Loss to Follow-Up in Patients with Proliferative Diabetic Retinopathy after Panretinal Photocoagulation or Intravitreal Anti-VEGF Injections

Abstract

Purpose: Loss to follow-up (LTFU) may contribute to vision loss in patients with active proliferative diabetic retinopathy (PDR). The aim of this study is to determine and compare the rates of LTFU in patients with PDR receiving panretinal photocoagulation (PRP) or intravitreal injections (IVIs) with anti-vascular endothelial growth factor (VEGF) over approximately 4 years. Moreover, this study evaluates various risk factors for LTFU.

Design: Retrospective cohort study.

Participants: A total of 2302 patients with PDR receiving IVIs with anti-VEGF or PRP between January 1, 2012, and April 20, 2016.

Methods: Intervals between each procedure and the subsequent follow-up visit were measured. Loss to follow-up was defined as at least 1 interval exceeding 12 months duration.

Main outcome measures: The LTFU rates and associated risk factors.

Results: A total of 1718 patients (74.6%) followed up postprocedure and 584 patients (25.4%) were LTFU over approximately 4 years. Of the patients receiving PRP, 28.0% were LTFU compared with 22.1% of patients receiving IVI with anti-VEGF (P = 0.001). The LTFU rates decreased as age increased, with rates of 28.1% for patients aged ≤55 years, 27.0% for patients aged 56 to 65 years, and 20.9% for patients aged >65 years (P = 0.002). Loss to follow-up also differed by race, with rates of 19.4% for whites, 30.2% for African Americans, 19.7% for Asians, 38.0% for Hispanics, Native Americans, and Pacific Islanders, and 34.9% for patients of unreported race (P < 0.001). The LTFU rates also increased as regional average adjusted gross incomes (AGIs) decreased, with rates of 33.9% for patients with regional average AGI of ≤$40 000, 24.0% for patients with regional average AGI from $41 000 to $80 000, and 19.7% for patients with regional average AGI >$80 000 (P < 0.001). Procedure type, age, race, and regional average AGI were all significant (P < 0.05) independent risk factors of LTFU in the multivariate regression.

Conclusions: A large proportion of patients with PDR were LTFU after receiving PRP or an anti-VEGF injection over approximately 4 years. Key risk factors included age, race, and regional average AGI.