Evaluation of fixation characteristics in amblyopia using microperimetry

Abstract

Purpose: To evaluate xation characteristics in amblyopia using macular analyzer integrity assessment (MAIA) microperimetry and to investigate the factors affecting xation stability.Methods: This prospective, cross-sectional study enrolled a total of 58 amblyopic patients (8-55 years old). Average threshold macular sensitivity (AT) and xation characteristics were assessed using the MAIA microperimetry (CenterVue, Padova, Italy). Two Bivariate contour ellipse areas (BCEA) xation indices (63% and 95% proportional values) and the percentage of xation points within 1° and 2° from the fovea (P1 and P2) were used to assess xation stability.Results: AT and xation stability parameters (P1, P2, BCEA 63%, BCEA 95%) were worse in the amblyopic eyes (p<0.05, for all). There was a positive correlation between BCVA, and AT, and P2, and negative correlations between BCVA, and BCEA 63%, and BCEA 95%. The eccentric xation was 48% in the amblyopic eyes (25% in anisometropic group, 52% in strabismic group, 69% in combined group) and 32% in the non-amblyopic eye. The preferred xation eccentricity in amblyopic eyes was signi cantly greater than the non-amblyopic eyes (p=0.004), and there was a negative correlation between preferred xation eccentricity and BCVA (p=0.012, r=-.327).Conclusions: Our data showed a decrease in xation stability, a positive correlation between xation stability and BCVA, and a negative correlation between preferred xation eccentricity and BCVA in amblyopic eyes. This result made us think that microperimetric acoustic biofeedback xation training, which is used to increase xation stability in low vision rehabilitation, may also be a useful approach in amblyopia.

Deficits of the “Good” Eye in Amblyopia: Processing Geometric Properties

“…Indeed, historically, the fellow eye has been regarded as a healthy control for the amblyopic eye in numerous studies. 7 – 9 Nevertheless, emerging evidence has gradually shed light on abnormalities in visual function within the fellow eye, such as reduced visual acuity and diminished grating sensitivity compared with typical eyes. 10 , 11 Furthermore, beyond spatial vision deficits, impairments have also been observed in higher-level cognitive processes, like degraded attentional modulation in the normal-acuity fellow eye.…”