Abstract
Purpose: :
To evaluate the long–term intraocular pressure (IOP) response after intravitreal injections of different doses of intravitreal triamcinolone acetonide (TA) at the end of pars plana vitrectomy (PPV) for macular edema secondary to diabetic retinopathy or retinal vein occlusion.
Methods: :
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 between January 2003 and December 2003 were enrolled. At the end of vitrectomy for those eyes, different doses of TA were randomly injected into the vitreous cavity: 14 eyes with 5mg TA (low TA group) and 13 eyes with 10mg TA (high TA group). The main outcome measure was intraocular pressure (IOP).
Results: :
All patients were followed up at least 12 months. Preoperative IOP was 12.6±2.6 mmHg (mean±standard deviation [SD]) in low TA group and 13.2±2.1 mmHg in high TA group. Postoperatively, IOP increased to a mean maximum of 20.6±5.5 mmHg in low TA group and 31.5±3.5 mmHg in high TA group (p<.01 for both groups). The difference between groups was also significant (p<.05). Five of 14 eyes (36%) in low TA group and 10 of 13 eyes (77%) in high TA group had an elevation of IOP exceeding 21 mmHg (p=0.03). The median interval from surgery to reach a maximal IOP was 7 days in both groups. The significant IOP elevation lasted 3 months in low TA group and 6 months in high TA group.
Conclusions: :
After injection of TA into the vitreous cavity at the end of PPV for macular edema, dose–dependent IOP elevation was observed, starting from early postoperative days and returning to normal values after several months. Additionally, the proportion of eyes with elevated IOP and the time course of IOP changes were different from eyes with intravitreal TA injection in the absence of vitrectomy.
Keywords: drug toxicity/drug effects • intraocular pressure • macula/fovea