Quantitative assessment of structural changes in the cornea against the background of long-term wearing of contact lenses according to the results of confocal microscopy

Abstract

Introduction. The article presents an objective assessment of the morphofunctional status of the cornea during the long-term wear of soft contact lenses (SCLs). Aim. To assess the qualitative and quantitative changes in the cornea microstructure using the laser confocal microscopy during the long-term wear of SCLs, as well as combined tear replacement therapy based on formulations consisting of trehalose and hyaluronic acid.  Materials and methods. The study included 62 patients (124 eyes) divided into three groups. The first two groups included 32 patients (64 eyes) with different degrees of myopia, using SCLs as an optical correction for 7–15 years (11 years on average): Group 1 included 15 patients (30 eyes) using tear replacement therapy in the form of a drug containing trehalose and hyaluronic acid twice a day for 3 months, Group 2 included 17 patients (34 eyes) who did not receive any tear replacement therapy. The laser corneal confocal microscopy was performed using Heidelberg Retinal Tomograph III followed by digital image processing aided by author software with the focus on the state of nerve fibers and dendritiform macrophages (Langerhans cells). Results and discussion. The laser corneal confocal microscopy with assessment of the structure of the corneal nerve fibers and Langerhans cells can be used for the dynamic monitoring of the state of the anterior segment of the eye in SCL users. When pathological changes are detected, a patient may be recommended the corneotrophic therapy and (or) switching to another type of contact lenses. Conclusion. The use of tear replacement medications containing trehalose and hyaluronic acid improves the subjective tolerance of SCLs and also makes it possible to significantly reduce the severity of epitheliopathy in patients, who use SCLs as optical correction for a long time.