Predictors of Good Motor and Sensory Outcomes Following Strabismus Surgery for Patients with Third Nerve Palsies

Abstract

Strabismus from third nerve palsy (3NP) is difficult to treat. Our goal was to explore factors associated with successful surgical outcomes in 3NP. Institutional records of all adult patients (>18 years) from 1988 to 2012 with 3NP who underwent strabismus surgery or botulinum toxin injections were retrospectively reviewed. Success was defined as absence of diplopia, vertical deviation ≤2 prism dioptres (PD), and horizontal deviation ≤10 PD. Fifty-six patients from four surgeons were included. Thirty (54%) were female; mean age was 48 (range: 20–80). Forty-four (79%) had unilateral 3NP; 9 (16%) had other ocular motor nerve palsies. 3NP were complete in 24 (43%). Underlying aetiology was idiopathic/microvascular in 5 (9%), traumatic in 13 (23%), neoplastic in 12 (21%), aneurysmal in 10 (18%), and other central nervous system related in 16 (29%). Trauma was associated more frequently with aberrant regeneration than other aetiologies: 9/13 (69%) versus 4/43 (9%) (p < 0.01). Ten patients (18%) had >1 surgery. Surgical success was achieved in 28/56 (50%). Success rate was unaffected by aetiology, degree of palsy, pupillary involvement, presence of aberrant regeneration, or number of other cranial nerves involved. However, adjustable sutures were used in 27 patients (48%), and there was a trend toward higher success rates when adjustable versus nonadjustable sutures were used (63% versus 38%; p = 0.06). Unlike with sixth nerve palsies, the aetiology and degree of 3NP does not appear to affect the success rates or number of procedures performed. Strabismus surgeries for 3NP with adjustable sutures may be associated with better outcomes.