Purpose:
Diabetic retinopathy (DR) is the leading cause of new blindness in working-aged adults in most developed countries. DR progresses (worsens) in discrete, well-defined steps, which are described by the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale. With advancing severity, the risk of developing vision-threatening complications increases; ≥2 and ≥3 step worsening on the ETDRS severity scale for eyes are associated with increased risk of vision loss. We evaluated effects of RBZ on DR severity over time in Phase III clinical trials of RBZ for diabetic macular edema (DME).
Methods:
In two double-masked, sham-controlled, multicenter trials (RISE - NCT00473330 and RIDE - NCT00473382), a total of 759 DME patients were randomized to receive monthly 0.3 mg or 0.5 mg RBZ or sham injections. Fundus photos taken at baseline and pre-specified intervals were graded by a central reading center; clinical exams were performed monthly. Outcomes of these secondary and exploratory analyses included ≥2 and ≥3-step change on the ETDRS Severity Scale and a composite clinical progression outcome including photographic changes plus clinical events (eg, vitreous hemorrhage, need for panretinal laser).
Results:
At two years, ≥2 or ≥3 step DR progression (worsening) was significantly lower and ≥2 or ≥3 step regression (improvement) was significantly higher in RBZ-treated eyes vs. sham. Over two years, 33.8% of sham-treated eyes experienced clinical progression of DR, compared to 11.2-11.5% of RBZ-treated eyes (Figure).
Conclusions:
Intravitreal RBZ reduced the risk and rate of DR progression in eyes with DME; additionally, many RBZ-treated eyes experienced improvements in DR severity. Implications of these findings will be discussed.
Clinical Trial:
http://www.clinicaltrials.gov NCT00473382
Keywords: diabetic retinopathy • neovascularization