Antonov A A, Kozlova I V
Research Institute of Eye Diseases, Moscow, Russia.
Vestn Oftalmol. 2021;137(5. Vyp. 2):255-261. doi: 10.17116/oftalma2021137052255.
Intraocular pressure is the one modifiable factor, which correct assessment and normalization initiates the treatment of glaucoma. The accuracy of its measurement by traditional methods depends on biomechanical properties of the fibrous tunic of the eye, which in modern clinical practice are most successfully studied by the method of bidirectional applanation of the cornea using the Ocular Response Analyzer (ORA). Mathematical integration of the parameters it measures makes it possible to calculate the coefficient of biomechanical stress (K) that characterizes changes in the fibrous tunic of the eye induced by intraocular pressure, and serves as a criterion for intraocular pressure compensation.
To determine the range of normal values of the K coefficient, and to evaluate its specificity and sensitivity as a criterion for the degree of intraocular pressure compensation.
Two consecutive studies on representative clinical material were used to determine the range of normal K values in patients without significant ophthalmic pathologies (400 patients, 800 eyes) and establish the sensitivity and specificity of the coefficient in the diagnosis of glaucoma in patients with newly diagnosed glaucoma (673 patients, 1346 eyes). The age and gender composition of patients in both study groups was similar.
The cut-off value for K is 1.0. In the range of values from 1.0 to 1.09, additional risk factors for glaucoma progression must be taken into account to assess intraocular pressure compensation. In cases when K is equal to or exceeds 1.1, the intraocular pressure is considered elevated and a high risk of disease development or progression is predicted. In glaucoma patients with uncompensated intraocular pressure, the specificity of K is 81.5%, the relative specificity (including the borderline range) is 98%. With K values over 1.1, its specificity reaches 100%.
The performed clinical and statistical analysis demonstrates high sensitivity and specificity of the biomechanical stress coefficient in the diagnosis and treatment of glaucoma.
眼压是一个可调节的因素，对其进行正确评估并使其正常化是青光眼治疗的开端。传统方法测量眼压的准确性取决于眼球纤维膜的生物力学特性，在现代临床实践中，使用眼反应分析仪（ORA）通过角膜双向压平法能最成功地研究这些特性。对其所测量参数进行数学整合，可以计算出生物力学应力系数（K），该系数可表征眼压引起的眼球纤维膜变化，并作为眼压补偿的标准。
确定K系数的正常值范围，并评估其作为眼压补偿程度标准的特异性和敏感性。
连续两项针对代表性临床资料的研究用于确定无明显眼科疾病患者（400例患者，800只眼）的正常K值范围，并确定该系数在新诊断青光眼患者（673例患者，1346只眼）青光眼诊断中的敏感性和特异性。两个研究组患者的年龄和性别构成相似。
K的临界值为1.0。在1.0至1.09的数值范围内，评估眼压补偿时必须考虑青光眼进展的其他危险因素。当K等于或超过1.1时，眼压被认为升高，并预测疾病发生或进展的风险较高。在眼压未得到补偿的青光眼患者中，K的特异性为81.5%，相对特异性（包括临界范围）为98%。当K值超过1.1时，其特异性达到100%。
所进行的临床和统计分析表明，生物力学应力系数在青光眼的诊断和治疗中具有高敏感性和特异性。
