Adult hypertropia: a guide to diagnostic evaluation based on review of 300 patients.

Objective: To highlight the key clinical features of various aetiologies of adult hypertropia and to discuss the diagnostic approach towards evaluation of vertical double vision.

Methods: This is a retrospective cross-sectional study. A total of 300 consecutive patients with vertical diplopia were evaluated by a single neuro-ophthalmologist and strabismologist in a tertiary care setting from 2005-2008. The medical records of all patients with vertical diplopia coded with one of the following diagnoses; hypertropia, diplopia, thyroid eye disease, fourth nerve palsy, ocular myasthenia, congenital strabismus, and third nerve palsy were reviewed. The main outcome measures were determination of aetiologies of hypertropia.

Results: Fourth nerve palsy and thyroid eye disease were the most common causes of vertical diplopia in our series and comprised more than 50% of patients. The other causes of vertical diplopia were ocular surgery, orbital fracture, neurosurgery, childhood strabismus, skew deviation, third nerve palsy, myasthenia gravis, and decompensated hyperphorias. Ocular motility deficits were seen in 33% of the cohort of whom thyroid eye disease comprised the largest group. Orbital ultrasonography was sensitive in detecting thyroid orbitopathy.

Conclusions: In the majority of patients, the aetiologies of hypertropias can be ascertained by history and careful ophthalmic examination alone. Fourth nerve palsy and thyroid eye disease were the most common causes of vertical diplopia in this series.