to a significant increase in OPP (P < 0.001) and a significant increase in end diastolic velocity (EDV) in all major ophthalmic arteries like ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA) (P < 0.001, P = 0.04, and P = 0.0075, respectively). A significant reduction in the intraocular pressure (IOP; P = 0.007) was observed posttreatment, with no adverse events reported.Conclusion: Dorzolamide 2% significantly improved parameters such as the EDV and OPP in major ophthalmic arteries. This pilot study shows promising results on using dorzolamide for treating Indian patients with OAG. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the change pattern of ocular perfusion pressure (OPP) and intra-ocular pressure (IOP) after short-term and long-term aerobic exercise. Methods: In this prospective, single-masked, randomized clinical trial, 123 patients with a primary open angle glaucoma that locally used prostaglandin analog alone were randomly divided into the exercise and control groups. In the short-term study, all individuals underwent a cycling exercise at moderate intensity (20% Wmax for 10 minutes) and high intensity (60% Wmax for 5 minutes). During the long-term study, the exercise group is characterized by regular jogging exercise lasting for 30 minutes during 6: 00–10: 00 in the morning for 3 months, with the exercise frequency of at least 20 times per month, and with the intensity reflected by the target heart rate. The control group is designed as a group with irregular exercise. Results: After short-term aerobic exercise, IOP significantly decreased, whereas the ocular perfusion pressure (OPP) significantly increased. The decreasing amplitude of IOP is related to the baseline of IOP, the intensity of exercise, gender, and so on. After 3 months of long-term exercise, the changes in the IOP level of the exercise group indicated a decreasing trend. Conclusion: The significant decrement of IOP and the increment of OPP suggest that aerobic exercise is beneficial for patients with primary open-angle glaucoma and appropriate aerobic exercise is appropriate in treating glaucoma patients. Trial registration: ChiCTR, ChiCTR-TRC-10001055. Registered one October 2010-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj = 8483

Purpose: Impaired ocular blood flow is an important risk factor in the pathogenesis of open-angle glaucoma (OAG). Studies have reported that dorzolamide 2% may be effective in improving ocular blood flow (OBF) in OAG patients. The objective of this study was to determine the efficacy of dorzolamide 2% (DORZOX, Cipla Ltd.) in improving retrobulbar blood flow in an Indian setting. Methods: The study was conducted as an interventional pilot project in 24 healthy subjects and 19 OAG patients. Baseline OBF measurements were done for all glaucoma patients with color Doppler imaging (CDI). Baseline ocular perfusion pressure (OPP) was calculated for all participants. Glaucoma patients were given dorzolamide 2% thrice daily for 12 weeks. The primary efficacy endpoints were mean changes in the CDI parameters of the retrobulbar vessels and OPP posttreatment. The secondary endpoint was mean change in the intraocular pressure (IOP) and adverse events, if any. Results: In comparison to healthy subjects, glaucoma patients displayed significantly reduced baseline OPP (P = 0.002). Treatment with dorzolamide 2% for 12 weeks led to a significant increase in OPP (P < 0.001) and a significant increase in end diastolic velocity (EDV) in all major ophthalmic arteries like ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA) (P < 0.001, P = 0.04, and P = 0.0075, respectively). A significant reduction in the intraocular pressure (IOP; P = 0.007) was observed posttreatment, with no adverse events reported. Conclusion: Dorzolamide 2% significantly improved parameters such as the EDV and OPP in major ophthalmic arteries. This pilot study shows promising results on using dorzolamide for treating Indian patients with OAG.

This study aimed to compare intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and central corneal thickness (CCT) acute adaptations to squat exercise using elastic bands (EB) or weight plates (WP) together with the weight of the bar and applying maximal or submaximal efforts. Cardiovascular parameters (pulse pressure, mean blood pressure, heart rate), rate of perceived exertion, kilograms, and number of repetitions served to monitor psychophysiological acute variations. Twenty physically active males (25.55 ± 4.75 y.o.) underwent two sessions (one for familiarization and one for the experimental trial). In the experimental session, ocular and cardiovascular pre-exercise measurements were taken. Then, two sets using WP and two using EB attached to the bar with the same load were performed by each subject in random order. Immediately after finishing each set, the subjects rated perceived exertion, and cardiovascular and ocular measurements were taken, in this order. An ANOVA with post-hoc LSD evaluated differences between sets. IOP significantly decreased ( p < 0.001, ηp² = 0.513), and MOPP ( p < 0.001, ηp² = 0.413) and cardiovascular variables significantly increased due to the exercise effect; CCT changes were non-significant. No significant effect of the material, level of effort, or their interaction was observed in the IOP and MOPP (p > 0.05). EB permitted more repetitions to be performed and led to non-significantly lower post-exercise IOP values (effect size [ d] compared to resting 0.79 and 1.00) in comparison to WP (d = 0.73--0.74). IOP and ocular and systemic hemodynamic responses are similar when using EB instead of WP to load the bar, with EB allowing a larger number of repetitions. Data presented in this paper may help with the prescription of resistance training for people with glaucoma risk factors. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the effects of hemodialysis (HD) on intraocular pressure (IOP), ocular perfusion pressure (OPP), and blood pressure (BP) in patients with end stage renal disease (ESRD). Material and Methods: The study included 106 eyes of 54 patients (32 women and 22 men) undergoing HD for ESRD. Systolic and diastolic blood pressure (SBP and DBP) were measured by sphygmomanometer; IOP was measured with a Tonopen before HD (pre-HD), at hour 2 of HD (mid-HD), and at the end of HD (post-HD). OPP was estimated by measuring the difference between two-thirds of the mean arterial pressure and the IOP value. Blood samples were obtained before and after HD for analysis of blood urea nitrogen (BUN), creatinine (Cr), and potassium (K) levels. Results: There was no statistically significant change in IOP between the three time points (ppre-mid=0.080, ppre-post=0.328, pmid-post=0.582). SBP, DBP, and OPP decreased significantly during HD compared to pre-HD values. Conclusion: Although there is no significant change in IOP during HD, the presence or suspicion of glaucoma should be questioned in patients undergoing HD in order to prevent possible optic disc damage due to the decrease in OPP. [ABSTRACT FROM AUTHOR]

This study aimed to compare intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and central corneal thickness (CCT) acute adaptations to squat exercise using elastic bands (EB) or weight plates (WP) together with the weight of the bar and applying maximal or submaximal efforts. Cardiovascular parameters (pulse pressure, mean blood pressure, heart rate), rate of perceived exertion, kilograms, and number of repetitions served to monitor psychophysiological acute variations. Twenty physically active males (25.55 ± 4.75 y.o.) underwent two sessions (one for familiarization and one for the experimental trial). In the experimental session, ocular and cardiovascular pre-exercise measurements were taken. Then, two sets using WP and two using EB attached to the bar with the same load were performed by each subject in random order. Immediately after finishing each set, the subjects rated perceived exertion, and cardiovascular and ocular measurements were taken,in this order. An ANOVA with post-hoc LSD evaluated differences between sets. IOP significantly decreased (p < 0.001, ƞp² = 0.513), and MOPP (p 0.05). EB permitted more repetitions to be performed and led to non-significantly lower post-exercise IOP values (effect size [d] compared to resting 0.79 and 1.00) in comparison to WP (d = 0.73–0.74). IOP and ocular and systemic hemodynamic responses are similar when using EB instead of WP to load the bar, with EB allowing a larger number of repetitions. Data presented in this paper may help with the prescription of resistance training for people with glaucoma risk factors.

