Decreased photoreceptor count in human eyes with secondary angle-closure glaucoma

Glaucoma has been known to be associated with a loss of retinal ganglion cells and their axons throughout the fundus and a decreased count of photoreceptors and retinal pigment epithelial (RPE) cells in the parapapillary region. This study investigated whether glaucomatous changes of the deep retinal layer occur outside the parapapillary region. The nuclei of the retinal photoreceptors and RPE cells were counted in histologic slides of 23 eyes with painful secondary angle-closure glaucoma resulting from perforating corneal injuries. Fourteen eyes with malignant choroidal melanoma not involving the ciliary body or trabecular meshwork served as the control group. No surgical procedure, including laser treatment, had been performed posterior to the ora serrata. There were no hints of retinal vessel occlusion and localized traumatic retinopathy, historically, ophthalmoscopically, or histologically. Photoreceptor count was significantly lower (P less than 0.05) in the glaucoma eyes than in the control group. Count of RPE cells did not differ between the two groups. This may indicate that glaucoma can be associated with a loss of photoreceptors. This could be important for psychophysical testing and may point to a more widespread involvement of ocular tissues in glaucoma than believed.