Gökhan Gürelik

Optical Coherence Tomographic Assessment of Diabetic Macular Edema: Comparison with Fluorescein Angiographic and Clinical Findings

Purpose: To compare the optical coherence tomographic (OCT) features with clinical and fluorescein angiographic (FA) findings in patients with diabetic retinopathy. Methods: In a retrospective study ophthalmologic examination together with FA and OCT images were obtained from 195 eyes of 110 patients with different stages of diabetic retinopathy and OCT images were obtained from 40 eyes of 20 control subjects. Fluorescein leakage characteristics were organized into five groups: no leakage (1), focal (2), diffuse (3), combined focal + diffuse leakage (4) and cystoid (5). The Pearson correlation test was used to test the correlation between visual acuity and central foveal thickness and ANOVA was used for the statistical comparison between the groups. Results: The OCT images demonstrated retinal swelling in 66.1% of eyes, cystoid macular edema (CME) in 11.8% of eyes, serous foveal detachment + swelling in 6.2% of eyes, serous foveal detachment + swelling + CME in 3.6% of eyes and normal foveal structure in 12.3% of eyes. The best-corrected visual acuity was significantly correlated with central foveal thickness (r: –0.528, p < 0.01). There was 77% agreement between clinical examination and OCT results. CME was detected with OCT in 15.4% of eyes in our study, 40% of which was not detected with slit-lamp biomicroscopy and 63.3% of which was not evident in FA. None of the serous foveal detachments could be detected during slit-lamp biomicroscopy or FA. Conclusions: OCT-3 provided objective documentation of foveal structural changes in eyes with diabetic retinopathy. Best-corrected visual acuity provided a significant correlation with the retinal thickness at the central fovea. These results indicate that OCT can facilitate deciding on the treatment protocol (surgical or medical) and follow-up of diabetic patients, which is especially important in the early stages of diabetic maculopathy when the structural changes are not yet evident with slit-lamp biomicroscopy or angiographically.

Scanning laser polarimetry in normal subjects and patients with myopia

AIMS To examine the changes in the retinal nerve fibre layer (NFL) thickness with age and myopia in normal population. METHODS Retinal nerve fibre layer thickness was measured with a scanning laser polarimeter (NFA-I) in 180 normal subjects of varying age (range 7–83 years) and in 110 eyes of 85 patients with myopia of varying degrees (range −1.00 to −15.00D). They were all voluntary Anatolian people. Superior to nasal (S/N), inferior to nasal (I/N), and the superior to inferior (S/I) ratios were used for the assessment of retinal NFL thickness. RESULTS The mean superior NFL ratio was 2.96 and the mean inferior NFL ratio was 2.93 in normal subjects. There was a gradual decrease in NFL ratio with increasing age (simple regression analysis, p<0.05). The mean S/I ratio was 1.01 with a large variation. In patients with myopia, the mean superior NFL ratio was 2.60 and the mean inferior NFL ratio was 2.72. Superior and inferior NFL retardations, and S/I ratio in myopic patients were significantly (15.5%, 10.8%, and 4.9% respectively) lower than that of age matched normals (ttest, p<0.05). There was also a gradual decrease in NFL thickness with increasing degree of myopia (simple regression analysis, p<0.05). CONCLUSIONS Nomograms we obtained for retinal NFL thickness may serve as reference points for the assessment of normal Anatolian people and myopic patients in future studies. NFL thicknesses gradually decreased with increasing age. Patients with myopia had significantly lower NFL thicknesses than normal subjects and, although weakened by wide age range of myopic group, there is a linear relation between severity of myopia and NFL thickness in myopic patients.

The effect of blood glucose regulation on retinal nerve fiber layer thickness in diabetic patients.