Introduction and objectives: Different regional anesthesia techniques for ophthalmology can have hemodynamic effects on the eye. We assessed the effects of adding clonidine to lidocaine on Intraocular Pressure (IOP), Ocular Pulse Amplitude (OPA), and Ocular Perfusion Pressure (OPP) after the sub-Tenon’s technique for cataract surgery. Methods: The study included 40 patients randomly allocated into two groups: sub-Tenon’s blockade with Lidocaine plus Saline Solution (LS) or Lidocaine plus Clonidine (LC). IOP, OPA and OPP were measured before anesthesia, and 1, 5 and 10 minutes after the injection of anesthetic solution. Results: There was no difference between the groups in IOP, OPA, and OPP baseline values. After the injection of the anesthetic solution, the IOP increased in both groups at minute one, with a mean difference of +4.67 mmHg (p = 0.001) and +2.15 mmHg (p = 0.013) at 5 minutes. The increase was lower in the LC group when compared to LS (p = 0.027). OPA decreased in both groups, with a baseline difference, after 1 minute, of -0.85 mmHg (p = -0.85 mmHg (p = 0.001), and at 5 and 10 minutes with differences of -1.17 (p = 0.001) and -0.89 mmHg (p = 0.001), respectively. The highest decrease was observed in group LC in relation to group LS (p = 0.03). There was no difference in OPP in relation to baseline measurements. Conclusions: Adding clonidine to lidocaine for sub-Tenon’s anesthesia reduced IOP and OPA without significant changes in OPP.

Background: Optical coherence tomography angiography (OCTA) is a novel technology that provides a noninvasive, dye-less method to visualize the blood vessels of the retina. In the present study, we investigate macular microvascular density and the correlation of ocular and demographic factors using OCTA in Posner-Schlossman syndrome (PSS) patients.Methods: This is a prospective observational study. All PSS patients and age- and sex-matched healthy subjects underwent complete ophthalmologic examination, and RE, BCVA, IOP, CCT, AL, CMT, GCIPI, RNFL, C/D ratio were recorded. The whole-image vessel density (wiVD) and whole-image perfusion density (wiPD), three-circle (1 mm central ring, 3 mm inner ring, 6 mm outer ring), and four-quadrant segmental VD and PD were calculated.Results: Seventeen PSS patients and 17 healthy subjects were enrolled in this study. The mean age was 42.65 ± 11.22 years in PSS patients and 42.71 ± 10.50 years in healthy controls. IOP, CCT, and C/D ratio were higher in PSS-attacked eyes, and BCVA, OPP and RNFL thickness was lower than those in the fellow eyes (p < 0.05). BCVA and OPP were improved in the PSS-attacked eyes in intermittent period (p < 0.05). The wiVD and wiPD were lower in the PSS-affected eyes than in the fellow eyes and in the control eyes in the PSS-attacked period (p < 0.05). All segmental VD and PD was lower in the PSS affected eyes than in the healthy control eyes (p < 0.05). In intermittent period, the wiVD and wiPD were lower in the PSS-affected eyes than in the fellow eyes (p < 0.05). Age, CCT, and SSI were associated with macular wiVD and wiPD in PSS attacked period. Age and CCT were associated with macular wiVD and wiPD in PSS intermittent period.Conclusion: Decreased macular superficial VD and PD was found in patients with Posner-Schlossman syndrome in attacked period and in remission. Macular wiVD and wiPD were associated with age, CCT and SSI in PSS patients. [ABSTRACT FROM AUTHOR]

Background and Objectives: The effect of positive end-expiratory pressure (PEEP) on intraocular pressure (IOP) is debatable. There have been no studies investigating the effects of PEEP on IOP during one-lung ventilation (OLV). We aimed to investigate the effects of PEEP on IOP in patients undergoing OLV for video-assisted thoracoscopic surgery (VATs). Materials and Methods: Fifty-two patients undergoing VATs were divided into a zero-PEEP (ZEEP) and a 6 cmH2O of PEEP (PEEP) groups. IOP, ocular perfusion pressure (OPP), and respiratory and hemodynamic parameters were measured before induction (T1), immediately following endotracheal intubation (T2), 30 min (T3) and 60 min (T4) after a position change to the lateral decubitus position (LDP) and OLV, and 10 min following two-lung ventilation near the end of the surgery (T5). Results: There was no significant difference in IOP and OPP between the two groups. The IOP of the dependent eye was significantly higher than that of the non-dependent eye during LDP in both groups. Peak inspiratory pressure was significantly higher in the PEEP group than in the ZEEP group at T3–T5. Dynamic compliance was significantly higher in the PEEP group than in the ZEEP group at T2–T5. The ratio of arterial oxygen partial pressure to fractional inspired oxygen was significantly higher in the PEEP group than in the ZEEP group at T4. Conclusions: Applying 6 cmH2O of PEEP did not increase IOP but enhanced dynamic compliance and oxygenation during OLV. These results suggest that 6 cmH2O of PEEP can be safely applied during OLV in LDP. [ABSTRACT FROM AUTHOR]

No abstract available.

Purpose: Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes. Methods: In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients' eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency. Results: The sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 ± 4.5, 2.8 ± 3.8, and 3.7 ± 4.7 mmHg for first, second, and third tertile, respectively (P < 0.000). OPP did not vary according to the optic disc size. Conclusion: Glaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation.

