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Updated: Sep 28, 2026

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Fourth nerve palsy with monovision
Pauline HN Yeung1, Andrew KC Lam
1Department of Optometry and Radiography, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
Abstract:
The fourth cranial nerve is the most vulnerable cranial nerve. Its damage gives rise to a vertical ocular deviation and usually the patient comes with a right head-tilt. The Parks-Bielschowsky three-step test is a simple and useful test for identifying the paretic extraocular muscle, giving rise to such a vertical ocular deviation. A case of long-standing fourth nerve palsy in a 45-year-old woman is reported. Monovision spectacles were prescribed to give the patient satisfactory distant and near vision.
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