Assessment of retinal nerve fiber layer thickness with NFA-GDx following successful scleral buckling surgery.

PURPOSE: To assess the effect of retinal detachment (RD) on retinal nerve fiber layer (RNFL) thickness by using a scanning laser polarimeter (NFA-GDx) after successful scleral buckling surgery for the treatment of rhegmatogenous RD. METHODS: Consecutive patients who had successful scleral buckling surgery in one eye were assessed for RNFL thickness by using NFA-GDx prospectively. Fellow healthy eyes of the patients formed the control group. Eyes with RD surgery were compared with the control group with respect to three variables (superior average, inferior average, and average thickness) of NFA-GDx by using two-sampled t-test. Additionally, a possible effect of duration of RD on RNFL thickness was assessed with a correlation test. RESULTS: The study group consisted of 16 patients with a mean age of 49.8 years. The mean duration of RD was 28 days. Although the retardation values in operated eyes were less than that of the control eyes, the difference was not statistically significant (p > 0.05). However, these three values were seen to increase with increased duration of detachment and this correlation was statistically significant (R > 0.5, p < 0.03). CONCLUSIONS: RD seemed to cause minimal or no change in RNFL thickness as determined by GDx variables. The positive correlation between RNFL thickness and duration of RD, however, may be because of the proliferated Muller cells in eyes with RD, which may be responsible for some of the retardation measurements, which may be even more prominent in longstanding RD cases. This needs to be supported by further studies in larger patient groups with longer duration of RD and with histopathologic studies.

Assessment of nerve fiber layer in diabetic patients with scanning laser polarimetry.

OBJECTIVES: To evaluate the effects of diabetes mellitus, diabetic retinopathy and degree of blood glucose (BG) regulation on retinal nerve fiber layer (RNFL) thickness by using a scanning laser polarimeter (NFA-GDx). METHODS: We prospectively assessed RNFL thickness in four groups of patients, who were all age matched. Diabetic patients without diabetic retinopathy were grouped according to their BG regulation level into two, as: BG-regulated group (BG <140 mg/dl, HbA1c <8%, fructosamine <285 micromol/l, TG <200 mg/dl, n = 50), and BG-non-regulated group (BG = 140-250 mg/dl, HbA1c >8%, fructosamine >285 micromol/l, TG >200 mg/dl, n = 44). A group of patients with nonproliferative diabetic retinopathy (NPDR) formed the 3rd group (n = 41). The 4th group consisted of healthy subjects and acted as a control group (n = 50). Symmetry, superior maximum, ellipse modulation and the average thickness variables of NFA-GDx were used for the assessment. ANOVA test was used for the statistical analysis of variables between groups. RESULTS: The mean superior maximum and ellipse modulation values were statistically significantly lower than the control group in BG-non-regulated and NPDR groups (P < 0.05). The average thickness value was also statistically significantly lower than the control group in NPDR group. These values in the BG-regulated group were not statistically significantly different from the control group (P > 0.05). CONCLUSIONS: This is the first clinical study demonstrating the effects of diabetic glucose regulation level on RNFL by using NFA-GDx. RNFL thickness was seen to decrease with development of diabetic retinopathy and with impairment of metabolic regulation. This issue should be taken into account while assessing RNFL in diabetic glaucomatous patients.

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.