Systemic hypertension or hypertension is a very common chronic age-related disease worldwide. It is typically characterised by a sustained elevation of blood pressure, particularly when the systolic blood pressure and/or diastolic blood pressure are of more than 140 mmHg and 90 mmHg, respectively. If hypertension is not well controlled, it may lead to an increased risk of stroke and heart attack. It has been shown that hypertension is linked to various ocular diseases, including cataract, diabetic retinopathy, age-related macular degeneration, and glaucoma. Glaucoma is the leading cause of irreversible blindness worldwide. Primary open angle glaucoma is the most common form of the disease and is usually characterised by an increase in intraocular pressure. This condition, together with normal tension glaucoma, constitutes open angle glaucoma. Systemic hypertension has been identified as a risk factor for open angle glaucoma. It is speculated that blood pressure is involved in the pathogenesis of open angle glaucoma by altering intraocular pressure or ocular blood flow, or both. Recent evidence has shown that both extremely high and low blood pressure are associated with increased risk of open angle glaucoma. Additional pathogenic mechanisms, including increased inflammation likely to be involved in the development and progression of these two diseases, are discussed. [ABSTRACT FROM AUTHOR]

Background and Aims: A present prospective study was conducted to evaluate ocular changes occurring in patients undergoing spine surgery in the prone position. Material and Methods: A total of 44 patients of either sex, belonging to American society of Anaesthesiology I and II (aged 18-60 years) scheduled for elective spine surgery in prone position were enrolled in the study. Baseline IOP and MAP measurement were taken prior to induction. After induction of anaesthesia patients were intubated using flexo-metallic tube of appropriate size. IOP and MAP were recorded after induction of anaesthesia, following completion of surgery and immediately after turning the patient supine and 30 min following extubation. Blood loss and duration of surgery was also noted. The OPP was derived using the formula (OPP = MAP-IOP). Ophthalmic examination was also performed using direct and indirect ophthalmoscopy on the day prior to surgery and on first post-operative day to rule out anterior ischemic optic neuropathy (AION), posterior ischemic optic neuropathy (PION), and retinal ischemia. Results: Mean IOP significantly increased (18.91 ± 3.56 mm Hg) (P < 0.001) at the end of surgery as compared to baseline value 12.85 ± 3.07 mm Hg. As a result mean OPP significantly reduced (75.12 ± 16.45) (P = 0.0018) at the end of the procedure. Conclusion: In patient's undergoing spine surgery in the prone position, careful patient positioning with no extrinsic pressure on the eyes, minimal surgical time and blood loss, and prevention of intraoperative hypotension, should be ensured to prevent the IOP rise and a reduction in OPP which can further prevent post-operative visual disturbance.

To investigate the effect of systemic arterial blood pressure (BP) on rates of progressive structural damage over time in glaucoma. Retrospective cohort study. A total of 7501 eyes of 3976 subjects with glaucoma or suspected of glaucoma followed over time from the Duke Glaucoma Registry. Linear mixed models were used to investigate the effects of BP on the rates of retinal nerve fiber layer (RNFL) loss from spectral-domain OCT (SD-OCT) over time. Models were adjusted for intraocular pressure (IOP), gender, race, diagnosis, central corneal thickness (CCT), follow-up time, and baseline disease severity. Effect of mean arterial pressure (MAP), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) on rates of RNFL loss over time. A total of 157 291 BP visits, 45 408 IOP visits, and 30 238 SD-OCT visits were included. Mean rate of RNFL change was −0.70 μm/year (95% confidence interval, −0.72 to −0.67 μm/year). In univariable models, MAP, SAP, and DAP during follow-up were not significantly associated with rates of RNFL loss. However, when adjusted for mean IOP during follow-up, each 10 mmHg reduction in mean MAP (−0.06 μm/year; P = 0.007) and mean DAP (−0.08 μm/year; P < 0.001) but not SAP (−0.01 μm/year; P = 0.355) was associated with significantly faster rates of RNFL thickness change over time. The effect of the arterial pressure metrics remained significant after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity, and corneal thickness. When adjusted for IOP, lower MAP and DAP during follow-up were significantly associated with faster rates of RNFL loss, suggesting that levels of systemic BP may be a significant factor in glaucoma progression. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the effects of timolol and latanoprost on calculated ocular perfusion pressure (OPP) in a multicenter, prospective, crossover-design study. Methods: Nonglaucomatous volunteers were evaluated at baseline, after 1 week of timolol 0.5% dosed twice daily, and after 1 week of latanoprost 0.005% dosed nightly (randomized treatment order; 6-week washout period). Pneumatonometric intraocular pressure (IOP) and brachial blood pressure (BP) were evaluated at each visit. Using 3 commonly used equations, OPP was calculated based on IOP and BP. The OPPs at each visit were compared by using linear mixed-effects models. Results: This analysis includes 121 participants (242 eyes; 75% female, 87% White, mean age 55 years). Mean OPP (standard deviation) calculated with mean arterial pressure was 46.8 (8.1) mmHg at baseline, 48.5 (7.9) mmHg with timolol (P = 0.005), and 49.6 mmHg (8.2) with latanoprost (P < 0.001). When compared with baseline, OPP calculated with diastolic BP was significantly increased with both timolol (1.3 mmHg) and latanoprost (3.1 mmHg). The OPP calculated with systolic BP was increased with latanoprost (2.8 mmHg) but decreased with timolol (-1.3 mmHg). Timolol reduced systolic BP by 3.2 mmHg. Compared with timolol, latanoprost conferred greater increases in OPP calculated with both systolic and diastolic BP compared with baseline; however, the difference in treatment effects on OPP calculated with mean arterial pressure was not significantly different (P = 0.068). Conclusion: In this crossover study of nonglaucomatous volunteers, latanoprost increased OPP. However, timolol's benefit to OPP may be limited in part because it reduced systolic BP. Clinical Trial Registration number: NCT01677507. [ABSTRACT FROM AUTHOR]

Purpose: To investigate choroidal blood flow changes after isometric exercise in patients with chronic central serous chorioretinopathy nontreated or treated with mineralocorticoid receptor antagonists (MRA). Methods: Foveolar choroidal laser Doppler flowmetry parameters – velocity (ChVel), volume (ChVol) and blood flow (ChBF) – of 22 eyes of 22 treated patients, 16 eyes of 16 untreated patients and 19 healthy controls were measured during a squatting test. Treatment consisted in MRA administration (eplerenone 50 mg/day or spironolactone 50 mg/day). The experiment comprised three successive periods: 30 seconds of rest, 2 min of continuous squatting exercise, and 150 seconds of recovery. Significance levels were calculated using a generalized estimating equation. Results: During the squatting period, nontreated CSCR eyes had a similar change in ChVel (p = 0.8), ChVol (p = 0.8), ChBF (p = 0.5) and resistance to healthy eyes. Treated CSCR eyes exhibited significantly smaller changes in ChVel (−0.1 ± 11%, p = 0.04) than healthy eyes (6 ± 8%). No significant difference was found for ChVol and ChBF between the groups. The increase in ChVol from baseline in the nontreated CSCR group (4.4 ± 9%) was lower than that of treated group (6.7%±11%; p = 0.01). Finally, ChBF and ChVel changes in the CSCR groups were not significantly different. Conclusions: No abnormalities were detected in the changes in ChBF parameters during increased ocular perfusion pressure in nontreated CSCR patients compared with controls. MRA treatment in CSCR patients induced a significant reduction in ChBVel and an increase in ChBVol in response to isometric exercise, suggesting that MRA exerts effects on choroidal vascular changes. [ABSTRACT FROM AUTHOR]

