Search

The Purpose of present study was to investigate the effect of riboflavin/ultraviolet-A-induced collagen cross-linking (CXL) on central cornea, limbus and intraocular pressure (IOP). This was an animal experimental study. The right corneas of 10 rabbits were ultraviolet-A irradiated (3 mW/cm2 for 30 minutes) after de-epithelialization and instillation of 0.1% riboflavin / 20% Dextran drops. Left corneas served as controls. Samples were examined histologically one month postoperatively. Before and after treatment, IOP measurements were recorded bilaterally. At central cornea of eyes underwent CXL keratocyte repopulation, normal arrangement of collagen fibres and a statistically significant change in fibres diameter were detected, compared to controls. At limbus area, there were not any significant histological differences after CXL. There was no statistically significant difference between pre- and postoperative IOP in all eyes.

Purpose of the study was to develop and assess a novel controlled drug delivery system of latanoprost acid (LA). Poly(lactide)/Monomethoxy-poly(ethyleneglycol) (PLA-PEG) nanoparticles (NPs) were prepared using an emulsification-solvent evaporation technique. NPs were characterized in vitro according to their size, ζ-potential, drug entrapment efficiency and LA release. LA-loaded NPs (equivalent to 8.5 μg LA) were administered into the subconjunctival space of normotensive rabbits (group A). A free LA solution of the same drug content was subconjunctivally injected in a second rabbit group (group B), while blank NPs were administered in a third group (group C). A group of untreated animals (group D) served as the control. Intraocular pressure (IOP) was monitored for 8 consecutive days, using the Tono-pen XL. Aqueous humor (AH) levels of LA were evaluated for 6 days post-administration, by means of HPLC. Mean nanoparticle size was 80 nm. The drug entrapment efficiency was 18.3%. NPs sustained the release of LA over several days in vitro. Non-significant differences in baseline IOP were found between groups (p = 0.22). LA-loaded NPs exerted a significant hypotensive effect on group A, while IOP values remained significantly lower compared to the rest groups, throughout the study (p = 0.04). LA AH concentrations in group B continuously decreased with time, while LA levels in group A steadily increased. On day 6, LA levels were higher in group A compared to group B (344 ± 73.5 ng/ml and 228 ± 41.01 ng/ml, respectively). No adverse effects were observed. In conclusion, after subconjunctival administration, the LA-loaded NPs provided sustained LA delivery in vivo. They appear to be a promising system for the controlled subconjunctival delivery of LA., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Purpose: To perform qualitative evaluation of the aqueous humor (AH) outflow mechanism in glaucoma and nonglaucoma patients by means of tonography assessment and mathematical analysis., Methods: Sixty-two primary open angle and 58 pseudoexfoliation glaucoma patients were recruited in a non-interventional, observational study between 2004 and 2007. Qualitative and quantitative outflow assessment was acquired by means of a digital tonographer and mathematical analysis. Qualitative results were represented using slope analysis of the change of the AH outflow rate over the tonography study. The results were compared to the control group (CG; n=100) as well as to a pseudoexfoliation group (PEX; n=46)., Results: Regarding quantitative analysis, glaucoma groups exhibited significantly lower outflow facility compared to nonglaucoma ones (p<0.001). Outflow facility value was significantly correlated to cup to disc ratio (Pearson correlation r=-0.3, p<0.001). Regarding qualitative analysis, the primary open-angle glaucoma (POAG) group presented a significant profile variation at the beginning of the tonography, expressed as an increased resistance of the AH outflow. Both glaucoma groups exhibited profile stabilization at the end of the measurement, suggesting that the outflow rate remained constant, while nonglaucoma groups followed a continuous reduction of the AH outflow rate throughout the study., Conclusions: The POAG, PXG, PEX, and CG groups demonstrated both qualitative and quantitative tonographic profile differences. The observed differences in the glaucoma groups suggest a distinct pathomechanism between POAG and PXG. It is suggested that POAG patients have a temporary disruption of the AH flow pathway, while PXG patients have a generalized increased flow resistance.

