BACKGROUND: Helicoid Peripapillary Chorioretinal Degeneration (HPCD) is a rare bilateral degeneration of the retinal pigment epithelium and choriocapillaris surrounding the optic nerve with progression to the macula. It is transmitted via an autosomal dominant pattern and tends to affect lighter complexioned ethnicities. The clinical presentation is an irregularly shaped, chronic, progressive atrophy of the retinal and choroidal tissue with an absence of inflammation. There is a correlation with the presence of astigmatism and characteristic electrodiagnostic test results. The macula is frequently affected with advancing age, resulting in reduced central vision.
CASE REPORT(S). A 70 year-old African American female presented with a complaint of an intermittent scotoma in the right eye for one month. Examination showed bilateral visual acuities of 20/30- OU, possibly due to grade 1+nuclear sclerotic and cortical cataracts accompanied by a dry eye syndrome. Dilated fundus exam revealed classic areas of peripapillary atrophy with pseudopod-like extensions toward the maculas. The macula of the right eye was more severely involved, while the left eye showed extension in the nasal direction. No areas of active inflammation or subretinal neovascularization were noted. Automated visual field testing revealed corresponding defects, with a shallow papillomacular defect OD and an enlarged blindspot with temporal extension OS. Electrodiagnostic testing revealed reduced amplitude with normal latentcy of the ERG. A review of the case history uncovered the patient's multi-racial origin. Follow-up over two years has shown no progression of either retinal signs or visual symptoms.
CONCLUSIONS. The diagnosis of this case is an unusual presentation of HPCD, an extremely rare condition. While the clinical picture is highly diagnostic, the preservation of central visual function, the relative stability, and the patient's African American ancestry make this case a diagnostic challenge. The patient's mixed racial heritage may contribute to relatively mild expression of this disorder.