Post-traumatic hyperlipofuscinosis in the human retinal pigment epithelium

Abstract

Light microscopy (including fluorescence microscopy) and electron microscopy were applied to a study of the photoreceptor-retinal pigment epithelium (RPE) complex in a human eye which had been severely traumatised nine months prior to enucleation. The main feature of interest was a massive accumulation of lipofuscin in the retinal pigment epithelium at the posterior pole, and quantitative fluorescence microscopy provided values three times those obtained in appropriate control tissue. The photoreceptor layer was normal at the posterior pole but became progressively atrophic towards the periphery. The concentration of lipopofuscin was proportional to the degree of preservation of the retinal photoreceptors. By electron microscopy the cells in the RPE were seen to be packed with a mixture of lipofuscin granules and melanolysosomal complexes, but occasional photoreceptor phagosomes were found. Bruch's membrane and the choriocapillaris were normal. We attribute this hitherto unreported abnormality of the RPE after trauma to a dysfunction consequent on an overload of the monolayer by photoreceptor debris at the time of trauma.