The relationship between the eyeball size and convexity of its anterior part and the efficacy of local vacuum compression of the eye performed using a new design suction cup for impedance ophthalmopneumoplethysmography was studied. Based on the mathematical modeling of the geometric shape of the anterior segment of 75 eyes obtained by ultrasound biomicroscopy examination, it was found that the horizontal meridian curve of the anterior eye segment with a base diameter of 16.00 mm could be best approximated by a hyperbola. The surface area under the new suction cup with an inside diameter of about 16.5 mm was calculated using the formula for the segment surface area of a hyperboloid of revolution. It was determined by the convexity of the anterior part of the eye and varied from 247.3 to 271.4 mm2. The conversion coefficient of the level of applied vacuum to the level of IOP rise, calculated on the basis of individual combinations of the surface area of local vacuum compression and the eyeball size, was on average 0.83 ranging from 0.44 to 1.33. Using an individual conversion coefficient according to eyeball anatomical parameters will make it possible to measure diastolic ocular perfusion pressure during impedance OPPG with high sensitivity and accuracy.

Background: Systemic hypertension has been recognized as a potential risk factor for primary open-angle glaucoma (POAG). Purpose: The purpose of this study is to study the correlation of systemic blood pressure, intraocular pressure (IOP), and ocular perfusion pressure (OPP) for the development of glaucoma in hypertensive individuals. Methods: After Institutional Ethics Committee approval, a hospital-based case–control study was conducted in a tertiary care hospital. The study group comprised of patients with systemic hypertension, and the control group had the age- and sex-matched normotensives. POAG was diagnosed if glaucomatous cupping and characteristics visual field defects were present with open angles on gonioscopy. OPP was compared between POAG and non-POAG groups. Results: In this study of 103 hypertensive and 100 normotensive patients, the mean IOP was higher among hypertensives. There were 9 (8.74%) cases of POAG in hypertensive group and 2 (2%) in the normotensive group. The mean IOP in hypertensive group was 16.5 ± 4.5 mmHg, and that of normotensive group was 13.14 ± 3.19 mmHg. The mean OPP in hypertensive patients with glaucoma was 49.38 ± 2.6 mmHg, which was significantly lower than that of patients without glaucoma, i.e., 60.16 ± 5.42 mmHg, as indicated by P < ,0.001. Conclusion: This study reveals that hypertensive patients taking anti-HT treatment with POAG have lower mean OPP as compared to those without POAG. The higher OPP could be protective against glaucomatous condition; however, interdisciplinary management of open-angle glaucoma and hypertension is the need for a better quality of life of such patients.

Background and Aims: A present prospective study was conducted to evaluate ocular changes occurring in patients undergoing spine surgery in the prone position. Material and Methods: A total of 44 patients of either sex, belonging to American society of Anaesthesiology I and II (aged 18-60 years) scheduled for elective spine surgery in prone position were enrolled in the study. Baseline IOP and MAP measurement were taken prior to induction. After induction of anaesthesia patients were intubated using flexo-metallic tube of appropriate size. IOP and MAP were recorded after induction of anaesthesia, following completion of surgery and immediately after turning the patient supine and 30 min following extubation. Blood loss and duration of surgery was also noted. The OPP was derived using the formula (OPP = MAP-IOP). Ophthalmic examination was also performed using direct and indirect ophthalmoscopy on the day prior to surgery and on first post-operative day to rule out anterior ischemic optic neuropathy (AION), posterior ischemic optic neuropathy (PION), and retinal ischemia. Results: Mean IOP significantly increased (18.91 ± 3.56 mm Hg) (P < 0.001) at the end of surgery as compared to baseline value 12.85 ± 3.07 mm Hg. As a result mean OPP significantly reduced (75.12 ± 16.45) (P = 0.0018) at the end of the procedure. Conclusion: In patient's undergoing spine surgery in the prone position, careful patient positioning with no extrinsic pressure on the eyes, minimal surgical time and blood loss, and prevention of intraoperative hypotension, should be ensured to prevent the IOP rise and a reduction in OPP which can further prevent post-operative visual disturbance. [ABSTRACT FROM AUTHOR]

Background: Ocular perfusion pressure (OPP) is defined as blood pressure (BP) minus intraocular pressure (IOP). Low OPP may result in decreased ocular blood flow (OBF) and oxygen to the optic nerve head (ONH) and retina. Aim: To review the role of systemic hypotension and similar conditions in OPP and its influence on retinal nerve fibre layer (RNFL) thickness and the ganglion cell complex (GCC). Method: A literature search was conducted using the following search terms: ‘systemic hypotension’; ‘glaucoma’; ‘retinal nerve fibre layer’; ‘optic nerve’; ‘ocular blood flow’ and ‘ocular perfusion pressure’. Results: The Los Angeles Eye Study and Barbados Eye Study found that decreased OPP and BP increased the risk of glaucoma development by up to six times. Reduced retinal perfusion with resultant thinning of the RNFL in conditions with a similar mechanism, such as obstructive sleep apnoea syndrome, has indicated the importance of reduced OPP in retinal thickness. In the absence of any study directly showing the effect of systemic hypotension on OPP and retinal thickness, a working hypothesis proposes that reduced BP with or without normal-to-raised IOP will reduce OPP. The reduced OPP and OBF in those with systemic hypotension may result in oxidative stress and hypoxia which may then cause retinal ganglion cell death and the resultant retinal thinning. Conclusion: The increased risk of glaucoma development and progression relating to decreased BP and OPP has been proven to be of importance. Monitoring patients with systemic hypotension and evaluating the macula, ONH RNFL and GCC thickness may alert clinicians to possible glaucomatous changes.

Background and Objectives: The effect of positive end-expiratory pressure (PEEP) on intraocular pressure (IOP) is debatable. There have been no studies investigating the effects of PEEP on IOP during one-lung ventilation (OLV). We aimed to investigate the effects of PEEP on IOP in patients undergoing OLV for video-assisted thoracoscopic surgery (VATs). Materials and Methods: Fifty-two patients undergoing VATs were divided into a zero-PEEP (ZEEP) and a 6 cmH2O of PEEP (PEEP) groups. IOP, ocular perfusion pressure (OPP), and respiratory and hemodynamic parameters were measured before induction (T1), immediately following endotracheal intubation (T2), 30 min (T3) and 60 min (T4) after a position change to the lateral decubitus position (LDP) and OLV, and 10 min following two-lung ventilation near the end of the surgery (T5). Results: There was no significant difference in IOP and OPP between the two groups. The IOP of the dependent eye was significantly higher than that of the non-dependent eye during LDP in both groups. Peak inspiratory pressure was significantly higher in the PEEP group than in the ZEEP group at T3–T5. Dynamic compliance was significantly higher in the PEEP group than in the ZEEP group at T2–T5. The ratio of arterial oxygen partial pressure to fractional inspired oxygen was significantly higher in the PEEP group than in the ZEEP group at T4. Conclusions: Applying 6 cmH2O of PEEP did not increase IOP but enhanced dynamic compliance and oxygenation during OLV. These results suggest that 6 cmH2O of PEEP can be safely applied during OLV in LDP.

