Дослідження показників внутрішньоочного тиску при різних видах тонометрії у пацієнтів з хворобою сухого ока.

Background. In recent years, glaucoma remains the main cause of irreversible blindness both in the world and in Ukraine. Increased intraocular pressure (IOP) remains a decisive risk factor for the development of glaucoma. Biomechanical properties of the cornea can potentially affect the accuracy of IOP measurements. Previous studies have shown that the relationship between central retinal thickness and IOP is non-linear and may be different in the corneas of normal eyes and eyes with chronic diseases. The purpose of our study was to investigate intraocular pressure indicators with different types of tonometry in patients with dry eye disease. Material and methods. Seventy-eight right eyes (78 patients) with emmetropia and mild myopic refraction were examined. The average age of patients was 23.8 ± 3.2 years. Among them, there were 36 men (46.15 %) and 42 women (53.85 %). Exclusion criteria: glaucoma, diabetes, hypertension, connective tissue disease, pregnancy, macular degeneration, corneal dystrophy, corneal scar, corneal edema, keratoconus, corneal and ocular surgery, spherical equivalent ≥ 4.00 diopter, corneal astigmatism ≥ 3.00 diopter. Before the start of the study, all patients signed informed consent to participate in it and were informed about the purpose and course. During the study, all patients underwent a comprehensive eye examination. When determining IOP, the principles of randomization were followed. In order to evaluate the biomechanical properties, the coefficient of corneal rigidity (KER), formulas and a method for assessing the corneal rigidity (Sergienko M.M., Shargorodska I.V., 2008) were used. For each eye, intraocular pressure was calculated taking into account the corneal rigidity coefficient — IOP(k) and the correction factor taking into account the corneal rigidity coefficient — k. Windows Microsoft Excel 2010, statistical software SPSS 17.0 (USA) were used for statistical processing of research results. Results. It was found that the non-invasive break-up time (NIBUT) was equal to 16.23 ± 10.20 seс on average for the group, while 34.16 % of the study participants had a NIBUT value below 10 sec. There was no statistically significant difference in NIBUT values between women and men (p = 0.518). It was found that the obtained average Ocular Surface Disease Index (OSDI) was 10.54 ± 6.41 points and in 41.02 % of cases, it exceeded 12 points. The detected differences between women and men were not statistically significant (p = 0.613). In addition, the analysis of the results showed that the average values of intraocular pressure measured using different tonometers with changes in the indicators of diagnostic tests and manifestations of dry eye were inflated. The least vulnerable were the values obtained using Goldmann applanation tonometry. A poor-quality tear film has a negative optical effect. An important result of our research is that the biomechanical properties of the cornea determined by the method for assessing the corneal rigidity (Sergienko M.M., Shargorodska I.V., 2008) did not depend on the quality and quantity of tears and other markers of dry eye. No statistically significant relationship was found between the corneal rigidity coefficient, the correction factor taking into account the corneal rigidity coefficient and NIBUT (< 10 s), OSDI (> 12 points), Schirmer’s test (< 15 mm) and fluorescein eye stain test (> 0.04 points). The value of IOP adjusted for corneal rigidity was not statistically significantly different between different models. Conclusions. The results of the study are evidence that the tear film influences the parameters of intraocular pressure measured by rebound tonometry (RT), Maklakov applanation tonometry (MAT) and pneumotonometry (PT). It has been shown that IOP measured by RT, MAT and PT has a certain relationship with OSDI and NIBUT, and a correlation with the LIPCOF and fluorescein eye stain test at MAT and PT. It was proved that there is no dependence between the coefficient of corneal rigidity KER, the correction factor k and IOP(k) and changes in the indicators of diagnostic tests. Further studies are needed to understand the nature of changes in corneal rigidity with severe degrees of dry eye disease, different conditions of the ocular surface, and in various age groups. [ABSTRACT FROM AUTHOR]