Binocular diplopia: a retrospective study of 204 cases

Objective

To describe the prevalence and form of onset of different causes of binocular diplopia in our setting.

Methods

We conducted a single-centre, cross-sectional, retrospective study reviewing the medical records of all patients visiting a tertiary-level centre between May 2019 and June 2021 with binocular diplopia as the main symptom. All patients underwent a complete neuro-ophthalmological evaluation and complementary tests for the aetiological diagnosis of diplopia. Data were collected on demographic variables, ocular deviation pattern, complementary test results, and diagnosis.

Results

A total of 204 patients with binocular diplopia were identified during the study period. The most frequent causes of diplopia overall were fourth nerve palsy (19.12%), sixth nerve palsy (14.71%), decompensated strabismus (14.22%), sagging eye syndrome (12.25%), third nerve palsy (10.78%), myasthenia (7.35%), supranuclear disorders (6.37%), and myopic esotropia (5.88%). Presentation was acute (less than 2 weeks’ progression) in 51% of cases. The most frequent causes of acute-onset diplopia were sixth nerve palsy (27.88%), third nerve palsy (21.15%), fourth nerve palsy (19.23%), supranuclear disorders (12.5%), and decompensated strabismus (6.73%). The most frequent causes of subacute/chronic presentation (more than 2 weeks) were decompensated strabismus (22%), sagging eye syndrome (22%), fourth nerve palsy (19%), myopic esotropia (12%), and myasthenia (11%).

Conclusions

The most frequent aetiology of diplopia in our environment was fourth nerve palsy, followed by sixth nerve palsy, decompensated strabismus, and sagging eye syndrome. Knowing the frequency of each cause of diplopia can help prioritise neuroimaging studies in each case.