Objective: To study the histology of the trabecular meshwork of eyes with glaucoma by intravitreal injection of triamcinolone acetonide (TA).

Methods: Two cases report. Methods: A 68-year-old Japanese man with branch retinal vein occlusion and a 48-year-old Japanese woman with uveitis were treated by cataract surgery, intraocular lens implantation, and TA-assisted pars plana vitrectomy. At the end of surgery, TA suspension (4 mg) was intravitreously injected. During the follow-up period, the intraocular pressure (IOP) of the patients increased over 30 mm Hg even with full medication. Trabeculectomy was performed at 4 months after TA injection in case 1 and at 6 months in case 2, and intraocular pressure returned to the normal range in both cases. Light and electron microscopic studies of the resected trabecular tissue were carried out.

Results: The histology showed minimal deposition of extracellular matrix in the trabecular meshwork in case 1. Case 2 showed the beginnings of deposition of extracellular matrix including fingerprintlike material in the trabecular meshwork with decreased intertrabecular spaces.

Conclusions: The ultrastructural changes in the trabecular meshwork of eyes with glaucoma after treatment with intravitreal TA might resemble those with glaucoma after topical corticosteroid treatment.