Gulfidan Bitirgen | Necmettin Erbakan University (original) (raw)

Papers by Gulfidan Bitirgen

Research paper thumbnail of Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID

British Journal of Ophthalmology

Background/AimsLong COVID is characterised by a range of potentially debilitating symptoms which ... more Background/AimsLong 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.MethodsForty 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.ResultsThe mean time after the diagnosis of COVID-19 was 3.7±1.5 months. Patients with neurological symptoms 4 weeks after a...

Research paper thumbnail of Abnormal Dynamic Pupillometry Relates to Neurologic Disability and Retinal Axonal Loss in Patients With Multiple Sclerosis

Translational Vision Science & Technology

Research paper thumbnail of Progressive Loss of Corneal and Retinal Nerve Fibers in Patients With Multiple Sclerosis: A 2-Year Follow-up Study

Translational Vision Science & Technology

Research paper thumbnail of Assessment of pupillary light reflex using dynamic pupillometry in laser-treated eyes with retinal vein occlusion

European Journal of Ophthalmology

Purpose: This study aims to evaluate the pupillary light reflex measured with dynamic pupillometr... more 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 phot...

Research paper thumbnail of Traumatic hyphema in a patient with severe hemophilia A: Clinical features and management

European Journal of Ophthalmology

Research paper thumbnail of Assessment of Corneal Sensation, Innervation and Retinal Nerve Fiber Layer in Patients Treated with Multiple Intravitreal Ranibizumab Injections

PLOS ONE

To evaluate the effects of repeated intravitreal ranibizumab injections on corneal sensitivity, c... more 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.

Research paper thumbnail of Use of Corneal Confocal Microscopy to Detect Corneal Nerve Loss and Increased Dendritic Cells in Patients With Multiple Sclerosis

JAMA Ophthalmology

Multiple sclerosis (MS) is characterized by demyelination, axonal degeneration, and inflammation.... more 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. 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. 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. 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). 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. 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.

Research paper thumbnail of Effects of panretinal laser photocoagulation on the corneal nerve plexus and retinal nerve fiber layer in retinal vein occlusion

European Journal of Ophthalmology

Purpose To determine the effects of panretinal photocoagulation (PRP) on corneal sub-basal nerve ... more 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 wi...

Research paper thumbnail of Unilateral Vision Loss without Ophthalmoplegia as a Rare Complication of Spinal Surgery

Journal of neurosciences in rural practice

Postoperative visual loss is an extremely rare complication of nonocular surgery. The most common... more 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.

Research paper thumbnail of Characteristics of the cornea in patients with pseudoexfoliation syndrome

Arquivos Brasileiros de Oftalmologia, 2015

Characteristics of the cornea in patients with pseudoexfoliation syndrome Características da córn... more Characteristics of the cornea in patients with pseudoexfoliation syndrome Características da córnea em pacientes com síndrome de pseudoexfoliação

Research paper thumbnail of Ophthalmic manifestations in recently diagnosed childhood leukemia

European Journal of Ophthalmology, 2015

To determine the prevalence and the pattern of ocular involvement in children with leukemia at th... more To determine the prevalence and the pattern of ocular involvement in children with leukemia at the time of diagnosis. 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. 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. 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.

Research paper thumbnail of Ex-PRESS® Mini Glokom İmplant Cerrahisi Sonuçlarımız

Turkiye Klinikleri Journal of Medical Sciences, 2014

Research paper thumbnail of Sağlıklı İnsan Korneasında Hücre ve Sinir Liflerinin İn Vivo Konfokal Mikroskopi ile Değerlendirilmesi

Turkiye Klinikleri Journal of Medical Sciences, 2014

Research paper thumbnail of Acute postoperative endophthalmitis with an unusual infective agent: Acinetobacter baumannii

Journal of Cataract & Refractive Surgery, 2013

Research paper thumbnail of Evaluation of Contact Lens-Induced Changes in Keratoconic Corneas Using In Vivo Confocal Microscopy

Investigative Ophthalmology & Visual Science, 2013

PURPOSE. To quantitatively analyze laser scanning in vivo confocal microscopy (IVCM) images of al... more 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 ¼ 29), keratoconus patients who did not wear contact lenses (group 2; N ¼ 30), and subjects who neither had keratoconus nor wore contact lenses (group 3; N ¼ 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 6 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 6 476 cells/mm 2 vs. 4503 6 461 cells/mm 2 , P ¼ 0.001) and anterior stromal keratocyte density (561 6 91 cells/mm 2 vs. 464 6 55 cells/mm 2 , P < 0.001), but there was no significant difference for posterior stromal keratocyte density (P ¼ 0.808), endothelial cell density (P ¼ 0.699), or subbasal nerve fiber density (P ¼ 0.142), nerve branch density (P ¼ 0.614), and nerve fiber length (P ¼ 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.

