30 results on '"Bitirgen G"'
Search Results
2. Surgical outcomes of Ex-PRESS® mini glaucoma shunt implantation [Ex-PRESS® mini glokom İmplant cerrahisi sonuçlarımız]
- Author
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Okka M., Bitirgen G., Kerimoğlu H., Bozkurt B., Yumak Erkoça H., and Selçuk Üniversitesi
- Subjects
genetic structures ,Intraocular pressure ,Glaucoma ,sense organs ,Glaucoma drainage implants ,eye diseases - Abstract
Objective: To evaluate intraocular pressure (IOP) lowering effect and safety of Ex-PRESS® mini glaucoma drainage implant (Alcon, Fort Worth, TX) for the surgical treatment of glaucoma. Material and Methods: The data of the subjects who underwent Ex-PRESS® mini glaucoma shunt (P-50) implantation surgery in 2011 and 2012 were retrospectively reviewed. IOP before and after the treatment, visual acuity, the number of medications and complications were analyzed. Success was defined as final IOP of 6-21 mmHg with or without antiglaucomatous medications. Results: Thirty two eyes of 32 patients were included in the study. The mean age of patients and mean follow-up time were 54.43±14.56 years (range 20-77 years) and 6.34±2.95 months (range 3-16 months), respectively. Mean pretreatment IOP was 30.71±4.72 mmHg, while it was 13.21±3.51 mmHg (p
- Published
- 2014
3. Transscleral diode laser cyclophotocoagulation in refractory glaucoma [Dirençli glokom olgularında transskleral diod lazer siklofotokoagülasyon]
- Author
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Bitirgen G., Okka M., Bozkurt B., Do?ru I., Kerimo?lu H., Öztürk B.T., Kamiş U., and Selçuk Üniversitesi
- Subjects
Diode laser cyclophotocoagulation ,genetic structures ,Refractory glaucoma ,Intraocular pressure ,sense organs ,eye diseases - Abstract
Purpose: To evaluate the safety and efficacy of transscleral diode laser cyclophotocoagulation (TSDLC) in advanced glaucoma refractory to medical or surgical treatment. Material and Method: The data of subjects who were treated with TSDLC between 2009 and 2011 were retrospectively reviewed. Intraocular pressure before and after treatment, visual acuity, the number of medications and complications were analysed. Success was defined as final IOP of 6-22 mmHg with or without antiglaucomatous medications. Results: Thirty seven eyes of 37 patients were included in the study. Mean age of patients and mean follow-up time were 61.73±17.13 years (range: 19-80 years) and 8.06±5.81 months (range: 3-22 months), respectively. Mean pretreatment IOP was 38.68±8.94 mmHg and IOP was 26.46±11.34 mmHg (p
- Published
- 2013
4. Corneal nerve fibre damage precedes diabetic retinopathy in patients with Type 2 diabetes mellitus
- Author
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Bitirgen, G., primary, Ozkagnici, A., additional, Malik, R. A., additional, and Kerimoglu, H., additional
- Published
- 2013
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5. Corneal nerve loss and increased Langerhans cells are associated with disease severity in patients with rheumatoid arthritis.
- Author
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Bitirgen G, Kucuk A, Ergun MC, Satirtav G, and Malik RA
- Subjects
- Humans, Cross-Sectional Studies, Cornea innervation, Patient Acuity, Microscopy, Confocal methods, Langerhans Cells, Arthritis, Rheumatoid complications
- Abstract
Background/objectives: Rheumatoid arthritis (RA) is a multisystem autoimmune disorder characterized by articular and extra-articular manifestations. Neuropathy is a poorly studied manifestation of RA. The aim of this study was to utilize the rapid non-invasive ophthalmic imaging technique of corneal confocal microscopy to identify whether there is evidence of small nerve fibre injury and immune cell activation in patients with RA., Subjects/methods: Fifty consecutive patients with RA and 35 healthy control participants were enrolled in this single-centre, cross-sectional study conducted at a university hospital. Disease activity was assessed with the 28-Joint Disease Activity Score and erythrocyte sedimentation rate (DAS28-ESR). Central corneal sensitivity was measured with a Cochet-Bonnet contact corneal esthesiometer. A laser scanning in vivo corneal confocal microscope was used to quantify corneal nerve fibre density (CNFD), nerve branch density (CNBD), nerve fibre length (CNFL), and Langerhans cell (LC) density., Results: Corneal sensitivity (P = 0.01), CNFD (P = 0.02), CNBD (P < 0.001), and CNFL (P < 0.001) were lower, and mature (P = 0.001) and immature LC densities (P = 0.011) were higher in patients with RA compared to control subjects. CNFD (P = 0.016) and CNFL (P = 0.028) were significantly lower in patients with moderate to high (DAS28-ESR > 3.2) compared to mild (DAS28-ESR ≤ 3.2) disease activity. Furthermore, the DAS28-ESR score correlated with CNFD (r = -0.425; P = 0.002), CNBD (ρ = -0.362; P = 0.010), CNFL (r = -0.464; P = 0.001), total LC density (ρ = 0.362; P = 0.010) and immature LC density (ρ = 0.343; P = 0.015)., Conclusions: This study demonstrates reduced corneal sensitivity, corneal nerve fibre loss and increased LCs which were associated with the severity of disease activity in patients with RA., (© 2023. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)
- Published
- 2023
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6. Corneal axonal loss as an imaging biomarker of neurodegeneration in multiple sclerosis: a longitudinal study.
