Long Term Incidence and Timing of Intraocular Hypertension Following Intravitreal Triamcinolone Acetonide Injection

Abstract

Purpose:: We report the long-term incidence and timing of ocular hypertension after intravitreal triamcinolone acetonide (IVTA) in a large cohort of patients.

Methods:: A retrospective review of 1000 eyes receiving IVTA injections for various ocular disorders was performed. Incidence of pressure spikes and increased use of pressure lowering medications was calculated with Kaplan-Meier (K-M) analysis. Two IOP thresholds were examined: >21 and >25 mmHg. Pressure measurements made during the first 6 days following the original injection were excluded from analysis. Comparisons were made with the log-rank test.

Results:: 929 eyes of 841 patients (55% women, mean age=71.5 years) were followed for an average of 14 months (median, 13.9 months). The number of IVTA injections ranged from 1 to 7 (mean =1.6). 88 (9.3%) had glaucoma diagnosed prior to the first injection. Cumulative K-M proportions of eyes with pressure spikes >21 at 6, 12, 18, and 24 months respectively were: 28.4%, 34.9%, 41.7%, and 45.6%. The mean months until pressure spikes occurred was significantly shorter (p<0.001) in eyes with prior glaucoma (13.8±1.4) than in eyes without (23.6±0.7). Cumulative K-M proportions of eyes with pressure spikes >25 at the same time points were: 14.8%, 19.2%, 24.4%, and 28.9%. The mean months until pressure spikes occurred was significantly shorter (p<0.001) in eyes with prior glaucoma (17.6±1.4) than in eyes without (28.6±0.6). Cumulative K-M proportions of eyes requiring additional pressure lowering medical therapy were: 13.2%, 17.1%, 20.8%, and 24.3%. Two eyes (0.2%) required trabeculectomy for adequate IOP control. The risk of ocular hypertension was greatest in the first 5 weeks post-IVTA injection. 256 (27%) eyes experienced IOP >21 prior to the first reinjection or loss to follow-up; after a single reinjection, 122 (35%) eyes experienced a IOP >21 prior to second reinjection or loss to follow-up; and after a second reinjection, 52 (43%) eyes experienced IOP >21 prior to third reinjection or loss to follow-up.

Conclusions:: The highest risk for IVTA induced ocular hypertension occurs in the first 5 weeks after injection. By two years after initial IVTA injection, about 1/3 of eyes experienced ocular hypertension of > 25 mmHg. The majority of these eyes required pressure lowering medical therapy.

Keywords: drug toxicity/drug effects • intraocular pressure • corticosteroids