PERIPHERAL OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN A CHOROIDEREMIA CARRIER

To describe the peripheral optical coherence tomography findings in a female choroideremia carrier.

A 56-year-old woman was referred for visual disturbance complaining of some occasional photopsias and increasing difficulty with her vision at night in both eyes. Best-corrected visual acuity was 20/20 in the right eye and 20/150 in the left eye. Fundus examination revealed mildly tilted disks and peripapillary atrophy with subtle retinal pigment epithelial changes in the periphery.

Macular optical coherence tomography in the right eye appeared unremarkable, but the in the left eye, there was diffuse ellipsoid zone band disruption. Green-light fundus autofluorescence revealed mottled areas of decreased autofluorescence in the mid and far periphery creating an irregular mosaic pattern. Peripheral optical coherence tomography scans revealed more diffuse ellipsoid zone alterations than were apparent on the fundus autofluorescence imaging. Genetic testing revealed a heterozygous pathogenic variant in the CHM gene (c.715C>T, p.Arg239). An additional heterozygous mutation was noted in the CNGB1 gene (c.290+2T>C, splice donor).

Choroideremia carriers may manifest widespread photoreceptor alterations, which may be more extensive than apparent on fundus autofluorescence imaging.