Purpose: To evaluate the Goldmann applanation tonometer (GAT), the Pascal dynamic contour tonometer (PDCT), and the ocular response analyzer (ORA) tonometer in measuring intraocular pressure (IOP) in keratoconic eyes before and after riboflavin/ultraviolet A corneal collagen crosslinking (CXL), to assess agreement among devices and to analyze the impact of some ocular parameters on their measurements., Methods: Fifty keratoconic eyes were included. Intraocular pressure was measured with GAT, PDCT, and ORA before and after CXL. Fifty nonkeratoconic eyes served as controls. Device agreements were calculated by Bland-Altman analysis. The effect of some ocular characteristics on IOP measurement differences between tonometers was determined., Results: Between the 2 groups, there were statistically significant differences in all examined parameters. Preoperatively, in both groups a statistically significant difference was found in IOP measurements among devices (p<0.05). Bland-Altman analysis showed a bias among devices. On average, PDCT overread GAT and ORA. The IOP measurement differences were better predicted by corneal resistance factor. Postoperatively, in keratoconus eyes, there was no statistically significant difference in IOP measurements among the 3 tonometers (p>0.05). The IOP readings with all tonometers after treatment were higher than those obtained preoperatively; however, not to a statistically significant level, with the exception of PDCT and ORA readings at the first month postoperatively. Corneal resistance factor measurements have no significant change after CXL., Conclusions: Pascal dynamic contour tonometer could provide more consistent and closer to the true IOP readings than GAT and ORA in healthy eyes with corneal thickness outside the 520-550 µm range, in keratoconus patients and after CXL. Corneal resistance factor was associated significantly with agreement among devices.

Background: To evaluate and compare the recorded IOP values of the Pascal dynamic contour tonometer (PDCT) and the Goldmann applanation tonometer (GAT) after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK)., Methods: Three groups of 84, 182 and 43 patients each were treated by PRK for myopia, LASIK for myopia and LASIK for hyperopia respectively. Intraocular pressure (IOP) measurements were performed in all eyes 1 day before and 1, 3, 6 and 12 months after treatment with PDCT and GAT. Ultrasound pachymetry was performed in all eyes preoperatively and at 1st month postoperatively., Results: Preoperatively and postoperatively, GAT readings were lower than PDCT in all groups (all p < 0.05). Postoperatively in the PRK group, compared to the preoperative value, the mean differences of IOP recorded with GAT at 1st, 3rd, 6th and 12th month were -1.4 mmHg, -1.7 mmHg, -1.7 mmHg and -1.9 mmHg respectively (all p < 0.05). In the myopic LASIK group; the corresponding values with GAT were -3.6 mmHg, -3.6 mmHg, -3.6 mmHg and -3.5 mmHg (all p < 0.05), while in the hyperopic LASIK group the corresponding values were -1.1 mmHg, -0.7 mmHg, -1.1 mmHg and -0.9 mmHg (all p < 0.05). The mean IOP difference (GAT-PDCT) for myopic PRK, myopic LASIK and hyperopic LASIK were respectively -3.8 mmHg, -4.1 mmHg and -1.5 mmHg at the 12-month follow-up. No statistically significant changes were found for any group with the PDCT., Conclusions: GAT-determined IOP values were significant lower at all time-points after hyperopic LASIK, as well as myopic PRK or LASIK. The Pascal tonometry values remained unaffected for all groups.

