Macular Abnormality Observed by Optical Coherence Tomography in Children With Amblyopia Failing to Achieve Normal Visual Acuity After Long-Term Treatment

Purpose: To investigate why some children with amblyopia fail to achieve normal visual acuity. Methods: Optical coherence tomography (OCT) was performed to observe the morphology of the macular tissue of children with various types of amblyopia who failed to achieve normal visual acuity (≤ 20/25). Average thickness of the retinal nerve fiber layer (RNFL) of the foveola and fovea (1-mm diameter range) was then assessed by macular retinal tomography map measurement. The data obtained were compared with those considered normal to detect any abnormality. Results: Fifteen patients (24 eyes) were examined. Images showed abnormality with thickened RNFL in the macular area in which either the fovea was not observed or the wave lines were flattened or unformed. The average RNFL thickness measured 201.5 ± 17.9 μm for the foveola and 226.9 ± 11.4 μm for the fovea (1-mm diameter range). The differences were highly statistically significant compared with normal values. Five cases were ametropic amblyopia, 5 were anisometropic amblyopia, and 5 were idiopathic amblyopia. Eleven cases showed improvement and 4 cases showed no response to the treatment. Twelve cases were myopic, 1 was mixed astigmatism, and 2 were normal. Nine cases were binocular amblyopia and 6 cases were uniocular amblyopia. Conclusion: Some children with various types of amblyopia who failed to achieve normal visual acuity after treatment showed macular abnormality on OCT examination.