Gürsel Yilmaz

The effect of smoking on choroidal thickness measured by optical coherence tomography

Background/aims To investigate the effect of smoking on choroidal thickness using Fourier domain optical coherence tomography. Methods 17 otherwise healthy smokers (study group) and 17 non-smokers (control group) were enrolled. In the study group, all participants underwent optical coherence tomography scanning at baseline, and 1 and 3 h following smoking one standard cigarette. Also the participants of the control group underwent optical coherence tomography scanning in the morning which was followed by two further examinations at the first and third hours, respectively. Choroidal thickness measurements were performed. Results The mean choroidal thickness at the fovea prior to smoking was 301.1±63.1 μm, which decreased to 284.2±56.7 μm at 1 h and 270.8±80.0 μm at 3 h following smoking (p=0.001). The mean choroidal thickness was significantly decreased following smoking at all five extrafoveal points. The difference in choroidal thickness was not statistically significant at 1 and 3 h of smoking at all six points. In the control group, the mean baseline choroidal thickness at the fovea was 270.6±57.9 μm, which was 272.5±52.4 μm at 1 h and 273.8±57.4 μm at 3 h (p=0.816). Conclusions Cigarette smoking causes a significant decrease in choroidal thickness following smoking. Fourier domain optical coherence tomography can effectively demonstrate choroidal thickness.

Elevated vitreous nitric oxide levels in patients with proliferative diabetic retinopathy

PURPOSE The aim of this study was to determine nitric oxide levels in the vitreous of patients with proliferative diabetic retinopathy. METHODS Using the spectrophotometric method based on Griess reaction, we measured levels of nitrite, the stable product of nitric oxide, in the vitreous of 21 eyes of 21 patients who underwent vitrectomy for the treatment of proliferative diabetic retinopathy with tractional retinal detachment, prospectively. Three samples were excluded from the study because of blood contamination. The control group was made up of vitreous samples from 15 eyes of 15 normal cadavers and five eyes of five patients who were undergoing vitrectomy for macular hole surgery. RESULTS Nitrite levels were 0. 524 +/- 0.27 microM and 0.383 +/- 0.17 microM in the vitreous of patients with proliferative diabetic retinopathy of diabetes type I and type II, respectively. In 15 cadaver eyes and five vitreous samples from patients who underwent macular hole surgery, nitrite levels were below the detection limit (less than 0.08 microM). There was no significant difference between nitrite levels in patients with type I and type II diabetes (P =.56), whereas there was a significant difference between diabetes groups and controls (P <. 00001). CONCLUSION Vitreous nitric oxide levels are elevated in patients with proliferative diabetic retinopathy with tractional retinal detachment. Nitric oxide may play a role in the pathogenesis of proliferative diabetic retinopathy.

Aqueous humor nitric oxide levels in patients with Behçet disease.

Purpose The purpose of this study was to quantify aqueous humor nitric oxide levels in patients with Behçet uveitis and age-matched controls to assess how nitric oxide is involved in this ocular condition. Methods Samples of aqueous humor were collected from 11 patients with Behçet uveitis who were undergoing cataract surgery. Sampling was done by paracentesis at the beginning of the operation. Similar samples were collected from 20 age-matched normal patients (controls). For each sample, we used the spectrophotometric method based on the Griess reaction to determine the amount of nitrite, which is the stable metabolite of nitric oxide. Results The amount of nitrite in aqueous humor samples from patients with Behçet disease was above the detection limit in 8 of 11 cases; the mean level ± SEM was 2.13 ± 0.621 &mgr;mol/L. Levels in the control group were below the detection limit in all cases (<0.08 &mgr;mol/L). There was a statistically significant difference between the aqueous humor nitrite levels in patients with Behçet disease and those in controls (P = 0.00002). Conclusions Aqueous humor nitric oxide levels are elevated in patients with a history of Behçet disease.

