Intraocular Pressure After Intravitreal Injection of Triamcinolone Acetonide Following Vitrectomy for Macular Edema

Abstract

To evaluate long-term intraocular pressure (IOP) response after intravitreal injections of different doses of triamcinolone acetonide (TA) upon completion of pars plana vitrectomy (PPV) for macular edema secondary to diabetic retinopathy or retinal vein occlusion. Retrospective, consecutive, comparative, interventional case series. Twenty-seven eyes of 25 consecutive patients with macular edema associated with diabetic retinopathy (n=18) or retinal vein occlusion (n=9), who underwent PPV for the treatment of macular edema between January 2003 and December 2003, were included. Upon completion of vitrectomy, different doses of TA were injected into the vitreous cavity: 14 eyes with 5 mg of TA (group 1) and 13 eyes with 10 mg of TA (group 2). The main outcome measure was IOP. All patients were followed up for at least 12 months. Preoperative IOP was 12.6+/-2.6 mm Hg (mean+/-standard deviation) in group 1 and 13.2+/-2.1 mm Hg in group 2. Postoperatively, IOP increased to a mean maximum of 20.6+/-5.5 mm Hg in group 1 and 31.5+/-3.5 mm Hg in group 2 (P<0.01 for both groups). The difference between groups was also significant (P<0.05). Five of 14 eyes (36%) in group 1 and 10 of 13 eyes (77%) in group 2 had an elevation of IOP exceeding 21 mm Hg (P=0.03). The median interval from surgery to reach maximal IOP was 7 days in both groups. The significant IOP elevation lasted for 3 months in group 1 and 6 months in group 2. After injecting of TA into the vitreous cavity upon completion of PPV for macular edema, a dose-dependent IOP elevation was observed, starting from early postoperative days and returning to normal values after several months. These results show that intravitreal TA injection in the vitrectomized eyes might have different IOP changes from in the nonvitrectomized eyes.