A comparative study between intravitreal ranibizumab and peripheral laser ablation in cases of prethreshold type I retinopathy of prematurity

Abstract

Purpose: The aim was to evaluate the efficacy and safety of intravitreal injection of ranibizumab for treatment of prethreshold type 1 retinopathy of prematurity (ROP) with conventional laser photocoagulation given for the same disease level. Subjects and Methods: In this retrospective comparative study, the charts of 16 premature babies, presenting from July 2009 to May 2014, were reviewed. All infants were diagnosed with prethreshold ROP (type 1). Patients received either intravitreal ranibizumab (0.625 mg/0.025 ml of solution) (group A, 12 eyes of 6 infants) or conventional diode laser (group B, 28 eyes of 14 infants), bilaterally. The main evaluated outcomes included time of regression, decrease of plus signs and incidence of recurrence. Infants were followed till 55 weeks postmenstrual age. The confidentiality of the patients was respected. Results: The mean age of the studied infants was 35.63 ± 1.58 weeks ranging from 33 to 39 weeks. The stage of ROP in the studied infants was either stage 2 in 7 cases (43.8%) or stage 3 in 9 cases (56.3%). The zones of ROP were zone I in 3 cases (18.8%) and zone II in 13 cases (81.3%). Group A had a mean gestational age (GA) of 36.6 ± 1.5 weeks, while cases in group B had mean GA of 35 ± 1.3 weeks. This was statistically significant (P = 0.037). The stage did not significantly affect the choice of treatment (P = 0.09). Looking at the subgroup analysis 66.7% (two cases) of cases with zone I disease were treated with intravitreal ranibizumab, whereas 69.2% (nine cases) with zone II disease were treated with conventional laser. The incidence of recurrence was not affected by the zone of the disease (P = 0.71) nor by the stage of the ROP or by the presence of plus sign (P = 0.29, P = 0.68, respectively). There was no statistically significant difference between the two treatment groups about the incidence of recurrence (P = 0.701). The mean GA for cases with recurrence of ROP (35.25 ± 2.6 weeks), did not differ significantly with the mean GA of the infants who did not suffer from recurrence 35.75 ± 1.2 weeks (P = 0.7). Conclusion: Both intravitreal ranibizumab and conventional laser were proven effective in the treatment of prethreshold type 1 ROP. Long-term favorable structural outcome may require extended observation and retreatment. Further large-scale studies are needed to address the long-term safety and efficacy.