QUANTITATIVE-ANALYSIS OF FOVEAL RETINAL THICKNESS IN DIABETIC-RETINOPATHY WITH THE SCANNING RETINAL THICKNESS ANALYZER

Purpose: This study sought to measure foveal retinal thickness in pati ents with diabetic retinopathy and to investigate the relationship bet ween foveal thickness and visual acuity, biomicroscopic findings, and angiographic features. Methods: A commercial scanning retinal thicknes s analyzer was used to measure retinal thickness. A laser slit was pro jected onto the retina and scanned in 400 milliseconds across the cent ral area of the fundus. The image where the laser slit intersects with the retina was digitally recorded and analyzed. Retinal thickness was measured in 35 patients (35 eyes; patient age, 57 +/- 13 years) with diabetic retinopathy. Patients also were examined by fluorescein angio graphy and slit-lamp biomicroscopy to detect foveal thickening. Result s: Linear regression analysis indicated a significant correlation betw een foveal thickness and visual acuity (adjusted R-2 = 0.72, P < 0.001 ). Foveal thickness was abnormal in 6 (100%) of 6 eyes in which foveal thickening was detected with slit-lamp biomicroscopy. Foveal thicknes s also was abnormal in 9 (31%) of 29 eyes that appeared normal by biom icroscopic examination. Foveal thickness was 136 +/- 65 mu m in 7 eyes without leakage, 175 +/- 35 mu m in 13 eyes with questionable leakage , and 291 +/- 120 mu m in 7 eyes with definite leakage (P = 0.0075). C onclusions: Retinal thickness analysis is shown to be more sensitive t han slit-lamp biomicroscopy for detecting small changes in retinal thi ckness. Retinal thickness analysis may prove to be a useful, noninvasi ve modality for the development or regression of macular edema.