Intravitreal triamcinolone acetonide with and without laser grid photocoagulation for the management of persistent diffuse macular edema in diabetics.

Abstract

Abstract: : Purpose:To compare the efficacy of intravitreal injection of triamcinolone acetonide alone and with laser grid photocoagulation in treating diffuse diabetic macular edema unresponsive to previous laser photocoagulation. Methods: 120 diabetic patients were diagnosed with diffuse clinically significant macular edema over an average duration of 16 months (range 8 to 48 months). During this time they received an average of 2.5 macular laser treatments (range 2 to 3). Upon presentation they were determined to have refractory edema despite adequate macular grid photocoagulation. On optical coherence tomography (OCT) minimal central macular thickness exceeded 300µ in all patients (normal <200µ). After signed informed consent, patients were randomized to receive a single injection of triamcinolone acetonide (4mg) through pars plana (group A) or same dose of triamcinolone and laser grid photocoagulation two weeks after injection (Group B). Response to therapy was monitored with OCT and ETDRS visual acuity chart. Results:Mean initial central macular thickness measure was 493 µ (range: 268 to 1000) by OCT in group A and 512µ (range: 338 to 990) in group B . After intravitreal injection alone (Group A), macular thickness decreased to 318 µ (range: 200 to 390) at 15 days, to 255µ (range: 128 to 350) at 1 month, to 183µ (range: 128 to 248) at 3 months and to 231 µ (140 to 290) at 6 months. After intravitreal injection and laser photocoagulation (Group B), macular thickness decreased to 287 µ (range: 198 to 370) at 15 days, to 229µ (range: 156 to 343) at 1 month, to 203µ (range: 170 to 233) at 3 months and to 226 µ (154 to 288) at 6 months (p=0.03). Best corrected visual acuity showed moderate improvement during the first three months, stabilizing at six months follow–up in both groups. No significant difference was found between the two groups (p>0.05) . Twenty four patients (20 %) required temporary ocular anti–hypertensive therapy. There was one case of sterile endophthalmitis (that responded to intravitreal antibiotics and steroids) and in four eyes, as intravitreal injection was performed, triamcinolone passed to the anterior chamber (it resolved spontaneously). Conclusions:Intravitreal triamcinolone appears to be an effective treatment for diffuse diabetic macular edema unresponsive to grid photocoagulation, with minimal complications. No statistical difference was found between the two groups.

Keywords: retina • diabetic retinopathy • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials