Abstract
Abstract: :
Purpose: To determine whether a test dose of 400 µg of intravitreal triamcinolone acetonide (TA) will have a predictive value for the rise of IOP. Methods: Twenty–seven eyes were treated with 400 µg of intravitreal TA. Eight eyes had clinically significant macular edema, 7 had cystoid macular edema, and 13 had age–related macular degeneration. Informed consent was obtained; visual acuity and IOP were evaluated in both eyes. After the surface was prepared, a 27–gauge needle was used for injection at the superior pars plana 3.5 to 4 mm posterior to the limbus. A 400 µg/0.1 ml dose of TA was prepared and injected intravitreally. All patients underwent an anterior chamber tap to normalize pressure. The IOP was measured at 1 or 2 days, 1 week, and 1 month postinjection by Goldmann applanation. Patients without an IOP elevation greater than 5 mmHg by day 1 or 2 were given a second intravitreal injection of either 4 mg or 8 mg at varying time points. Patients with an IOP elevation greater than 5 mmHg were not given another injection. Results: The incidence of preexisting glaucoma was 3/27 eyes. Only 1 (33%) showed an increase in IOP. Overall, 4/27 eyes (15%) showed an increased in IOP > 5 mmHg 1–2 days after injection of TA. Of these 4 eyes, only 1 had a history of primary open–angle glaucoma with an increase of IOP of 25 mmHg; the rest included diabetes in 1 and ARMD in 2 patients with a rise of IOP of 7–8 mmHg. All pressures returned to preinjection IOP by topical antiglaucoma therapy. The remaining 24 eyes received a second injection of high–dose TA. Only 2 (8.3%) had an IOP elevation of 6–8 mmHg within 1 month postinjection. These eyes were treated successfully with topical medication. Conclusions: An intravitreal microdose of 400 µg TA may serve as a test dose to determine which patients will develop a steroid response IOP elevation after intravitreal TA injection. A patient who tolerates a 400–µg injection is less likely to have an IOP elevation with a 4 or 8 mg injection. Patients who have increased IOP with 400 µg are controlled medically. It is not clear whether a preexisting history of POAG is always a risk factor for the development of glaucoma after intravitreal TA injection.
Keywords: retina • intraocular pressure • drug toxicity/drug effects