Congenital hypertrophy of the retinal pigment epithelium: enhanced-depth imaging optical coherence tomography in 18 cases.

OBJECTIVE: To describe the imaging characteristics of congenital hypertrophy of the retinal pigment epithelium (CHRPE).

DESIGN: Retrospective, observational case series.

PARTICIPANTS: Eighteen eyes of 18 patients with CHRPE.

METHODS: Review of chart, fundus photography, ultrasonography, fundus autofluorescence, infrared reflectance (IR) imaging, and enhanced-depth imaging optical coherence tomography (EDI-OCT).

MAIN OUTCOME MEASURES: Features of CHRPE as analyzed by EDI-OCT.

RESULTS: The mean age at diagnosis was 48 years (range, 13-73 years). There were 5 males and 13 females, and 17 Caucasian and 1 African American patients. The mean best-corrected visual acuity was 20/22 (range, 20/20-20/40). The CHRPE was located in the retinal periphery (n = 16) with intralesional lacunae (n = 14) and surrounding nonpigmented (n = 4) and pigmented (n = 14) halo. By ultrasonography, the mean CHRPE thickness was 1.0 mm (range, 0.9-1.4 mm). Fundus autofluorescence disclosed hypoautofluorescence (n = 18) with lacunae (n = 14) showing isoautofluorescence (n = 10) or hypoautofluorescence (n = 4). Infrared reflectance imaging displayed hyporeflectivity in the area of pigmentation (n = 16) and hyperreflectivity within lacunae (n = 14). On EDI-OCT, all 18 lesions were flat with a mean basal diameter of 4529 μm (median, 3707 μm; range, 697-11 617 μm). The mean central sublesional choroidal thickness (126.4 μm) was not different compared with thickness 50 μm outside the margin (126.8 μm; P = 0.99). The retinal pigment epithelium (RPE) was absent (n = 2), thickened (n = 16), or irregular (n = 15). Of 9 lesions in which lacunae were imaged, 8 showed absent RPE. The overlying retinal findings included thinning or absence of the outer retina beginning at the ganglion cell layer (n = 1), outer plexiform layer (n = 4), outer nuclear layer (n = 12), or inner segment/outer segment junction (n = 1). Additional retinal findings included hyperreflective spots (n = 11), cystoid edema (n = 5), and subretinal cleft (n = 6). Subretinal cleft specifically occurred at the site of absent photoreceptors.

CONCLUSIONS: Generally, CHRPE displays hypoautoflouorescence and hyporeflectivity with hyperreflective lacunae on IR imaging. On EDI-OCT, CHRPE seems flat with thickened, irregular RPE and absent RPE within lacunae. A prominent feature is outer retinal loss, generally involving the outer nuclear layer to photoreceptors, occasionally with a characteristic subretinal cleft.