Purpose: To study the effects of maximum dynamic physical exercise on retrobulbar blood flow and ocular perfusion pressure (OPP)., Methods: Thirty male subjects undergoing routine periodic medical evaluation were included. All participants underwent cardiac stress test according to a standard protocol. Before the test, the intraocular pressure was measured and colour Doppler imaging was performed with a 7.5 MHz linear probe, to record peak systolic velocity (PSV), end diastolic velocity and resistivity index at the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal branches of short posterior ciliary arteries (SPCA). The same measurements were repeated 1 and 30 min after the test., Results: OPP and PSV at the OA were significantly higher at the 1-min interval, compared with the pretest scores (P = 0.01, in both cases), whereas the respective differences on the 30-min interval were statistically not significant. On the contrary, PSV at the CRA and SPCA were not significantly changed on the same intervals. Differences between pretest and post-test scores for end diastolic velocity and resistivity index were statistically not significant for all examined vessels., Conclusions: Maximal physical exercise increases OPP and blood flow at the OA without affecting blood flow at the CRA and SPCA, implying that auto-regulative mechanisms are active in both retinal and choroidal circulations.

Purpose: To evaluate the 24-hour intraocular pressure (IOP)-lowering effect of latanoprost and the dorzolamide/timolol fixed combination (DTFC) after 2 and 6 months of treatment., Design: Randomized, prospective, crossover comparison., Participants: Thirty-nine patients had primary open-angle glaucoma, and 14 patients had ocular hypertension., Methods: After a 6-week washout period, patients were randomized to either 6 months of treatment with the DTFC twice daily or latanoprost every evening and then crossed over to the opposite treatment for an additional 6 months., Main Outcome Measure: Mean 24-hour IOP after 2 and 6 months of treatment., Results: Fifty-three patients had an average 24-hour baseline IOP of 25.2+/-2.3 mmHg. After 6 months of treatment, 24-hour IOPs were 18.1+/-1.9 mmHg for the DTFC and 18.3+/-1.9 mmHg for latanoprost. Compared with 2 months of therapy, at 6 months the DTFC showed no significant change in mean 24-hour IOP, whereas latanoprost demonstrated a reduction of 0.3 mmHg (P = 0.01). The DTFC had more burning (P<0.001) and bitter taste (P = 0.01), whereas the latanoprost had more hypertrichosis (P = 0.02)., Conclusions: After 6 months of therapy, the DTFC and latanoprost have clinically similar 24-hour IOP-lowering efficacies.

Objective: To evaluate 24-hour intraocular pressure (IOP) efficacy of latanoprost versus travoprost, each given every evening, in exfoliative glaucoma patients., Design: Prospective, observer-masked, crossover comparison., Participants: Forty patients with exfoliation glaucoma., Methods: Patients with a pressure of >24 mmHg were randomized to latanoprost or travoprost for an 8-week treatment period after a 6-week medicine-free period. Patients were then switched to the opposite treatment for the second period. At untreated baseline and at the end of each treatment period the IOP was measured at 6 am, 10 am, 2 pm, 6 pm, 10 pm, and 2 am., Main Outcome Measure: Diurnal IOP., Results: The mean 24-hour IOP was 25.1+/-2.5 mmHg at baseline, 17.8+/-2.1 mmHg on latanoprost, and 17.3+/-2.2 mmHg on travoprost (P = 0.001). Individual time points were similar between treatments, except at 6 pm when travoprost provided lower IOP (16.7+/-2.6 vs 17.9+/-2.5 mmHg, P<0.001). Adverse events showed more conjunctival hyperemia with travoprost (n = 15) than latanoprost (n = 6; P = 0.03)., Conclusions: Latanoprost and travoprost both significantly reduce the 24-hour IOP from baseline in exfoliative glaucoma, but travoprost may demonstrate a greater hypotensive efficacy in the late afternoon.

