Multi-luminance mobility tests (MLMT) may be able to detect functional vision changes over time in patients with retinal dystrophies, according to the findings of a recent study published in Clinical & Experimental Ophthalmology.¹

Fifty-four participants (28 visually impaired due to inherited retinal dystrophies and 26 controls) underwent MLMT three times over a one-year period. At each visit, subjects were asked to complete a maze with one eye, and then both eyes, at up to nine standardized, increasing luminance levels (range of 1lux to 400lux). Researchers evaluated accuracy and speed and then compared that with visual acuity (VA), visual fields (VF) and visual function questionnaires. The main outcome measures were accuracy and speed of normal and visually impaired subjects on MLMT and reliability and content validity of the testing modality.

Control subjects all passed MLMT attempts at all tested light levels. Visually impaired subjects’ performance varied widely, including some that declined over one year. Additionally, performance declined markedly below certain VA and VF thresholds. Concordance on performance on two baseline visits was high.

The investigators concluded that MLMT differentiated visually impaired from control populations. In subjects with inherited retinal dystrophies, researchers were able to identify a range of performances and track performance declines over time, consistent with this progressive condition.