Estimating functions for visual field progression in newly diagnosed exfoliation glaucoma patients in Sweden

Abstract

This study aimed to determine whether glaucoma progression was linear or not in newly diagnosed exfoliation glaucoma patients. A total of 96 patients with newly diagnosed exfoliation glaucoma were included. These patients were required to undergo at least seven visual field tests within 3 years (± 1 month), and all were treated at the time of inclusion. The study was a non-randomized, prospective cohort study. The outcome of the study was visual field progression. Progression was assessed based on mean deviation (MD), visual field index (VFI), and “Guided Progression Analysis”. The MD and VFI values were plotted against time, and distribution and curve fit were calculated. The results showed that the general rate of progression of the cohort was − 3.84 (± 2.61) dB for the MD values and 9.66 (± 6.25)% for the VFI values over 3 years. The best-fitted curve for MD and VFI values in the 36 months period was significant for both linear and exponential curves (p ≤ 0.001; p ≤ 0.001). However, in the MD group, the F and the R2 values were higher for exponential than for linear function (linear: F = 42.60, R2 = 0.059; exponential: F = 53.26, R2 = 0.073). The opposite results were found among VFI values. The F and the R2 values were slightly better for linear than for exponential (linear: F = 37.22, R2 = 0.052; exponential: F = 35.55, R2 = 0.050). In conclusion, the study found that visual field progression between diagnosis and 18 months seemed to be exponential. However, after 18 months, the IOP reduction effects probably ameliorated progression, making the curve linear.