Purpose:
To describe ultrastructural features of an epiretinal membrane (ERM) from a patient with autosomal recessive retinitis pigmentosa (arRP) caused by PDE6A mutation and compare histopathology of a mouse model for autosomal recessive retinitis pigmentosa with missense mutations in the Pde6a gene.
Methods:
A 46-year-old man who had had arRP with extensive vitreous veils and epiretinal membranes causing vitreoretinal traction, underwent 23-gauge pars plana vitrectomy to remove vitreous and epiretinal membrane. The specimen was fixed in 2% glutaraldehyde, and reviewed under the transmission electron microscope (EM) after routine tissue processing. Eyes from arRP mouse model with amino acid residue mutation, C57BL/6J-Pde6anmf363/nmf363 sacrificed at P18 through P72 were enucleated and fixed. The retinas were examed and photographed under a light microscope after staining with hematoxylin and eosin.
Results:
The EM showed multiple fibroblasts and fibrocytes surrounded by abundant collagen maxtrix. The slender cytoplasmic extensions of fibroblasts were overlying the collagen layers. The thickness of outer nuclear layer and inner and out segments of photoreceptors was significantly decreased at postnatal day 30 and there was no identifiable photoreceptor layer at postnatal day 72. The thickness of the inner nuclear layer was also decreased leaving only a few cell layers at postnatal day 72.
Conclusions:
The EM of an ERM from an eye with arRP and vitreoretinal traction revealed multiple active fibroblasts producing collagen. Features of arRP mouse model, C57BL/6J-Pde6anmf363/nmf363 minic some aspects of the human disease.
Keywords: retinal degenerations: hereditary • pathology: human • vitreoretinal surgery