Bülent Gürler

The role of oxidative stress in diabetic retinopathy

Purpose To investigate the role of oxidative stress in the development of diabetic retinopathy.Methods This study included 25 patients with diabetic retinopathy (group 1), 34 patients with non-insulin-dependent diabetes mellitus without any angiopathy complications (group II) and 26 healthy subjects (group III). The serum malondialdehyde (MDA)-like metabolite levels as an index of lipid peroxidation, the erythrocyte glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and serum vitamin C levels of the patients and healthy subjects were measured.Results The mean serum concentration of MDA-like metabolites of patients in group I was 4.38 ± 1.31 nmol/ml, in group II was 3.38 ± 0.95 nmol/ml and in group III was 2.61 ± 0.85 nmol/ml. There were significant differences between the groups (p = 0.001 for group I compared with group II, p = 0.0001 for group I compared with group III and p = 0.002 for group II compared with group III). There was a significant correlation between the serum lipid peroxidation concentrations and duration of the disease (r = 0.36, p = 0.047). The mean erythrocyte GSH-Px and SOD levels of group I were respectively 68.97 ± 18.04 and 1597.78 ± 296.46 U/g Hb, of group II were 64.30 ±19.26 and 1581.33 ± 278.08 U/g Hb, and of group III were 65.52 ± 17.58 and 1587.44 ± 281.17 U/g Hb. There were no significant differences among the antioxidant enzyme levels in the three groups (p > 0.05). The mean serum vitamin C level in group I was 42.72 ± 8.90 μmol/l, in group II was 49.26 ± 11.52 μmol/l and in group III was 58.57 ± 9.75 μmol/l. There were significant differences among the mean serum vitamin C levels of the three groups (p = 0.02 for group I versus group II p = 0.001 for group I versus group III and p = 0.002 for group II versus group III).Conclusions Free radicals forming in diabetes mellitus and increasing over time may play a role in the development of diabetic retinopathy, which is an important complication of the disease.

Enhanced Depth Imaging Optical Coherence Tomography Findings in Behçet Disease

Abstract Purpose: Investigation of subfoveal choroidal thickness in Behçet disease (BD) with enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: The study included 35 patients with posterior uveitis (PU) associated with BD, 35 patients with BD without ocular involvement, and 30 healthy controls. Results: There were no significant differences between the groups in terms of age, gender, axial length, or spherical equivalent refractive error. The mean subfoveal choroidal thickness was thinner in eyes with PU than in eyes without PU and healthy controls (p = 0.026). Conclusion: EDI-OCT is a beneficial test for evaluating choroid morphology in BD. Thinning of the subfoveal choroidal tissue has been observed in patients with BD-associated PU.

Risk Factors in Post-LASIK Corneal Ectasia.

Purpose. To evaluate the risk factors for post-laser in situ keratomileusis (LASIK) ectasia. Materials and Methods. Medical records of 42 eyes of 28 (10 women, 18 men) patients who developed corneal ectasia after LASIK were retrospectively reviewed. Topographical features and surgical parameters of those patients were evaluated. Results. The mean age of patients was 34.73 ± 6.50 (23–48) years and the mean interval from LASIK to the diagnosis of post-LASIK ectasia was 36.0 ± 16.92 (12–60) months. The following factors were determined as a risk factors: deep ablation (>75 μm) in 10 eyes, FFK (forme fruste keratoconus) in 6 eyes, steep cornea (>47 D) in 3 eyes, pellucid marginal degeneration (PMD) in 2 eyes, thin cornea (<500 μm) in 2 eyes, thin and steep cornea in 2 eyes, thin cornea and deep ablation in 5 eyes, FFK and steep cornea in 2 eyes, and FFK, steep cornea, and deep ablation in 1 eye. However no risk factor has been determined in 9 eyes (21.4%). Conclusion. The findings of our study showed that most of the patients who developed post-LASIK ectasia have a risk factor for post-LASIK ectasia. However, the most common risk factor was deep ablation.

Cyclosporine a 0.05% eye drops for the treatment of subepithelial infiltrates after epidemic keratoconjunctivitis.

