Outcomes of horizontal strabismus surgery in newly appointed UK trained strabismologists

Sir,

It is expected that ophthalmologists who perform strabismus surgery will participate in audit of the outcomes of their surgery to assist revalidation. However, there is not yet widespread agreement amongst strabismus surgeons on a standard format for auditing outcomes.¹ A comprehensive review of the literature shows that very little evidence exists to help reach a consensus. The only prospective multicentre study of the accuracy of surgery for horizontal strabismus showed 92% esotropes and 100% exotropes within ±10 prism dioptres (PD) of intended surgical goal.² We feel that these results might be non representative of a typical newly appointed strabismologists experience and conducted a retrospective study in our region to further inform the debate.

A multicentre review of horizontal strabismus surgery done between 2005 and 2009 was carried out. Cases were done by one of three strabismologists within 3 years of appointment to a consultant post. All had at least 1 year of sub-speciality training in strabismology in the United Kingdom. The measured outcome was the accuracy of surgical alignment (measured as angle of deviation within 5 PD, within 10 PD or greater than 10 PD of orthophoria). Of the 114 cases, 40 were aged 16 years or older (average age 40 years) and 74 were aged less than 16 (average age 5.6 years). In all, 52% operations were for exodeviations and 48% for esodeviations. Six-week follow-up results are shown in Table 1. Six-month follow-up results are shown in Table 2. The discrepancy between what is available in the literature and our results highlights the difficulty in defining standards in strabismus surgery. Indeed strabismus surgery remains a complex procedure with many different factors affecting outcomes.³ Based on the surgeons personal audits, patients in the region are happy with the service provided. Therefore we suggest that any future debate on revalidation standards should stress the importance not just of surgical goal achievement but also patient (and family) perception of the service provided alongside the outcome.

Table 1 Six-week follow-up results (near measurements available for 104 patients and distance measurements for 100 patients)

Table 2 Six-month follow-up results (near measurements available for 69 patients and distance measurements for 68 patients)