Mehmet Gurkan Tatar

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.

Choroidal and peripapillary retinal nerve fiber layer thickness in adults with anisometropic amblyopia.

Purpose To evaluate choroidal thickness, macular thickness, and peripapillary retinal nerve fiber layer (RNFL) thickness in amblyopic eyes compared to fellow and normal control eyes using high-definition spectral-domain optical coherence tomography (SD-OCT). Methods Fifty-four without any systemic problem and ocular disease participated in this prospective study. Inclusion criteria included individuals older than 18 years with anisometropic amblyopia. Choroidal thickness, central macular thickness (CMT), and RNFL thickness were measured by using enhanced depth imaging SD-OCT. The choroidal thickness was measured at the fovea and at 500 μm intervals from the foveal center in both temporal and nasal directions. Axial length measurements of the cases were also recorded. Results Mean peripapillary RNFL thickness of the amblyopic, fellow, and control eyes was 107.5 ± 15.5 μm, 109.3 ± 12.7 μm, and 108.8 ± 8.6 μm, respectively (p = 0.343). The average CMT was 231.7 ± 14.7 μm in amblyopic eyes, 232.5 ± 15.7 μm in fellow eyes, and 230.8 ± 14.8 μm in control eyes (p = 0.599). Mean subfoveal choroidal thickness was significantly greater in the amblyopic eyes than in the fellow and control eyes (396.3 ± 104.3 μm, 361.0 ± 103.9 μm, 390.6 ± 91.7 μm). Mean axial measurement in amblyopic eyes was 22.7 ± 1.3 mm (20.5–26.1), in fellow eyes 23.1 ± 0.9 mm (20.9–25.0), and in control eyes 23.3 ± 0.9 mm. Conclusions In adults with anisometropic amblyopia, subfoveal, temporal, and nasal choroidal thickness of amblyopic eyes are significantly thicker than in fellow eyes. However, no significant differences in peripapillary RNFL thickness or CMT were found between amblyopic and fellow or control eyes.

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.

Comparison of corneal topographic measurements and high order aberrations in keratoconus and normal eyes

PURPOSE The aim of this report was to compare corneal topographic measurements and anterior high order corneal aberrations in eyes with keratoconus and normal eyes by using Scheimpflug-Placido topography. METHODS Eighty cases diagnosed with mild (group 1), moderate (group 2), and advanced (group 3) stage keratoconus (KC) according to Amsler-Krumeich Classification and 81 healthy (control group) cases were retrospectively examined. The mean keratometric measurements (as both diopters (Kavg) and mm values (mmavg)), central corneal thickness values (CCT), high order aberration (HOA), total wavefront aberration (TWA), coma, trefoil, and spherical aberration measurements were performed using Sirius topography equipment. The topographic values were compared between the groups. RESULTS There were 25 cases in group 1 KC (15.5%), 34 cases in group 2 KC (21.1%), 21 cases in group 3 KC (13.1%), and 81 cases (50.3%) in the control group. In terms of mean age and gender distributions, there was no statistically significant difference between the groups (p>0.05). However, there was significant difference between the groups in terms of Kavg, CCT, HOA, TWA, coma, trefoil, and spherical aberration values (p<0.01). Mean HOA, TWA, coma, trefoil, and spherical aberration values were observed to increase with the severity of KC disease. CONCLUSIONS Anterior high order corneal aberrations were significantly increased in eyes with moderate and advanced keratoconus. Anterior high order corneal aberration measurements are a useful tool to guide the physician in diagnosis and classification of keratoconus.

Retinal nerve fiber layer, ganglion cell complex, and choroidal thicknesses in migraine

PURPOSE To evaluate the thicknesses of the peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCL), and choroid layer using spectral domain optical coherence tomography (SD-OCT) for investigating the effects of vascular changes on the eye and optic nerve in patients who have migraine with aura. METHODS Forty-five patients who had migraine with aura (migraine group) and 45 healthy individuals (control group) were enrolled in the study. Age, gender, duration after migraine diagnosis, intraocular pressure, and axial length measurements were recorded in each case. RNFL, GCL, and choroid layer thicknesses were measured using SD-OCT in all participants. RESULTS The mean age was 36.1 ± 6.7 (20-45) years in the migraine group and 35.7 ± 8.6 (19-45) years in the control group. There was no significant difference in the RNFL thicknesses of the temporal and nasal quadrants (p >0.05). The RNFL thicknesses of the superior and inferior quadrants were significantly lower in the migraine group compared with those in the control group (p =0.001, p <0.01, respectively). Measurements for the superior and inferior GCL were not significantly different between the groups (p >0.05). Subfoveal, temporal, and nasal choroidal thickness measurements at 500 µm, 1000 µm, and 1500 µm were significantly lower in the migraine group than in the control group (p =0.001; p <0.01, respectively). CONCLUSIONS Compared with the controls, the RNFL and choroid layer were determined to be thinner in patients who had chronic migraine with aura.