Purpose: The aim of this study was to evaluate the efficacy and safety in ocular hypertensive or open-angle glaucoma patients changed to a latanoprost/timolol fixed combination (LTFC) from previous therapy., Methods: We employed a retrospective, multicenter, active-controlled study evaluating patients who had a previous therapy substituted with LTFC and had a 3-month follow-up., Results: In the 168 patients included in the trial, LTFC reduced the intraocular pressure (IOP) after switching from previous therapies: timolol (22.8+/-3.5 to 19.0+/-3.9 mmHg, N=49, p<0.001), latanoprost (21.2+/-3.8 to 18.3+/-2.5 mmHg, N=54, p<0.001), and a dorzolamide/timolol fixed combination (20.9+/-2.4 to 20.0+/-2.7 mmHg, N=32, p=0.03). In switching from a latanoprost and timolol unfixed combination, the pressure changed from 18.3+/-3.8 to 18.9+/-3.0 mmHg (N=33, p=0.38). LTFC was persistent in 131 (78%) patients within the 3-month treatment period. The most common adverse event with LTFC was conjunctival hyperemia, which occurred in patients not previously treated with latanoprost therapy (N=16, 10%)., Conclusions: LTFC generally provides reduced IOP and limited side effects when substituted for other common glaucoma therapies, while providing similar pressure when switched from its own individual components.

Purpose: To determine the efficacy of brimonidine tartrate 0.2% drops given 2 times a day in reducing intraocular pressure (IOP) spikes during the first 24 hours after phacoemulsification cataract surgery., Setting: Department of Ophthalmology, General Hospital of Patras Agios Andreas, Patras, Greece., Methods: In this prospective double-blind placebo-controlled study, 1 eye of 40 consecutive normotensive cataract patients having small-incision cataract surgery was randomized into 1 of 2 treatment arms. Twenty patients received a placebo (artificial tears) and 20 patients received brimonidine tartrate 0.2% drops 2 times a day the day before and the day of surgery. Diurnal IOP variation was the primary efficacy variable; IOP was measured at baseline, before surgery, and 4, 6, 12, and 24 hours postoperatively., Results: The placebo group had higher IOPs at every time point after surgery. Peak elevation of IOP occurred 6 hours after surgery. The mean IOP in the placebo group (27.71 mm Hg +/- 3.75 [SD]) was statistically significantly higher than in the brimonidine group (21.45 +/- 1.32 mm Hg) (P<.001). A major IOP rise (>/=20 mm Hg above baseline IOP) occurred in 1 patient (5%) in the placebo group who required emergency hypotensive therapy. Twenty-four hours after surgery, 11 eyes (55%) in the brimonidine group and 4 eyes (20%) in the placebo group had an IOP lower than baseline., Conclusion: Prophylactic treatment with brimonidine tartrate 0.2% 2 times a day for 2 days was effective in reducing IOP peaks throughout the first 24 hours after phacoemulsification surgery.

