The worse eye is not as bad as it seems to be in AMD cases

It is the aim of this study to review residual vision in the less used eye of patients with age-related macular degeneration (AMD) using modern concepts for residual visual functions in addition to traditional methods for assessing visual acuity.

The study was designed as a retrospective, nonrandomized, observational case series.

Consecutive cases tested with microperimetry instruments were identified from archives. Included were cases with diagnosed AMD of all age groups and all visual acuity levels.

In all cases, microperimetric technology was used to assess residual visual function. Outcome measures selected for analysis were visual acuity, preferred retinal loci (PRL) topography, fixation stability, and PRL span.

Data were collected and analyzed for both eyes from 51 patients with AMD low vision. There were 23 males and 28 females whose mean age was 84 (± 7) years. Within the group the difference in visual acuity estimates between the better seeing and the less used eye was statistically significant (p = 0.001). Similar positive statistical significant differences were noticed at all spatial frequencies (except at 6 cycles/degree) when testing contrast sensitivity. All other measurements were not statistically different between the better seeing and the poorer eye. This applies to the fixation stability and PRL span estimates. Almost half (49%) of the cases showed retinal noncorrespondence of PRLs between the 2 eyes.

Visual acuity estimates are not a reliable measure for residual vision. The less used eye in AMD cases has much better residual vision than thought before according to modern outcome measures. This new concept should be taken into account by all practitioners and be applied during all low vision rehabilitation interventions.