Changes in relative peripheral refraction and optical quality in Chinese myopic patients after small incision lenticule extraction surgery

PurposeTo observe changes in retinal refraction difference values (RDV) and aberrations after small incision lenticule extraction (SMILE) surgery and evaluate their correlations. MethodsThis study recruited 112 patients (112 eyes) who underwent SMILE for myopia. Participants were classified into the Low and Moderate Myopia group (LM, -0.50 to -6.0 D) and High Myopia group (HM, >-6.0 D) according to the central spherical equivalent (SE). RDVs in the five retinal eccentricities from 0 degrees to 10 degrees, 10 degrees to 20 degrees, 20 degrees to 30 degrees, 30 degrees to 40 degrees, and 40 degrees to 53 degrees are recorded as RDV-(0-10), RDV-(10-20), RDV-(20-30), RDV-(30-40), and RDV-(40-53), respectively; additionally, RDVs have four sectors, i.e., RDV-Superior (RDV-S), RDV-Inferior (RDV-I), RDV-Temporal (RDV-T), and RDV-Nasal (RDV-N). With a 3-month follow-up, changes in RDV (Delta RDV) and changes in aberrations [Delta trefoil, Delta coma, Delta spherical aberration (SA), and Delta total higher-order aberrations (HOA)] after surgery were recorded. ResultsNo significant differences were observed in total RDV (TRDV), RDV-(0-53), RDV-S, RDV-I, RDV-N, trefoil, coma, and SA between the two groups before SMILE surgery. However, after SMILE, hyperopic defocus values [TRDV, RDV-(20-53), RDV-S, RDV-T, and RDV-N] in the LM group and hyperopic defocus values [TRDV, RDV-(20-53), RDV-S, and RDV-N] in the HM group were significantly lower at 3 months postoperatively than preoperatively, and the RDV-(40-53), RDV-S, and RDV-N were lower in the HM group than in the LM group. Aberrations [trefoil (vertical), coma, and HOA] in the LM group and aberrations (trefoil, coma, SA, and HOA) in the HM group were significantly higher at 3 months postoperatively than preoperatively, and the coma, trefoil(horizontal), SA, and HOA were higher in the HM group than in the LM group. In the multivariate analysis, Delta RDV-(40-53) was significantly correlated with Delta SA, and Delta RDV-T and Delta RDV-N were significantly correlated with Delta coma (horizontal). ConclusionsOur findings suggest that SMILE reduces retinal peripheral hyperopic defocus but introduces some higher-order aberrations, especially in people with high myopia refractive errors.

Automated summary

The study found that SMILE surgery reduces retinal peripheral hyperopic defocus but introduces higher-order aberrations, especially in individuals with high myopia refractive errors.