Disease severity in newly diagnosed glaucoma patients with visual field loss: trends from more than a decade of data

PurposeLarge archives of visual field (VF) records from automated perimetry are used to examine severity of vision loss at diagnosis in glaucoma patients over a 13year period in England. MethodsA total of 473252 Humphrey VFs recorded at four regionally different glaucoma clinics in England were retrospectively examined. Patients were required to have a Humphrey mean deviation (MD) outside 95% normative limits in at least one eye and had at least two visits to the glaucoma clinic in a study period between the start of 1999 and the end of 2011. No other clinical data was considered. MD of the worse eye at the first hospital visit was used as an estimate of vision loss for a patient at diagnosis; proportion of patients categorised as having early' (better than -6dB) or advanced' (worse than -12dB) VF loss were also calculated. Simple linear regression of MD against the date of first visit was used to estimate changes in vision loss at diagnosis over time. ResultsMedian age, at the time of diagnosis, of the 25521 patients included in the analysis was 67 (interquartile range 55-76) years. Average level of glaucoma vision loss at diagnosis, in those patients presenting to secondary care with a VF defect, improved by an average 0.11dB per year over the study period (95% confidence interval: 0.08-0.13dB per year; p<0.0001). Percentage of patients with advanced' VF loss in at least one eye at diagnosis changed from 30% (1999-2001) to 21% in (2009-2011) (p<0.0001). ConclusionsSeverity of vision loss at the point of glaucoma detection, in those patients diagnosed with a VF defect, is improving over time in England. Nevertheless, the improvement is modest and large numbers of patients still present at glaucoma clinics with significant vision loss in at least one eye. Large scale digital VF data can be used to help monitor and audit health service delivery of glaucoma.