TRACTION on the retina from vitreous bands and membranes may result in failure of retinal detachment surgery. Part I of this report is concerned with methods of producing membranes in the vitreous cavity of the rabbit and with the evaluation of techniques and instruments1-10 for visualizing and cutting them. Part II describes a technique and an instrument designed for cutting vitreous membranes in humans.
Methods
Seventeen male and 12 female albino rabbits, each weighing over 2 kg, were used in this study. The rabbits were anesthetized with pentobarbital administered intravenously, and the pupils were maximally dilated with phenylephrine. Membranes were produced in the vitreous cavity of 58 eyes by one of the three following methods.
In 21 eyes, vitreous hemorrhage was caused by perforating a large choroidal blood vessel. A 25-gauge needle was inserted through the pars plana ciliaris and directed under ophthalmoscopic control to the vessel.
In 27