Abstract

AIM To compare the performance ofprogressor (pointwise linear regression) and statpac2 (comparison with baseline values) in detecting early deterioration in the visual fields of glaucoma patients.

METHODS Visual field series from 19 untreated normal tension glaucoma eyes which were deteriorating on clinical grounds were analysed by progressor and statpac2. Progression criteria forprogressor were (1) inner points: slope < −1 dB/year, p < 0.05 and (2) edge points: slope < −2 dB/year, p < 0.05. Criteria for statpac 2 were p < 0.05 change probability for any point on three consecutive fields. Detection time was defined as the time interval between the initial field and the first field in which at least one progressing point was identified. Detection times produced by the two techniques were compared.

RESULTS progressor and statpac2 agreed on progression in all 19 eyes. Mean detection time for progressor was 1.077 (SD 0.985) years and for statpac 2 was 2.161 (1.357) years. progressor detected progression sooner thanstatpac 2 in 18 eyes (p < 0.01, Wilcoxon matched pairs signed rank test). progressordetected progression earlier by a mean of 1.085 (0.936) years.

CONCLUSIONS progressor consistently detected progression earlier than statpac2. The progressor software is a useful tool for the early detection of visual field deterioration in glaucoma.