Assessment of prognostic coefficients as predictors of primary angle-closure glaucoma development

Abstract

PURPOSE: To study and compare the prognostic capabilities of the Lowe coefficient and the Shirshikov axial coefficient in the eyes with an anatomical predisposition to the development of primary angle-closure glaucoma (PACG).

MATERIALS AND METHODS: We examined 135 patients (201 eyes) with a first-time diagnosis of PACG. Prior to the treatment we measured biometric parameters of the eyes and used them to calculate the prognostic Lowe coefficient and Shirshikov axial coefficient. A comparison of these coefficients’ informativeness was conducted.

RESULTS: It has been confirmed that the predisposition to PACG is the result of a combination of anatomical parameters involved in the development of hydrodynamic blocks, and not the clinical influence of any single parameter. According to the authors of the coefficients, in the eyes of those predisposed to PACG development, Lowe coefficient usually equals ≤0.2, while Shirshikov axial coefficient reaches ≥10. According to the calculation results, the average value of Lowe coefficient was 0.21±0.02≤0.2, while Shirshikov axial coefficient was 15.79±3.05≥10. When comparing the data, it was established that the reliability of the Shirshikov axial coefficient in predicting PACG was significantly higher (2.44 times; DI 2.06; 2.90) than that of Lowe coefficient.

CONCLUSION: The informativeness of the Shirshikov axial coefficient (poorly known among ophthalmologists) for predicting PACG turned out to be higher than that of the Lowe coefficient, which gives reason to recommend its wider use in clinical practice.