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Petropoulos IN, Al-Shibani F, Bitirgen G, Ponirakis G, Khan A, Gad H, Mahfoud ZR, Altarawneh H, Rehman MH, John K, Al-Merekhi D, George P, Uca AU, Ozkagnici A, Ibrahim F, Francis R, Canibano B, Deleu D, El-Sotouhy A, Vattoth S, Own A, Shuaib A, Akhtar N, Kamran S, and Malik RA
- Abstract
Background: Resourceful endpoints of axonal loss are needed to predict the course of multiple sclerosis (MS). Corneal confocal microscopy (CCM) can detect axonal loss in patients with clinically isolated syndrome and established MS, which relates to neurological disability., Objective: To assess corneal axonal loss over time in relation to retinal atrophy, and neurological and radiological abnormalities in MS., Methods: Patients with relapsing-remitting (RRMS) ( n = 68) or secondary progressive MS (SPMS) ( n = 15) underwent CCM and optical coherence tomography. Corneal nerve fibre density (CNFD-fibres/mm
2 ), corneal nerve branch density (CNBD-branches/mm2 ), corneal nerve fibre length (CNFL-mm/mm2 ) and retinal nerve fibre layer (RNFL-μm) thickness were quantified along with neurological and radiological assessments at baseline and after 2 years of follow-up. Age-matched, healthy controls ( n = 20) were also assessed., Results: In patients with RRMS compared with controls at baseline, CNFD ( p = 0.004) and RNFL thickness ( p < 0.001) were lower, and CNBD ( p = 0.003) was higher. In patients with SPMS compared with controls, CNFD ( p < 0.001), CNFL ( p = 0.04) and RNFL thickness ( p < 0.001) were lower. For identifying RRMS, CNBD had the highest area under the receiver operating characteristic (AUROC) curve (0.99); and for SPMS, CNFD had the highest AUROC (0.95). At follow-up, there was a further significant decrease in CNFD ( p = 0.04), CNBD ( p = 0.001), CNFL ( p = 0.008) and RNFL ( p = 0.002) in RRMS; in CNFD ( p = 0.04) and CNBD ( p = 0.002) in SPMS; and in CNBD ( p = 0.01) in SPMS compared with RRMS. Follow-up corneal nerve loss was greater in patients with new enhancing lesions and optic neuritis history., Conclusion: Progressive corneal and retinal axonal loss was identified in patients with MS, especially those with more active disease. CCM may serve as an imaging biomarker of axonal loss in MS., Competing Interests: The authors declared the following potential conflicts of interest with respect to the research, authorship and/or publication of this article: Drs Ioannis N. Petropoulos, Fatima Al-Shibani, Gulfidan Bitirgen, Georgios Ponirakis, Adnan Khan, Hoda Gad, Ziyad R. Mahfoud, Heba Altarawneh, Muhammad Hassan Rehman, Karen John, Dhabia Al-Merekhi, Pooja George, Ali Ulvi Uca, Ahmet Ozkagnici, Faiza Ibrahim, Reny Francis, Beatriz Canibano, Dirk Deleu, Ahmed El-Sotouhy, Surjith Vattoth, Ahmed Own, Ashfaq Shuaib, Naveed Akhtar and Saadat Kamran declare no conflict of interest. Dr. Rayaz A. Malik is a principal investigator on grants from Proctor and Gamble and Pfizer and has received consulting honoraria for serving on advisory boards for Novo Nordisk, Aventis Pharma, and Proctor and Gamble., (© The Author(s), 2023.)- Published
- 2023
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7. Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID.
- Author
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Bitirgen G, Korkmaz C, Zamani A, Ozkagnici A, Zengin N, Ponirakis G, and Malik RA
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- Humans, Cross-Sectional Studies, SARS-CoV-2, Microscopy, Confocal, Cornea innervation, Nerve Fibers, Dendritic Cells, Post-Acute COVID-19 Syndrome, COVID-19
- Abstract
Background/aims: Long COVID is characterised by a range of potentially debilitating symptoms which develop in at least 10% of people who have recovered from acute SARS-CoV-2 infection. This study has quantified corneal sub-basal nerve plexus morphology and dendritic cell (DC) density in patients with and without long COVID., Methods: Forty subjects who had recovered from COVID-19 and 30 control participants were included in this cross-sectional comparative study undertaken at a university hospital. All patients underwent assessment with the National Institute for Health and Care Excellence (NICE) long COVID, Douleur Neuropathique 4 (DN4) and Fibromyalgia questionnaires, and corneal confocal microscopy (CCM) to quantify corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), and total, mature and immature DC density., Results: The mean time after the diagnosis of COVID-19 was 3.7±1.5 months. Patients with neurological symptoms 4 weeks after acute COVID-19 had a lower CNFD (p=0.032), CNBD (p=0.020), and CNFL (p=0.012), and increased DC density (p=0.046) compared with controls, while patients without neurological symptoms had comparable corneal nerve parameters, but increased DC density (p=0.003). There were significant correlations between the total score on the NICE long COVID questionnaire at 4 and 12 weeks with CNFD (ρ=-0.436; p=0.005, ρ=-0.387; p=0.038, respectively) and CNFL (ρ=-0.404; p=0.010, ρ=-0.412; p=0.026, respectively)., Conclusion: Corneal confocal microscopy identifies corneal small nerve fibre loss and increased DCs in patients with long COVID, especially those with neurological symptoms. CCM could be used to objectively identify patients with long COVID., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2022
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8. Abnormal quantitative pupillary light responses following COVID-19.
- Author
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Bitirgen G, Korkmaz C, Zamani A, Iyisoy MS, Kerimoglu H, and Malik RA
- Subjects
- Cross-Sectional Studies, France, Humans, Light, Pupil, Reflex, Pupillary, Post-Acute COVID-19 Syndrome, COVID-19 complications
- Abstract
Purpose: To characterize alterations in pupillary light reflex responses in subjects following coronavirus disease 2019 (COVID-19), especially those with long-COVID., Methods: Thirty-five subjects with previous COVID-19 and 30 healthy control participants were enrolled in this cross-sectional comparative study. An infrared dynamic pupillometry system (MonPack One; Metrovision, France) was used to quantify pupillary light responses. The National Institute for Health and Care Excellence (NICE) long-COVID questionnaire was used to identify persisting symptoms at least 4 weeks after acute COVID-19., Results: The median time after the diagnosis of acute COVID-19 was 4.0 (2.0-5.0) months. There was an increase in the latency of pupil contraction (P = 0.001) and a reduction in the duration of pupil contraction (P = 0.039) in post-COVID-19 subjects compared to healthy controls. No significant differences were observed in the initial pupil diameter, amplitude and velocity of pupil contraction or latency, velocity and duration of pupil dilation. Long-COVID was present in 25/35 (71%) subjects and their duration of pupil contraction was reduced compared to subjects without long-COVID (P = 0.009). The NICE long-COVID questionnaire total score (ρ = - 0.507; P = 0.002) and neurological score (ρ = - 0.412; P = 0.014) correlated with the duration of pupil contraction and the total score correlated with the latency of dilation (ρ = - 0.352; P = 0.038)., Conclusion: Dynamic pupillometry reveals significant alterations in contractile pupillary light responses, indicative of parasympathetic dysfunction after COVID-19., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)
- Published
- 2022
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9. Subclinical Corneal Nerve Fiber Damage and Immune Cell Activation in Systemic Lupus Erythematosus: A Corneal Confocal Microscopy Study.
