Diagnosis of Congenital and Acquired Hyperdeviation: What are the Rules?

Abstract

INTRODUCTION Acquired or congenttal hyperdeviation (HD) is caused by dysfu netic n of one or more vertical rectus or oblique muscles or tendons, (e.g. Graves' ophthalmopathy, orbital myosttis) or the nerve supply to these stnuctures. Neural impairment may occur from involvement of nuclear or supranuclear pathways (e.g. nuclear third or fourth nerve palsy, skew deviation) or of the peripheral nerve itself (e.g. third or fourth nerve palsy). Myoneural junction involvement (e.g. ocular myasthenia) should be sought in any painless, pupil sparing ophthalmoplegia, especially when variable. The purpose of this monograph is to clearly outline the steps in evaluation of congenital or acquired HD. Motility examination techniques will be described in detail. Anatomic localization of the lesion based on clinical data alone is possible in most cases (The nules). Neuro-radiologic studies, in conjunction, will allow an orderly differential diagnosis of HD to be developed.