Abstract
Purpose:
Cystoid macular edema (CME) is a complication of retinal degenerations often found in patients with Usher syndrome. We used optical coherence tomographs (OCTs) to evaluate macular structure in pediatric patients with a genetic diagnosis of Usher syndrome, a recessively inherited condition characterized by hearing loss and retinal degeneration.
Methods:
Spectral-domain OCTs centered on the fovea and spanning 20° horizontally were recorded from seven patients with Usher syndrome (median age 13 years) and compared to those from 10 healthy control subjects. Three of the Usher syndrome patients had a clinical diagnosis of CME. The depth and breadth of the foveal pit, the thickness of the retinal laminae, and total retinal thickness were measured using ImageJ in scans containing at least 49 frames in which all retinal layers were clearly visible. ANOVA was used to compare retinal thickness as a function of eccentricity (center, temporal rim, and nasal rim of the foveal pit).
Results:
There was no significant difference between Usher patients and controls in the depth of the foveal pit (median135 μ, range 63 to 149 μ; median125 μ, range 75 to 149 μ, respectively) or in the breadth of the foveal pit (median 1.1°, range 0.9° to 1.8°; median 1.0° range 0.9° to 1.4°μ, respectively). Total retinal thickness and ONL thickness were less in Usher patients than in controls. Of note, these thicknesses were significantly more variable among Usher patients than controls, including those who did NOT have a clinical diagnosis of CME. Total retinal thickness varied significantly with eccentricity in both controls (as expected) and in these young patients with Usher syndrome. Interestingly, there was a significant interaction of group (Usher, control) and eccentricity.
Conclusions:
Among the patients with Usher syndrome, the combination of thinner mean total retinal and OPL thickness and significantly greater variability in these thicknesses may be due to a range of severity of photoreceptor disease, subclinical CME, or both.
Keywords: 550 imaging/image analysis: clinical •
696 retinal degenerations: hereditary •
688 retina