Abstract
Purpose: :
To define the histopathology in autopsy eyes from a male with X-linked retinitis pigmentosa (RP) and an RPGR Gly436Asp mutation and correlate abnormalities with his clinical findings.
Methods: :
Autopsy eyes were obtained from a 53 year-old male with retinitis pigmentosa who died from colon cancer with metastasis to the liver. His right eye was fixed 3 hours after death in a phosphate buffer containing 2.5% glutaraldehyde and 1% formaldehyde for ultrastructural studies and the left eye in buffered 4% formaldehyde for immunocytochemistry.
Results: :
This patient had night deficiency in early childhood and loss of side vision in adolescence at which time the diagnosis of RP was made. His living brother, age 50, is similarly affected. His late maternal grandmother and mother showed clinical and histologic findings of the carrier state of X-linked RP (Ophthal 92: 271-278, 1985 and AJO 142: 515-518, 2006). At his last ocular exam 3 years prior to death he had a visual acuity of 20/400 and a 10º diameter paracentral island of field in each eye. He was pseudophakic, showed bone spicule pigment around the periphery, and had nondetectable rod ERGs with reduced but detectable cone ERGs in both eyes. Microscopic examination of the right eye showed some surviving photoreceptors in the nasal and temporal parafovea and the nasal far periphery; ultrastructural examination showed that these were mainly cones lacking outer segments. In the area of surviving photoreceptors the retinal pigment epithelium was relatively intact with some pigment containing cells in the subretinal space. The inner nuclear layer and ganglion cell layer were relatively preserved in the macula. Immunocytochemical studies of the left eye are in progress.
Conclusions: :
This first report of a male with RP and an RPGR mutation shows that his visual loss can be explained by loss of photoreceptors across most of the retina. The basis for the distribution of surviving photoreceptors remains to be clarified.
Keywords: retinal degenerations: hereditary • pathology: human • photoreceptors