Correlations between visual fixation parameters, photosensitivity of the retina and visual acuity in various types of amblyopia

Abstract

To study the parameters of visual fixation, photosensitivity in the macular region of the retina, and their correlation with the best-corrected visual acuity (BCVA) for various types of amblyopia. The study included 50 patients with an average age of 11.02±4.2 years. All patients were divided into 3 groups depending on amblyopia type; group 4 consisted of the paired eyes of patients with amblyopia; group 5 was the control group. Retinal photosensitivity and fixation parameters were studied on the Nidek MP-3 microperimeter (Japan). Correlation analysis was performed using the linear Pearson correlation coefficient (r). Retinal photosensitivity was the lowest in the groups with relative amblyopia with nystagmus (25.7±3.6 dB; group 3) and congenital myopia (26.1±2.9 dB; group 2), which is consistent with the partially organic nature of relative amblyopia. In the group with strabismic and refractive amblyopia (group 1), photosensitivity did not significantly differ from the control group (p>0.05). Fixation density was the lowest in the first (85.1±0.2% and 92.8±0.16% at 2° and 4°, respectively) and the third (62.6±0.16% and 89.3±0.05% in 2° and 4°, respectively) groups. In the first group, a strong correlation (r=0.77) of the fixation density and BCVA was revealed; no such correlation was observed in groups 2 and 3. No correlation of photosensitivity and BCVA was detected in group 1 (r=0.2). Fixation density in the group of paired eyes was significantly lower than in the control group (p<0.001). Microperimetry is an innovative tool for differential diagnosis, monitoring, method selection and evaluation of the effectiveness of treatment of various types of amblyopia.