- Author
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Bitirgen G, Kucuk A, Ergun MC, Baloglu R, Gharib MH, Al Emadi S, Ponirakis G, and Malik RA
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- Adult, Cross-Sectional Studies, Humans, Microscopy, Confocal, Middle Aged, Nerve Fibers, Young Adult, Cornea diagnostic imaging, Lupus Erythematosus, Systemic complications
- Abstract
Purpose: The purpose of this study was to evaluate the utility of corneal confocal microscopy (CCM) in identifying small nerve fiber damage and immune cell activation in patients with systemic lupus erythematosus (SLE)., Methods: This cross-sectional comparative study included 39 consecutive patients with SLE and 30 healthy control participants. Central corneal sensitivity was assessed using a Cochet-Bonnet contact corneal esthesiometer and a laser scanning CCM (Heidelberg, Germany) was used to quantify corneal nerve fiber density (CNFD), nerve branch density (CNBD), nerve fiber length (CNFL), and Langerhans cell (LC) density., Results: Age was comparable among patients with SLE (33.7 ± 12.7) and controls (35.0 ± 13.7 years, P = 0.670) and the median duration of disease was 3.0 years (2.0-10.0 years). CNBD (P = 0.003) and CNFL (P = 0.019) were lower and mature LC density (P = 0.002) was higher, but corneal sensitivity (P = 0.178) and CNFD (P = 0.198) were comparable in patients with SLE compared with controls. The SELENA-SLEDAI score correlated with CNFD (ρ = -0.319, P = 0.048) and CNFL (ρ = -0.373, P = 0.019), and the total and immature LC densities correlated with CNBD (ρ = -0.319. P = 0.048, and ρ = -0.328, P = 0.041, respectively). Immature LC density was higher (P = 0.025), but corneal sensitivity and nerve fiber parameters were comparable between patients with (33%) and without neuropsychiatric symptoms and SLE., Conclusions: Corneal confocal microscopy identifies distal corneal nerve fiber loss and increased immune cell density in patients with SLE and corneal nerve loss was associated with disease activity., Translational Relevance: Corneal confocal microscopy may enable the detection of subclinical corneal nerve loss and immune cell activation in SLE.
- Published
- 2021
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10. Assessment of pupillary light reflex using dynamic pupillometry in laser-treated eyes with retinal vein occlusion.
- Author
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Turk HB, Bitirgen G, Satirtav G, and Kerimoglu H
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- Aged, Choroid, Humans, Laser Coagulation, Lasers, Middle Aged, Reflex, Retinal Vein Occlusion diagnosis, Retinal Vein Occlusion surgery
- Abstract
Purpose: This study aims to evaluate the pupillary light reflex measured with dynamic pupillometry in patients who underwent retinal laser photocoagulation due to unilateral retinal vein occlusion (RVO)., Methods: A total of 48 patients with unilateral RVO were included in the study. Thirty-four patients had undergone retinal laser photocoagulation while the remaining 14 patients that did not undergo laser treatment were observed for control purposes. Of the laser-treated eyes, 14 eyes (41.2%) had central RVO (CRVO) and 20 eyes (58.8%) had branch RVO (BRVO). Among the 14 patients with RVO without laser treatment, nine eyes (64.3%) had CRVO and five eyes (35.7%) had BRVO. Pupillary light reflexes were assessed with dynamic pupillometry (MonPackOne®; Metrovision, France). The parameters of the eyes with RVO were compared with that of fellow healthy eyes., Results: Mean patient age was 65.8 ± 10.4 years and median time after photocoagulation was 25.5 months. Eyes that received laser photocoagulation had lower pupil contraction amplitude ( p = 0.037), prolonged contraction latency ( p = 0.027), slower contraction velocity ( p = 0.043), and slower dilation velocity ( p < 0.001) compared to healthy fellow eyes. Subgroup analysis revealed that eyes with CRVO had lower contraction amplitude ( p = 0.013) and slower dilation velocity ( p = 0.003), and eyes with BRVO had slower dilation velocity ( p = 0.003). Non-laser-treated eyes with RVO revealed no significant difference in any of the pupillary light reflex parameters compared to fellow eyes., Conclusion: Laser-treated eyes with RVO demonstrated changes in pupillary light reflex parameters including reduced contraction amplitude, prolonged contraction latency, and slower contraction and dilation velocities measured with dynamic pupillometry.
- Published
- 2021
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11. Corneal Confocal Microscopy to Image Small Nerve Fiber Degeneration: Ophthalmology Meets Neurology.
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Petropoulos IN, Bitirgen G, Ferdousi M, Kalteniece A, Azmi S, D'Onofrio L, Lim SH, Ponirakis G, Khan A, Gad H, Mohammed I, Mohammadi YE, Malik A, Gosal D, Kobylecki C, Silverdale M, Soran H, Alam U, and Malik RA
- Abstract
Neuropathic pain has multiple etiologies, but a major feature is small fiber dysfunction or damage. Corneal confocal microscopy (CCM) is a rapid non-invasive ophthalmic imaging technique that can image small nerve fibers in the cornea and has been utilized to show small nerve fiber loss in patients with diabetic and other neuropathies. CCM has comparable diagnostic utility to intraepidermal nerve fiber density for diabetic neuropathy, fibromyalgia and amyloid neuropathy and predicts the development of diabetic neuropathy. Moreover, in clinical intervention trials of patients with diabetic and sarcoid neuropathy, corneal nerve regeneration occurs early and precedes an improvement in symptoms and neurophysiology. Corneal nerve fiber loss also occurs and is associated with disease progression in multiple sclerosis, Parkinson's disease and dementia. We conclude that corneal confocal microscopy has good diagnostic and prognostic capability and fulfills the FDA criteria as a surrogate end point for clinical trials in peripheral and central neurodegenerative diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. There is no conflict of interest related to this work for any of the authors., (Copyright © 2021 Petropoulos, Bitirgen, Ferdousi, Kalteniece, Azmi, D'Onofrio, Lim, Ponirakis, Khan, Gad, Mohammed, Mohammadi, Malik, Gosal, Kobylecki, Silverdale, Soran, Alam and Malik.)
- Published
- 2021
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12. Altered pupillary light responses are associated with the severity of autonomic symptoms in patients with Fabry disease.
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Bitirgen G, Turkmen K, Zengin N, and Malik RA
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- Adult, Case-Control Studies, Cross-Sectional Studies, Fabry Disease blood, Female, Humans, Male, Reflex, Pupillary, Severity of Illness Index, Surveys and Questionnaires, Tertiary Care Centers, alpha-Glucosidases blood, Autonomic Nervous System physiopathology, Fabry Disease physiopathology, Pupil Disorders physiopathology
- Abstract
Symptoms of autonomic dysfunction are common in Fabry disease. In this study we aimed to evaluate alterations in the pupillary response to white light stimulation in patients with Fabry disease and their association with the severity of autonomic symptoms. Fourteen consecutive patients with Fabry disease and 14 healthy control participants were enrolled in this cross-sectional study. The Mainz Severity Score Index (MSSI) was used to measure the severity of Fabry disease and the Composite Autonomic Symptom Scale 31 (COMPASS 31) questionnaire was used to evaluate the severity of autonomic symptoms. The pupil light responses were assessed with an infrared dynamic pupillometry unit. There were significant reductions in the amplitude (P = 0.048) and duration (P = 0.048) of pupil contraction, and the latency of pupil dilation (P = 0.048) in patients with Fabry disease compared to control subjects. The total weighted COMPASS 31 score correlated with MSSI (r = 0.592; P = 0.026) and the duration of pupil dilation (ρ = 0.561; P = 0.037). The pupillomotor weighted sub-score of the COMPASS 31 correlated inversely with the duration of pupil contraction (r = - 0.600; P = 0.023) and latency of pupil dilation (ρ = - 0.541; P = 0.046), and directly with the duration of pupil dilation (ρ = 0.877; P < 0.001) and MSSI (r = 0.533; P = 0.049). In conclusion, abnormal pupillary function is demonstrated in patients with Fabry disease, which is associated with the severity of autonomic symptoms.