Purpose: Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes. Methods: In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients' eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency. Results: The sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 ±4.5, 2.8 ±3.8, and 3.7 ±4.7 mmHg for first, second, and third tertile, respectively (P <0.000). OPP did not vary according to the optic disc size. Conclusion: Glaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation. [ABSTRACT FROM AUTHOR]

Purpose: Assessment of Ocular Perfusion Pressure (OPP) requires estimation of the Mean Central Retinal Artery Pressure (MCRAP) [OPP = MCRAP-IOP]. In a seated position, MCRAP is currently estimated as 2/3 of the Mean Arterial Pressure (MAP) to account for the hydrostatic reduction of MAP at eye level. We tested a surrogate method for direct MCRAP assessment by measuring MAP with Arm-Up and cuff at eye level (AUMAP) at different postures and ages. Methods: MAP and AUMAP were assessed in a mixed population of 136 subjects (mean age 44 ± 17.39 years) including healthy participants (N = 30) and patients with optic neuropathies (Glaucoma suspects, N = 14; Open-Angle Glaucoma, N = 26, LHON, N = 19; MS, N = 47) not expected to alter systemic blood pressure. None of the subjects had history of carotid stenosis or pharmacological treatment to regulate blood pressure. AUMAP was also tested in two subgroups in supine (N = 42) and −10° Head Down body Tilt position (HDT, N = 46). Results: In the seated position, both 2/3MAP and AUMAP increased with increasing age, however with steeper (2x) slope for AUMAP (P <.0001). With decreasing angle of body tilt, AUMAP increased while MAP decreased. The mean AUMAP/MAP ratio (posture coefficient) was, seated, 0.73 (SE 0.003); supine, 0.90 (SE 0.005); HDT, 0.97 (SE 0.005). In the seated position only, the AUMAP/MAP ratio significantly increased with age (P <.0001). Mean posture coefficients obtained with AUMAP were in the range of those based on either direct ophthalmodynamometric measurements or hydrostatic estimations. Conclusions: Surrogate measurement of MCRAP in individual subjects is feasible using the simple AUMAP approach that provides a straightforward estimation of OPP (OPP = AUMAP – IOP) at different body postures. The standard method OPP = 2/3*MAP-IOP in the seated posture underestimates OPP at older ages. Clinical estimation of OPP would benefit from the use of AUMAP, in particular for head-down postures. [ABSTRACT FROM AUTHOR]

Background: Ocular perfusion pressure (OPP) is defined as blood pressure (BP) minus intraocular pressure (IOP). Low OPP may result in decreased ocular blood flow (OBF) and oxygen to the optic nerve head (ONH) and retina. Aim: To review the role of systemic hypotension and similar conditions in OPP and its influence on retinal nerve fibre layer (RNFL) thickness and the ganglion cell complex (GCC). Method: A literature search was conducted using the following search terms: 'systemic hypotension'; 'glaucoma'; 'retinal nerve fibre layer'; 'optic nerve'; 'ocular blood flow' and 'ocular perfusion pressure'. Results: The Los Angeles Eye Study and Barbados Eye Study found that decreased OPP and BP increased the risk of glaucoma development by up to six times. Reduced retinal perfusion with resultant thinning of the RNFL in conditions with a similar mechanism, such as obstructive sleep apnoea syndrome, has indicated the importance of reduced OPP in retinal thickness. In the absence of any study directly showing the effect of systemic hypotension on OPP and retinal thickness, a working hypothesis proposes that reduced BP with or without normal-to-raised IOP will reduce OPP. The reduced OPP and OBF in those with systemic hypotension may result in oxidative stress and hypoxia which may then cause retinal ganglion cell death and the resultant retinal thinning. Conclusion: The increased risk of glaucoma development and progression relating to decreased BP and OPP has been proven to be of importance. Monitoring patients with systemic hypotension and evaluating the macula, ONH RNFL and GCC thickness may alert clinicians to possible glaucomatous changes. [ABSTRACT FROM AUTHOR]

Innovative applications of clinical ocular diagnostic tools are emerging to help identify systemic disorders that extend beyond ocular diseases. Ophthalmodynamometry (ODM) is a screening tool that non-invasively determines mean central retinal artery pressure (MCRAP) and ocular perfusion pressure (OPP). Decreased OPP and MCRAP on Falck Medical Multifunctional Device (FMD, Falck Medical, Inc., Mystic, CT), along with reverse ophthalmic artery flow (ROAF) on transcranial Doppler ultrasonography (TCD), indicate increased collateral brain perfusion and possible stenosis of the ophthalmic artery or internal carotid artery (ICA). In this case report, we describe the case of a 78-year-old female with ROAF, reduced MCRAP, and OPP in the right eye, confirmed by carotid duplex of 50-79% right ICA stenosis. Early application of ODM and TCD allowed for prompt diagnosis and management with a vascular specialist., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Murillo et al.)

Background: Reduced ocular perfusion pressure (OPP) from hypotension and consistent OPP variability due to blood pressure (BP) fluctuations are predisposing factors for glaucoma. Low resting BP and orthostatic hypotension (OH) in spinal cord injury (SCI) patients may increase the risk of glaucoma post-injury. This study investigated BP, intraocular pressure (IOP), and OPP changes between supine and sitting positions in SCI and normal individuals., Methods: Twenty SCI cases (high paraplegia, T1-T6 n  = 6; low paraplegia, T7-L3 n  = 14) and matched controls (1:1) were included. Systolic and diastolic BP (SBP and DBP) were measured digitally, and IOP with rebound tonometry. Measurements were taken one minute apart in both positions. Mean arterial pressure (MAP) was calculated, and OPP was determined using position-specific formulas., Results: No SCI subjects exhibited OH. Both groups experienced significant BP increment ( P  < 0.05) from supine to sitting. SBP increased by 4.4 ± 8.4 mmHg (SCI) and 3.6 ± 6.2 mmHg (normal), while DBP increased by 4.2 ± 5.1 mmHg (SCI) and 6.7 ± 5.5 mmHg (normal). IOP and OPP decreased significantly ( P  < 0.05) after postural change in both groups, yet differences between them were not significant. Analysis by injury level revealed lower parameter values in high paraplegia than in low paraplegia, with the latter group showing a more significant reduction in OPP after postural change., Conclusion: Postural changes differently affect BP, IOP, and OPP in SCI compared to normal individuals, with variations based on the level of SCI. While not directly assessing glaucoma, the study offers insights into ocular hemodynamics in SCI compared to normals.

