Milder ocular findings in Hermansky-Pudlak syndrome type 3 compared with Hermansky-Pudlak syndrome type 1
To compare clinically 2 different subtypes of Hermansky-Pudlak syndrome (HPS), type 1 (HPS-1) and type 3 (HPS-3). Cross-sectional study of a series of patients. Sixteen patients with HPS-1 and 14 patients with HPS-3 were studied. Complete eye examination, including best-corrected visual acuity and photographs and photographic grading of iris transillumination and macular transparency using a previously established grading system. Snellen visual acuity was 20/160-2 in the HPS-1 group and 20/125+2 in the HPS-3 group (P = 0.017). Iris grading was statistically significant for less translucence in the HPS-3 patients. The HPS-3 patients also tended to have less transparent maculas, but the difference was not statistically significant. Patients with HPS-3 have less severe ophthalmic manifestations than patients with HPS-1. Ophthalmologists treating patients with albinism should consider HPS in their differential diagnosis even in the case of mild iris and macular hypopigmentation.