Tony Brune, DO, Department of Neurology, The Johns Hopkins School of Medicine; Daniel R. Gold, DO, Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine
Divergence insufficiency should be suspected in patients with binocular horizontal diplopia at distance (but not near) who lack abduction deficits. There should be an esodeviation greater at distance, and in older patients with levator dehiscence (or previous ptosis surgery) and prominent superior sulci, the so-called ‘sagging eye syndrome' should be considered. Divergence insufficiency may also be associated with cerebellar (or other neurologic) disease, so a complete ocular motor and neurologic exam is necessary. ; Patients with divergence insufficiency will have a poor divergence amplitude - that is, when the patient views a target at distance (if diplopia is not experienced to begin with), even a small amount of base-in prism will cause doubling of the target, also known as the ‘break point'. Although there are no universally-accepted normative values for divergence amplitude, the inability to fuse even a small amount of base-in prism at distance (e.g., 1 prism diopter) is generally considered abnormal, especially in patients with complaints suggestive of divergence insufficiency.
Spencer S. Eccles Health Sciences Library, University of Utah