Decompensation of distance exotropia reduces accommodation

April 17, 2012

Decompensation of distance exotropia reduces accommodation, meaning it must be prevented in near vision.

Decompensation of distance exotropia reduces accommodation, meaning it must be prevented in near vision, reveals a study in the British Journal of Ophthalmology.

The investigation, led by Dr Anna Horwood, School of Psychology & Clinical Language Sciences, University of Reading, Reading, UK, consisted of 19 participants with distance exotropia. Each patient was tested using the PlusoptiXSO4 photo refractor set in a remote haploscopic device.

The refractor recorded simultaneous vergence and accommodation of a range of targets demonstrating the various combinations of blur, disparity and proximal cues. The assessments were made at four fixation distances between 2 m and 33 cm.

The study discovered that manifest exotropia was more common in the more impoverished cue conditions. The mean accommodation increase for the all-cure target was considerably reduced. The mean under-accommodation was 2.33 D at 33 cm. Blur and proximity drove residual responses when the profile of near cues usage changed after decompensation.