No abstract

Purpose: To compare the efficacy of surgically removing or not removing the internal limiting membrane (ILM) during pars plana vitrectomy on the visual acuity and retinal thickness in eyes with diabetic macular edema. Methods: A prospective, case-control study was carried out on 30 eyes of 29 patients undergoing pars plana vitrectomy for diabetic macular edema. Fifteen eyes underwent pars plana vitrectomy with ILM removal and 15 eyes without ILM removal. Results: In 7 of 15 eyes (47%) in the ILM-removed group, the visual acuity improved by 0.2 or more log of the minimum angle of resolution (log MAR) units and remained unchanged in 8 eyes (53%). In the ILM-preserved group, the final visual acuity improved in 9 of 15 eyes (60%) and remained unchanged in 6 eyes (40%). The difference in visual acuity between the two groups after 11 months the surgery was not significant (Fisher’s exact test, p = 0.4938). In the ILM-removed group, the final retinal thickness decreased by more than 20% of the preoperative retinal thickness in 12 of 15 eyes (80%), remained unchanged in 2 of 15 eyes (13%), and increased in 1 of 15 eyes (7%). In the ILM-preserved group, the final retinal thickness decreased in 13 of 15 eyes (87%) and remained unchanged in 2 of 15 eyes (23%). The differences in the changes in the retinal thickness between the two groups were not statistically significant (Fisher’s exact test, p = 0.5945). Conclusion: Vitrectomy in eyes with diabetic macular edema without ILM removal was as effective in reducing the retinal thickness and improving the visual acuity as eyes with ILM removal. We conclude that ILM need not be removed to treat eyes with diabetic macular edema.

The authors report a new biconcave contact lens capable of providing superior surgical views of eyes during vitrectomy and intraocular lens implantation under both fluid-filled and air-filled conditions. The new biconcave lens is made of a glass with a high refractive index (nd = 1.883). The lens is placed on the cornea using a regular lens ring for the floating vitrectomy lens system. During vitrectomy, the new biconcave lens provides a view as clear as that of the commercially available flat-concave lens when the vitreous cavity is filled with fluid. The lens also provides a more magnified view than the commercially sold biconcave lens during fluid-air exchange, with no need for replacement. The new biconcave vitrectomy lens spares the surgeon the trouble of replacing different refractive lenses during the fluid-air exchange procedure in an eye undergoing intraocular lens implantation, and may be helpful for vitreous surgery.