Comparison of Approaches for the Removal of Metallic Intraocular Foreign Bodies

PURPOSE: To review the management of posterior segment metallic intraocular foreign bodies (IOFB) and to compare the use of an external approach using a large electromagnet and an internal approach using vitrectomy and its tools for their removal. METHODS: A retrospective review was performed on 49 eyes of 49 patients who underwent surgical removal of metallic IOFBs with either an internal or an external approach at a single institution between January 2003 and December 2006. We divided 49 eyes into two groups based on the type of approach: 26 external (n=26) and 23 internal (n=23). Visual acuity and the presence of any complications occurring with the two approaches were the main outcome measures studied. RESULTS: Thirty of 49 eyes (61%) showed improvements in visual acuity. When we compared patients treated with an external versus an internal approach, we found no statistically significant difference in regard to visual outcome. Preoperative vitreous hemorrhage and endophthalmitis were more common in the internal approach group. A trend toward a higher rate of reoperation was more common in the external approach group, but they were not statistically significant. Postoperative complications found to be significantly different between the two groups were the rate of postoperative endophthalmitis and retinal detachment, which were more common in the external approach group. CONCLUSIONS: Surgical removal of metallic IOFBs results in significant visual improvement regardless of the approach method. The internal approach by vitrectomy is recommended as the first choice in preoperative conditions such as severe cataracts, vitreous hemorrhage and endophthalmitis, as well as in groups at high risk for postoperative endophalmitis and retinal detachment.

Transplantation of Cultured Retinal Pigment Epithelium to Rabbit Retina Injured by Sodium Iodate

The authors investigated the possibility of transplanting cultured retinal pigment epithelial (RPE) cells to impaired retina. The authors induced injury of the outer sensory retina and RPE cells with the intravenous injection of 2% sodium iodate in forty pigmented rabbits. Transplantation of RPE cells was done by internal approach with a 30 gauge blunt needle. The neural retina spontaneously reattached within 36 hours. Light microscopic autoradiography showed that some labeled cells were attached to Bruch's membrane as early as in 2 hours and still found in 4 weeks after transplantation. Regeneration of the photoreceptor outer segment and its connection with transplanted RPE cell was not found. Present study demonstrates that cultured rabbit RPE cells can be successfully transplanted to injured rabbit retina if Bruch's membrane is intact. Although the regeneration of the photoreceptor outer segment failed to be demonstrated, further studies are necessary to confirm or disprove these results.