Abstract
Abstract: :
Purpose: To establish the proportion of eyes that show significant change in Heidelberg Retina Tomograph (HRT) summary measures during the period that they develop glaucomatous visual field loss. Methods: HRT data were taken from 77 ‘high risk’ eyes (due to ocular hypertension or a fellow eye with POAG) of patients attending a large–scale longitudinal glaucoma study. HRT summary measures considered were 3 discriminant function analyses (DFA) (described by Mikelberg, Burk and Bathija) and the Moorfields Regression Analysis (MRA). Results: Thirty seven eyes showed perimetric conversion (defined by the glaucoma hemifield test) during the period of follow–up (3.3 ± 0.9 years), whilst 40 had consistently normal visual fields throughout the study (follow–up 3.0 ± 0.8 years). At baseline, the Mikelberg, Burk and Bathija DFAs categorised as ‘glaucomatous’ 48.6, 37.8 and 67.6% of converters and 30.0, 17.5 and 50.0% of patients with repeatedly normal fields. At the final examination, these proportions had increased by 8.2, 10.8 and 0.0% (converters) and 10.0, 5.0 and 12.5% (normal fields). Significant deterioration (p<0.05) of the DFA statistic was found in 5.4, 13.5 and 16.2% of cases (converters) and 7.5, 10.0 and 7.5% (non–converters). MRA results are shown in the table. Overall, a deterioration in MRA category was found in 24.3% and 17.5% of subjects showing perimetric conversion and normality, respectively.
Conclusions: Summary measures of HRT data do not appear to change in a large proportion of patients during the period that they develop glaucomatous visual field loss.
Keywords: imaging/image analysis: clinical • optic disc