- Published
- 2021
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13. Abnormal Dynamic Pupillometry Relates to Neurologic Disability and Retinal Axonal Loss in Patients With Multiple Sclerosis.
- Author
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Bitirgen G, Akpinar Z, Turk HB, and Malik RA
- Subjects
- Cross-Sectional Studies, Humans, Retina diagnostic imaging, Tomography, Optical Coherence, Multiple Sclerosis complications, Optic Neuritis diagnosis
- Abstract
Purpose: To assess alterations in quantitative dynamic pupil responses to light in relation to neurologic disability and retinal axonal loss in patients with multiple sclerosis (MS)., Methods: Twenty-five patients with relapsing-remitting MS and 25 healthy subjects were included in this cross-sectional study. Pupillary responses were measured with an infrared dynamic pupillometry unit, and peripapillary retinal nerve fiber layer (RNFL) thickness was measured with spectral-domain optical coherence tomography. Neurologic disability was assessed by the Expanded Disability Status Scale (EDSS). Patients with a history of optic neuritis (ON) within 6 months were excluded. Only the right eyes were assessed, except in 11 patients with a history of unilateral ON in whom both eyes were further analyzed to evaluate the effect of previous ON., Results: The initial pupil diameter (P = 0.003) and pupil contraction amplitude (P = 0.027) were lower in patients with MS compared with healthy controls. Initial pupil diameter correlated with EDSS score (ρ = -0.458; P = 0.021), and RNFL correlated with contraction latency (ρ = -0.524; P = 0.007). There were no significant differences in any of the pupil parameters between eyes with and without a history of ON, and between the ON and fellow eyes of the 11 patients with previous unilateral ON., Conclusions: Dynamic pupillometry reveals significant alterations in pupillary light reflex responses associated with neurologic disability and retinal axonal loss, independent of previous ON., Translational Relevance: Dynamic pupillometry is a simple, noninvasive tool that may be useful in detecting autonomic dysfunction in patients with MS.
- Published
- 2021
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14. Traumatic hyphema in a patient with severe hemophilia A: Clinical features and management.
- Author
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Belviranli S, Ozkagnici A, Tokgoz H, Bitirgen G, and Caliskan U
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- Adolescent, Anterior Chamber drug effects, Coagulants therapeutic use, Eye Injuries drug therapy, Eye Injuries etiology, Factor VIII therapeutic use, Hemophilia A drug therapy, Humans, Hyphema etiology, Intraocular Pressure, Male, Visual Acuity, Wounds, Nonpenetrating drug therapy, Wounds, Nonpenetrating etiology, Eye Injuries diagnosis, Hemophilia A complications, Hyphema diagnosis, Hyphema drug therapy, Wounds, Nonpenetrating diagnosis
- Abstract
Purpose: To describe a case of traumatic hyphema in a patient with severe hemophilia A., Case: We present a case of a 16-year-old boy with severe hemophilia A who presented to our ophthalmology department with total hyphema and elevated intraocular pressure 3 days after a history of blunt ocular trauma on his right eye. Due to the persistent intraocular pressure elevation and total hyphema despite medical intervention, an early anterior chamber washout was performed with the replacement of factor VIII preoperatively and postoperatively. Re-bleeding or any other complications were not experienced during surgery or postoperatively. At the first postoperative week, 20/20 visual acuity and a normal intraocular pressure without antiglaucoma medication was retained and remained stable during the 6-month follow-up., Conclusion: In such cases with hemophilia A, traumatic hyphema, and intraocular pressure elevation despite medical intervention, an early surgical clot removal under intense factor VIII replacement could be performed. In the early postoperative period, factor replacement should be resumed in order to avoid re-bleeding.
- Published
- 2021
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15. Progressive Loss of Corneal and Retinal Nerve Fibers in Patients With Multiple Sclerosis: A 2-Year Follow-up Study.
- Author
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Bitirgen G, Akpinar Z, Uca AU, Ozkagnici A, Petropoulos IN, and Malik RA
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- Cornea diagnostic imaging, Follow-Up Studies, Humans, Nerve Fibers, Retina, Multiple Sclerosis diagnostic imaging
- Abstract
Purpose: To determine longitudinal alterations in corneal nerve fiber morphology, dendritic cell (DC) density, and retinal nerve fiber layer (RNFL) thickness over 2 years in patients with multiple sclerosis (MS)., Methods: Thirty-one consecutive patients with relapsing-remitting MS (RRMS) underwent assessment of the Kurtzke Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS), corneal confocal microscopy to quantify corneal subbasal nerve morphology and DC density, and spectral-domain optical coherence tomography to quantify RNFL thickness at baseline and after 2 years., Results: There was a significant reduction in corneal nerve fiber area (CNFA) ( P = 0.003), nerve fiber width (CNFW) ( P = 0.005), and RNFL thickness ( P = 0.004) with an increase in EDSS ( P = 0.01) over 2 years. The change in corneal nerve fiber density (CNFD) correlated with the change in EDSS (ρ = -0.468; P = 0.008), MSSS (ρ = -0.442; P = 0.01), DC density (ρ = -0.550; P = 0.001), and RNFL (ρ = 0.472; P = 0.007). The change in corneal nerve fiber length (CNFL) correlated with the change in EDSS (ρ = -0.445; P = 0.01) and MSSS (ρ = -0.490; P = 0.005). Furthermore, there was a significant decrease in CNFL ( P < 0.001), CNFA ( P = 0.02), CNFW ( P = 0.04), corneal total branch density ( P = 0.01), and RNFL thickness ( P = 0.02) and a significant increase in DC density ( P = 0.04) in patients with worsening EDSS ( n = 15)., Conclusions: Corneal confocal microscopy can be used to detect progressive corneal nerve fiber loss that relates to a progression of disability in patients with RRMS., Translational Relevance: Corneal confocal microscopy acts as a sensitive imaging biomarker for progressive nerve degeneration in patients with MS., Competing Interests: Disclosure: G. Bitirgen, None; Z. Akpinar, None; A.U. Uca, None; A. Ozkagnici, None; I.N. Petropoulos, None; R.A. Malik, None, (Copyright 2020 The Authors.)