BackgroundTo evaluate the treatment with topical 0.05% cyclosporine A (CsA) in patients with subepithelial corneal infiltrates (SEI).MethodsWe reviewed 16 patients (22 eyes) before and after the treatment with 0.05% CsA eye drops. All patients had been treated previously with topical corticosteroids without any improvement and also they had to stop the medication secondary to intraocular pressure elevation. The objective data recorded included best-corrected visual acuity (BCVA), evaluation of corneal subepithelial infiltrate scores (CSIS), intraocular pressure (IOP) prior to treatment and the last follow-up visit.ResultsSix males (37.5%) and 10 females (62.5%), mean age of 35.2 ± 16.6 years, were included. The patients’ average topical CsA use duration was 5.1 ± 3.5 months (1 – 13 months). The average follow up time of the patients was 9.2 ± 4.7 months (4 – 22 months). One patient, although he didn’t have a 0 scale of SCIS, did not show up for follow up examinations after six months. The mean BCVA (logarithm of the minimum angle of resolution) before and after the treatment were 0.15 ± 0.15 and 0.07 ± 0.07 respectively, CSIS 1.68 ± 0.89 and 0.23 ± 0.53 respectively, IOP 18.50 ± 3.82 and 16.86 ± 2.76 mmHg respectively. There were statistically significant improvements in BCVA (p = 0.002), reduction of CSIS (p = 0.002) and reduction of IOP (p < 0.001) prior to treatment and the last follow-up visit. 18 eyes (81.9%) showed clinical improvement and 4 (18.1%) had decreased SEI which did not fully disappear during the treatment period. The eyes which reached CSIS score 0 (18 eyes) were treated with CsA for 1 – 13 months; while the eyes which had clinical improvement but had not CSIS score 0 (4 eyes) were decided to discontinue of CsA treatment in last follow-up visit. There were recurrences in 2 eyes 3 months after the treatment. Patients reported reduction in the severity of symptoms after the treatment. Most of the patients reported no foreign body sensation, glare, or other side effects with topical CsA treatment. Overall, patients noted an improvement in vision and satisfaction with topical 0.05% CsA treatment.ConclusionsTopical 0.05% CsA is a safe and effective alternative treatment in patients with SEI who do not respond to other treatment modalities or have undesired side effects from topical steroids.

Visual functions in epilepsy patients on valproate monotherapy.

Gamma-aminobutyric acid-induced ion transport changes in the retinal pigment epithelium are described. Valproate acts as an inhibitor of gamma-aminobutyric acid transaminase. The purpose of this study was to investigate whether early visual impairment is related to valproate in patients with and without visual symptoms. Thirty-two patients, presenting with a history of seizures currently being treated with valproate, were included in the study. A complete clinical neuroophthalmologic examination was performed, including electroretinogram and visual field test. The electroretinogram parameters of epileptic patients were compared with those of 28 age- and sex-matched healthy volunteers. There was no significant difference in ERG parameters between the two groups. The visual field and visual acuity of all patients were within normal limits. When valproate is not used in conjunction with other antiepileptic drugs and serum levels are within therapeutic levels, it does not cause electrophysiologically detectable retinal dysfunction or any functional defect in visual perception that can be determined clinically.

Effects of corrective surgery on social phobia, psychological distress, disease-related disability and quality of life in adult strabismus patients

Background Corrective surgery is done for ocular alignment and disrupted facial expression in some cases of adult strabismus patients. The effects of corrective surgery on the presence of social phobia (SP) diagnosis, the severity of social anxiety symptoms, the disease-related disability and the quality of life (QoL) among strabismus patients have not been thoroughly studied yet. Methods The study sample was composed of patients who had undergone corrective surgery for strabismus. Preoperative and postoperative evaluations made by using standardised measures of social phobia diagnosis (DSM-IV-TR) and severity (Liebowitz Social Anxiety Scale (LSAS)), anxiety and depression (Hospital Anxiety and Depression Scale (HADS)), disability (Sheehan Disability Scale) and quality of life (short form-36). Results Preoperatively, SP diagnosis was detected in 17 of 31 (54.8%) patients, whereas postoperatively 6 of 31 (19.4%) patients had SP (p=0.001). Participants showed a significant decrease in all subscale scores and total score of both LSAS and HADS compared with their preoperative scores. Significant improvements were observed in QoL and disability scores as well. Conclusions Adult strabismus patients seem to gain benefits from corrective surgery not only for their ocular misalignment but also for social anxiety levels that may be associated with improvements in their QoL and disability levels.

Association Between Thr21Met and Ser89Asn Polymorphisms of the Urotensin-II (UTS2) Gene, Diabetes Mellitus, and Diabetic Retinopathy

Purpose: To evaluate possible role of the UTS2 gene polymorphisms (Thr21Met and Ser89Asn) in the genetic susceptibility to diabetic retinopathy (DR) in a Turkish population. Methods: Total number of 280 patients with DR (nonproliferative DR 170 and proliferative DR 110), 291 nondiabetic healthy controls, and 113 diabetic controls (without DR) were included to this study. The detection of UTS2 gene polymorphisms was achieved with PCR-RFLP technique. The Discovery Studio 2.1 program was used for molecular modeling analysis. Results: Thr21Met (T21M) and Ser89Asn (S89N) polymorphisms of the UTS2 gene were associated with the risk of developing diabetes and DR. M21M genotype frequencies were high in PDR (8.9% in diabetic control vs. 54.6% in PDR, P = 0.0092) group. Increases in 21M allele frequency (52.7% in diabetic control vs. 76.4% in PDR, P < 0.0001) frequency in PDR group were detected. However, there were no changes in genotype and allele frequencies for T21M in NPDR group. There were decreases in the S89N genotype (23.9% in diabetic control vs. 13.5%) and 89N allele frequencies (11.9% in diabetic control vs. 6.8%) in NPDR group. However, S89S genotype (76.1% in diabetic control vs. 86.4%) and 89S allele frequencies (88.1% in diabetic control vs. 93.2%) were high in NPDR group. Three haplotypes (MN, MS and TS) were associated with NPDR patients (P < 0.001), but only MN (P < 0.001) and TS haplotypes (P = 0.018) were associated in PDR group. Molecular modeling analysis showed that these two polymorphisms changed the 3D structure of UTS2, and provided interactions with neighboring residues. Conclusion: The associations between Thr21Met and Ser89Asn polymorphisms in the UTS2 gene and DR strongly suggest that these SNPs may be an important a risk factor for the development of DR in Caucasians, and could be candidate markers for earlier diagnosis and targets for DR therapy.

