Objectives: To determine the natural history of primary divergence insufficiency and to identify clinical features that distinguish patients with this neurologically isolated form of divergence insufficiency from those harboring neurologic disorders.
Methods: Retrospective survey of patients with divergence insufficiency. Patients were categorized into 2 groups, primary (ie, neurologically isolated based on clinical criteria) and secondary (ie, associated with a neurologic or systemic disorder). Long-term follow-up and clinical features of the 2 groups were compared.
Results: Of the 20 patients with primary divergence insufficiency, 19 (95%) were older than 50 years. Symptoms resolved in 8 (40%) of 20 patients after a median of 5 months. None of these patients developed signs of an underlying neurologic disorder during follow-up. Of the 15 patients with secondary divergence insufficiency, an underlying neurologic or systemic disorder was either known or initially suspected in all based on the initial history and physical examination. Divergence fusion amplitudes were significantly larger in patients with secondary divergence insufficiency compared with those with primary divergence insufficiency, although there was considerable overlap of values between the 2 groups.
Conclusions: Primary divergence insufficiency is generally a benign condition. Many affected patients experience spontaneous resolution of double vision within several months. The clinical neurologic evaluation is a powerful tool that distinguishes those with a primary disorder from those harboring an underlying neurologic or systemic condition. It is reasonable to initially defer further investigation, including neuroimaging, in patients who have no other neurologic symptoms or signs. Arch Ophthalmol. 2000;118:1237-1241