Long-term outcomes of type 1 retinopathy of prematurity following monotherapy with bevacizumab: a Canadian experience

Objective: To report long-term structural, visual, and refractive outcomes after monotherapy with intravitreal bevacizumab injection. Design: Cohort retrospective chart review. Participants: A total of 56 premature infants with type 1 retinopathy of prematurity. Methods: This is a chart review at 2 Canadian institutions. Inclusion criteria were single injection of 0.625 mg intravitreal bevacizumab and minimum age at last follow-up of 3 years. Primary outcome was retinal structure. Secondary outcomes were refractive error in spherical equivalent, monocular visual acuity, strabismus, and amblyopia. Results: Fifty-six infants (101 eyes) met inclusion criteria. Mean birth weight was 707 +/- 178 g (range, 420-1520 g). Mean gestational age was 25.0 +/- 1.3 weeks (range, 22.9-29.7 weeks). Twenty-four eyes were in zone I (24%) and 77 in zone II (76%). Mean postmenstrual age at treatment was 36.9 +/- 2.1 weeks (range, 32.8-42.0 weeks). At a mean age of 5.4 +/- 1.6 years (range, 3.0-8.0 years), all eyes had a favourable structural outcome with no reactivation requiring treatment. Mean monocular visual acuity was 0.29 +/- 0.27 logMAR (range, 0.0-1.3 logMAR; 89 of 101 eyes). Mean spherical equivalent was -1.98 +/- 4.91 D (range, -16.63 to +5.38 D; 101 of 101 eyes). Prevalence of emmetropia (>-1.0 to -1 D) was 43.6%; low myopia (-1.0 to <5 D) was 17.8%; high myopia (-5 to <8 D) was 8.9 %; very high myopia (-8.0 D) was 12.9%; and hyperopia (>1 D) was 16.8%. Twelve children (23%) had amblyopia, and 17 (32%) developed strabismus. Conclusions: All patients demonstrated a favourable structural outcome with a single bevacizumab injection without the need for additional laser. We suggest regular monitoring following regression of acute retinopathy of prematurity as an alternative to universal, preplanned delayed prophylactic laser treatment. Future studies to evaluate other aspects of visual function are needed.