NEW APPROACH TO ESTIMATING VARIABILITY IN VISUAL-FIELD DATA USING AN IMAGE-PROCESSING TECHNIQUE

Aims-A new framework for evaluating pointwise sensitivity variation in computerised visual field data is demonstrated. Methods-A measure of local spatial variability (LSV) is generated using an image processing technique. Fifty five eyes from a sample of normal and glaucomatous s ubjects, examined on the Humphrey field analyser (HFA), were used to i llustrate the method. Results-Significant correlation between LSV and conventional estimates - namely, HFA pattern standard deviation and sh ort term fluctuation, were found. Conclusion-LSV is not dependent on n ormals' reference data or repeated threshold determinations, thus pote ntially reducing test time. Also, the illustrated pointwise maps of LS V could provide a method for identifying areas of fluctuation commonly found in early glaucomatous field loss.