The decrease of visual acuity in cataract patients waiting for surgery

Purpose: To investigate the rapidity of vision loss in eyes waiting for cataract surgery and to estimate what proportion of life expectancy the extended wait for surgery comprised. Methods: The visual acuities at the time of referral and on the day before surgery were compared in 124 patients operated on for cataract in the Vaasa Central Hospital, Finland. The expected survival of the patients after surgery was calculated individually using the Finnish life statistics. Results: During the waiting time of 13 months on the average, the visual acuity in the study eye decreased from 0.68 logMAR (0.2 in decimal values) to 0.96 logMAR (0.1). The average decrease in vision was 0.27 logMAR per year varying from none to 2.07 logMAR units. 30% of the eyes experienced worsening of vision by 60% or more while 48% had no or minimal worsening (<0.2 logMAR). The rapidity of change in visual acuity was somewhat less in older patients (75 years or older), but the difference was not statistically significant. The percentage of persons with visual acuity of 0.5 or better in the better eye decreased from 66% to 41% and those with low vision (<0.3 in the better eye) increased from 8% to 21%. The mean waiting time in relation to the expected survival for all patients was 13% varying from less than 5% in 10 patients to more than 25% in 8 patients. Conclusion: Progression of vision loss in eyes waiting for cataract surgery varies significantly. For many patients the extended delay caused remarkable disability for a considerable part of their remaining lifetime.