Authors: AC Viswanathan, AI McNaught, D Poinoosawmy, L Fontana, DP Crabb, FW Fitzke, RA Hitchings.
Institute of Ophthalmology, Bath Street, London, UK and Moorfields Eye Hospital, City Road, London, UK.
Purpose: To elucidate the relationship between glaucoma patients’ assessment of the severity of their visual loss and their monocular and binocular visual fields.
Methods: Seventy-seven patients were studied. 62 took part in the cross-sectional study: they each completed a binary forced-choice questionnaire relating to perceived visual disability and underwent binocular (Humphrey Esterman program) field testing. Correlation analysis and logistic regression were used to examine the strength of association between each question and the number of defects in the binocular field (both on a whole-field and a hemifield basis). 15 normal-tension glaucoma patients who had had at least 5 Humphrey 24-2 visual fields over at least 7 months were studied longitudinally: they were asked “Have you noticed any deterioration in your sight over the last few years?” and were allowed an answer of yes or no. The association between their answers and an objective measure of visual field progression (obtained using PROGRESSOR software: pointwise linear regression of sensitivity on time) was examined.
Results: Cross-sectional: Questions which correlated well (correlation coefficient > 0.4) with Esterman Disability Scores (percentage of points missed) related to problems with stairs, colour vision, bumping into things and finding things which have been dropped. Logistic regression additionally identified a strong association (p < 0.05) between Esterman Disability Scores and questions about patient awareness of field loss, difficulty following lines of print, and dark adaptation. Hemifield analysis revealed a strong association (correlation coefficient > 0.4, logistic regression p < 0.05) between trouble with stairs and defects in the inferior hemifield. Longitudinal: All the patients who reported noticing visual deterioration (3 out of 15) showed visual field progression. Of the 12 patients who did not notice visual deterioration, 7 also showed visual field progression.
Conclusions: There is strong correlation between patient responses to certain questions about visual disability and the severity of binocular field loss. If a patient reports noticing visual deterioration, they are likely to show progressive visual field loss.
References:
1. Mills RP, Drance SM. (1986) Esterman Disability Rating in Severe Glaucoma. Ophthalmology 93: 371-378.
2. Fitzke FW, Hitchings RA, Poinoosawmy D, McNaught AI, Crabb DP. (1996) Analysis of Visual Field Progression in Glaucoma. Br J Ophthalmol 80: 40-48.
(Presented at the Vth Meeting of the European Glaucoma Society, Paris 1996)
