Factors tied to outcomes following ranibizumab, PRP treatment for diabetic retinopathy
In the treatment of proliferative diabetic retinopathy (DR), eyes gain vision and rarely develop vision-impairing central-involved diabetic macula oedema (DME) over 2 years with ranibizumab, according to a posthoc analysis. In contrast, factors such as poor glycaemic control and more severe DR increase the likelihood of losing visual acuity and developing DME following panretinal photocoagulation (PRP).
The present analysis involved two cohorts from the Diabetic Retinopathy Clinical Research Network Protocol S, one with available 2-year follow-up data (328 eyes) and another without vision-impairing central-involved DME at baseline (302 eyes). Study eyes had proliferative DR, no prior PRP and best-corrected visual acuity letter score of at least 24 (Snellen equivalent, 20/320 or better). Treatment with either intravitreous ranibizumab (0.5 mg/0.05 ml) or PRP was given.
In the ranibizumab group, no factors emerged as associated with the main outcome measures of change in visual acuity and development of vision-impairing (20/32 or worse) central-involved DME over 2 years.
In the PRP group, on the other hand, worse change in visual acuity was more likely to occur with higher glycated haemoglobin level (HbA1c; –0.6 letters per 1 percent increase; p=0.03), more severe DR (high-risk DR or worse vs moderate DR or better: difference, –2.8 letters; p=0.003) and higher mean arterial pressure (≥100 mm Hg vs <100 mm Hg: difference, –2.0 letters; p=0.009).
Likewise, eyes treated with PRP were at high risk of developing vision-impairing central-involved DME in the presence of higher HbA1c level (hazard ratio [HR] per 1 percent increase, 1.31; p<0.001), more severe DR (high-risk DR or worse vs moderate DR or better: HR, 1.46; p=0.03) and cystoid abnormalities within 500 μm of the macula centre (HR, 2.90; p=0.006).
The present data provide information on factors that potentially influence the outcomes associated with each treatment method for proliferative DR, although they hardly inform decision-making when it comes to selecting one treatment over the other, researchers said.
Given that PRP or anti-VEGF as monotherapies can be effective treatments for DR, it is likely that clinicians will continue to consider both in the management of patients, they added.