[Symmetric or asymmetric surgery for basic intermittent exotropia]

Surgical results after symmetrical and asymmetrical surgery performed by the same surgeon (M.S.) as initial procedure for basic intermittent exotropia were retrospectively analysed in 55 young patients. Twenty-five patients underwent unilateral recess-resect surgery on the non-fixating eye (Groupe 1) and 30 patients bilateral lateral rectus recessions (Group 2). The average age at surgery was 6.5 yrs (range: 2-18). The average post-operative follow-up was 2.81 yrs (range: 0.50-8 yrs), (p = 0.143). Sensory fusion was assessed by the Bagolini straited glasses and/or the Worth test and stereopsis by either the TNO and/or Lang stereoacuity test prior and after surgery. Prior to surgery, 84% of the patients had reached isoacuity. Ocular motility was normal in all patients. The average size of preoperative exotropia measured by prism and alternate cover test was 28 PD (SD = 5) for both Groups. In the immediate postoperative period, 53% of the patients were overcorrected without any statistically significant difference between the 2 groups (p = 0.053). Nine (16%) patients had a "mixed" deviation (from eso- to exo depending of the fixation distance), 8 (15%) patients were orthophoric (20% in Group 1 vs 10% in Group 2) and 9 (16%) patients were undercorrected (12% in Group 1 vs 20% in Group 2). The results at last exam, were similar between the 2 Groups; good or fair alignment was achieved in 29 (53%) patients (p = 0.512); 23 (42%) patients had still X(T) (p = 0.829) and 3 (5%) patients were overcorrected. We concluded that even if the immediate postoperative results seem better with asymmetrical surgery, in the long-term there is no significant difference between the two surgical procedures.