Visual Symptoms And Binocular Involvement In Corneal Refractive Surgery

The aim of this study was to evaluate the binocular function and the visual symptomatology before and after corneal refractive surgery.

1. Vissum Grupo Miranza, Alicante, Spain; 2. Grupo de Investigación en Optometría (GIOptom), Universidad de Alicante, Alicante, Spain; 3. Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain

This is a prospective and longitudinal study involving patients who underwent a bilateral corneal refractive surgery by LASIK and SMILE. It was composed of 54 patients aged 18 to 52 years who undergone the standard ocular examination preoperatively and 1 month postoperatively, as well as the assessment of visual symptomatology using the Symptom Questionnaire for Visual Disfunction (SQVD), and the evaluation of the binocular function by the Alternate Prism Cover Test (APCT), Near Point of Convergence (NPC) and stereopsis in both visits. A comparison between the preoperative and postoperative variables was performed by Wilcoxon signed rank test considering a significance level of 0.05.

The visual results after the operation were suitable, observing a significative improvement in the binocular uncorrected visual acuity as was expected, but also in the binocular corrected visual acuity (p< 0.001), reaching an efficacy and security indices of 1.06 and 1.07, respectively. Regarding the binocular results a significative decrease in the near heterophoria was observed after the operation (-1.60±2.23 prism diopters (pd) preoperative vs. –2.53±3.15 dp postoperative, p: 0.035), not founding differences in the far heterophoria, NPC and stereopsis (p> 0.05). The visual symptoms improved after the operation presenting a mean score of 23.39 at the preoperative status and of 17.38 at the postoperative status (p: 0.017).

This study indicates that corneal refractive surgery may produce an improvement of the near heterophoria and the visual symptoms, not affecting the rest of parameters involved in the binocular function. It would require confirming these results by increasing the sample size, dividing the analysis according to the surgical technique and enlarging the follow-up period.