Purpose: The aim of this study was to evaluate and compare the changes in Intraocular Pressure (IOP) and other ocular parameters: the Anterior Chamber Angle (ACA), Anterior Chamber Volume (ACV), and Anterior Chamber Depth (ACD) during phacoemulsification surgery in Greek patients with normotensive eyes and those with well-controlled Open-Angle Glaucoma (OAG). Additionally, parameters such as the Corneal Thickness (CCT), Axial Length (AL), Central Macular Thickness (CMT), and Retinal Nerve Fibre Layer (RNFL) were also examined. Patients and Methods: This was a prospective observational case–control study that included 50 phakic eyes, 25 normotensive (Group 1), and 25 with OAG: 15 Primary Open-Angle Glaucoma (POAG) and 10 Exfoliation Glaucoma (EXG) (Group 2). Ophthalmic assessment included IOP measurements, ocular biometry, and anterior and posterior segment optical coherence tomography evaluation of the aforementioned ocular parameters, prior and 6 months after phacoemulsification surgery. Results: At the 6 months post-operative review, a greater IOP reduction was recorded in eyes with OAG, in comparison to normotensive ones (5.3mmHg and 1.6 mmHg respectively). In addition, a significant but similar increase was recorded in the values of the ACA, ACV, and ACD of both groups between the pre- and the post-op period. Furthermore, the CCT and AL values remained unaltered. Finally, there was a non-statistically significant change in the mean CMT and the mean average RNFL of both groups. Conclusion: Eyes with OAG tend to undergo a greater reduction in IOP post-phacoemulsification surgery, in comparison to normotensive eyes. This reduction may not be solely attributed to ocular anatomical changes after phacoemulsification surgery but may also be due to the remodeling of the trabecular meshwork and the ciliary body. This may be especially true in the case of OAG eyes, which already start off with a compromised trabecular endothelium prior to surgery. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to evaluate the correlation between several ocular parameters (intraocular pressure [IOP], corneal biomechanical properties) and the visual field (VF) mean deviation (VF MD) in eyes with open-angle glaucoma (OAG). Methods: We conducted a cross-sectional, observational study in which we measured the IOP with Goldmann applanation tonometry, the central corneal thickness (CCT), and the corneal parameters obtained from the Ocular Response Analyzer® (ORA®) and the Corvis® ST non-contact tonometer, in newly diagnosed and treatment-naïve eyes with OAG, to investigate whether there was any correlation between these ocular parameters and the VF MD. Results: A total of 51 eyes were analyzed. A statistically significant correlation was found only between the VF MD and corneal hysteresis (CH) (P = 0.003, r2 = 0.16) and CCT (P = 0.03, r2 = 0.08). Conclusions: These results demonstrate that CH and CCT are associated with the amount of VF damage in treatment-naïve OAG eyes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of tafluprost on the central corneal thickness (CCT) in patients with primary open-angle glaucoma (POAG). Methods: This was a prospective study and included 100 eyes of 54 patients with POAG. All patients received tafluprost 0.0015% (Saflutan®) once daily in one or both eyes. CCT was measured by using noncontact pachymetry prior to the treatment and after 6 and 12 months. Results: Mean CCT of all treated eyes ( n = 100) was 547.79 ± 29.48 μm at baseline, 535.61 ± 26.54 μm after 6 months and 533.55 ± 26.45 μm after 12 months (Student's t test, p < 0.0001). Ninety-three percent of all treated eyes showed a decrease of CCT. CCT reduction was more significant within the first six months of the treatment period (Student's t test, p < 0.0001). After 12 months, a CCT reduction >25 μm occurred in 5% of all treated eyes. There was a significant positive correlation between the magnitude of corneal thinning and the initial CCT (Pearson, r = 0.49, p < 0.0001) but not between the magnitude of corneal thinning and intraocular pressure (IOP) reduction (Pearson, r = 0.145, p = 0.15). Discussion: Long-term use of tafluprost may decrease the CCT in patients with POAG. Consequently, clinicians must be aware of prolongated CCT variations that may arise throughout the follow-up period for proper IOP targeting and management. [ABSTRACT FROM AUTHOR]

. Purpose: To evaluate the diagnostic capacity of the Ocular Response Analyser's keratoconus match index (KMI) and keratoconus match probability (KMP) classification in a sample of keratoconus (KC) patients. Methods: Keratoconus match index and KMP from 114 KC eyes, randomly selected from 114 patients with bilateral keratoconus (KCG), were compared with the corresponding ones from 109 normal eyes (CG). Keratoconus match index's predictive accuracy was assessed by receiver operating curves (ROC). Keratoconus match probability level of agreement was evaluated at the different KC stages of the Amsler-Krumeich classification. Correlations were estimated with topographic keratoconus classification (TKC), keratoconus index (KI), index of surface variance (ISV), vertical asymmetry (IVA), height asymmetry (IHA), height decentration (IHD), minimal radius (Rmin), central corneal thickness (CCT), thinnest corneal thickness (TCT) mean keratometry (Km) and intraocular pressure (IOPg). Results: Mean KMI in KCG and CG was 0.20 ± 0.38 and 0.98 ± 0.25, respectively (p < 0.01). Significant KMI differences (p < 0.01) were detected in different KC groups [range: 0.62 ± 0.38 (KC 1), −0.62 ± 0.04 (KC 4)]. Significant correlation was detected between KC staging and KMI ( r = −0.56, p < 0.0001). Keratoconus match probability identified 22.03% of the CG eyes as suspect. Moreover, KMP identified 7.01% and 23.68% of the KCG eyes as normal and suspect, respectively. Receiver operating curves analysis for KMI parameter indicated a predictive accuracy of 97.7% (cut-off point: 0.512, sensitivity: 91.18%, specificity: 94.34%). Conclusions: Keratoconus match index seems to be a reliable index in keratoconus diagnosis and staging. Keratoconus match probability identifies a significant percentage of topographically defined KC and CG eyes as suspect. Diagnostic capacity of these novel indexes needs to be further explored. [ABSTRACT FROM AUTHOR]

