Long-term refractive and biometric outcomes following diode laser therapy for retinopathy of prematurity

PURPOSE To assess the long-term refractive and biometric outcomes of diode laser-treated eyes in threshold retinopathy of prematurity (ROP). METHODS Cycloplegic autorefraction and biometry (Zeiss IOLMaster) were performed, at a mean follow-up of 11 years, on 16 laser-treated eyes with threshold ROP and 9 comparison eyes with subthreshold untreated ROP. RESULTS The laser-treated eyes had a mean spherical equivalent of -2.33 D with a mean astigmatic error of 1.38 D. The comparison eyes had a mean spherical equivalent of +1.07 D with a mean astigmatic error of 0.42 D. This trend toward increased myopia in treated eyes did not achieve statistical significance (p = 0.08). The myopia in the laser group appeared to be slowly progressive in nature when compared with earlier refractive data for these patients. The laser-treated eyes had reduced anterior chamber depth (ACD) compared with the subthreshold eyes (p = 0.02). When physiologic accommodation was inhibited by cycloplegic drops, the anterior chamber deepened by 0.13 mm in the laser-treated eyes and by 0.06 mm in the comparison eyes. This effect of accommodation on ACD did not differ significantly between the two groups (p = 0.23). The laser-treated eyes and the comparison eyes did not differ significantly in terms of axial length, corneal power, corneal diameter, or lens power. However, both groups had steeper corneas, shallower anterior chambers, and shorter axial lengths when compared with historical full-term controls. CONCLUSIONS Myopia in premature infants requiring laser treatment for ROP is associated with a shallowing of the anterior chamber and a steepening of the cornea. Physiological accommodation is not impaired by laser therapy or by severe ROP.