Purpose: To study the usefulness of intravitreal triamcinolone acetonide injection during vitrectomy in highly myopic eyes with retinal detachment due to a macular hole. Methods: Pars plana vitrectomy was performed in 6 patients with retinal detachment resulting from a highly myopic eye with a macular hole. After separation of the posterior hyaloid and removal of any visible epiretinal membrane, triamcinolone acetonide was injected over the posterior pole. Excised specimens were evaluated by transmission electron microscopy. Results: Upon injection of triamcinolone acetonide, the entire epiretinal membrane and residual vitreous cortex could be visualized in all patients. The epiretinal membrane and residual posterior vitreous cortex were completely removed. Successful reattachment was performed without retinal damage in all cases. Electron microscopy revealed a cellular epiretinal membrane within a collagenous matrix lining the smooth internal surface of the internal limiting membrane. No complications related to the use of triamcinolone acetonide were encountered. Conclusion: Intraoperative visualization of the epiretinal membrane and residual posterior vitreous cortex with triamcinolone acetonide was found to be a useful adjunct to vitrectomy. Using triamcinolone acetonide during vitrectomy may facilitate both removal of the epiretinal membrane around the macular hole and separation of the residual vitreous cortex from the retina in highly myopic eyes with retinal detachment.