Insight into light:The influence of luminance on visual functioning in glaucoma

Abstract

Glaucoma is a progressive eye disease in which the visual field is permanently damaged but which remains without symptoms until a late stage. Visual field loss in one eye is compensated by the other eye and the brain fills in missing parts. At the ophthalmology outpatient clinic, many glaucoma patients indicated that they experienced difficulty with seeing in extreme (low, high and rapidly changing) luminance conditions – complaints that are not typical for glaucoma. Therefore, the aim of this thesis was to unravel the effect of luminance on the visual function of glaucoma patients. With a questionnaire, we confirmed glaucoma patients had much more difficulty with seeing in extreme luminance conditions, especially in the dark. In a series of experiments we found that glaucoma patients had a standard amount of lower vision in all luminance conditions; from very dark to extremely light. Glaucoma patients did not need longer adaptation times to get used to the dark. With the national citizen science project ‘Insight into light’ we used an app to map the luminance of the Netherlands at night. 6700 measurements of almost 2000 people showed that subjects with an eye disease had more difficulty with walking at night than subjects without an eye disease – an interesting fact given the trend towards fewer streetlights. This thesis confirms that glaucoma patients see less in all luminance conditions and this can be a considerable challenge especially in the dark. Further research is needed to confirm whether these findings can help us to diagnose glaucoma more efficiently in the future