Experimental tractional retinal detachment: an immunohistochemical study

Purpose. This study investigated the pathogenesis of tractional retinal de tachment associated with proliferative vitreoretinopathy in an experimental model, using immunohistochemical staining. Methods. To produce tractional retinal detachment in rabbit eyes, homologou s cultured ii broblasts obtained from the gluteal muscle fascia were inject ed intravitreously. Right eyes of 20 rabbits in the study group, and 7 rabb its in the control group were followed for 28 days at weekly intervals with indirect ophthalmoscopy and fundus photographs. Results. During the follow-up period grade III tractional retinal detachmen t developed in II eyes, grade II in six, and grade I in three eyes. The spi ndle-shaped cells contributed pre dominantly to the development of epiretin al membrane, and a smaller number of round small and large cells. In 10/17 grade II and III eyes, spindle-shaped cells had vimentin, 7/10 had actin, 5 /17 had GFAP, 4/17 had S-100 protein immunoreactivity. Round small and larg e cells expressed S-100 protein, GFAP and actin in 5/17 eyes. Epiretinal me mbrane appeared to be formed by spindle-shaped fibroblast-like cells and sm all and large round glia-like cells. Actin positivity of spindle-shaped and round cells was taken as a marker of contractile elements of the cells and their locomotional features. Conclusions. These features are believed to be involved in contraction of t he membrane and retinal detachment.