Diode laser treatment of pre‐threshold and threshold retinopathy of prematurity

Abstract

Retinopathy of prematurity (ROP) is a sight-threatening condition of premature infants. This study aimed to investigate the efficacy of diode laser photocoagulation in the treatment of pre-threshold and threshold ROP. A retrospective review was conducted of patients who underwent diode laser treatment for ROP by one author (GAG) from 1992 to 2000. During this time, 2137 babies <1500 g birthweight or <32 weeks post-conception age were examined. Seventy-six eyes in 40 infants (20 male, 20 female) were treated for ROP. Treatment was performed on average at 37 weeks post-conception age (range 31-50 weeks, SD = 3.2). The number of burns per eye for the first session of laser ranged between 193 and 1937 (mean 933), with power ranging from 200 to 1000 mW (mean 484). Eighteen (45.0%) of these 40 infants underwent a second session of laser (mean number of burns 683, range 167-1618), which was performed in 29 (38.2%) of the 76 eyes that initially underwent laser treatment. Complete regression was observed in 61 eyes (80.3%), occurring on average at 39 weeks post-conception age (range 35-45, SD = 2.2). Six (7.9%) eyes progressed to stage IVA disease, two (2.6%) to stage IVB and three (3.9%) to stage V ROP. In the latter part of the study as the number of laser burns per eye increased it was found that the number of patients requiring a second session of laser treatment decreased, with no adverse outcomes observed in the last 3 years of the study. At last follow up, the average refractive error in the treated eyes was -0.40 D spherical equivalent (range -12.75 D to +4.25 D, SD = 3.0). The degree of myopia induced showed no significant correlation with the number of laser burns administered. Diode laser treatment is able to stop progression of ROP in the majority of cases.