Purpose: This study investigated the effects of posterior sub-Tenon capsule (PST) injection of triamcinolone acetonide (TA) on intraocular pressure (IOP) in the human eye.
Methods: The study included 115 patients who received PST injections of 40-mg TA to treat macular edema with diabetic retinopathy (n=57), branch retinal vein occlusion (n=35), central retinal vein occlusion (n=13), or other disorders (n=10). IOP measurements were performed on the day of injection, and 0.5, 1, 2, 3, 6, 9, and 12 months later.
Results: In 26 (22.6%) of the 115 eyes, an IOP of 24 mm Hg or higher was observed during the 12-month follow-up period after PST TA injection. IOP elevation significantly correlated with young age, but not with past history of diabetes mellitus or systemic hypertension, sex, or type of retinal disease with macular edema. In total, 23 eyes were treated with antiglaucoma medications to control elevated IOP (24 mm Hg or higher). External trabeculotomy was performed in 1 case where medications failed to correct elevated IOP.
Conclusions: PST TA injection is associated with high rates of steroid-induced IOP elevation in eyes with previously normal IOP. However, IOP elevation may be less common after PST injection than after intravitreal injection. Our findings indicate that IOP must be carefully monitored after PST TA injection.