Location and stability of the preferred retinal locus in native Persian‐speaking patients with age‐related macular degeneration

ABSTRACT

Clinical relevance

The findings of this study can be used in the selection of the preferred retinal locus to establish better rehabilitation services such as eccentric viewing training for patients with age‐related macular degeneration.

Background

The aim of this study was to determine the characteristics of the preferred retinal locus in native Persian‐speaking patients with age‐related macular degeneration.

Methods

In this non‐interventional case series, all patients with a diagnosis of age‐related macular degeneration referred to the Retina Clinic of the Rassoul Akram Hospital, Tehran, Iran, were evaluated. The fixation characteristics were evaluated monocularly using the MP1 microperimeter (Nidek Technologies, Padua, Italy). Optical coherence tomography was used to determine the location of the central fovea. The images were overlaid and the preferred retinal locus‐fovea distance was measured using Image J software.

Results

Fifty‐one eyes of 35 patients with a mean age of 73.8 ± 7.7-years were evaluated in this study. Inferior‐field, left‐field, central‐field, right‐field, and superior‐field preferred retinal locus were detected in 49 per cent, 33.3 per cent, 7.8 per cent, 5.9 per cent, and 3.9 per cent of the subjects, respectively. Fixation was stable in 70.6 per cent, relatively unstable in 15.7 per cent, and unstable in 13.7 per cent of the participants. Significant differences were not found in the mean values of logMAR visual acuity between different fields of the preferred retinal locus after Bonferroni correction (p = 0.031). Analysis of co‐variance showed no significant difference in mean sensitivity values between different locations of the preferred retinal locus (p = 0.07). The mean preferred retinal locus‐fovea distance was not significantly different between different fields of the preferred retinal locus (p = 0.063).

Conclusions

Native Persian‐speaking patients with central scotoma secondary to age‐related macular degeneration place their self‐selected preferred retinal locus most frequently in the inferior and left visual field, which would result in scotoma displacement to the superior and right visual field. Fixation stability was statistically similar in different locations of preferred retinal locus, but it improved with decreasing the preferred retinal locus‐fovea distance.

KEYWORDS:

• Age‐related macular degeneration
• fixation stability
• microperimetry
• optical coherence tomography
• preferred retinal locus

Acknowledgements

The authors would like to thank Ahad Sedaghat, MD, Reza Mirshahi, MD, Pasha Anvari, MD, Behrouz Saeedian, MD, Shahriar Ghasemizadeh, BS, Pegah Kazemi, BS, Amirpouya Alemzadeh, MD, Mohammad Reza Zarrin, MSc, and Abtahiteb Inc., for their support.