Refractive outcomes of laser-treated and non-laser-treated retinopathy of prematurity at Hospital Selayang: a 2-year retrospective review

Objective: To compare the refractive outcomes of laser-treated and non-laser-treated retinopathy of prematurity (ROP) infant, at 2 years of age in Hospital Selayang.Methods: Retrospective review involving patients born between 2016 and 2018. They were divided into those who were treated with laser photocoagulation, and those who were observed. Laser treatment was given to infants with threshold and high-risk, pre-threshold disease. Refractive error was identified by cycloplegic refraction at 2 years of age.Results: There were 22 eyes from 11 infants in the laser-treated group, all of which had zone II ROP with plus disease; of these, four had stage 2 ROP and 18 had stage 3 ROP. There were 53 eyes from 28 patients in the non-laser-treated group. The mean birth weight for the laser-treated and non-laser-treated groups was 966.9 ± 92.6 g and 1019.3 ± 282.0 g, respectively (P = 0.398). Mean gestational age for the laser-treated and non-laser-treated groups was 28.2 ± 2.2 weeks and 27.7 ± 2.2 weeks, respectively (P = 0.390). At 2 years, the mean spherical equivalence for the laser-treated and non-laser treated groups was -0.55 ± 2.49 D and +0.17 ± 1.43 D, respectively, although the difference was not statistically significant (P = 0.120). Myopia was commoner in the laser-treated group (six eyes [27%] vs five eyes [9%], P = 0.047), and two eyes from two different infants (10%) from this group also developed high myopia (> -6.00 D). For hypermetropia and astigmatism, there were no statistically significant differences between the groups (all P > 0.05). High myopia was strongly related to the post-conceptual age when receiving laser therapy (P = 0.025). In the laser-treated group, two infants (9%) had amblyopia and one (5%) had exotropia at 2 years of age. None of the eyes developed structural retinal sequelae.Conclusion: Despite successful treatment of ROP, a significant number of laser-treated eyes developed myopia. This highlights the need for long-term refractive screening in these patients.