Research paper thumbnail of Corneal nerve fibre damage precedes diabetic retinopathy in patients with Type 2 diabetes mellitus

Diabetic Medicine, 2014

To quantify the morphological alterations in corneal nerve fibres and cells in patients with type... more To quantify the morphological alterations in corneal nerve fibres and cells in patients with type 2 diabetes mellitus in relation to the severity of diabetic retinopathy. One hundred and thirty-two eyes of 132 patients with type 2 diabetes and 32 eyes of 32 healthy control subjects were evaluated with in vivo corneal confocal microscopy. Patients with diabetes were classified into three groups: patients without diabetic retinopathy, patients with non-proliferative diabetic retinopathy and patients with proliferative diabetic retinopathy. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve fibre structure were evaluated. Significant reductions in basal epithelial cell, anterior stromal keratocyte and endothelial cell densities were observed only in patients with diabetic retinopathy. However, nerve fibre density, nerve branch density and nerve fibre length were reduced in patients without diabetic retinopathy and worsened progressively with increasing severity of retinopathy. Corneal cell pathology occurs in patients with diabetic retinopathy, but corneal nerve fibre damage seems to precede the development of diabetic retinopathy.

Research paper thumbnail of Effect of mydriasis induced by topical 0.5% tropicamide instillation on the corneal biomechanical properties in healthy individuals measured by ocular response analyzer

Cutaneous and Ocular Toxicology, 2014

Purpose: This observational study aims to investigate the effects of tropicamide (0.5%) on cornea... more 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.

Research paper thumbnail of GAPO syndrome: Four new patients with congenital glaucoma and myelinated retinal nerve fiber layer

American Journal of Medical Genetics Part A, 2013

This article reports on the ophthalmological features of four Turkish children with GAPO syndrome... more 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.

Research paper thumbnail of In vivo corneal confocal microscopic analysis in patients with keratoconus

International journal of ophthalmology, 2015

To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in pat... more To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects. 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. 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), ...

Research paper thumbnail of Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID

British Journal of Ophthalmology

Background/AimsLong COVID is characterised by a range of potentially debilitating symptoms which ... more Background/AimsLong 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.MethodsForty 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.ResultsThe mean time after the diagnosis of COVID-19 was 3.7±1.5 months. Patients with neurological symptoms 4 weeks after a...

Research paper thumbnail of Abnormal Dynamic Pupillometry Relates to Neurologic Disability and Retinal Axonal Loss in Patients With Multiple Sclerosis

Translational Vision Science & Technology

Research paper thumbnail of Progressive Loss of Corneal and Retinal Nerve Fibers in Patients With Multiple Sclerosis: A 2-Year Follow-up Study

Translational Vision Science & Technology

Research paper thumbnail of Assessment of pupillary light reflex using dynamic pupillometry in laser-treated eyes with retinal vein occlusion

European Journal of Ophthalmology

Purpose: This study aims to evaluate the pupillary light reflex measured with dynamic pupillometr... more 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 phot...

Research paper thumbnail of Traumatic hyphema in a patient with severe hemophilia A: Clinical features and management

European Journal of Ophthalmology

Research paper thumbnail of Assessment of Corneal Sensation, Innervation and Retinal Nerve Fiber Layer in Patients Treated with Multiple Intravitreal Ranibizumab Injections

PLOS ONE

To evaluate the effects of repeated intravitreal ranibizumab injections on corneal sensitivity, c... more 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.

Research paper thumbnail of Use of Corneal Confocal Microscopy to Detect Corneal Nerve Loss and Increased Dendritic Cells in Patients With Multiple Sclerosis

JAMA Ophthalmology

Multiple sclerosis (MS) is characterized by demyelination, axonal degeneration, and inflammation.... more 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. 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. 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. 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). 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 &amp;amp;amp;amp;lt; .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&amp;amp;amp;amp;#39;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. 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.

Research paper thumbnail of Effects of panretinal laser photocoagulation on the corneal nerve plexus and retinal nerve fiber layer in retinal vein occlusion

European Journal of Ophthalmology

Purpose To determine the effects of panretinal photocoagulation (PRP) on corneal sub-basal nerve ... more 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 wi...

