Nd:YAG-laser surgery of anterior segment structures’ influence on cornea parameters

Relevance Laser photodestruction of tissues is the basis of YAG laser surgery of the anterior segment of the eye - laser discission of secondary cataract (LDSC) and laser iridectomy (LIRE), performed on patients with closed-angle glaucoma (CAG) or suspected of it [1, 2]. Laser-induced complications include corneal edema and Descemet's layer tears. The traditional method of assessment is specular microscopy limited to the study of the posterior epithelium. A more detailed analysis is possible using corneal confocal microscopy (CCM) [3-5]. Objective Using CCM, to assess corneal complications after LDSC and LIRE. Material and methods The study included 56 patients (65 eyes), in the 1st group - with a diagnosis of "Artifakia. VK» (41 eyes), divided into two subgroups - 1A without corneal pathology (22 eyes), 1B - with a burdened history (19 eyes). All underwent LDVC. The 2nd group included patients with a diagnosis of ZUG or suspicion of it (24 eyes), they underwent LIRE. Results Immediately after treatment, single hyperreflective deposits (HRD) were detected in subgroup 1A. The loss of corneal endothelial cells (ECR) was minimal. Changes depended on the energy level (p < 0.05), to a lesser extent - on its total values ​​(p = 0.02). After 1 month, the CMR pattern remained unchanged. In subgroup 1B, a decrease in the ECR density led after 1 month to an increase in polymegethism and a decrease in ECR pleomorphism, an increase in the reflectivity of ECR ​​nuclei, and the appearance of a moderate amount of HRD. The severity depended on the energy level of a single pulse (p < 0.05). In the 2nd group, a large number of GRD of different sizes, increased reflectivity of nuclei, and a significant decrease in the density of the ECR were noted. The changes depended on the total energy and the distance from the cornea to the iris (p < 0.05). Conclusion The risk of complications correlates with the initial state of the cornea, increases with a decrease in the focal distance "cornea - irradiated structure" and with an increase in the energy of laser irradiation. Key words: Nd: YAG laser; laser discision; laser iridectomy; confocal microscopy of the cornea