Orthoptic evaluation of patient who undergo Lasik. First Part

Abstract

Antecedents: There is few information about the binocular behavior of patients after Lasik. Many practitioners have the perception of the occurrence of a symptomatic imbalance in the binocular vision mechanisms, as documented in case reports of and case series without statistical power. <em><strong>Objective:</strong></em> determine the frequency of symptomatic and asymptomatic changes of orthoptic function after Lasik surgery; secondary, to explore the existence of associations between orthoptic alterations after surgery and the findings before surgery. Design: This is an observacional analytical study, 223 patients of with ages between 18 and 66 years submitted to refractive surgery Lasik has participated in the study, patients had orthoptic evaluation before and after the surgery. Measurement: trained Optometrist, ophthalmologist and orthoptic specialist measure refractive error , visual acuity, the realized correction and the obtained correction, complications, symptoms (jump of the line, letter inversion, headaches, and sleepiness) and the orthoptic function ( primary gaze, near point of convergence, cover test , accommodation, stereopsis and fusion) before and after Lasik surgery. <em><strong>Results:</strong></em> Refractive surgery (Lasik) induces an improvement in the symptoms: sleepiness in the reading task (28% P 0,00), near point of convergence (7,6 % P 0,007), Cover Test (16% P 0,00) and fusión (41% P 0,00). After surgery the RNA (relative negative accommodation) in the young patients (without presbiopia)(20% P 0,009) and in the presbiopic patients (38% P 0,0008) comparing the data before and after surgery. Discussion: this results differ from the results published by other authors, showing an improvement of the symptoms, signs and a binocular vision dysfunction. This results most be confirmed by means of other studies with a Significant sample and more prolongated follow-up.