Until what age should glaucoma be monitored and/or treated? A novel index that facilitates clinical decision making

Purpose To calculate for which combinations of age and perimetric disease stage (mean deviation [MD]) treated and untreated glaucoma patients are unlikely to become blind during lifetime. Methods The probability of dying without blindness was calculated using the age and gender adjusted life expectancy values from the Statistics Netherlands and the progression rates of treated and untreated glaucoma patients from the Early Manifest Glaucoma Trial and the Groningen Longitudinal Glaucoma Study. Absence of blindness was defined as an MD better than ‐20 dB. Because it is difficult ‐ or even impossible – to determine someone's individual life expectancy and rate of progression accurately, patients were assumed to reach the 90th percentile of the adjusted life expectancy and to progress with the 90th percentile of the rate of progression, leaving an a priori probability of becoming blind during lifetime of 2.5%. Results If MD+0.8*age, with MD in dB and age in years, is larger than 59, treated male patients were unlikely to become blind during lifetime. For untreated male patients the cut‐off value was 66, and for treated and untreated female patients 61 and 68 respectively. Conclusion With this novel index, MD+0.8*age, the intensity of glaucoma monitoring and/or treatment can be reduced well‐founded in the ageing patient. The index can be applied to either the worse or the better eye, depending on what is considered acceptable or possible given limited resources.