PP176 : Decoding Choroideremia -unraveling the natural history of the disease with multimodal imaging.

Dr.Puneeth Isloor

A 50 Year old male with night blindness and long term diminution of vision in both eyes was found to have a BCVA of 20/80 OD ,N8and 20/60,N8 OS.Anterior segment was normal OD and an early posterior subcapsular cataract OS .Fundus examination OU revealed diffuse RPE atrophy with a preserved central island of RPE at the macula. Fundus Autoflourescence(FAF )OU showed the presence of patchy areas of hypoautoflourescence with a central island of normal autofluorescence having pseudopodial extensions at the macula .Outer Retinal Tubulations(ORT) were also noted at the junction of the preserved and atrophied RPE . En-face OCT angiography(OCTA) images at the level of the Bruchs membrane(BM) and 39µm below the BM showed that area of choriocapillaris atrophy exceeded the area of RPE atrophy. In contrast to older case reports, our case shows that the atrophy of choriocapillaris precedes that of RPE and highlights the use of OCTA in analyzing the natural history of retinal diseases.