Duration 5min, Q&A 3min
A Method to Improve the Estimation of Glaucomatous Visual Field Defects by Testing Additional Points at the 'Edges' of Scotomata
To develop a method to map glaucomatous visual field (VF) damage by allocating additional test points to the VF test pattern, considering the distribution of VF scotomata.
21 glaucomatous patients.
Gradients of sensitivity were calculated for 'squares' of VF test points in a patient's Humphrey Field Analyzer 24-2 / 30-2 results, so that the 'edges' of VF scotomata could be identified where gradients were steep. Next, ten new VF test points were placed in these locations for each patient individually. The patient's VF was then measured twice using this novel test grid (52 standard 24-2 test points and 10 additional points examined concurrently or at the end of the VF test) on two separate occasions (Full threshold and Custom mode algorithms). The absolute difference between the measured sensitivity at each new additional test point and the average of the sensitivities of its surrounding four test points was calculated (Δave). The reproducibility of VF damage was estimated using intra- and inter-visit intraclass correlation coefficients (ICCs) and the coefficient of variation (CV).
Results and Conclusion
Δave increased as the gradient of the plane steepened. Reproducibility was better (ICC was higher and CV was lower) for the novel test grid compared with the standard 24-2 test pattern. It may be advantageous to increase the density of VF test patterns when assessing glaucomatous VF damage, by carrying out additional VF measurements at the edges of scotomata.
[ Keyword ]
Glaucoma / Visual Field / Test Grid
[ Conflict of Interest ]