[Effects of intravitreal pegaptanib or bevacizumab and laser in treatment of threshold retinopathy of prematurity in zone I and posterior zone II--four years results]

Abstract

Purpose: To evaluate efficacy and safety of intravitreal injection of pegaptanib or bevacizumab and laser photocoagulation for treatment of threshold stage 3+ retinopathy of prematurity (ROP) affecting zone I and posterior zone II, and to compare the results in terms of regression, development of peripheral retinal vessels with conventional laser photocoagulation or combined with cryotherapy.

Methods: In this prospective comparative study, 174 eyes of 87 premature babies, from January 2008 to December 2011, were included. All infants were diagnosed with stage 3+ ROP for zone I or posterior II. Patients were randomly assigned to receive intravitreal pegaptanib (0.3 mg) or bevacizumab (0.625 mg/0.025 ml of solution) with conventional diode laser photocoagulation (Group A, 92 eyes of 46 infants) or laser therapy combined with cryotherapy (Group 8, 82 eyes of 41 infants), bilaterally. The main evaluated outcomes include time of regression and decrease of plus signs and development of peripheral retinal vessels after treatment, final structural-anatomic outcomes compared in the both groups of patients. Risk factors and other characteristics of infants include birth weight, gestational age, Apgar score, duration of intubation and hospitalizations, postmenstrual age at treatment, sepsis, surgery for necrotizing enterocolitis, intraventricular hemorrhage. Primary outcome of treatment success was defined as absence of recurrence of stage 3+ ROP in one or both eyes (reccurrence rate = 0) by 55 weeks' postmenstrual age. Treatment failure was defined as the recurrence of neovascularization (reccurrence rate = 1 or 2) in one or both eyes requiring retreatment. The mean follow-up after treatment was 23.5 months (range 4 - 45 months) in the Group A, and 25.2 months in the Group B (range 3 - 48 months).

Results: Final favorable anatomic outcome and stable regression of ROP at last control examination have 90.2% of eyes after adjuvant intavitral pagaptanbib or bevacizumab in the Group A, and 62% of eyes after only conventional treatment in the Group B (P = 0.0214). Regression of plus disease and peripheral retinal vessels development appeared significantly more rapidly in Group A patients who received intravitreal VEGF inhibitors and laser. An absence of recurrence of neovascularization (stage 3+ ROP) was identified at 87% of patients in the Group A, and 53% of patients in the Group B. This difference between the both groups was statistically significant (P = 0.0183). ROP reccured in 7 from 92 eyes (7.6%) in the Group A, and 23 from 82 eyes (28%) in the group B (P = 0.0276). Significantly better treatment effect was found for adjuvant intravitreal pagaptanib or bevacizumab with laser compared with conventional therapy of ROP 3+ in zone I and posterior zone II. Perioperative retinal haemorrhages after laser photocoagulation occured in 8% of eyes in the Group A, and 11% of eyes in the group B (P = 0.358), in all eyes with spontaneous resorption. No systemic or significant ocular complications of intravitreal anti-VEGF injections, such as endophthalmitis or retinal detachment were found during follow-up period after operation.

Conclusions: A combination of intravitreal pegaptanib or bevacizumab injection and laser photocoagulation showed to be a safe, well tolerated and effective therapy in patients with stage 3+ ROP in zone I and posterior zone II. Adjuvant intravitreal antiVEGF injection, as compared with conventional laser or cryotherapy, showed significant benefit in terms of better final anatomic outcome, induction of prompt regression, rapid development of peripheral retinal vascularization and decrease of recurrence rate of neovascularization. Results of this study support the administration of pegaptanib and bevacizumab as an alternative usefull therapy in the management of stage 3+ ROP.