Purpose: To evaluate the relationship between the number of laser shots applied during laser photocoagulation treatment and the degree of myopia at 3 years in children with laser-treated retinopathy of prematurity (ROP).
Method: A total of 68 eyes of 34 infants who had developed prethreshold ROP and were treated by diode laser therapy were included in the current study. Cycloplegic retinoscopic refraction testing was performed in the children at the age of 3 years, and the spherical equivalent (SE) was calculated for all the examined eyes. The number of laser shots that had been applied was compared between the eyes with and without high myopia (SE < - 5 diopters (D)). In addition, the relationship between the difference in the SE values between the two eyes in each infant and the difference in the number of laser shots applied between the two eyes was also analyzed.
Results: The number of laser shots applied was significantly higher for the eyes with high myopia than for those without high myopia (p = 0.0088), and the number of laser shots applied was significantly positively correlated with the degree of myopia (p < 0.001). A significant correlation was also observed between the differences in the SE values between the two eyes and the differences in the number of laser shots applied between the two eyes (p = 0.0013).
Conclusion: The number of laser shots applied in photocoagulation treatment for ROP is significantly associated with the degree of myopia seen subsequently in the children.
Keywords: Laser photocoagulation; Myopia; Prethreshold retinopathy of prematurity; Refractive error.