Indocyanine Green and Fundus Fluorescein Angiographic Findings in Patients with Active Ocular Behcet's Disease

Purpose: To define the indocyanine green (ICG) and fundus fluorescein angiographic (FFA) features of Behçets disease. Methods: The study included 49 eyes of 25 patients (19 males, 6 females; mean age: 34.1 years; age range: 14–68 years) with Behçets disease and active ocular involvement that fulfilled the criteria of the International Study Group for Behçets Disease. In each patient, FFA and ICG angiography were performed consecutively in the same session using a TRC-50I/A fundus camera (Topcon, Tokyo, Japan) coupled to an Image Net digitizing system. All images were analyzed and FFA, ICG, and clinical findings summarized. Results: The mean duration of ocular involvement was 52.4 months (range: 2–240 months). FFA showed staining and dye leakage at the optic disc in 44 (89.8%) eyes and diffuse vasculitis in 36 (73.5%) eyes. Macular edema and ischemia were observed in 31 (63.3%) and 3 (6.1%) eyes, respectively. Eight (16.3%) eyes exhibited detectable retinal FFA alterations, but no abnormalities on ICG angiography. Disc ICG hyperfluorescence was observed in 23 (46.9%) eyes. ICG angiography revealed choroidal fuzziness in 16 (32.6%) eyes, hyperfluorescent spots in 13 (26.5%) eyes, and hypofluorescent plaques in 12 (24.5%) eyes. Eleven eyes (22.4%) showed no abnormal findings on ICG angiography. Conclusion: ICG and FFA complement each other as tools for diagnosing patients with Behçets disease. FFA often serves as a fairly reliable guide. Although some ICG findings cannot be demonstrated by FFA, they are not specific or pathognomonic. We do not recommend performing both procedures for Behçets disease.

Indocyanine green and fluorescein angiography in nonarteritic anterior ischemic optic neuropathy.

Purpose To assess the value of indocyanine green angiography (ICGA) for demonstrating choroidal vascular abnormalities in patients with nonarteritic anterior ischemic optic neuropathy (NAION). Methods The authors compared the ICGA and fluorescein fundus angiography characteristics of peripapillary circulation in 11 patients with acute NAION. There were 7 men and 4 women; the age range for the patients was 36 years to 72 years (mean ± SD, 47.7 ± 10.76 years). The angiographic factors considered significant were delay of peripapillary choroidal filling in the vertical watershed zone, leakage from the optic disk, and absolute filling defects on the disk. The authors compared the incidence of a vertical peripapillary watershed zone in the eyes of the 11 patients with that in the normal eyes of 50 controls (age range, 44–79 years) who had unilateral age-related macular degeneration. Results Indocyanine green angiography revealed a peripapillary watershed zone in 8 of 11 patient eyes and 23 of 50 control eyes. There was no statistical difference in the number of eyes affected in each group (&khgr;2 = 0.53;P = 0.47). Fluorescein fundus angiography showed leakage from the disk in 10 of 11 patients, whereas ICGA highlighted this problem in only 7 of the patients. The choroidal filling time of the watershed zones was significantly longer with ICGA (t = 3.13;P = 0.011). Conclusion Although ICGA allows better visualization of the choroidal watershed zones associated with NAION, it did not reveal any significantly different incidence of vertical choroidal watershed zone encompassing the optic disk for patients with NAION and controls. Fluorescein fundus angiography better visualized leakage from the disk in the patient group. These findings indicate that ICGA offers no significant advantage in terms of clinical diagnosis and management of NAION.

Inflammation of the posterior uvea: findings on fundus fluorescein and indocyanine green angiography.

