Comparison of higher order aberration profiles between normal and amblyopic eyes in children with idiopathic amblyopia

Aim: To evaluate the higher order aberrations and resultant bilateral wavefront patterns in paediatric patients with idiopathic amblyopia. Material and Methods: In this cross sectional observational trial, seventeen consecutive patients of previously diagnosed idiopathic amblyopia underwent wavefront analysis on Zyoptix platform (Bausch and Lomb, Rochester, NY, USA). Results: The mean age was 9 +/- 3 years. There was no significant difference in comparison with means for the Zernike coefficients between normal and amblyopic eye. However, interrelation between Zernike coefficients, which is responsible for their interaction leading to difference in visual function, was different between amblyopic and fellow eyes. This was noticed using stepwise regression analysis. Predicting variables and R2 (r squared) values for each Zernike polynomial were calculated. The sets of significantly predicting coefficients were different in mostpatients, with only seven common pairs and 42 dissimilar dependent-predictor sets. Maximum difference in the R-squared values between amblyopic and normal (fellow) eyes was seen with coma-like and trefoil-like aberrations (third order and fifth order terms). Conclusion: It seems a strong possibility that a subset of 'idiopathic' amblyopia may be associated with loss of symmetry in wavefront patterns of the two eyes.