SCREENING METHODS FOR THE HYPOXIC KERATOPATHY EVALUATION IN THE REFRACTIVE SURGERY

Abstract

background. Hypoxic keratopathy (HK) is the most common cause of dysregenerative conditions after corneal refractive surgery in case of long-term contact lenses wears. purpose: to study the correlation between the tears osmolarity, OSDI index and in vivo histo-morphological lesions in the corneas in patients with long-term contact lenses use. patients and methods. 3 groups of patients with mild (34 people), moderate (32 people) and severe (29 people) degrees of HK were examined. Control group consisted with 34 healthy volunteers. In all patients we performed the confocal microscopy of the cornea, the tears osmolarity assess and the calculation of the OSDI index. results and discussion. According to the confocal microscopy the intact corneas were visualized in the controls as well as the mean OSDI index was 5.1±0.9 points, and the tears osmolarity was 291,3 of ±9.8 mOsm/l, which corresponded to the norm. In the mild degree of HK the moderate pseudo-keratinization of the corneal epithelium was noted, the OSDI index was 20.8±4.4 points, which corresponded to the initial lesion of the ocular surface, and the tears osmolarity was 308.9±23 (most patients were within the limits of the norm values). In the moderate degree of HK cornea showed the changes in all layers with a prevalence of noninfectious inflammation signs; mean OSDI index was 22.9±7.2 points that was not significantly different from the mild HK, and osmolality greatly exceeded the mild HK (332,3±14,2, p<0.05). Severe HK was characterized by the significant changes in all corneal layers with a prevalence of autoimmune inflammatory and degenerative processes; mean OSDI index was significantly higher than in moderate degree of the HK (62,5±9,7, p<0.001), and the value of the tears osmolarity (364,9±26,7 mOsm/l) corresponds to the moderate or severe dry eye syndrome. Conclusion. The screening methods for the HK evaluation in refractive surgery will provide a rapid assessment of the ocular surface during contact lens wear and by conducting the preventive and corrective measures will reduce the frequency of the postoperative dysregenerative conditions.