progression.vfi: progression according to VFI (significant slope, p<=0.05)
Description
progression.vfi returns the progression criterion used in Aptel et al. (2015).
Usage
progression.vfi(measmatrix)
Arguments
measmatrix
is a data frame. MUST contain the following columns: 'vfi' (visual field index), 'yearsfollowed', and 'eyeid'. Rows represent the single measurements. The minimum measurements (rows) is 3.
Value
"stable", "worsening", or "improving" of measurements in timepoints