Abstract
Purpose: :
To determine binocular sensory and motor outcomes after strabismus surgery in children with cerebral palsy (CP).
Methods: :
A cross-sectional observational study was conducted on 50 children whose CP severity spanned milder (level 1-2) to severe (level 3-5) using the standardized Gross Motor Function Classification System. Optimal motor outcome was defined as 8 PD or less deviation (microtropia) 1 yr post-surgery; sensory outcome was defined as restoration of fusion or stereopsis. Mean age = 3.5 yrs; mean follow-up = 4.1 yrs. Across GMFCS levels children did not differ in gestational age, examination age, preoperative angle or follow-up period (ANOVA p=0.9, p=0.23, p=0.53 respectively).
Results: :
Children with mild CP achieved a 2.6x greater rate of optimal motor outcome and 3.1x greater stereopsis outcome compared to children with severe CP (50% vs. 19% and 25% vs. 8%). Gain of binocularity was 1.7x greater in children with primary ET (63%) versus primary XT (37%). Outcomes did not differ in children with stable vs. variable-angle preoperative deviation (chi sqr p=0.5). In primary ET children, 38% had optimal motor outcome after 1 surgery and 71% after 2 surgeries. 42% of primary ET children developed a secondary macro XT after 1 surgery, which responded favorably to a 2nd surgery. Shorter duration of strabismus before surgery 1 was associated with better motor outcome [2.6 yrs vs. 4.3 yrs in suboptimal-macrotropia outcome (p=0.05)] and gain in binocularity [2.1 yrs vs. 4.8 yrs (p=0.05)]. Children with dyskinetic strabismus (variable ET/XT) did not achieve optimal motor outcome or gain in binocularity.
Conclusions: :
Children with milder CP, primary ET and earlier treatment benefit substantially from strabismus surgery. Variable deviation and secondary XT is common, but should not deter earlier treatment.
Keywords: strabismus: treatment • visual impairment: neuro-ophthalmological disease • esotropia and exotropia