Object: herpetic keratitis and dry eye syndrome. Purpose: to improve the effectiveness of treating patients with herpetic keratitis (HK) having dry eye syndrome (DES) by using an antioxidant drug (bioflavonoid quercetin) based on the study of metabolic disorders in the tissues of the cornea, conjunctiva and lacrimal fluid. Methods: clinical ophthalmological methods - determination of the ocular surface diseaseindex according to the OSDI scale; visometry; Schirmer test, tear film break-up time; biomicroscopy: study of bulbar conjunctiva fold; Baylor and Van Bijsterveld test; evaluation of the corneal condition using the Draize criteria; spectrophotometric methods for determining the content of metabolites and enzyme activity in the tissues of the anterior segment of the eye; statistical methods of data processing. Scientific novelty: scientific data on the state of redox processes and antioxidant system in the experimentally induced DES have been supplemented. A significant labilization of the lysosomal membranes of the corneal and conjunctival tissues has been discovered, as evidenced by the increased activity of the marker lysosomal enzyme in these structures – nonsedimentable acid phosphatase by 25.6 and 30.7% respectively, and a decrease in the activity of its sedimentable form by 26.9 and 31.3% respectively, as compared to the norm. The corneal and conjunctival tissues showed a decrease in cytochrome oxidase activity by 39.6 and 46.5% respectively. There is also a significant decrease in the level of reduced form of glutathione in the cornea by 25.3%, and in the lacrimal fluid – by 30.6%, as compared to the norm. For the first time, it has been found that in experimentally induced keratitis (EIK) with DES in animals, clinical indicators of the inflammatory process in the cornea are more pronounced. Indicators of the degree of inflammatory infiltration, corneal edema and fluorescein test were higher by 21, 21, and 17% respectively, as compared to the group of animals with EIK without induced DES. For the first time, it was found that the development of EIK with DES leads to more significant metabolic disorders in the cornea and lacrimal fluid, as compared with the same indicators for EIK without DES. On days 7 and 14, there was a significant decrease in the level of reduced form of glutathione in the cornea by 23.8 and 21.8% respectively, and an increase in the level of oxidized form of glutathione both in the cornea by 21.8 and 19.8% and in the lacrimal fluid by 26.3 and 46.0% respectively. The effectiveness of correction of metabolic disorders in the tissues of the anterior segment of the eye of animals with EIK and DES was proved for the first time by the use of eye drops containing the antioxidant bioflavonoid quercetin, as evidenced by an increase in MDH activity in corneal and conjunctival tissues by 15.1 and 21.8%, in cytochrome oxidase activity – by 16.2 and 18%, and a decrease in the activity of the nonsedimentable acid phosphatase by 15.6 and 20.0% respectively, in comparison with the group in which quercetin was not used. Reduction potential of the glutathione system, was also corrected by the use of quercetin. It was established for the first time that the development of HK in patients with DES has a more pronounced destructive effect on cellular and subcellular membranes of the tissues of the anterior segment of the eye, as indicated by the increase in the activity of mitochondrial enzymes LDH and MDH in the lacrimal fluid by 33.0 and 37.3% respectively, as compared to patients with HK without DES, and the use of quercetin helps reduce the level of these enzymes. Practical value: the inclusion of eye drops with quercetin in the complex treatment of patients with HK and DES significantly increases the effectiveness of therapy, as evidenced by the acceleration of corneal epithelization time, reduction of inflammatory corneal infiltration and corneal edema, in comparison with the indicators of patients for whose treatment quercetin was not used. The use of eye drops with quercetin improves indicators of the Schirmer test, increases the tear film break-up time and reduces the degree of conjunctival folding, in comparison with the group of patients who did not receive quercetin. The positive effect of the use of quercetin is confirmed by a decrease in the activity of enzymes in the lacrimal fluid of patients on HK with DES - LDH and MDH. The results obtained allow to recommend the use of eye drops containing bioflavonoid quercetin in the complex treatment of patients on HK with DES. The results of the work were implemented into the clinical practice of the Ophthalmology Department of the Lviv Regional Clinical Hospital, the ophthalmology clinic "Vizex" and the Department of Corneal Pathology of the State Institution "The Filatov Institute of Eye Diseases and Tissue Therapy of the NAMS of Ukraine". Scope – medicine, ophthalmology.
