Purpose: To determine the refractive outcome after treatment with laser photocoagulation, intravitreal antiangiogenic injection or both, for the treatment of type 1 ROP and/or aggressive posterior ROP using defocus equivalent terms. These results will be compared with the spherical equivalent (SE) notation in an initial refraction (during the first 3 years after treatment) and in a final evaluation (three years after treatment).
Methods: Clinical charts review of preterm patients who developed type 1 ROP and/or aggressive posterior ROP who were treated with laser photocoagulation, intravitreal antiangiogenic injection, or both, between January 2007 and December 2014 at Fundación Oftalmológica de Santander were reviewed. Refractive error was evaluated at two different time points in three different treatment groups.
Results: Seventy-seven eyes (56 patients) with ROP diagnosis treated with laser, antiangiogenics or in a combined scheme were included. Median gestational age was 29 weeks (IQR = 3), median birth weight was 1100 (IQR = 335) and mean corrected age at the time of treatment was 37.3 weeks (SD 2.2). Refractive outcomes in SE terms for the first refraction had a median of -0.50 diopters and in defocus terms, 4.00 diopters (D). For the second refraction, -3.00 diopters and 4.00 diopters (D), respectively. Pearson correlation test result for the first measurement was 93% (p = 0.000) and for the second evaluation was 99% (p = 0.000).
Conclusions: Low birth weight had a statistically significant association to the increase of the refractive outcome. The high correlation between SE and DE for refractive errors allows us to confirm that DE is an appropriate metric to report refractive outcomes in this group of patients due to the presence of combined refractive ametropias.
Keywords: Retinopathy of prematurity; defocus equivalent; premature infants; preterm; refractive errors; spherical equivalent.