Purpose: To evaluate the effect of blood glucose (BG) regulation on the retinal nerve fiber layer (RNFL) in diabetic patients by using a scanning laser polarimeter (NFA-GDx). Methods: We prospectively assessed RNFL thickness in diabetic patients and an age-matched control group. Patients without diabetic retinopathy, with BG >250 mg/dl, HbA1c >8%, fructosamine >285 µmol/l and triglyceride >200 mg/dl were included in the study. RNFL assessment was performed before and after metabolic regulation of diabetes. Symmetry, superior maximum, ellipse modulation and the average thickness variables of NFA-GDx were used for the assessment. Mann-Whitney U and Wilcoxon tests were used for the statistical analysis. Results: A total of 40 diabetic patients were included in the study and a repeat RNFL examination could be performed in 22 of them following regulation of BG levels. None of the GDx variables were significantly different between pre- and postregulation measurements (p > 0.05, Wilcoxon test). The mean superior maximum, ellipse modulation and average thickness values of the diabetic group were significantly lower than the control group (p < 0.05, Mann-Whitney U-test). Conclusions: Poor metabolic control of diabetes mellitus adversely affects the thickness of RNFL and this effect does not seem to be acute since it was not reversed by short-term BG regulation. This issue needs to be kept in mind when assessing glaucomatous progress in diabetic patients.

Topical vitamin E and hydrocortisone acetate treatment after photorefractive keratectomy.

Purpose To investigate the effects of topical vitamin E and hydrocortisone acetate treatments on corneal healing response after -10.0 D photorefractive keratectomy (PRK) in rabbits.Methods Thirty-three New Zealand white rabbits were divided into four groups and -10 D PRK was performed under in vivo conditions. Following PRK, group 1 (n = 9) received no topical treatment and served as control. Group 2 (n = 8) received 0.1% hydrocortisone acetate ointment twice a day, group 3 (n = 8) received 1% vitamin E ointment and group 4 (n = 8) received both 0.1% hydrocortisone acetate and 1% vitamin E twice a day for a month. At the end of the third month, corneal haze was graded and the corneal hydroxyproline levels were measured, as a crude indicator of new collagen synthesis. Finally corneal samples were examined by transmission electron microscopy.Results Non-homogeneously distributed strong haze was identified in group 1 which was greater than in the other groups; haze was least in groups 2 and 4. Corneal hydroxyproline levels were found to be significantly lower in groups 2, 3 and 4 compared with the control (Students t-test, p < 0.05). Histopathologically, the most aggressive wound healing response was detected in group 1. The corneal wound healing response of group 2 was less than that of group 1 and equal to or more than that of group 4.Conclusions Deep corneal photoablation induces an aggressive healing response, and topical hydrocortisone acetate reduces this corneal wound healing effectively. The inhibitory effect of topical vitamin E on corneal wound healing seems to be less than that of hydrocortisone acetate, but combined treatment with these two drugs may have an additive effect in controlling corneal wound healing after PRK.

Neuroprotective effect of topically applied brimonidine tartrate 0.2% in endothelin-1-induced optic nerve ischaemia model.

Background:  To investigate the neuroprotective effects of topically applied brimonidine tartrate 0.2% (BMD), an α2‐receptor agonist, on the retinal ganglion cell (RGC) layer and inner nuclear layer (INL) of rabbit retina in endothelin‐1 (ET‐1)‐induced optic nerve (ON) ischaemia model.

Posterior Subtenon Triamcinolone, Intravitreal Triamcinolone and Grid Laser Photocoagulation for the Treatment of Macular Edema in Branch Retinal Vein Occlusion