Introduction: Elevated intraocular pressure (IOP) and reduced ocular perfusion pressure (OPP) related to hemodialysis (HD) are risk factors for the development and progression of glaucoma. The aim of this study was to evaluate the effect of HD on IOP and OPP in our patients., Methods: This was a cross-sectional, descriptive, and analytical study conducted between January 2 and February 5, 2024, in the HD and ophthalmology departments of the Heinrich Lübke Regional Hospital in Diourbel. The IOP of both eyes was measured one hour before the start of the HD session and within 30 minutes after the end of the session, by the same ophthalmologist, for all included patients, using a Goldmann applanation tonometer. OPP were calculated and other socio-demographic data collected., Results: Fifty-eight eyes from 29 chronic HD patients were included. The mean age of the patients was 47.58±12.94 years, with a predominance of women (17 women or 58.6%; sex ratio 0.71). In the left eye, mean IOP increased significantly from 12.21±2.96 mmHg before the HD session to 14.10±4.27 mmHg at the end of the session (p=0.04). For the right eye, the IOP also increased with a strong tendency to significance from 12.97±3.79 mmHg before the HD session to 15.03±5.23 mmHg at the end of the session (p=0.05). OPP did not change significantly after the HD session., Conclusion: The HD session significantly increased IOP with no significant change in OPP., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Sarr et al.)

Erika Cantor,1 Fabián Méndez,2 Carlos Rivera,3 Andrés Castillo,4 Alexander Martínez-Blanco5 1Research Institute, Centro Médico Imbanaco, Cali, Colombia; 2School of Public Health, GESP Group, Universidad del Valle, Cali, Colombia; 3Centro Medico Farallones, Fundación Oftalmológica del Valle, Cali, Colombia; 4Department of Biology, Faculty of Natural and Exact Sciences, Universidad del Valle, Cali, Colombia; 5Department of Ophtalmology, Universidad del Valle, Research Institute, Centro Médico Imbanaco, Cali, Colombia Background: The aim of the study was to evaluate the relationship between blood pressure (BP), ocular perfusion pressure (OPP) and occurrence of primary open-angle glaucoma (POAG) among patients with systemic hypertension.Participants and methods: A cross-sectional study of hypertensive patients was conducted in six cities in Colombia. The participants underwent a complete ophthalmological examination. The intraocular pressure measurement was obtained by Goldmann tonometry. The diagnosis of glaucoma was confirmed by visual field and optic nerve photos. Interviews and questionnaires were used to evaluate participants’ lifestyle and other health conditions. A multinomial logistic regression was used to assess the relationship between BP, OPP and presence of suspected or confirmed POAG.Results: A total of 1,272 individuals were included in this study; 131 (10.3%) were diagnosed with suspected glaucoma and 65 (5.1%) with confirmed glaucoma. High values of diastolic BP (>90 mmHg) and low values of OPP (

Purpose: To provide theoretical substantiation of the potential for a new technique, impedance oculopneumoplethysmography (OPPG), to assist in diagnosing microvascular ciliary body ischemia. Methods: Modeling the distribution of high-frequency current in ocular tissues during ocular rheography; modeling the conversion of the local short-term vacuum compression of the globe to the increase in intraocular pressure (IOP); estimating the height of scleral deflection averaged over the site of local vacuum compression based on the IOP rise. Results: A new method for estimating the state of intraocular circulation, impedance OPPG, was proposed, and its potential to assist in diagnosing microvascular ciliary body ischemia by identifying low (< 35.0 mm Hg) diastolic ocular perfusion pressure (OPP) in the ciliary body metarterioles was theoretically substantiated. The diastolic OPP corresponds to the “local short-term vacuum compression” induced IOP rise at which a decrease in the pulsatile blood volume amplitude is registered by ocular rheography. With this method used as per the utility model (i.e., with a ring-shaped suction cup (RSCP) applied perilimbally, and with rheography electrodes, as per Pat. UA 112192), the diastolic perfusion pressure is estimated only in the arterioles of the ciliary body microcirculation system. Using a mathematical model, a formula K×(VAC/D4) was derived for estimating the increase in IOP based on the vacuum pressure applied, VAC, and globe diameter, D, with the factor K depending on the dimensions of the specific RSCP. Conclusion: The approach proposed for estimating the OPP in the metarterioles may be useful for early diagnosis of impaired vascular microcirculation in eyes with glaucoma (including low-tension glaucoma), myopia, diabetic angiopathy, peripheral retinal degeneration, age-related macular degeneration, or uveitis, and may enable estimating the efficiency of treatment for these disorders after conservative therapy or surgical procedures.