Retinopathy of prematurity: incidence, risk factors, and evaluation of screening criteria.

BACKGROUND/AIM The goal of this study was to investigate the incidence of retinopathy of prematurity (ROP) and the relationship between risk factors and disease in premature newborns in our neonatal intensive care unit. MATERIALS AND METHODS A total of 219 premature subjects were retrospectively evaluated for retinopathy. Demographic information, clinical data, and risk factors were reviewed. RESULTS The gestational ages of the infants included in the study ranged between 25 and 36 weeks, and the birth weights ranged between 670 and 4460 g. In this study, the incidence of ROP was 20.1% (44) in preterm infants: 16 had stage 1 (36.4%), 15 had stage 2 (34.1%), 11 had stage 3 (25%), 1 had stage 4 (2.3%), 1 had stage 5 (2.3%), and 6 had plus (+) disease (7.2%). The risk factors associated with the development of ROP included low birth weight, ventilation treatment, bronchopulmonary dysplasia, and maternal preeclampsia. The risk factors were analyzed with logistic regression analysis. The odds ratios were 5.952 (95% confidence interval [CI]: 2.030-17.447), 20.070 (95% CI: 4.213-95.600), 5.879 (1.916-18.037), and 3.200 (95% CI: 1.002-11.535), respectively. CONCLUSION In this study, birth weight, ventilation treatment, bronchopulmonary dysplasia, and maternal preeclampsia were the most important risk factors for the development of ROP.

Investigation of the Rho-kinase Gene Polymorphism in Primary Open-angle Glaucoma

Abstract Purpose: Genetic factors are shown to have a role in the development of primary open-angle glaucoma (POAG). The aim of this study was to determine the effects of genetic polymorphisms of Rho-kinase (ROCK) genes on the risk of POAG in a Turkish population. Methods: Genomic DNA was extracted from leukocytes of the peripheral blood, and 8 single nucleotide polymorphisms in the ROCK1 and ROCK2 genes were analysed in 179 patients with POAG and in 182 healthy controls of similar age by using BioMark HD dynamic array system. Results: Neither genotype distributions nor the allele frequencies for the ROCK1 (rs35996865) and ROCK2 [rs2290156, rs965665, rs10178332, rs2230774 (Thr431Asn), rs2230774 (Thr431Ser), rs6755196, and rs726843] gene polymorphisms showed a significant difference between the groups. There were also no marked associations between the haplotype frequencies and POAG. Conclusions: This is the first study to examine the involvement of ROCK1 and ROCK2 gene variations in the risk of POAG development. This study demonstrated that the polymorphisms studied are not associated with the increased risk of development of POAG in the Turkish population.

Surgical outcomes of isolated lens coloboma with or without cataract among young adults

OBJECTIVE To evaluate the visual and refractive outcomes after phacoemulsification surgery in eyes with isolated lens coloboma. DESIGN Prospective, consecutive case series. PARTICIPANTS Eighteen eyes with isolated lens coloboma of 13 patients were included in the study. Mean patient age was 13.9 ± 6.5 years. METHODS Patients underwent phacoemulsification surgery, with combined implantation of capsular tension ring (CTR) and intraocular lens. In colobomas of less than 120°, a CTR was used, whereas in colobomas of more than 120°, a Cionni-modified single eyelet CTR was used to achieve better capsular centration. The main outcome measures were uncorrected distance visual acuity, corrected distance visual acuity, refraction, and keratometry. RESULTS Mean logMAR uncorrected distance visual acuity and corrected distance visual acuity improved significantly from 1.53 ± 0.35 and 1.02 ± 0.47 before surgery to 0.67 ± 0.51 and 0.52 ± 0.49 at the last visit of the follow-up (p < 0.001). Mean refractive cylinder and spherical equivalent decreased significantly from -6.73 ± 1.73 and -6.72 ± 4.07 D preoperatively to -1.40 ± 1.39 and -0.83 ± 1.31 D at the end of the follow-up (p = 0.001 and p = 0.01, respectively). Mean keratometric astigmatism at preoperative and postoperative visits were 1.58 ± 0.97 and 1.65 ± 0.94 D, respectively (p = 0.70). CONCLUSIONS Phacoemulsification with CTR and intraocular lens implantation is an effective and safe option for providing a refractive correction and a significant visual improvement in eyes with isolated lens coloboma.