To compare the clinical outcomes, failure of treatments and regression time in babies with type 1 ROP treated with intravitreal bevacizumab (IVB) versus panretinal photocoagulation (PRP).

n this retrospective case series, the medical records of consecutive preterm infants who were born from January 2011 to December 2014, admitted to ROP Clinic of Farabi Eye Hospital and screened for ROP were retrospectively reviewed. Included babies are infants with type 1 ROP who received either IVB or PRP during this period.

From 523 patients who were treated for Type 1 ROP, a total of 986 eyes of 493 patients were included in this study. Seven hundreds twenty-four eyes (73.4%) were treated with Bevacizumab (IVB group), and 262 eyes (26.5%) were treated with laser therapy (Laser group). There was no significant difference in the re-treatment rate between the two groups in zone I. (p=0.978) Treatment failure was significantly higher in IVB group in comparison with laser group in zone II (p=0.017). The time to regression was significantly lower for eyes with type 1 ROP that received bevacizumab (2.3±1.5) after single injection compared with laser-treated eyes (9.3±5.3 weeks) (P=0.001). One year after treatment in the IVB group, 82.8% of eyes in this group had an avascular area in Zone III (despite ROP regression). After two years, 387 eyes (53.4%) had still an avascular area in the retinal periphery.

Re-treatment rate was significantly lower in eyes treated with laser versus IVB among infants with Type 1 ROP in zone II ROP. Although reinjection of IVB causes regression in most recurrent cases, the peripheral retina will remain avascular for an extended period after the injection; therefore, longer follow-up is mandatory in infants treated with intravitreal bevacizumab. Therefore laser photocoagulation could be a safe and efficient method for infants with Type 1 ROP in zone II ROP.