Wavefront aberrations in children with different types of amblyopia

Abstract

Purpose. To quantify and characterize higher-order aberrations in eyes of children with amblyopia caused by different etiology factors; to evaluate the relationship between the wavefront profile and the effectiveness of the amblyopia treatment. Material and methods. This study involved 26 children (52 eyes) from 3 to 9 years old (average age 6.2±3 years) with different types of amblyopia: unilateral amblyopia due to impaired binocular vision and anisometropia, as well as unilateral or bilateral amblyopia caused by hyperopia. Patients were divided into four groups depending on the effectiveness of pleoptic treatment: 14 children (24 eyes) – with positive treatment results, 8 children (12 eyes) – with refractory amblyopia, 4 pre-treatment newly diagnosed patients (6 eyes) without previous history of optical correction, and 10 non-amblyopic contralateral eyes (control group). All patients had central fixation and didn`t have any severe systemic diseases. Higher-order aberrations were measured with iTrace Visual Function Analyzer (Tracey Technologies, Houston, TX) after instillation of 1% cyclopentolate eyedrops. Results and discussion. Wavefront profiles were significantly different in the studied groups. Total spherical aberrations and astigmatism were significantly higher in group with refractory amblyopia (-0.53±1.19 and 2.25±1.07, p=0.02) compared with all the other groups: the group of patients before pleoptic treatment (-0.17±0.23 and 1.79±1.47), group treated with high efficiency (-0.31±0.81 and 1.04±0.13) and with control group (-0.13±0.17 and 1.38±0.11). Total coma-like aberrations didn`t show statistically significant differences in all studied groups (р=0.06). The level of corneal higher-order aberrations (total, coma, spherical) in all three amblyopic groups was higher than in the control group without amblyopia. Conclusion. We revealed statistically significant differences in the wavefront profiles in children with amblyopia of various etiologies in comparison with the control group, including higher-order aberrations. The data obtained indicate that an amblyopic eye with hyperopia has higher level of spherical aberrations and astigmatism due to higher level of internal HOAs, particularly spherical aberrations and astigmatism, which is typical for patients with unsuccessful treatment. Therefore, that type of aberrations is likely to be the main cause of refractory amblyopia.