Characteristics of Preferred Retinal Locus in Eyes with Central Vision Loss Secondary to Different Macular Lesions

Abstract

Objective: Preferred retinal locus (PRL) training has been applied to low-vision rehabilitation for patients with central vision loss (CVL). This study aimed to explore the characteristics of a natural PRL in eyes with different macular lesions. The data may be useful in customizing training programs.Methods: A total of 72 eyes with CVL were included and assigned into two groups. In group A, 29 eyes diagnosed with macular holes featured relatively sharp borders and small areas of lesions. In group B, 44 eyes showed lesions characterized by irregular borders and large areas. The PRL location relative to a scotoma in the retina, fixation stability, and the average threshold surrounding the PRL were determined and compared between the two groups.Results: In group A, the PRL was located above in 48.28%, below in 27.59%, left in 62.07%, right in 31.03%, and inside in 3.45% of the eyes. In group B, the PRL was located above in 39.53%, below in 4.65%, left in 44.19%, right in 6.98%, and inside in 27.91% of eyes. The amount of retinal displacement occurring within 1° from an initial reference point (P< .05) and the 95% bivariate contour ellipse area (P< .05) in group A were respectively higher and lower than those in group B. However, the average thresholds around the PRLs in the two groups showed no significant difference (P > .05).Conclusions: A PRL to the left of or above a scotoma tends to develop to avoid the right and inferior field defect, regardless of the scale and boundary of lesions. Although light sensitivity around a PRL shows no relation to lesion features, fixation stability is worse in irregular and large lesions.

The effect of duration between sessions on microperimetric biofeedback training in patients with maculopathies

“…However, the authors did not make personalized choices based on the patient's condition. Our previous study found that natural PRL may be optimal for patients with small and sharp scotomas, whereas patients with large and rough scotomas need to develop new training target 24 . In our study, four patients in whom the original PRL was used also improved visual performance, providing additional validation for our prior assertion that training targets should be selected individually.…”

“…(1) Choice of the Fixation Training Target(FTT): The selection of FTT was performed based on the microperimetry result and the following criteria: (1) PRL as FTT if the natural PRL is within an area of good retinal sensitivity and in a convenient location or (2) set an FTT with good retinal sensitivity, closest to the fovea, and choose the upper side of the natural PRL as far as possible, which presents the inferior visual field; this criterion is based on our extensive literature review and clinical experience spanning several years 23,24 .…”

Visual function and biofeedback training of patients with central vision loss: a review

“…The best personalized location of the TRL varies from person to person. While the patient has a larger scotoma, lower fixation stability, or PRL located away from the fovea, choosing a better TRL to conduct visual rehabilitation can significantly improve the visual function of patients with CVL [87] . The closer the distance between the fovea and TRL, the greater the maximum reading speed, reading acuity, and critical print size [67] .…”