- Published
- 2020
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16. Evaluation of Pupillary Light Reflex in Amblyopic Eyes Using Dynamic Pupillometry
- Author
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Bitirgen G, Daraghma M, and Özkağnıcı A
- Subjects
- Adolescent, Anisometropia physiopathology, Child, Cross-Sectional Studies, Humans, Light, Physical Examination, Pupil physiology, Strabismus physiopathology, Visual Acuity, Amblyopia physiopathology, Reflex, Pupillary physiology
- Abstract
Objectives: To evaluate the pupillary light reflex responses in patients with unilateral strabismic and anisometropic amblyopia using dynamic pupillometry., Materials and Methods: A total of 102 eyes of 51 patients with unilateral amblyopia were included in this cross-sectional study. Of the 51 patients, 37 (72.5%) had strabismic amblyopia and 14 (27.5%) had anisometropic amblyopia. All patients underwent complete ophthalmological examination, and pupillary light reflex responses were measured using a computerized dynamic pupillometry system (MonPack One; Metrovision, France). Initial pupil diameter; the amplitude, latency, duration, and velocity of pupil contraction; and the latency, duration, and velocity of pupil dilation were recorded. Results obtained from the patients’ amblyopic and normal fellow eyes were compared using paired-samples t-test and Wilcoxon signed rank test., Results: The mean age of the patients was 11.9±6.0 years. Amblyopic eyes had longer contraction latency (p=0.009), shorter contraction duration (p=0.002), and higher dilation velocity (p=0.033) compared to fellow eyes, while other parameters did not show significant differences. In subgroup analysis, eyes with strabismic amblyopia had longer contraction latency (p=0.006) and shorter contraction duration (p=0.017), while eyes with anisometropic amblyopia had shorter contraction duration (p=0.030) when compared with fellow eyes., Conclusion: In this study, the objective records obtained by dynamic pupillometry showed that pupillary light reflex responses are affected in amblyopic eyes. This finding may shed light on unclear aspects of the pathophysiology of amblyopia.
- Published
- 2019
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17. Analysis of Peripapillary Choroidal Thickness in Unilateral Amblyopia.
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Bitirgen G, Mirza E, Ozkagnici A, and Iyisoy MS
- Abstract
Purpose: To evaluate the peripapillary choroidal thickness (CT) in children with unilateral amblyopia using spectral-domain optical coherence tomography (SD-OCT)., Methods: One hundred and six eyes of 53 children with unilateral amblyopia and 20 eyes of 20 children with normal vision were involved in this study. Of the 53 children with unilateral amblyopia, 29 (54.7%) had hyperopic anisometropic amblyopia and 24 (45.3%) had strabismic amblyopia. Peripapillary CT was measured from 6 mm length radial B-scans at the optic nerve head using the enhanced depth imaging program of an SD-OCT (Heidelberg Engineering, Germany). Age, sex, refractive error, and best-corrected visual acuity were also recorded., Results: The average peripapillary CT was greater in amblyopic eyes than in the fellow eyes of the children with amblyopia ( P = 0.002), and control eyes ( P < 0.001). There was no significant difference between the fellow eyes of children with amblyopia and the control eyes ( P = 0.158). The average peripapillary CT was negatively correlated with axial length (AL) in amblyopic eyes ( r = -0.381; P = 0.005) and fellow eyes ( r = -0.392; P = 0.004) but not in control eyes ( r = -0.232; P = 0.325). After adjustment for the possible effects of AL, the average peripapillary CT in amblyopic eyes was still greater than in fellow eyes ( P = 0.014) and control eyes ( P = 0.022)., Conclusion: The peripapillary choroid of eyes with amblyopia was thicker than that of the fellow eyes and control eyes. No significant difference was observed between fellow eyes and control eyes., Competing Interests: There are no conflicts of interest.
- Published
- 2019
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18. Corneal confocal microscopy detects corneal nerve damage and increased dendritic cells in Fabry disease.
- Author
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Bitirgen G, Turkmen K, Malik RA, Ozkagnici A, and Zengin N
- Subjects
- Adult, Cell Count, Endothelial Cells pathology, Enzyme Replacement Therapy, Fabry Disease immunology, Fabry Disease pathology, Fabry Disease therapy, Female, Humans, Male, Cornea diagnostic imaging, Cornea innervation, Dendritic Cells cytology, Fabry Disease diagnostic imaging, Microscopy, Confocal, Nerve Fibers pathology
- Abstract
Fabry disease is characterised by neuropathic pain and accelerated vascular disease. This study evaluates the utility of corneal confocal microscopy (CCM) to non-invasively quantify corneal nerve and endothelial cell morphology and dendritic cell (DC) density in relation to disease severity in subjects with Fabry disease. Seventeen consecutive participants with Fabry disease and 17 healthy control subjects were included in this cross-sectional study. Fabry disease severity was measured using the Mainz Severity Score Index (MSSI). Central corneal sensitivity was assessed with a contact corneal esthesiometer. There was a significant reduction in the corneal sensitivity (5.75 [5.25-6.00] vs. 6.00 [6.00-6.00] cm, P = 0.014), nerve fiber density (NFD) (26.4 ± 10.1 vs. 33.7 ± 7.9 fibers/mm
2 , P = 0.025) and nerve fiber length (NFL) (15.9 ± 3.4 vs. 19.5 ± 4.4 mm/mm2 , P = 0.012) and an increase in DC density (38.3 [17.5-97.3] vs. 13.5 [0-29.4] cells/mm2 , P = 0.004) in subjects with Fabry disease compared to the healthy control subjects. The total MSSI score correlated with NFD (ρ = -0.686; P = 0.006), NFL (ρ = -0.692; P = 0.006), endothelial cell density (ρ = -0.511; P = 0.036), endothelial cell area (ρ = 0.514; P = 0.036) and α-galactosidase A enzyme activity (ρ = -0.723; P = 0.008). This study demonstrates reduced corneal sensitivity, corneal nerve fiber damage and increased DCs in subjects with Fabry disease.- Published
- 2018
- Full Text
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19. In Vivo Confocal Microscopic Evaluation of Corneal Nerve Fibers and Dendritic Cells in Patients With Behçet's Disease.
- Author
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Bitirgen G, Tinkir Kayitmazbatir E, Satirtav G, Malik RA, and Ozkagnici A
- Abstract
Central and peripheral nervous system involvement may occur during the course of Behçet's disease (BD). In vivo corneal confocal microscopy (CCM) can detect corneal small fiber damage and immune cell density. The aim of this study was to assess central corneal sensitivity, corneal subepithelial nerve plexus morphology and dendritic cell (DC) density in patients with BD. Forty-nine consecutive patients with BD and 30 healthy control subjects were included in this cross-sectional study conducted at a tertiary referral university hospital. Central corneal sensitivity was measured using the contact corneal esthesiometer (Cochet-Bonnet; Luneau, France). The laser scanning CCM (Heidelberg, Germany) was used to quantify corneal nerve fiber density (NFD), nerve branch density (NBD), nerve fiber length (NFL), and DC density. There was a significant reduction in NFD ( P = 0.001) and NFL ( P = 0.031) and an increase in DC density ( P = 0.038) in patients with BD compared to healthy controls, whereas corneal sensitivity ( P = 0.066) and NBD ( P = 0.067) did not differ significantly. There was no difference in corneal sensitivity, corneal nerve parameters, or DC density between BD patients with [ n = 18 (36.7%)] and without a previous history of uveitis ( P > 0.05 for all). Disease duration [median (IQR), 6.5 (4.0-14.5) years] correlated with corneal sensitivity (ρ = -0.463; P = 0.001) and NFD (ρ = -0.304; P = 0.034) and corneal sensitivity correlated with NFD (ρ = 0.411; P = 0.003) and NFL (ρ = 0.295; P = 0.039) in patients with BD. CCM demonstrates corneal sub-basal nerve fiber loss and increased DC density, providing a non-invasive ophthalmic means to identify peripheral neuropathy and inflammation in patients with BD.