To evaluate the association between diabetic retinopathy (DR) and mean ocular perfusion pressure (MOPP) in patients with type 2 diabetes mellitus (T2DM). Patients from the Fushun Diabetic Retinopathy Cohort Study (FS-DIRECT), a community-based prospective cohort study conducted in northeast China, were included in this study. The presence and severity of DR were determined by grading fundus photographs according to the Early Treatment Diabetic Retinopathy Study (ETDRS) retinopathy scale. Systolic and diastolic blood pressure (SBP and DBP) were recorded using an electronic sphygmomanometer. Intraocular pressure (IOP) was measured using an iCare rebound tonometer. MOPP was calculated using the formula MOPP = 2/3 [DBP + 1/3 (SBP – DBP)] – IOP. In total, 1,857 patients who had gradable fundus photography and MOPP data were enrolled in this study. Male patients had a higher MOPP than female patients (52.25 ± 8.75 vs. 50.96 ± 8.74 mmHg, P = 0.002). Overall, both male and female patients with any type of DR, non-proliferative DR (NPDR), or non-sight-threatening DR (non-STDR) had significantly higher MOPP relative to patients without DR. Increased MOPP (per 1 mmHg) was in turn associated with the presence of any type of DR [odds ratio (OR) = 1.03, 95% confidence interval (CI): 1.02–1.04], NPDR (OR = 1.03 95% CI : 1.02–1.04), and non-STDR (OR = 1.03, 95% CI : 1.01–1.04) after adjusting for confounders. Increased MOPP (per 1 mmHg) was also associated with an increased likelihood of macular edema (OR = 1.02, 95% CI : 1.01–1.04). The results suggest that increased MOPP was associated with DR and macular edema in northeastern Chinese patients with T2DM. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the associations between mean ocular perfusion pressure (MOPP) and several variables including body mass index (BMI), comorbid medical conditions and various ocular parameters in a population-based sample. Study design: Cross-sectional. Methods: Data of 2091 healthy participants from a previous population based cross-sectional study were reviewed. Inclusion criteria were adults ≥40 years of age who were screened on-site for glaucoma. Data on medical history, height, weight, systolic and diastolic blood pressures (SBP and DBP, respectively) were obtained. A basic ocular examination was performed which included intraocular pressure (Tono-Pen XL, Reichert Technologies) and central corneal thickness (Pacline pachymetry;) measurement, slit-lamp examination and non-mydriatic optic disc photography (nonmydα fundus camera, Kowa). MOPP was calculated using the formula [2/3 x (DBP + 1/3(SBP-DBP)]-IOP and low MOPP was defined as MOPP ≤45 mmHg. Results: Mean age of the subjects was 63.04 ± 9.7 years (range: 44 and 99 years) and the majority were women (74.1%, n = 1549). Mean MOPP values in normal weight (BMI < 25), overweight (BMI = 25-29.9) and in obese individuals were 46.9 ± 9.0 mmHg, 48.6 ± 9.2 mmHg and 50.7 ± 10.0 mmHg, respectively (p < 0.001, in all pairwise comparisons). In the multivariable logistic regression analysis, migraine and IOP elevation (per 1 mmHg increment) were significantly associated with a low MOPP (OR: 2.10 and 1.22, p = 0.008 and < 0.001, respectively). On the other hand, risk of low MOPP was reduced in subjects with hypertension, and with increasing age (per 1-year increment) and BMI (per 1-unit increment) (OR: 0.15, 0.97, and 0.95, respectively, and p < 0.001 for all). Conclusion: Migraine and elevated IOP increase the risk of low MOPP and this may have a causal relationship with impaired optic nerve head blood flow. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate exercise-induced changes in ocular blood flow (OBF) parameters in primary open-angle glaucoma (POAG) patients. Methods: A prospective observational study was carried out, in which medically treated patients with POAG were enrolled. Following inclusion, all patients performed a 40-min cycloergometry in a standardized fashion. The following parameters were measured and compared immediately before and 1 and 30 min after the exercise: intraocular pressure (IOP; Goldman applanation tonometry), mean arterial pressure (MAP), ocular pulse amplitude (OPA; assessed by dynamic contour tonometry), and ocular perfusion pressure (OPP; 2/3 MAP – IOP). In addition, we investigated possible factors associated with OBF parameter changes immediately after exercise. Results: A total of 30 eyes (30 patients; mean age was 62.9 ± 1.7 years) were included. Most patients were women (53%), and median visual field mean deviation index was –3.5 dB. Both MAP (mean change, 21%) and IOP (mean change, 17.3%) increased significantly immediately after the workout (p < 0.01), persisting higher than baseline following 30 min (p < 0.01%). Regarding OBF parameters, both OPA (mean change, 58.8%) and OPP (mean change, 21.7%) increased significantly immediately after the workout and persisted higher than baseline 30 min after the workout (p < 0.01). Regression analysis revealed that only age was significantly associated with OPA variation (R2 0.14; p < 0.05). No significant associations were found for OPP (p ≥ 0.19). Conclusion: Aerobic exercise leads to a significant short-time increase in OBF parameters in patients with POAG. Even though IOP seems to present a modest elevation, it is accompanied by a significant increase in MAP, leading to higher OBF measurements. Exercise-induced short-term changes and its possible implications for glaucoma prognosis deserve further investigation. [ABSTRACT FROM AUTHOR]

The relationship between the eyeball size and convexity of its anterior part and the efficacy of local vacuum compression of the eye performed using a new design suction cup for impedance ophthalmopneumoplethysmography was studied. Based on the mathematical modeling of the geometric shape of the anterior segment of 75 eyes obtained by ultrasound biomicroscopy examination, it was found that the horizontal meridian curve of the anterior eye segment with a base diameter of 16.00 mm could be best approximated by a hyperbola. The surface area under the new suction cup with an inside diameter of about 16.5 mm was calculated using the formula for the segment surface area of a hyperboloid of revolution. It was determined by the convexity of the anterior part of the eye and varied from 247.3 to 271.4 mm2. The conversion coefficient of the level of applied vacuum to the level of IOP rise, calculated on the basis of individual combinations of the surface area of local vacuum compression and the eyeball size, was on average 0.83 ranging from 0.44 to 1.33. Using an individual conversion coefficient according to eyeball anatomical parameters will make it possible to measure diastolic ocular perfusion pressure during impedance OPPG with high sensitivity and accuracy. [ABSTRACT FROM AUTHOR]

Low ocular perfusion pressure (OPP) may increase the risk of optic neuropathy. This study investigated the effects of OPP on the ganglion cell complex (GCC) and optic nerve head-retinal nerve fibre layer (ONH-RNFL) thickness in presumed systemic hypotensives (PSH). Fifteen participants with PSH and 14 controls underwent automated sphygmomanometry and Icare tonometry to calculate OPP: mean OPP (MOPP), systolic OPP (SOPP), and diastolic OPP (DOPP). ONH-RNFL and macula GCC thickness were evaluated using the Optovue iVue optical coherence tomographer. Statistical analysis comprised independent t-tests, the Mann–Whitney U test and binary logistic regression analysis. There was no significant difference when comparing ONH-RNFL and macula GCC thickness between both groups. Increased MOPP (OR = 0.51; 95% CI: 0.27–0.97; p = 0.039) and SOPP (OR = 0.79; 95% CI: 0.64–0.98; p = 0.035) were significantly associated with a decreased risk of reductions in GCC total thickness. Increased SOPP (OR = 0.11; 95% CI: 0.01–0.89; p = 0.027) was significantly associated with a decreased risk of reductions in the average ONH-RNFL thickness. The study found no significant retinal thickness changes in PSH’s, in comparison to the controls. The study established that, by increasing MOPP and SOPP, there was a decreased risk of reductions in the total GCC thickness and average ONH-RNFL thickness. Higher SOPP may decrease the possibility of retinal thinning of the GCC and ONH-RNFL. However, higher MOPP may decrease the odds of thinning of the GCC before ONH-RNFL changes.

