Analysis of the Recurrence of Plus Disease after Intravitreal Ranibizumab as a Primary Monotherapy for Severe Retinopathy of Prematurity.

Purpose: To assess the outcomes of severe retinopathy of prematurity (ROP) in zone I or posterior zone II, and of aggressive posterior ROP treated with a single dose of intravitreal ranibizumab (IVR) as monotherapy.

Design: Retrospective study.

Participants: The study included premature babies diagnosed with aggressive posterior ROP or ROP 3+ in zone I or posterior zone II.

Methods: Intravitreal injection of 0.25 mg (0.025 mL) ranibizumab was performed in the operating room. A disposable 1-mL syringe with a 30-gauge needle was used.

Main Outcome Measures: Favorable outcome was considered regression of ROP after treatment (meaning regression of the retinal neovascularization and plus disease). Unfavorable outcome was progression to stages 4 and 5 of ROP.

Results: The study included 43 infants (85 eyes). The mean birth weight and gestational age were 1276±302 g and 29.7±2.0 weeks, respectively. The mean postmenstrual age at ROP diagnosis was 36±2.7 weeks and at treatment was 37.2±2.2 weeks. All 85 eyes demonstrated total regression of plus disease after a single dose of IVR. Twelve infants (29.2%) developed full vascularization of the peripheral retina in both eyes. Twenty-two infants (43 eyes [53.6%]) developed ROP reactivation at a mean interval of 7.1±3 weeks (range, 3-15 weeks) after IVR and needed rescue laser treatment of the peripheral avascular retina. The mean postmenstrual age at rescue laser was 43±3.2 weeks (range, 35.5-54.5 weeks). Six patients (11.6%) had persistent peripheral avascular retina in zone II for >6 months (or 24 weeks) after IVR treatment.

Conclusions: Although there was complete regression of plus disease in all treated eyes, only 29.2% of the patients reached complete peripheral retinal vascularization. There was a disease reactivation in 53.6% of the patients and they needed additional laser therapy. The results of IVR treatment in severe ROP, even when initial control of the disease was achieved, did not eliminate the risk of late reactivation of the disease by retinal neovascularization. Some of the treated patients may achieve a permanent interruption in the development of the peripheral retinal vascularization.