Asymmetrical accommodation in hyperopic anisometropic amblyopia
Toor S, Horwood AM, Riddell P. British Journal of Ophthalmology Published Online First: 19 October 2017. doi: 10.1136/bjophthalmol-2017-310282
- Accommodation is generally considered to be symmetrical in each eye.
- We found that in children with a particular type of amblyopia, accommodation was frequently asymmetrical (poorer in the amblyopic eye) and could even be inverse, with the amblyopic eye accommodating more in the distance than near.
To investigate the presence of asymmetrical accommodation in hyperopic anisometropic amblyopia
Accommodation in each eye and binocular vergence were measured simultaneously using a PlusoptiX SO4 photorefractor in 26 children aged 4–8 years with hyperopic anisometropic amblyopia and 13 controls (group age-matched) while they viewed a detailed target moving in depth.
Without spectacles, only 5 (19%) anisometropes demonstrated symmetrical accommodation (within the 95% CI of the mean gain of the sound eye of the anisometropic group), whereas 21 (81%) demonstrated asymmetrical accommodation. Of those, 15 (58%) showed aniso-accommodation and 6 (23%) demonstrated ‘anti-accommodation’ (greater accommodation for distance than for near). In those with anti-accommodation, the response gain in the sound eye was (0.93±0.20) while that of the amblyopic eye showed a negative accommodation gain of (−0.44±0.23). Anti-accommodation resolved with spectacles. Vergence gains were typical in those with symmetrical and asymmetrical accommodation.
The majority of hyperopic anisometropic amblyopes demonstrated non-consensual asymmetrical accommodation. Approximately one in four demonstrated anti-accommodation.