Abstract: Objective To determine if primary intravitreal injection of triamcinolone acetonide (TA) in combination with grid laser photocoagulation (GLP) is effective in treating cystoid macular edema. Methods A prospective comparative non- randomized clinical trial was carried out. Fourteen eyes (14 patients) diagnosed with cystoid macular edema were treated with GLP and an intravitreal injection of 2mg TA. A matched control group (16 eyes,16 patients) treated with GLP was selected retrospectively from our medical records. Best-corrected visual acuity (BCVA), intraocular pressure and quantitative changes in optical coherence tomography (OCT) macular thickness were assessed. Results Compared with the pre-treatment, BCVA was significantly elevated in the two groups on 3 and 6 months post-treatment(P<0.01). No obvious improvement of visual acuity was found between the two groups after treatment at any time point (P≥0.05).Macular thickness was significantly decreased after the treatment in the two groups(P<0.01). No significant changes in macular thickness were found between the two groups before the treatment (P>0.05), but macular thickness was lower in the trial group compared with the control group at various time point(P<0.05). IOP raised in 4 eyes(28%) in the trial group. Conclusion Treatment with IVTA injections in combination with grid laser photocoagulation seems to be more effective in decreasing central subfoveal thickness in patients with cystoid macular edema. However, higher intraocular pressure and development of glaucoma must be considered seriously in patients who receive IVTA injection.

Key words: Triamcinolone acetonide, Cystoid macular edema, Visual acuity, Grid laser photocoagulation