Purpose: To evaluate the efficacy of posterior subtenon triamcinolone (PSTT), intravitreal triamcinolone (IVT) injections and grid laser photocoagulation (GLP) in eyes with macular edema secondary to branch retinal vein occlusion (BRVO). Material and Methods: Patients with macular edema due to BRVO treated with PSTT, IVT injections or GLP were evaluated retrospectively. Complete ophthalmic examination with fluorescein angiography and optic coherence tomography were noted before and in the 1st, 3rd, and 6th months of the treatment. The visual and anatomical responses were evaluated and compared between the groups using paired t test and one-way ANOVA test. Results: There were 20, 35 and 24 eyes in the PSTT, IVT and GLP groups. In the PSTT group, the mean visual acuity (VA) and central foveal thickness (CFT) were 0.23 ± 0.23 and 413.2 ± 143.5 µm before treatment and 0.23 ± 0.18 and 358.7 ± 109.2 µm at the 3rd month, respectively (p = 0.504 and p = 0.031). The mean VA increased from 0.14 ± 0.15 to 0.33 ± 0.26 and the mean CFT decreased from 518.2 ± 145 to 292.9 ± 121 µm in IVT group at the 3rd month (p = 0.001). The mean VA increased from 0.29 ± 0.25 to 0.47 ± 0.32 (p = 0.001); CFT decreased from 397.3 ± 105.9 to 307.1 ± 88.4 µm (p = 0.005) in the GLP group. VA and CFT changes were significantly different between the groups at the 3rd month (p = 0.031). VA increase was significantly greater in the IVT group than in the PSTT group. Decrease in CFT was the highest in the IVT group (Tukey, p = 0.001). Conclusions: IVT and GLP seemed to be more effective than PSTT for the treatment of BRVO-associated macular edema. Possible complications of IVT and GLP must be weighted with the advantages of each treatment modality for each patient.

Simultaneous central retinal vein and retinal artery branch occlusions in two patients with homocystinaemia.

Simultaneous central retinal vein and retinal artery branch occlusions in two patients with homocystinaemia

High-density silicone oil as an intraocular tamponade in complex retinal detachments

OBJECTIVE To evaluate the efficacy and safety of high-density silicone oil (HDSO) as an internal retinal tamponade after vitrectomy for complicated retinal detachment. DESIGN Retrospective, non-randomized study. PARTICIPANTS Forty-one eyes of 41 patients who were 5-73 years of age. METHODS Medical records of patients with retinal detachment (RD) complicated with inferior proliferative vitreoretinopathy (PVR) requiring internal tamponade with HDSO were reviewed. Eyes with retinal vascular diseases and inflammatory diseases were excluded from the study. Follow-up examinations were scheduled at 1 week and 1, 3, 6, and 12 months after the initial surgery. RESULTS Median value of follow-up was 8 months (range, 3-40 months). Twenty-five patients had rhegmatogenous RD with significant PVR and the remaining patients had complicated RD secondary to trauma. Preoperative visual acuity was 2.55 ± 0.75 logMAR, which became 1.89 ± 0.91 at the last follow-up visit (p < 0.05). Complications included increased intraocular pressure (9.7%), hypotony (2.4%), cataract (57.1%), silicone oil in anterior chamber (17%), persistent total corneal edema (7.3%), band keratopathy (7.3%), and significant inflammation (2.4%). Intraretinal or subretinal fibrosis was found in 12 eyes (29.2%). HDSO removal was performed after a mean period of 5.7 months (range, 3-34 months) in 34 patients. The anatomical success was 87.8%. CONCLUSIONS The high anatomical success rate of 87.8% is a satisfactory result for these complicated RD cases. Subretinal proliferations and early emulsification limit the results. Further studies, with longer follow-ups and more patients, are needed to be conclusive.

A case of choroidal osteoma with subsequent laser induced decalcification

A rare benign tumor, choroidal osteoma with accompanying choroidal neovascularization treated with laser photocoagulation is reported. Limited decalcification was noted at the borders of laser photocoagulation.

Reactivation of presumed adenoviral keratitis after laser in situ keratomileusis

We report a patient with reactivation of presumed adenoviral keratoconjunctivitis after laser in situ keratomileusis (LASIK) to correct high myopia. The preoperative refraction was -13.00 diopters (D) in the right eye and -14.00 D in the left eye, and the best corrected visual acuity was 20/20 in both eyes. On the first postoperative day, mild conjunctival hyperemia and multiple subepithelial infiltrations localized in the flap zone consistent with adenoviral keratoconjunctivitis were seen. After prompt treatment, the lesions resolved. As a consequence, LASIK successfully corrected the high myopia. Adenoviral keratoconjunctivitis can be reactivated after LASIK, unlike after photorefractive keratectomy, despite the absence of symptomatic and clinical findings before the procedure.