- Published
- 2018
- Full Text
- View/download PDF
20. Effects of panretinal laser photocoagulation on the corneal nerve plexus and retinal nerve fiber layer in retinal vein occlusion.
- Author
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Bitirgen G, Belviranli S, Malik RA, Kerimoglu H, and Ozkagnici A
- Subjects
- Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Follow-Up Studies, Humans, Male, Middle Aged, Retinal Vein Occlusion diagnosis, Time Factors, Cornea innervation, Laser Coagulation methods, Nerve Fibers pathology, Retinal Ganglion Cells pathology, Retinal Vein Occlusion surgery, Tomography, Optical Coherence methods
- Abstract
Purpose: To determine the effects of panretinal photocoagulation (PRP) on corneal sub-basal nerve plexus (SBNP) and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with unilateral central retinal vein occlusion (CRVO) who had previously undergone PRP treatment., Methods: Sixty-four eyes of 32 patients (19 male, 13 female) with unilateral ischemic type CRVO who had undergone PRP treatment at least 6 months previously were included in this cross-sectional study. The laser scanning in vivo corneal confocal microscope was used to determine corneal SBNP parameters. The peripapillary RNFL thickness was assessed with spectral-domain optical coherence tomography. Data obtained from the PRP-treated eyes were compared with those of the fellow unaffected eyes., Results: The mean age of patients was 63.5 ± 10.7 years (range 45-85 years). The mean nerve fiber density (NFD), nerve branch density, and nerve fiber length (NFL) were significantly lower in PRP-treated eyes compared with fellow eyes (p<0.001 for all). Average peripapillary RNFL thickness was significantly lower in PRP-treated eyes than in fellow eyes (p = 0.007). The NFD and NFL showed a modest but significant positive correlation with average peripapillary RNFL thickness (r = 0.310, p = 0.013 and r = 0.272, p = 0.030, respectively)., Conclusions: Significant reductions in corneal SBNP parameters and average peripapillary RNFL thickness were observed in the eyes of patients receiving PRP for the treatment of ischemic CRVO.
- Published
- 2017
- Full Text
- View/download PDF
21. Use of Corneal Confocal Microscopy to Detect Corneal Nerve Loss and Increased Dendritic Cells in Patients With Multiple Sclerosis.
- Author
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Bitirgen G, Akpinar Z, Malik RA, and Ozkagnici A
- Subjects
- Adult, Cell Count, Cornea pathology, Corneal Diseases etiology, Cross-Sectional Studies, Female, Humans, Male, Multiple Sclerosis complications, Nerve Fibers, Retinal Ganglion Cells pathology, Tomography, Optical Coherence methods, Visual Acuity, Cornea innervation, Corneal Diseases diagnosis, Dendritic Cells pathology, Microscopy, Confocal methods, Multiple Sclerosis diagnosis
- Abstract
Importance: Multiple sclerosis (MS) is characterized by demyelination, axonal degeneration, and inflammation. Corneal confocal microscopy has been used to identify axonal degeneration in several peripheral neuropathies., Objective: To assess corneal subbasal nerve plexus morphologic features, corneal dendritic cell (DC) density, and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with MS., Design, Setting, and Participants: This single-center, cross-sectional comparative study was conducted at a tertiary referral university hospital between May 27, 2016, and January 30, 2017. Fifty-seven consecutive patients with relapsing-remitting MS and 30 healthy, age-matched control participants were enrolled in the study. Corneal subbasal nerve plexus measures and DC density were quantified in images acquired with the laser scanning in vivo corneal confocal microscope, and peripapillary RNFL thickness was measured with spectral-domain optical coherence tomography., Main Outcomes and Measures: Corneal nerve fiber density, nerve branch density, nerve fiber length, DC density, peripapillary RNFL thickness, and association with the severity of neurologic disability as assessed by the Kurtzke Expanded Disability Status Scale (score range, 0-10; higher scores indicate greater disability) and Multiple Sclerosis Severity Score (score range, 0.01-9.99; higher scores indicate greater severity)., Results: Of the 57 participants with MS, 42 (74%) were female and the mean (SD) age was 35.4 (8.9) years; of the 30 healthy controls, 19 (63%) were female and the mean (SD) age was 34.8 (10.2) years. Corneal nerve fiber density (mean [SE] difference, -6.78 [2.14] fibers/mm2; 95% CI, -11.04 to -2.52; P = .002), nerve branch density (mean [SE] difference, -17.94 [5.45] branches/mm2; 95% CI, -28.77 to -7.10; P = .001), nerve fiber length (mean [SE] difference, -3.03 [0.89] mm/mm2; 95% CI, -4.81 to -1.25; P = .001), and the mean peripapillary RNFL thickness (mean [SE] difference, -17.06 [3.14] μm; 95% CI, -23.29 to -10.82; P < .001) were reduced in patients with MS compared with healthy controls. The DC density was increased (median [interquartile range], 27.7 [12.4-66.8] vs 17.3 [0-28.2] cells/mm2; P = .03), independent of a patient's history of optic neuritis. Nerve fiber density and RNFL thickness showed inverse associations with the Expanded Disability Status Scale (ρ = -0.295; P = .03 for nerve fiber density and ρ = -0.374; P = .004 for RNFL thickness) and the Multiple Sclerosis Severity Score (R = -0.354; P = .007 for nerve fiber density and R = -0.283; P = .03 for RNFL thickness), whereas other study measures did not., Conclusions and Relevance: These data suggest that corneal confocal microscopy demonstrates axonal loss and increased DC density in patients with MS. Additional longitudinal studies are needed to confirm the use of corneal confocal microscopy as an imaging biomarker in patients with MS.
- Published
- 2017
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- View/download PDF
22. Unilateral Vision Loss without Ophthalmoplegia as a Rare Complication of Spinal Surgery.
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Akpınar E, Gürbüz MS, Bitirgen G, and Okutan MÖ
- Abstract
Postoperative visual loss is an extremely rare complication of nonocular surgery. The most common causes are ischemic optic neuropathy, central retinal artery occlusion, and cerebral ischemia. Acute visual loss after spinal surgery is even rarer. The most important risk factors are long-lasting operations, massive bleedings, fluid overload, hypotension, hypothermia, coagulation disorders, direct trauma, embolism, long-term external ocular pressure, and anemia. Here, we present a case of a 54-year-old male who developed acute visual loss in his left eye after a lumbar instrumentation surgery and was diagnosed with retinal artery occlusion., Competing Interests: There are no conflicts of interest.
