Long term outcomes in dry age-related macular degeneration following low vision rehabilitation interventions

Background: Age-related macular degeneration (AMD) is the leading cause of loss of vision in the older age groups. In the absence of a known therapy, low vision rehabilitation aims at preserving residual functional vision at optimal levels. Long term functional outcomes from Low Vision Rehabilitation (LVR) in AMD cases were never scrutinized in the past. This study brings some clarification in this matter. Methods: This is a retrospective case series study including data up to 2 years following the baseline visit. Low Vision Assessments included microperimetry testing and recommendations for low vision devices for distance vision. Outcomes measures selected for this study were best corrected distance visual acuity, fixation stability and preferred retinal locus (PRL) topography and LVR interventions. Results: Data on 17 patients with an average age of 89.2 +/- 4.4 years was collected. In those with better vision than 20/400 loss of vision was about 1.4 letter per year as tested with ETDRS charts compared with losses of four letters per year in a population without LVR interventions. Fixation stability continued to deteriorate while PRL eccentricity seemed to remain the same. In about half of cases there was a change in the topographic location of the PRL to a different retinal quadrant. Conclusion: Long term, as expected, changes were noticed in visual acuity, fixation stability and PRL topography. However, it seems that LVR interventions for distance vision help patients retain significantly better functional vision at the 2 years follow up interval when compared to others.