Acquired paralytic strabismus in Southern Taiwan

Third, fourth, and sixth cranial nerve (CN3, CN4, and CN6) palsies are not uncommon in neuro-ophthalmology. The time and quality of recovery depend on the causes of the cranial nerve palsy. The purpose of our study was to evaluate the causes and outcome of acquired paralytic strabismus (PS) in a southern Taiwan population.

This study involved a retrospective chart review of patients at Kaohsiung Veterans General Hospital from January 2006 through July 2009. A total of 196 patients were enrolled. Outcomes and recovery times were recorded for the patients who exhibited C3, C4, and C6 palsies. The patients were categorized into four etiologic groups: vascular, idiopathic, traumatic, and neoplastic. The onset of PS, its continuing medical management, recovery, and other outcomes were followed up in these patients over a period of up to 10 years.

The mean age of the 196 patients enrolled was 58.35 ± 17.60 years (range 11-90 years), and the mean follow-up time was 13.6 months. Seventy-seven patients (39.29%) had CN3 palsy, 38 patients (19.39%) had CN4 palsy, and 81 patients (41.33%) had CN6 palsy. The most common causes were vascular diseases (35.20%), followed by trauma (33.67%), and idiopathic causes (21.94%). About 50% of the patients recovered within 6 months. Among the four etiologic groups of patients, the vascular group showed the best recovery: about half of the patients recovered within 3 months. Longer recovery periods were necessary for patients in the neoplastic group than for those in the traumatic, vascular, and idiopathic groups (p = 0.01; p < 0.001; p < 0.001, respectively).

The prognosis for patients with PS depended mostly on the cause of their disease. Patients with PS attributable to a vascular cause had a better prognosis than the other patients, and those in the neoplastic group required the longest time to recover.