- Published
- 2017
- Full Text
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23. Assessment of Corneal Sensation, Innervation and Retinal Nerve Fiber Layer in Patients Treated with Multiple Intravitreal Ranibizumab Injections.
- Author
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Bitirgen G, Belviranli S, Malik RA, Kerimoglu H, Satirtav G, and Zengin N
- Subjects
- Aged, Aged, 80 and over, Cornea innervation, Cornea physiopathology, Female, Humans, Intravitreal Injections, Macular Degeneration pathology, Male, Microscopy, Confocal, Middle Aged, Nerve Fibers drug effects, Nerve Fibers ultrastructure, Ranibizumab administration & dosage, Ranibizumab adverse effects, Retina pathology, Retina ultrastructure, Cornea drug effects, Macular Degeneration drug therapy, Ranibizumab therapeutic use, Retina drug effects
- Abstract
Purpose: To evaluate the effects of repeated intravitreal ranibizumab injections on corneal sensitivity, corneal sub-basal nerve plexus (SBNP) and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with neovascular age-related macular degeneration (AMD)., Methods: Sixty-six eyes of 33 patients who had received unilateral repeated intravitreal ranibizumab injections (0.5 mg/0.05 ml) for the treatment of AMD and 25 eyes of 25 healthy subjects were included in the study. Central corneal sensation was measured using the contact Cochet-Bonnet esthesiometer. The laser scanning in vivo corneal confocal microscope was used to determine corneal SBNP parameters. The peripapillary RNFL thickness was assessed with spectral-domain optical coherence tomography. Data obtained from the ranibizumab-injected eyes were compared with those of the fellow non-treated eyes and the eyes of the healthy control subjects., Results: The mean number of ranibizumab injections per eye was 8.9±5.0 (range 3-20). There were no statistically significant differences in the central corneal sensitivity threshold and corneal SBNP parameters between the ranibizumab-injected eyes and the fellow untreated eyes or between those with neovascular AMD and the healthy control group (P>0.05 for all). The average peripapillary RNFL thickness of the treated eyes did not differ significantly to the fellow eyes (P = 0.237), and the eyes of healthy control subjects (P = 0.918). There were no significant correlations between the number of ranibizumab injections and any of the study parameters., Conclusions: Multiple intravitreal injections of ranibizumab seem to have no harmful effects on corneal sensitivity, innervation and peripapillary RNFL thickness in patients with AMD., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2017
- Full Text
- View/download PDF
24. Ophthalmic manifestations in recently diagnosed childhood leukemia.
- Author
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Bitirgen G, Belviranli S, Caliskan U, Tokgoz H, Ozkagnici A, and Zengin N
- Subjects
- Adolescent, Child, Child, Preschool, Eye Neoplasms etiology, Female, Humans, Infant, Leukemia, Myelogenous, Chronic, BCR-ABL Positive complications, Leukemia, Myeloid, Acute complications, Male, Precursor Cell Lymphoblastic Leukemia-Lymphoma complications, Prevalence, Retrospective Studies, Eye Neoplasms diagnosis, Leukemia, Myelogenous, Chronic, BCR-ABL Positive diagnosis, Leukemia, Myeloid, Acute diagnosis, Precursor Cell Lymphoblastic Leukemia-Lymphoma diagnosis
- Abstract
Purpose: To determine the prevalence and the pattern of ocular involvement in children with leukemia at the time of diagnosis., Methods: The data of patients with leukemia who underwent complete ophthalmic examination at the time of diagnosis between January 2005 and December 2014 were retrospectively reviewed. Demographic data, type of leukemia, ocular findings, blood parameters, and duration of follow-up were analyzed., Results: A total of 185 patients (111 male and 74 female) were included in the study, with a median age of 6.0 years (range 0.5-18.0 years) and a median follow-up time of 36.0 months (range 0.5-108.0 months). Ocular signs were present in 24.3% of the patients at the time of diagnosis and 37.8% of them were symptomatic. The prevalence of ocular involvement was 20.4% in patients with acute lymphocytic leukemia (ALL) and 36.4% in patients with acute myelocytic leukemia (AML) (p = 0.051). Fatality rate was significantly higher in subjects with AML compared with ALL (p = 0.019), but was not significantly different between patients with and without ocular involvement (p = 0.166). There were no significant differences in hemoglobin levels, white blood cell counts, or platelet counts between patients with ALL and AML. Platelet counts were significantly lower in patients with ocular signs compared with subjects without ocular involvement (p = 0.012), while hemoglobin levels and white blood cell counts did not differ significantly., Conclusions: Various ocular signs may be present at the time of diagnosis in childhood leukemia, even in patients without any symptoms. Routine ophthalmic examination should be performed in recently diagnosed children with leukemia.
- Published
- 2016
- Full Text
- View/download PDF
25. Characteristics of the cornea in patients with pseudoexfoliation syndrome.
- Author
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Oltulu R, Satirtav G, Kayitmazbatir ET, Bitirgen G, Ozkagnici A, and Karaibrahimoglu A
- Subjects
- Aged, Aged, 80 and over, Case-Control Studies, Cell Count, Cornea innervation, Female, Humans, Male, Microscopy, Confocal, Middle Aged, Nerve Fibers pathology, Reference Values, Statistics, Nonparametric, Cornea pathology, Endothelial Cells pathology, Exfoliation Syndrome pathology
- Abstract
Purpose: To quantify the morphological alterations in corneal nerve fibers and cells in patients with pseudoexfoliation syndrome (PEX) and their relationship with the presence of hyperreflective endothelial deposits observed using in vivo confocal microscopy., Methods: One eye each of 37 patients with PEX and 20 age-matched healthy control subjects was evaluated by in vivo corneal confocal microscopy. Patients with PEX were further classified into two groups: those with and without hyperreflective endothelial deposits. We evaluated the densities of basal epithelial cells, anterior and posterior stromal keratocytes, and endothelial cells and structure of sub-basal nerve fibers., Results: The mean anterior and posterior stromal keratocyte and endothelial cell densities and corneal sub-basal nerve plexus variables were significantly lower in patients with PEX compared with those in healthy control subjects. The mean basal epithelial cell density did not significantly differ., Conclusion: Eyes with PEX presented decreased corneal sub-basal nerve plexus variables and cell densities in all corneas, except for the mean basal epithelial cell density. Further, a trend of lower corneal sub-basal nerve plexus measurements in patients with hyperreflective endothelial deposits compared with those without endothelial deposits was observed.
