TRANSMISSION ELECTRON-MICROSCOPIC ANALYSIS OF TRABECULAR MESHWORK IN SECONDARY GLAUCOMA AFTER INTRAVITREAL SILICONE OIL INJECTION

Put-pose: We analysed morphological changes in trabecular meshwork in glaucoma developing after intravitreal silicone oil injection with tra nsmission electron microscopy (TEM). Methods: Specimens obtained from 2 patients after surgical trabeculectomy were fixed in Me Dowell fixat ive in one patient and in buffered formaldehyde in the other, dehydrat ed and embedded in Epon. Ultrathin sections were made and stained with lead citrate and uranyl acetate for TEM. Results: In specimens mainly connective tissue sheets with disorganized and narrowed intertrabecul ar spaces were observed. At higher magnification the collagen sheets w ere composed of interstitial collagen and some of them were covered by amorphous basal membrane structures resembling material. Cellular rem nants were present along the intertrabecular spaces. No other cells or clearly evident silicone oil were noted. Conclusion: Changes such as decrease in cell content, fibrosis and build-up of basement membrane-l ike material have been described by other authors. They are not specif ic and can be seen in many secondary glaucomas. No macrophages and for eign-body granulomas in response to silicone oil were present. The pat hological changes in angle structures are probably caused by other mec hanisms and are not induced by silicone oil itself.