Abstract
Purpose: :
To analyze the effect of supine positioning on intraocular pressure following injection of intravitreal Triamcinolone Acetonide (IVT).
Methods: :
Fifty-seven eyes of 57 patients with progressive exudative age-related macular degeneration (n=21), diabetic macular edema (n=21), cystoid macular edema (n=3), branch retinal vein occlusion (n=8), central retinal vein occlusion (n=2), and uveitis (n=2) were included. Each subject received an intravitreal injection of triamcinolone acetonide 4mg (n=39) or 12mg (n=18). Twenty- nine subjects were instructed to lie supine for 24 hours after injection and 28 were allowed to maintain any comfortable position after injection. Intraocular pressure (IOP) was measured using tonopen. Elevated IOP was defined as >25 mm Hg or as a rise >10 mm Hg from baseline. Mean follow up time was 30.7 weeks (range 5-77 weeks).
Results: :
There were 57 patients with a mean age of 72.4 years. The mean baseline IOP was 14.7 mm Hg (14.4 mm Hg for the supine group and 15.0 mm Hg for the non-positioned group). Ten of the 57 patients experienced an IOP elevation >10 mmHg from baseline. Five of those were from the supine group (17%) and 5 were from the non-positioned group (17%). Of the supine group, 2 of the 29 subjects experienced an IOP elevation of >25 mm Hg (7%). Eight of the 28 subjects in the non-positioned group (29%) experienced an elevation of IOP >25 mm Hg. Of nonglaucomatous patients (n=55) 16% experienced a pressure elevation >25 mm Hg. In glaucoma patients, 1 of the 2 (50%) experienced a pressure elevation >25, and this elevation was not correlated with baseline pressure. Six out of the 39 (15%) patients who received the 4mg dose of IVT had an IOP >25 mm Hg, while 4 of the 18 (22%) patients who received the 12 mg dose experienced a rise >25 mm Hg. Out of those who had an initial IOP of 20 mm Hg or higher, 3 of 6 (50%) had an IOP elevation to >25 mm Hg. When compared with patients who had initial IOPs below 20 mm Hg, it was found that only 14% (7 of 51) had an IOP rise of >25 mm Hg. Pressure elevation was controlled with topical medications in all patients.
Conclusions: :
Supine positioning is associated with a decreased rate of IOP elevation > 25 mm Hg. Furthermore, those patients with initial IOP > 20 mm Hg were found to be at greater risk of IOP elevations ≥ 25 mm Hg. These results suggest the use of topical antihypertensive medications in patients whose initial IOP exceeds 20 mm Hg prior to IVT injection. The use of prophylactic antihypertensives along with advising patients to lie supine for the first 24 hours post-injection may lead to decreased rates of IOP rise after intravitreal Triamcinolone injection.
Keywords: retina • intraocular pressure