Objective: To evaluate the effect of triamcinolone acetonide (ITA) on intraocular pressure (IOP) following intravitreal injection, and, in those patients who experience post-injection elevation of IOP, to determine the time course, effect of multiple injections, and risk factors for the pressure rise.
Methods: A retrospective chart review of 85 consecutive patients who received ITA (0.1 mL of 40 mg/mL solution) at the University of Texas South-western Medical Center between January 2002 and April 2004 was performed. Patient age, history of open-angle glaucoma (OAG), previous intraocular surgery, prior steroid exposure, type of retinal pathology treated, pre- and post-injection IOP, and post-injection glaucoma medications were tabulated. Patients with previous exposure to topical, intraocular or systemic steroids, and those without at least 16 weeks of follow-up were excluded. A student's paired t-test was used for statistical analysis.
Results: Seventy-seven eyes of 70 patients were included. Forty-eight eyes (62.3%) experienced an increase in IOP of at least 5 mmHg. Twenty-five eyes (32.5%) experienced elevation in IOP of 5-9 mmHg, and 23 eyes (29.9%) experienced an increase in IOP of > or = 10 mmHg during the review period. The mean time for elevations of 5-9 mmHg and > or = 10 mmHg to occur following injection were 6.9 weeks and 8.8 weeks, respectively. Fifty percent of eyes (3/6) in patients with OAG experienced a maximum IOP level of > 30 mmHg. Of all eyes with IOP elevation following injection, 32.5% required topical glaucoma therapy. Thirteen eyes received a second ITA injection. All eight eyes with IOP elevation after the first injection experienced another rise in IOP after the second. Of the five eyes which had no rise in IOP after the first injection, four had no rise after the second. At the final visit, 50% of eyes (3/6) with OAG required additional glaucoma medication compared to baseline. No patients required surgery for IOP control during the period under review.
Conclusions: ITA is frequently associated with a significant elevation in IOP, typically within the first 2-months after injection. Most patients who do not have an elevated IOP after an initial injection will not experience a pressure rise after an additional one. About one-third will require topical glaucoma therapy for IOP control. Patients with OAG may be more difficult to control and require a longer duration of therapy. The inconsistent post-injection follow-up visit intervals among patients in this retrospective review may have affected our results, as some patients with maximum IOP changes may have been missed between office visits. In addition, practice patterns among treating physicians typically differ as to thresholds for the treatment of elevated IOP. A randomized, prospective, controlled trial could better address these issues.