Sixty-eight patients (74 eyes) with chronic endogenous uveitis underwent pars plana vitrectomy. An increase in visual acuity was observed in 70% postoperatively. Visual results basically depended on the extent of previous damage to the macula. A lensectomy-vitrectomy was done in 23 eyes, while 51 eyes underwent merely a pars plana vitrectomy. The frequency and severity of uveitic relapses were diminished in virtually all cases.

The effect of topical anaesthetic ointments (4% cocaine, 4% xylocaine, 0.5% proparacaine, 0.2% oxybuprocaine) on the corneal epithelium of rabbits was examined using a scanning electron microscope. Even after a single application, the more toxic effect of cocaine compared to the other topical anaesthetics was evident. Cocaine caused disruption of both the plasma membrane and the cytoplasm. After a single application, the other preparations caused a marked decrease in the microvilli and microphcae, disruption of the intercellular spaces and the prominence of the cell nucleus which under normal condition is not visible. Repeated applications caused regular cell desquamation and damage to the plasma membrane and cytoplasm. The damage also affected several cell layers. The cell reactions described are clearly a consequence of the topical anaesthetics, as the ointment base itself produced no essential cell damage. The scanning electron microscope findings were supported by results from the transmission electron microscope.

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