Comparison of the Modified Early Treatment Diabetic Retinopathy Study and Mild Macular Grid Laser Photocoagulation Strategies for Diabetic Macular Edema

Abstract

Purpose-To compare two laser photocoagulation techniques for treatment of diabetic macular edema (DME): modified-ETDRS direct/grid photocoagulation (mETDRS) and a, potentially milder, but potentially more extensive, mild macular grid (MMG) laser technique in which small mild burns are placed throughout the macula, whether or not edema is present, and microaneurysms are not treated directly.Methods-263 subjects (mean age 59 years) with previously untreated DME were randomly assigned to receive laser photocoagulation by mETDRS (N=162 eyes) or MMG (N=161 eyes) technique. Visual acuity, fundus photographs and OCT measurements were obtained at baseline and after 3.5, 8, and 12 months. Treatment was repeated if DME persisted.Main Outcome Measure-Change in OCT measures at 12-months follow up.Results-From baseline to 12 months, among eyes with baseline central subfield thickness ≥ 250 microns, central subfield thickening decreased by an average of 88 microns in the mETDRS group and decreased by 49 microns in the MMG group (adjusted mean difference: 33 microns, 95% confidence interval 5 to 61 microns, P=0.02). Weighted inner zone thickening by OCT decreased by 42 and 28 microns, respectively (adjusted mean difference: 14 microns, 95% confidence interval 1 to 27 microns, P=0.04), maximum retinal thickening (maximum of the central and four inner subfields) decreased by 66 and 39 microns, respectively (adjusted mean difference: 27 microns, 95% confidence interval 6 to 47 microns, P=0.01), and retinal volume decreased by 0.8 and 0.4 mm 3 , respectively (adjusted mean difference: 0.3 mm 3 , 95% confidence interval 0.02 to 0.53 mm 3 , P=0.03). At 12 months, the mean change in visual acuity was 0 letters in the mETDRS group and 2 letters worse in the MMG group (adjusted mean difference: 2 letters, 95% confidence interval −0.5 to 5 letters, P=0.10).Conclusions-At 12 months after treatment, the MMG technique is less effective at reducing OCT measured retinal thickening than the more extensively evaluated current mETDRS laser photocoagulation approach. However, the visual acuity outcome with both approaches is not substantially different. Given these findings a larger long-term trial of the MMG technique is not justified. Application to Clinical Practice-ModifiedETDRS focal photocoagulation should continue as a standard approach for treating diabetic macular edema. Clinical Sites that Participated in this Protocol Sites are listed in order by number of subjects randomized into the study. The number of subjects randomized is noted in parenthesis preceded by the site location and the site name. Personnel are listed as (I) for Investigator, (C) for Coordinator, (V) for Visual Acuity Tester, and (P) for Photographer. Southeastern Retina Associates, PC (3): Howard L. Cummings (I); D. Allan Couch (I); Gail Darnell (C); Deanna Jo Long (C); Stacy Carpenter (V); Rachel Mallard (V); Julie P. Berry (P); Melissa Sturgill (P); Los Angeles, CA -Doheny Eye Institute (3): Jennifer I. Lim (I); Christina J. Flaxel (I); Margaret Padilla (C); Jesus M....

Detection of Fovea-Threatening Diabetic Macular Edema by Optical Coherence Tomography to Maintain Good Vision by Prophylactic Treatment

“…Laser therapy was performed according to a modified ETDRS protocol [20]. The eyes were examined every month after focal/grid lasering.…”

Comparison of Grid Laser, Intravitreal Triamcinolone, and Intravitreal Bevacizumab in the Treatment of Diffuse Diabetic Macular Edema

“…One eye of each patient which was perfectly matched for both preoperative BCVA and OCT-based CMT (Stratus™) values was selected, if she/he had both eyes eligible for the study. Group 1 eyes were treated with GL photocoagulation (modified ETDRS protocol) [6], group 2 with 1.25 mg IVB (0.05 ml; Altuzan®) injection, and group 3 with 4.0 mg/0.1 ml IVTA (Kenacort™) injection. Patients who had CMT values of less than 300 µm, and associated ocular and/or systemic conditions affecting visual outcome including those who had undergone cataract surgery and panretinal photocoagulation within the previous 6 months, amblyopia, glaucoma and vitreoretinal surgery at any time, vitreomacular traction, vitreoretinal interface abnormalities including epiretinal membrane, and ischemic maculopathy; hypertension, increased glycosylated hemoglobin (8%), diabetic nephropathy and pregnancy at any time, were excluded.…”

Recent advancements in diabetic retinopathy treatment from the Diabetic Retinopathy Clinical Research Network

“…A summary of past and ongoing DRCR network trials can be found in Table 1. The early trials within the DRCR network helped evaluate techniques of laser for the treatment of diabetic macular edema (DME)[1] and helped define the natural history of progression of DME as observed using the newly available tools of OCT.[16,17] Special interest in the utilization of triamcinolone for the treatment of DME was investigated with protocol B and the clinical efficacy of this steroid for DME was found to be inferior to macular laser. [2] The focus of the DRCR network was then turned to the use of anti-VEGF agents and the network’s first trial evaluating bevacizumab for DME was published in 2007.…”