Purpose: To prospectively monitor intraocular pressure (IOP) and gonioscopy changes within the first month after a single 4-mg intravitreal injection of triamcinolone acetonide (IVK) (Kenalog, Briston-Meyers Squibb, New York).
Design: Prospective comparative interventional case series.
Methods: A consecutive series of 28 eyes of 14 patients with no prior intravitreal injections or history of glaucoma were prospectively enrolled. After baseline evaluation in both eyes, including IOP, gonioscopy, and optic nerve evaluation, a single 4-mg IVK was given in a standard sterile fashion in the eye to be treated. Eyes received IVK for macular edema associated with retinal vein occlusions and in conjunction with photodynamic therapy for choroidal neovascularization secondary to age-related macular degeneration, ocular histoplasmosis, and high myopia. The fellow eye served as the control. After the injection, IOP and gonioscopy were repeated at 1, 2, and 4-week intervals in both eyes.
Results: Of the 14 patients, the 5 women and 9 men had a mean age of 67.6 years. Mean baseline IOP of the treated and fellow control eyes were similar at 15.9 versus 16.6 mm Hg, respectively. The control eyes maintained a small IOP range (15.6 to 16.6 mm Hg) during the 1-month follow-up period. In the treated eyes, the mean maximum IOP was 54% above baseline during follow-up, compared with 11% for control eyes. Six of 14 (43%) treated eyes had IOP elevation to 24 mm Hg or higher with mean change of 8.6 mm Hg and a mean maximum IOP of 32.1 mm Hg. There was no correlation between IOP rise and age, sex, diagnosis, or optic nerve appearance. However, during the course of the study, 4 of 6 (67%) of the treated eyes that required topical drops for the IOP elevation had documented abnormal inferior angle changes characterized by pigmented particulate matter in the inferior angle not present at the baseline exam. The most frequent time point for an IOP elevation that required treatment was at 2-week postinjection. No eyes required surgical management of IOP during the course of this 4-week study.
Conclusions: We observed a significant IOP rise in eyes after a single intravitreal injection of 4 mg of triamcinolone within 1 month of injection. In this study, the most frequent time point that required IOP treatment was at 2-week postinjection, suggesting that early and frequent monitoring of IOP should be considered. Two-thirds of eyes that required medical control of IOP developed gonioscopy changes, characterized by particulate matter in the inferior angle, not present at baseline. Eyes that developed gonioscopic changes were 5 times more likely to be treated for IOP elevation than those without gonioscopic findings.