- Published
- 2015
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- View/download PDF
26. In vivo corneal confocal microscopic analysis in patients with keratoconus.
- Author
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Bitirgen G, Ozkagnici A, Bozkurt B, and Malik RA
- Abstract
Aim: To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects., Methods: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated., Results: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm(2) vs 4802±508 cells/mm(2), P<0.001), anterior stromal keratocyte density (800±111 cells/mm(2) vs 555±115 cells/mm(2), P<0.001), posterior stromal keratocyte density (333±34 cells/mm(2) vs 270±47 cells/mm(2), P<0.001), endothelial cell density (2875±223 cells/mm(2) vs 2686±265 cells/mm(2), P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm(2) vs 18.1±9.2 nerves/mm(2), P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm(2) vs 16.1±5.1 mm/mm(2), P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm(2) vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm(2), P<0.001) were observed in patients with keratoconus., Conclusion: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.
- Published
- 2015
- Full Text
- View/download PDF
27. Effect of mydriasis induced by topical 0.5% tropicamide instillation on the corneal biomechanical properties in healthy individuals measured by ocular response analyzer.
- Author
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Oltulu R, Satirtav G, Altunkaya O, Bitirgen G, and Okka M
- Subjects
- Administration, Topical, Adolescent, Adult, Aged, Cornea physiology, Female, Healthy Volunteers, Humans, Intraocular Pressure drug effects, Male, Middle Aged, Young Adult, Cornea drug effects, Mydriasis chemically induced, Mydriatics pharmacology, Tropicamide pharmacology
- Abstract
Purpose: This observational study aims to investigate the effects of tropicamide (0.5%) on corneal biomechanical properties, with the ocular response analyzer (ORA), in healthy individuals., Methods: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) measurements of 38 (21 female and 17 male) healthy individuals, before and after 30 min of 0.5% tropicamide instillation, were performed by using the ORA., Results: The mean CH, CRF, IOPg and IOPcc measurements of the eyes were 10.2 ± 1.9 mmHg, 10.3 ± 2.1 mmHg, 15.7 ± 3.4 mmHg, 16.4 ± 3.3 mmHg pre-tropicamide, and 10.4 ± 1.7 mmHg, 10.3 ± 2.1 mmHg, 15.3 ± 3.4 mmHg, 15.8 ± 2.7 mmHg post-tropicamide, respectively. The differences between the pre- and post-tropicamide measurements of the eyes were insignificant (p = 0.184, p = 0.659, p = 0.294, p = 0.150, respectively; paired t-test)., Conclusions: A tropicamide instillation does not lead to significant changes in the corneal biomechanical properties. Therefore, it can be used safely in disease, i.e. in the diagnosis and follow-up ORA as it does not cause any change.
- Published
- 2015
- Full Text
- View/download PDF
28. Evaluation of contact lens-induced changes in keratoconic corneas using in vivo confocal microscopy.
- Author
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Bitirgen G, Ozkagnici A, Malik RA, and Oltulu R
- Subjects
- Adolescent, Adult, Cell Count, Corneal Topography, Female, Humans, Keratoconus rehabilitation, Male, Severity of Illness Index, Young Adult, Contact Lenses adverse effects, Cornea pathology, Keratoconus pathology, Microscopy, Confocal methods
- Abstract
Purpose: To quantitatively analyze laser scanning in vivo confocal microscopy (IVCM) images of all corneal layers in contact lens-wearing and noncontact lens-wearing keratoconus patients., Methods: The study population included rigid gas permeable (RGP) contact lens-wearing keratoconus patients (group 1; N = 29), keratoconus patients who did not wear contact lenses (group 2; N = 30), and subjects who neither had keratoconus nor wore contact lenses (group 3; N = 30), with groups 2 and 3 matched to group 1 by age and sex. The central cornea was examined with IVCM in all subjects. The mean duration of contact lens wear was 5.50 ± 3.68 years (range, 2-15 years)., Results: Eyes with keratoconus showed significantly lower basal epithelial cell and anterior and posterior stromal keratocyte densities, as well as subbasal nerve fiber density, nerve branch density, and nerve fiber length compared with healthy control subjects. Furthermore, compared with group 2, group 1 had significantly lower basal epithelial cell density (4920 ± 476 cells/mm(2) vs. 4503 ± 461 cells/mm(2), P = 0.001) and anterior stromal keratocyte density (561 ± 91 cells/mm(2) vs. 464 ± 55 cells/mm(2), P < 0.001), but there was no significant difference for posterior stromal keratocyte density (P = 0.808), endothelial cell density (P = 0.699), or subbasal nerve fiber density (P = 0.142), nerve branch density (P = 0.614), and nerve fiber length (P = 0.850)., Conclusions: Significant corneal microstructural abnormalities were observed in eyes with keratoconus. RGP contact lens wear was associated with a further reduction in the basal epithelial cell and anterior stromal keratocyte densities, but with no effect on posterior stromal keratocyte density, endothelial cell density, or corneal nerve morphology.
- Published
- 2013
- Full Text
- View/download PDF
29. GAPO syndrome: four new patients with congenital glaucoma and myelinated retinal nerve fiber layer.
- Author
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Bozkurt B, Yildirim MS, Okka M, and Bitirgen G
- Subjects
- Abnormalities, Multiple genetics, Adolescent, Child, Consanguinity, Eye Abnormalities genetics, Eye Abnormalities pathology, Facies, Female, Glaucoma congenital, Humans, Male, Nerve Fibers, Myelinated, Pedigree, Retina pathology, Alopecia diagnosis, Anodontia diagnosis, Growth Disorders diagnosis, Optic Atrophies, Hereditary diagnosis
- Abstract
This article reports on the ophthalmological features of four Turkish children with GAPO syndrome, a very rare autosomal recessive condition characterized by growth retardation (G), alopecia (A), pseudoanodontia (P) (failure of tooth eruption), and optic atrophy (O). The children were from two unrelated families born to consanguineous parents. They had the characteristic facial appearance of alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, midfacial hypoplasia, hypertelorism, and thickened eyelids and lips. Two children had severe end-stage glaucoma in both eyes and unilateral corneal opacity, whereas other two children had myelinated retinal nerve fiber layer; one with bilateral optic atrophy and the other one with persistent pupillary membrane in the left eye., (Copyright © 2013 Wiley Periodicals, Inc.)
- Published
- 2013
- Full Text
- View/download PDF
30. Acute postoperative endophthalmitis with an unusual infective agent: Acinetobacter baumannii.
- Author
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Bitirgen G, Ozkagnici A, Kerimoglu H, and Kamis U
- Subjects
- Acinetobacter Infections diagnosis, Acinetobacter Infections drug therapy, Acute Disease, Aged, Anti-Bacterial Agents therapeutic use, Drug Therapy, Combination, Endophthalmitis diagnosis, Endophthalmitis drug therapy, Eye Infections, Bacterial diagnosis, Eye Infections, Bacterial drug therapy, Humans, Intraocular Pressure physiology, Lens Implantation, Intraocular, Male, Visual Acuity physiology, Vitrectomy, Vitreous Body microbiology, Acinetobacter Infections microbiology, Acinetobacter baumannii isolation & purification, Endophthalmitis microbiology, Eye Infections, Bacterial microbiology, Phacoemulsification, Postoperative Complications
- Published
- 2013
- Full Text
- View/download PDF
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