Abstract
Purpose::
To investigate the effect of intravitreal injections of bevacizumab (Avastin) in persistent diffuse diabetic macular edema.
Methods::
Fifty-nine patients, 31 female and 28 male, with diffuse diabetic macular edema with a mean age of 66 years were consecutively incorporated in the study. Inclusion was performed independently from the size of edema, retinal thickness, visual acuity (VA), age, metabolic control, type of diabetes or previous treatments beyond a period of six months. Each patient underwent a complete preoperative eye examination. Retinal thickness and edema was measured using OCT, fluorescein angiography, and fundus photography. All patients were treated with injections of 0.05 ml containing 1.25 mg bevacizumab.
Results::
21 patients had received at least two intravitreal injections. At baseline VA was mean 25.88 +/- 14.43 ETDRS letters (0.86 +/- 0.38 in logMar of Snellen letters). Mean central retinal thickness on OCT was 508 +/- 167 µm (range 252 to 1031 µm). VA increased to 0.75 +/- 0.37 logMar at six weeks (p=0.001). Retinal thickness decreased to 425 +/- 185 µm at two weeks (p=0.002), 416 +/- 180 µm (p=0.001) at six weeks, and 377 +/- 117 µm (p=0.001) at twelve weeks. Changes of retinal thickness and VA correlated weakly (r= -0.480 (p=0.03) 6 weeks and r= -0.462 (p=0.07) 12 weeks). All patients completed 6 weeks follow-up, 12 weeks follow-up was performed in 28. 21 patients had received at least two intravitreal injections. All patients had received previous treatments such as focal laser therapy (35%), full scatter panretinal laser therapy (37%), vitrectomy (12%) or intravitreal injection of triamcinolone (33%). The mean diameter of the foveal avascular zone was 511 µm, with 49% showing values above 500 µm. At baseline VA was mean 25.88 +/- 14.43 ETDRS letters (0.86 +/- 0.38 in logMar of Snellen letters). Mean central retinal thickness on OCT was 508 +/- 167 µm (range 252 to 1031 µm). VA increased to 0.75 +/- 0.37 logMar at six weeks (p=0.001). Retinal thickness decreased to 425 +/- 185 µm at two weeks (p=0.002), 416 +/- 180 µm (p=0.001) at six weeks, and 377 +/- 117 µm (p=0.001) at twelve weeks. Changes of retinal thickness and VA correlated weakly (r= -0.480 (p=0.03) 6 weeks and r= -0.462 (p=0.07) 12 weeks).
Conclusions::
Even in cases of diffuse diabetic macular edema which did not respond to previous treatments an improvement of visual acuity and decrease of retinal thickness can be observed following intravitreal injection of bevacizumab.
Keywords: diabetic retinopathy • injection