Abstract Background Interscalene block (ISB) is commonly associated with Horner’s syndrome due to spread of local anesthetic to the cervical sympathetic chain. Postganglionic neurons that originate from superior cervical ganglia form the sympathetic innervation of eye. Decrease in sympathetic tone may change intraocular pressure (IOP) and ocular perfusion pressure (OPP). The aim of the study was to investigate whether ISB affects IOP and/or OPP. Methods Thirty patients scheduled for ambulatory shoulder surgery under regional anesthesia with a single-shot ISB (15 mL 0.5% bupivacaine and 15 mL 2% lidocaine) were recruited. The IOP and OPP in both eyes, mean arterial pressure (MAP), heart rate (HR) and end-tidal CO2 (ETCO2) were measured before ISB and 5, 10, 20, 30 and 60 min after ISB in the beach-chair position. Results The baseline IOP and OPP were similar in the blocked and unblocked sides (IOP 17.60 ± 1.69 and 17.40 ± 1.96 respectively p = 0.432; OPP 49.80 ± 8.20 and 50 ± 8.07 respectively p = 0.432). The IOP in the blocked side significantly decreased between 10th to 60th min following ISB, compared to the baseline values (p

Abstract Background To investigate postural effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with non-arteritic ischemic optic neuropathy (NAION). Methods IOP and blood pressure (BP) were measured in 20 patients with unilateral NAION 10 min after changing to each of the following positions sequentially: sitting, supine, right lateral decubitus position (LDP), supine, left LDP, and supine. IOP was measured using a rebound tonometer and OPP was calculated using formulas based on mean BP. The dependent LDP (DLDP) was defined as the position when the eye of interest (affected or unaffected eye) was placed on the dependent side in the LDP. Results IOPs were significantly higher (P = 0.020) and OPPs were significantly lower (P = 0.041) in the affected eye compare with the unaffected eye, with the affected eye in DLDP. Compared with the mean IOP of the unaffected eyes, the mean IOP of the affected eyes increased significantly (+2.9 ± 4.4 versus +0.7 ± 3.1 mmHg, respectively; P = 0.003) and the mean OPP decreased significantly (−6.7 ± 9.4 versus −4.9 ± 8.0 mmHg, respectively; P = 0.022) after changing positions from supine to DLDP. In addition, changing position from supine to DLDP showed significantly larger absolute changes in IOP (4.13 ± 3.19 mmHg versus 2.51 ± 1.92 mmHg, respectively; P = 0.004) and OPP (9.86 ± 5.69 mmHg versus 7.50 ± 5.49 mmHg, respectively; P = 0.009) in the affected eye compared with the unaffected eye. In the affected eye, there was a significant positive correlation between absolute change in IOP and OPP when changing position from supine to DLDP (Rho = 0.512, P = 0.021). Conclusions A postural change from supine to DLDP caused significant fluctuations in IOP and OPP of the affected eye, and may significantly increase IOP and decrease OPP. Posture-induced IOP changes may be a predisposing factor for NAION development.

AIM: To observe the changes of intraocular pressure(IOP), ocular perfusion pressure(OPP), central anterior chamber depth(CACD)and subfoveal choroidal thickness(SFCT)in peri-hemodialysis in patients with end-stage diabetic nephropathy(ESDN), for evaluating the influences of hemodialysis(HD)on ocular blood supply of the ESDN patients. METHODS: Totally 42 cases(84 eyes)of ESDN patients treated with HD in the Department of Nephrology were observed. Systolic and diastolic blood pressure, IOP with the hand-held rebound tonometer were measured at 30min before HD, 2h after HD duration and 30min after HD completion. OPP was calculated(OPP= 4/9 diastolic pressure + 2/9 systolic pressure - IOP). CACD measured by optical coherence measuring instrument(IOL-Master)and SFCT measured by optical coherence tomography(OCT)were observed at 30min before HD and 30min after HD completion. The outcomes were assessed by analysis of homogeneity test of variance, one-way ANOVA, LSD-t test and t-test, to look for differences of the parameters in various time of HD. RESULTS: Totally 84 eyes of ESDN patients: in 30min before HD, 2h after HD duration and 30min after HD completion, systolic blood pressure was no statistically significant(F=0.254, P=0.783), and diastolic blood pressure was no statistically significant(F=0.114, P=0.896), and IOP was statistically significant(F=7.527, P=0.001), and OPP was statistically significant(F=4.692, P=0.027). In 2h after HD duration and 30min after HD completion, IOP was statistically significant(t=-3.646, P=0.001), and OPP was statistically significant(t=2.321, P=0.022). In 30min before HD and 30min after HD completion, increase of IOP was statistically significant(t=-2.977, P=0.003), and OPP was no statistically significant(t=0.219, P=0.872), and decrease of CACD was statistically significant(t=6.291, Pt=5.736, PCONCLUSION: IOP increasing, OPP transiently decreasing, CACD shallow and SFCT thin were presented in peri-hemodialysis. It is important to evaluate eye conditions of ESDN patients before HD, and to take effective preventive measures to reduce the possible risk factors in peri-hemodialysis.

A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide. These patients were previously diagnosed as having glaucoma, ocular hypertension, or had responded previously with sustained elevated intraocular pressure. Of 1661 procedures were performed. Totally 219 (13%) of the injections were on phakic patients. A median (SD) of 210 μL (40 μL) of aqueous was removed during each paracentesis. There were no reported incidences of any complications. We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension, glaucoma, and retinal vein or artery occlusion.

Background: Caffeine has a well-established effect on intraocular pressure (IOP) and ocular perfusion pressure (OPP); however, the possible differences between low- and high-caffeine consumers remain unknown.Methods: In this placebo-controlled, double-blind, and balanced crossover study, 40 healthy individuals were divided in low- (n = 21) and high (n = 19)-caffeine consumers, according to their daily caffeine consumption. All participants ingested either caffeine (4 mg/kg) or placebo, and IOP and OPP were measured after 30, 60, and 90 min of ingesting caffeine or placebo. Subjective feelings of arousal were also obtained.Results: Caffeine induced an acute IOP rise (p < 0.001, ƞp2 = 0.408), whereas habitual caffeine demonstrated a mediating effect on the IOP changes induced by caffeine intake, with high-caffeine consumers showing a less accentuated IOP rise in comparison to low-caffeine consumers. The greatest IOP change induced by caffeine intake was reached after 90 min from capsule ingestion, being more accentuated for the low-caffeine consumers (+ 3.4 mmHg) than for the high-caffeine consumers (+ 1.2 mmHg). Consequently, the participants reported higher levels of perceived arousal after ingesting caffeine in comparison to placebo (p = 0.002, ƞp2 = 0.222); however, similar responses were given by high- and low-caffeine consumers (p = 0.256). Our data did not reveal any effect of caffeine consumption on OPP (p = 0.304).Conclusions: These results suggest that IOP responsiveness to caffeine ingestion is subject to tolerance, which could have important implication in the management of glaucoma. This finding may be due to alterations in the adenosine receptor system caused by chronic caffeine consumption. Future studies are needed to assess if these findings are also applicable to patients with glaucoma. [ABSTRACT FROM AUTHOR]