Foveal thickening in retinitis pigmentosa patients with cystoid macular edema

• Published in: Retina (Philadelphia, Pa.) Vol. 14; no. 3; p. 243
• Main Authors: Shahidi, M, Fishman, G, Ogura, Y, Ambroz, K, Zeimer, R
• Format: Journal Article
• Language: English
• Published: United States 1994
• Subjects: Adult; Cross-Over Studies; Double-Blind Method; Fluorescein Angiography; Fovea Centralis - drug effects; Fovea Centralis - pathology; Fundus Oculi; Humans; Image Processing, Computer-Assisted; Macular Edema - drug therapy; Macular Edema - etiology; Macular Edema - pathology; Methazolamide - therapeutic use; Retinitis Pigmentosa - complications; Retinitis Pigmentosa - drug therapy; Retinitis Pigmentosa - pathology
• ISSN: 0275-004X
• DOI: 10.1097/00006982-199414030-00009

Clinical evaluation of cystoid macular edema (CME), known to occur in patients with retinitis pigmentosa (RP), is based on the presence of vascular leakage on fluorescein angiography. Due to an inability to quantitatively assess retinal thickening, the degree of thickening from fluid accumulation and its relation to fluorescein dye leakage into the extravascular retinal space has not been established. The relationship between fluorescein dye leakage and foveal thickening and the effect of methazolamide treatment was studied.
The retinal thickness analyzer was used to measure the degree of thickening in six patients with RP and CME. A laser beam was projected at an oblique angle to the retina, and images of the intersection of the laser slit with the anterior and posterior retinal surfaces were recorded. The digitized images were analyzed using a dedicated software program to provide quantitative measurements of retinal thickness. Routine fluorescein angiography was performed.
The amount of fluorescein dye leakage was not indicative of the degree of retinal thickening due to fluid accumulation. Foveal thickening and fluorescein dye leakage were reduced in five of six eyes after methazolamide treatment. Eyes with moderate thickening reversed to normal, whereas eyes with severe thickening showed only a minimal reduction in thickness.
Retinal thickness measurement is a useful method of evaluating both the extent of and changes in retinal thickness after carbonic anhydrase treatment.