Diode laser photocoagulation posterior to the ridge in severe stage 3+ threshold retinopathy of prematurity

Abstract

Purpose: To evaluate the results of diode laser photocoagulation (DLP) of the retina posterior to the ridge in eyes with severe Zone II, Stage 3+ threshold retinopathy of prematurity (ROP).

Method: DLP was applied posterior to the fibrovascular ridge for advanced Zone II, Stage 3+ threshold ROP patients, either as the primary treatment combined with DLP of the avascular retina (group 1), or as a secondary treatment in eyes that had previously undergone DLP of the avascular retina (group 2). Statistical analysis was performed using SPSS software trail version 16.0. Values are presented as mean ± SD.

Results: A total of 50 eyes of 29 premature infants were treated (14 [48%] male, 15 [52%] female). The mean gestational age was 29.5 ± 2.2 weeks (range: 26-34 weeks). The mean birth weight was 1259 0.72 ± 409.15 g (range: 500-2050 g). The mean gestational age for DLP of the avascular region anterior to the ridge and DLP posterior to the ridge was 37 ± 3 weeks and 38 ± 3 weeks, respectively. The mean follow-up was 26 ± 5 weeks (18-38 weeks). In 48 eyes, the tractional fibrovascular ridge had regressed. Transient retinal hemorrhage was the most common complication. Three eyes exhibited optic-disc dragging; two eyes progressed to Stage 4a ROP; two eyes presented with macular traction, without any detachment; and one eye developed a vitreous hemorrhage, which resolved spontaneously. There were no statistically significant differences between complicated and uncomplicated eyes regarding gestational age, birth weight and applied laser spot numbers (p > 0.05 for all, Mann-Whitney U test).

Conclusion: DLP, posterior to the ridge as an additive treatment in the management of severe Zone II, Stage 3+ threshold ROP patients, is safe and effective; this approach could be used as either the primary treatment, or as the follow-up to failed laser treatment of the avascular retina to halt the progression of the disease.

Keywords: Diode laser; retinopathy of prematurity; stage 3 threshold.