Photoreceptor loss overlying congenital hypertrophy of the retinal pigment epithelium by optical coherence tomography

Objective: To describe the cross-sectional retinal anatomy overlying congenital hypertrophy of the retinal pigment epithelium (CHRPE) using optical coherence tomography (OCT). Design: Retrospective, observational, noncomparative case series. Participants: Ten consecutive patients with CHRPE. Main Outcome Measures: The main outcome measures were retinal and retinal pigment epithelium (RPE) thickness relative to normal tissue and the status of the retinal layers, in particular the photoreceptor layer. Results: The median patient age was 36 years (mean, 34 years; range, 7-56 years). The CHRPE was within 6 mm of the optic disc or foveola in all patients. All patients showed retinal thinning and complete photoreceptor loss overlying the CHRPE. The sensory retina measured a mean of 68% of normal thickness (range, 47%-87%). Of the 8 patients with pigmented CHRPE, the CHRPE was 52% thicker than adjacent RPE. All 8 patients with pigmented CHRPE showed moderate relative shadowing of the underlying choroid. The 2 patients with nonpigmented CHRPE, presumed to represent large lacunae with thin CHRPE rim, showed absent RPE and increased transmission of light, not shadowing, into the choroid by OCT. Both patients with visual field testing showed a visual field defect corresponding to the photoreceptor loss. Conclusions: Using OCT, overlying retinal thinning and photoreceptor loss directly over CHRPE was found in 10 consecutive patients. These findings likely account for related visual field loss.