Research paper thumbnail of Unilateral Vision Loss without Ophthalmoplegia as a Rare Complication of Spinal Surgery

Journal of neurosciences in rural practice

Postoperative visual loss is an extremely rare complication of nonocular surgery. The most common... more 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.

Research paper thumbnail of Characteristics of the cornea in patients with pseudoexfoliation syndrome

Arquivos Brasileiros de Oftalmologia, 2015

Characteristics of the cornea in patients with pseudoexfoliation syndrome Características da córn... more Characteristics of the cornea in patients with pseudoexfoliation syndrome Características da córnea em pacientes com síndrome de pseudoexfoliação

Research paper thumbnail of Ophthalmic manifestations in recently diagnosed childhood leukemia

European Journal of Ophthalmology, 2015

To determine the prevalence and the pattern of ocular involvement in children with leukemia at th... more To determine the prevalence and the pattern of ocular involvement in children with leukemia at the time of diagnosis. 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. 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. 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.

Research paper thumbnail of Ex-PRESS® Mini Glokom İmplant Cerrahisi Sonuçlarımız

Turkiye Klinikleri Journal of Medical Sciences, 2014

Research paper thumbnail of Sağlıklı İnsan Korneasında Hücre ve Sinir Liflerinin İn Vivo Konfokal Mikroskopi ile Değerlendirilmesi

Turkiye Klinikleri Journal of Medical Sciences, 2014

Research paper thumbnail of Acute postoperative endophthalmitis with an unusual infective agent: Acinetobacter baumannii

Journal of Cataract & Refractive Surgery, 2013

Research paper thumbnail of Evaluation of Contact Lens-Induced Changes in Keratoconic Corneas Using In Vivo Confocal Microscopy

Investigative Ophthalmology & Visual Science, 2013

PURPOSE. To quantitatively analyze laser scanning in vivo confocal microscopy (IVCM) images of al... more 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 ¼ 29), keratoconus patients who did not wear contact lenses (group 2; N ¼ 30), and subjects who neither had keratoconus nor wore contact lenses (group 3; N ¼ 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 6 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 6 476 cells/mm 2 vs. 4503 6 461 cells/mm 2 , P ¼ 0.001) and anterior stromal keratocyte density (561 6 91 cells/mm 2 vs. 464 6 55 cells/mm 2 , P < 0.001), but there was no significant difference for posterior stromal keratocyte density (P ¼ 0.808), endothelial cell density (P ¼ 0.699), or subbasal nerve fiber density (P ¼ 0.142), nerve branch density (P ¼ 0.614), and nerve fiber length (P ¼ 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.

Research paper thumbnail of Corneal nerve fibre damage precedes diabetic retinopathy in patients with Type 2 diabetes mellitus

Diabetic Medicine, 2014

To quantify the morphological alterations in corneal nerve fibres and cells in patients with type... more To quantify the morphological alterations in corneal nerve fibres and cells in patients with type 2 diabetes mellitus in relation to the severity of diabetic retinopathy. One hundred and thirty-two eyes of 132 patients with type 2 diabetes and 32 eyes of 32 healthy control subjects were evaluated with in vivo corneal confocal microscopy. Patients with diabetes were classified into three groups: patients without diabetic retinopathy, patients with non-proliferative diabetic retinopathy and patients with proliferative diabetic retinopathy. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve fibre structure were evaluated. Significant reductions in basal epithelial cell, anterior stromal keratocyte and endothelial cell densities were observed only in patients with diabetic retinopathy. However, nerve fibre density, nerve branch density and nerve fibre length were reduced in patients without diabetic retinopathy and worsened progressively with increasing severity of retinopathy. Corneal cell pathology occurs in patients with diabetic retinopathy, but corneal nerve fibre damage seems to precede the development of diabetic retinopathy.

Research paper thumbnail of Effect of mydriasis induced by topical 0.5% tropicamide instillation on the corneal biomechanical properties in healthy individuals measured by ocular response analyzer

Cutaneous and Ocular Toxicology, 2014

Purpose: This observational study aims to investigate the effects of tropicamide (0.5%) on cornea... more 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.

Research paper thumbnail of GAPO syndrome: Four new patients with congenital glaucoma and myelinated retinal nerve fiber layer

American Journal of Medical Genetics Part A, 2013

This article reports on the ophthalmological features of four Turkish children with GAPO syndrome... more 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.

Research paper thumbnail of In vivo corneal confocal microscopic analysis in patients with keratoconus

International journal of ophthalmology, 2015

To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in pat... more To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects. 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. 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), ...