Purpose: To investigate the additional benefit of indocyanine green angiography (ICGA) over fundus fluorescein angiography (FA) in patients with posterior uveal inflammation. Methods: The features of 19 patients with different forms of posterior uveitis (Vogt-Koyanagi-Harada disease [n = 5], serpiginous choroiditis [n = 5], multifocal choroiditis [n = 5], and sarcoidosis [n = 4]) were analyzed. Results: On ICGA, inflammatory lesions were hypofluorescent in all phases, and early choroidal vessel dilation and leakage was noted near the lesions. Conclusions: The combined use of FA and ICGA helps gauge the severity of inflammation in the choroid and the retina during active inflammation. In quiescent stages, however, ICGA does not give any additional information.

Structural consequences after intravitreal bevacizumab injection without increasing apoptotic cell death in a retinopathy of prematurity mouse model

Purpose:  To evaluate the effect of different bevacizumab concentrations on retinal endothelial cell proliferation, retinal structures and apoptotic activity after intravitreal injection in a retinopathy of prematurity (ROP) mouse model.

Retinal vein occlusion and factor V Leiden and prothrombin 20210 G:A mutations

Purpose The aim of this study was to establish whether the factor V Leiden mutation and the prothrombin 20210 G:A mutation were risk factors for retinal vein occlusion. Methods Blood samples were obtained from 40 patients with retinal vein occlusion and from 50 healthy normal volunteers as controls. Polymerase chain reaction assays were done to detect factor V Leiden and prothrombin 20210 G:A mutations, and the two groups were compared. Results Two (5%) of 40 patients with retinal vein occlusion and three (6%) of 50 controls were heterozygous for factor V Leiden (p=0.84). None of the individuals in either group had the prothrombin 20210 G:A mutation. Conclusions There was no significant association between retinal vein occlusion and the factor V Leiden mutation.

Retinal and choroidal thickness changes after single anti-VEGF injection in neovascular age-related macular degeneration: ranibizumab vs bevacizumab

Purpose To evaluate and compare the effects of single intravitreal injection of ranibizumab and bevacizumab on central retinal and choroidal thickness in patients with neovascular age-related macular degeneration (AMD). Methods Forty eyes of 40 patients with neovascular AMD that underwent intravitreal injection of vascular endothelial growth factor inhibitors (anti-VEGFs) were included. Patients were randomized into 2 groups: 20 eyes received ranibizumab and 20 eyes received bevacizumab injection. Central retinal and choroidal thicknesses of all eyes at baseline and 1 month postinjection scans were measured with Fourier-domain optical coherence tomography (OCT). Student t test and Mann-Whitney U test were used to compare the data. Results The mean central retinal thickness (CRT) showed significant decrease after single injection of ranibizumab (from 345.0 μm to 253.5 μm, p<0.01) and bevacizumab (from 329.5 μm to 251.0 μm, p<0.01) at the first month, respectively. There was no significant difference regarding the CRT change between groups (p = 0.39). The mean choroidal thickness decreased from 158.6 μm (115-317) to 155.5 μm (111-322) in the ranibizumab group and from 211.5 μm (143-284) to 201.5 μm (93-338) in bevacizumab group. The decrease was not significant between groups (p = 0.35). Conclusions Intravitreal injection of both ranibizumab and bevacizumab provided a significant decrease in CRT; however, the agents caused no significant change in choroidal thickness. Additionally, no difference between ranibizumab versus bevacizumab was observed related to macular edema inhibition.

Intravitreal injection of bevacizumab in Eales disease.

Purpose: To report a case of presumed Eales disease that showed regression of retinal neovascularization after the use of intravitreal bevacizumab. Design: Retrospective, interventional case report. Methods: Broad retinal neovascularization in a patient with presumed Eales disease did not regressed despite adequate photocoagulation treatment, and bevacizumab (1.25 mg) was injected intravitreally. The patient was followed up for 1 year. Results: One week after injection, fluorescein angiography demonstrated dramatic regression of retinal neovascularization. After 12-months, visual acuity was improved and no signs of recurrence were observed. Conclusion: Intravitreal bevacizumab may be effective as an adjunctive treatment of retinal neovascularization in patients with Eales disease.