On Classification and Application of Monovision Technique for Excimer Laser Correction and on Possible of Preliminary Target Refraction Modeling in Patients with Primary Myopia, Astigmatism, Anisometropia and Presbyopia

Abstract

The combination of such refractive errors as high and medium astigmatism with anisometropia and presbyopia considerably reduces patients’ standard of living, first of all because methods of the correction stated are very limited. Spectacle correction is, as a rule, extremely uncomfortable or impossible in case of an anisometropia of more than 2.0 dioptres and a high degree of astigmatism; opportunities of contact lenses correction are limited in case of an astigmatism of more than 2.5 dioptres. Therefore these patients are often deprived of adequate visual rehabilitation and prefer not to use means of optical vision correction at all which considerably lowers their quality of life and can be the reason of asthenopia, violation of binocular vision and decrease in fusional reserves. This problem is aggravated with the development of a presbyopia when patients get older. The first manifestations of it reveal themselves in such patients earlier than in emmetrops, their age-mates. Excimer laser technology development has made it possible to help a large number of patients with the most severe refractive disorders, but these techniques still have significant limitations in patients with presbyopia, especially in case of a patient’s strong need for keen eyesight at a close distance. In addition, these patients require a particularly careful examination and preliminary modeling of target refraction at the planning stage of a surgical intervention, for which we use soft contact lenses in our practice. Target refraction modeling with spectacle lenses does not always allow to adequately predict the patient satisfaction with the results of correction. We consider the method of target refraction modeling using soft contact lenses to be the most accurate for this objective; it is widely used in our clinic. This technique is especially effective in patients with presbyopia, who are planning excimer laser correction of the most common types of refractive errors. The article presents a clinical case of binocular excimer laser correction of a high and medium degree compound myopic astigmatism in a patient with anisometropia and presbyopia, which was performed in two stages using LASIK (Custom Q) technology after the preliminary target refraction modeling with the use of soft contact lenses.