Purpose: To determine the direct costs of therapy over 5 years of a European monotherapy cohort begun on a prostaglandin (PTG) versus timolol in patients with primary open-angle glaucoma or ocular hypertension. Methods: A retrospective, multicenter, active-controlled, observational study. Data were abstracted for European patients treated as initial monotherapy in 1996 or afterward, with 5 years of available records. Results: This study included 271 patients (166 on a PTG and 105 on timolol at baseline). The average cost/month/patient over 5 years was $45.47±12.61 for PTG and $31.50±15.47 for timolol ( P<0.001, based on German prices). After 5 years, although there was no difference in number of glaucoma medicines prescribed between groups (1.0 PTGs and 1.1 timolol, P=0.41), the timolol group demonstrated a higher intraocular pressure (17.7±2.9 vs. 16.5±3.0 mm Hg, P<0.001), more medication changes ( P=0.01), greater incidence of glaucomatous progression ( P=0.04), and less patients persistent on original monotherapy ( P<0.001) than the PTG cohort. Conclusions: Patients originally on timolol monotherapy have a lower cost of care over 5 years than those started on a PTG. However, timolol patients during follow-up may demonstrate a higher intraocular pressure, more progression, more medication changes, and lower persistency of the original monotherapy. [ABSTRACT FROM AUTHOR]

Background: To evaluate and compare the recorded IOP values of the Pascal dynamic contour tonometer (PDCT) and the Goldmann applanation tonometer (GAT) after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Methods: Three groups of 84, 182 and 43 patients each were treated by PRK for myopia, LASIK for myopia and LASIK for hyperopia respectively. Intraocular pressure (IOP) measurements were performed in all eyes 1 day before and 1, 3, 6 and 12 months after treatment with PDCT and GAT. Ultrasound pachymetry was performed in all eyes preoperatively and at 1st month postoperatively. Results: Preoperatively and postoperatively, GAT readings were lower than PDCT in all groups (all p < 0.05). Postoperatively in the PRK group, compared to the preoperative value, the mean differences of IOP recorded with GAT at 1st, 3rd, 6th and 12th month were −1.4 mmHg, −1.7 mmHg, −1.7 mmHg and −1.9 mmHg respectively (all p < 0.05). In the myopic LASIK group; the corresponding values with GAT were −3.6 mmHg, −3.6 mmHg, −3.6 mmHg and −3.5 mmHg (all p < 0.05), while in the hyperopic LASIK group the corresponding values were −1.1 mmHg, −0.7 mmHg, −1.1 mmHg and −0.9 mmHg (all p < 0.05). The mean IOP difference (GAT-PDCT) for myopic PRK, myopic LASIK and hyperopic LASIK were respectively −3.8 mmHg, −4.1 mmHg and −1.5 mmHg at the 12-month follow-up. No statistically significant changes were found for any group with the PDCT. Conclusions: GAT-determined IOP values were significant lower at all time-points after hyperopic LASIK, as well as myopic PRK or LASIK. The Pascal tonometry values remained unaffected for all groups. [ABSTRACT FROM AUTHOR]