Abstract
Purpose :
To report on the relationship between severity of diabetic retinopathy (DR) as measured by the Early Treatment Diabetic Retinopathy Scale and treatment outcomes in participants of the Ranibizumab treatment of diabetic macular oEdema with bimonthLy monItorinG after a pHase of initial Treatment (RELIGHT) Study
Methods :
The RELIGHT study enrolled 109 participants who were treated with ranibizumab monthly for 3 months (loading phase) and then re-treated on pre-specified criteria. The colour images were systematically graded for DR severity scores, and spectral domain tomograms were graded for neuroretinal thickness, disruption of outer retinal zones and DMO type (cystoid dome shaped, diffuse, subretinal fluid) and presence of hyperreflective foci. Descriptive statistics were generated and the relationship between DR severity at baseline (BL) and responsiveness to treatment at M3, 5 and 12 was examined using chi-squared tests.
Results :
Of the 109 participants enrolled colour and OCT images were available in 81%. DR severity at M12 was unchanged or improved in 81.4% of patients. There was no association between DR severity at BL and response to DMO treatment, as defined by >10% decrease on OCT thickness (p=0.5). Retinal thickness on OCT was maximum in the central retinal subfield. Sub-retinal fluid when present at BL, was resolved in all cases by M12. Both maximum retinal thickness and foveal centre point thickness reduced between BL and M12, while choroidal thickness remained unchanged. There was no difference in the presence of any level of severity of ellipsoid layer disruption between BL and M12 (91.8% and 87.8% respectively), but the proportion of eyes with extensively disrupted layer decreased from 31.8% to 19.5%. Intraretinal hyper-reflective foci which were found in three-quarters of eyes at BL did not change over time. None of the OCT characteristics predicted visual acuity outcomes.
Conclusions :
In this study population, no clear pattern emerged based on OCT and colour imaging characteristics to predict treatment outcomes at 12-months in DMO and DR. When response was defined as a reduction of >10% in OCT thickness at any time-point during the treatment period, 92% of patients showed reduction in DMO with ranibizumab during some stage of their treatment cycle during the 12-month follow-up.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.