Real-Time Photographic- and Fluorescein Angiographic-Guided Management of Diabetic Retinopathy: Randomized PRIME Trial Outcomes.

Purpose: To assess the safety and efficacy of as-needed (PRN) intravitreal aflibercept injections (IAI) in managing diabetic retinopathy (DR) guided by the real-time DR severity scale (DRSS) level or panretinal leakage index (PLI) assessment among eyes without diabetic macular edema (DME).

Design: Prospective, randomized phase 2 trial (PRIME).

Methods: A total of 40 eyes with nonproliferative (NPDR) or proliferative DR (PDR) received monthly IAIs until a DRSS improvement of ≥2 steps was achieved and eyes were randomized (1:1) to DRSS-guided or PLI-guided management strategies graded by a central reading center. Main outcome measurements included safety and changes in DRSS and PLI.

Results: Through week 52, 95% of eyes achieved a DRSS improvement of ≥2 steps. Following DRSS improvement, 97% of eyes required at least 1 PRN IAI. In eyes requiring PRN IAI and completing week 52, 100% and 59% experienced DRSS worsening (P = .01) in the DRSS- and PLI-guided arms, respectively. Through week 52, mean PLI decreased 18.2% (P = .49) and 54.6% (P <.0001), respectively, in the DRSS- and PLI-guided arms. NPDR versus PDR eyes at baseline achieved a DRSS improvement of ≥2 steps after a mean 4.9 and 3.6 IAIs (P = .03). Two eyes developed a PDR event at week 52 following 5 months of quiescence.

Conclusions: The randomized PRIME study analyzed 2 imaging-based biomarkers to guide PRN management with IAI of DR without DME: DRSS level and PLI. Within the context of this study with limitations, most patients required IAI re-treatment every 3-4 months, and deterioration of PLI appeared to precede DRSS level worsening. Finally, these findings reaffirm the fact that close clinical follow-up is important even among eyes that achieve substantial DRSS improvements with apparently quiescent disease.