A new magnetic technique for the treatment of giant retinal tears

Using surgical techniques similar to those for closed vitreous surgery, we introduced a small magnetic sphere into the intraocular cavity of experimental animals. The sphere was subsequently maneuvered gently over the retina to unfold and reposition it with a small external permanent magnet probe. We used 68 enucleated canine eyes; eight eyes were operated in vivo and then examined microscopically. Retinal damage was caused by friction and excessive pressure when we used external magnets that were too strong or spheres that were too large. When small intraocular magnetic spheres coated with silicone or teflon or encased in a hollow oversize epoxy sphere were used the damage to the retina was minimal, or absent. We suggest using this same technique to treat retinal tumors through the introduction of radioactive material or antitumoral drugs. The intraocular magnetic sphere of this type would be left inside the eye in contact with the lesion for an extended period (seven days to three months) by suturing a small magnet to the sclera over the lesion.