Current View on the Postoperative Asthenopic Syndrome Problem in Patients with Corneal Refractive Surgery. Review

Abstract

Laser technologies of corneal surgery perfection was one of the important events in ophthalmology in the past decades. Despite to the significant success in refractive surgery and the achieved high result in visual acuity, the ideal healing of the cornea, the absence of dry eye syndrome, some patients in the postoperative period present asthenopic complaints. Patients may notice a decrease in visual acuity when working near, difficulty in refocusing from far to near distance, fuzzy, blurred images, red eyes, tearing, periodic or permanent diplopia at different distances in the postoperative period. Adaptation to emmetropic refraction in these patients can cause discomfort, headache and visual fatigue even with insignificant visual loads, which leads to the development of asthenopia and worsening of their subjective status. Corneal refractive surgery leads to changes in the anatomical and optic parameters of the eye, which contributes to the formation of new accommodation-convergence interactions. If the accommodative and binocular functions were disrupted preoperatively, there is a risk of decompensation and development of postoperative asthenopic syndrome (AS). Refractive surgery, saving patients from glasses and contact lenses, can not completely eliminate their existing imbalances between accommodation and convergence. This can be explained with the fact that the existence of a formed pathological system does not cease with the elimination of the etiologic factor. In order to correct the disturbed parameters, additional research methods and effective methods of functional treatment of patients in the postoperative period were suggested. However, most of them are aimed at pathogenetic effects on accommodative muscles, often without taking into account disturbances in the oculomotor apparatus and binocular function. Thus, existing algorithms for investigating and managing patients with refractive disorders do not allow us to identify predictors for the development of asthenopia before refractive surgery, there is no set of preventive restoration measures aimed at restoring accommodative capacity and binocular interaction in the preoperative period to increase satisfaction with the results of surgery in patients at risk of postoperative AS.