Cornea in PCOS patients as a possible target of IGF-1 action and insulin resistance

ObjectivesPrevious studies suggest that serum IGF-1 is higher in women with polycystic ovary syndrome (PCOS). The ophthalmologic effects of IGF-1 excess have not yet been investigated in women with PCOS. The aim of the current study is to compare the corneal thickness of patients with PCOS and those of healthy subjects.MethodsForty three patients with PCOS and 30 age-matched and gender-matched healthy individuals were enrolled in this cross-sectional study. Central corneal thickness (CCT) was measured in patients with PCOS and in healthy individuals with an ultrasound pachymeter. IGF-1 values were also determined in the study group.ResultsWomen with PCOS had significantly higher levels of IGF-1 and homeostasis model assessment (HOMA-IR) levels than the control group. Right and left CCT measurements were higher in the PCOS group than in the control group. A positive correlation between IGF-1 and right and left CCT was identified in both groups. In multiple linear stepwise regression analyses, IGF-1 independently and positively associated with HOMA-IR in women with PCOS. A correlation between total testosterone and CCT was identified in the whole group. In multiple stepwise regression analyses, total testosterone independently and positively associated with left central corneal thickness in the whole group.ConclusionsThese findings indicate that PCOS has target organ effects on the eye. Consequently, it can change central corneal thickness. Higher IGF-1 levels seem to be the main causes of increased corneal thickness. Insulin resistance in PCOS is one of the underlying causes and promotes increase in IGF-1. We suggest a careful and detailed corneal evaluation in PCOS patients to prevent the potential risk of increased CCT, in addition to the already-known complications.

A PILOT STUDY OF CHOROIDAL THICKNESS IN LONG-TERM SMOKERS.

Purpose: To compare the choroidal thicknesses in long-term smokers with those of nonsmoking healthy individuals using spectral domain optical coherence tomography. Participants: Forty-six individuals who had been smoking at least for 20 years, but otherwise without systemic problems, participated in this prospective pilot study. The control group comprised 42 nonsmoking individuals. Methods: The ages, refractions, and axial length measurements of the cases were recorded. Central macular thickness and choroidal thickness at the fovea and at 500 &mgr;m intervals from the foveal center in both temporal and nasal directions were measured using spectral domain optical coherence tomography. Results: Although the smoking period of the smokers was mean 32.4 ± 9 years (range: 20–60), the mean pack-years of cigarettes was 35.1 ± 23.8 (range: 10–120). No significant difference was observed regarding refraction value and axial length between smokers and nonsmokers group. In addition, no significant difference was observed for central macular thickness and choroidal thickness values at 500, 1,000, 1,500, and 2,000 &mgr;m nasal and temporal part of the fovea, between 2 groups. Conclusion: Macular and choroidal thicknesses in long-term smokers were observed to be similar to those of healthy individuals.

Effect of Hydroxychloroquine on the Retinal Layers: A Quantitative Evaluation with Spectral-Domain Optical Coherence Tomography

Purpose. To evaluate the effect of hydroxychloroquine on retinal pigment epithelium- (RPE-) Bruchs membrane complex, photoreceptor outer segment, and macular ganglion cell-inner plexiform layer (GCIPL) thicknesses using spectral-domain optical coherence tomography (SD-OCT). Methods. In this prospective case-control study, 51 eyes of 51 hydroxychloroquine patients and 30 eyes of 30 healthy subjects were included. High-quality images were obtained using a Cirrus HD-OCT with 5-line raster mode; the photoreceptor inner segment (IS) and outer segment (OS), sum of the segments (IS + OS), and RPE-Bruchs membrane complex were analyzed. Results. The thicknesses of the IS + OS and OS layers were significantly lower in the hydroxychloroquine subjects compared to the control subjects (P < 0.05). RPE-Bruchs membrane complex thicknesses were significantly higher in the hydroxychloroquine subjects than for those of the control subjects (P < 0.05). The minimum and temporal-inferior macular GCIPL thicknesses were significantly different between the patients with hydroxychloroquine use and the control subjects (P = 0.04 and P = 0.03, resp.). Conclusions. The foveal photoreceptor OS thinning, loss of GCIPL, and RPE-Bruchs membrane thickening were detected in patients with hydroxychloroquine therapy. This quantitative approach using SD-OCT images may have important implications to use as an early indicator of retinal toxicity without any visible signs of hydroxychloroquine retinopathy.

Efficiency of endoscopic imaging in repetitive probing following unsuccessful probing

Purpose. To show the efficiency of repetitive probing performed with intranasal endoscopic imaging in cases who underwent unsuccessful probing and the accompanying nasal pathologies. Methods. Eighty-four eyes of the 64 patients in whom primary probing was found to be unsuccessful were included in the study. Cases were divided into 3 groups, depending on the number of unsuccessful attempts (1 [group 1], 2 [group 2], and 3 [group 3] unsuccessful probings). Diagnosis of congenital nasolacrimal duct obstruction was confirmed by history taking, clinical examination, and fluorescence disappearance test. All cases underwent nasal endoscopic-assisted probing and were followed up on the first week, first month, and third month following the procedure. Results. There were 50 eyes in group 1, 23 in group 2, and 11 in group 3. The causes of failure that were determined with endoscopy were as follows: functional insufficiency 8.3%, lower nasal concha tension 4.7%, thin membrane in Hasner valve 3.6%, thick membrane and fibrosis in the distal side of the duct 21.4%, probe progressed submucosally on the nasal wall 33.3%, different exit location in the nose 20.2%, nasal mucosa ballooning in the distal side of the duct 4.7%, mucocele 2.4%, and nasal polyposis 1.2%. The success rate in the groups was estimated as 86% in the first group, 69.5% in the second group, and 54.5% in the third group. Conclusions. Performing the repetitive probings via nasal endoscopy provided information about the location and the shape of the obstruction and the opportunity to approach, according to the cause of the failure.