An Audit of The Royal College of Ophthalmologists Strabismic Amblyopia Treatment Protocol: A Departmental Review

Introduction: Children presenting with strabismus and mixed (anisometropic/strabismic) amblyopia are managed by a local protocol as per guidelines from the Royal College of Ophthalmologists. Decisions regarding intervention for occlusion are currently delayed until a 22 week review allowing for refractive adaptation, with intermediate reviews at 6 and 14 weeks. Purpose: The purpose of this audit was to determine adherence to the protocol and the benefit of the 14 week review. Materials and Methods: We performed a prospective data collection of all children attending the orthoptic department with strabismus without pathology, both with and without unequal vision, from October 2007 to July 2008 managed using the protocol. Results: 26 patients were eligible. Mean age at presentation was 3.3 years (1.4 to 6.5). Cycloplegic spherical equivalent (SE) mean was 2.6 dioptres (?2.25 to +7.25). Five patients failed to comply with the protocol; one patient was listed surgery, four patients commenced premature occlusion. At presentation 8 patients had equal vision (defined as < 0.1 logMAR difference) between the two eyes or would only perform BEO vision, by week 14, over 60% were found to have a difference in vision between the eyes, despite refraction correction (mean 0.4 logMAR, range 0 to 1.4 logMAR). In a subgroup of patients (n = 8 at 6 weeks) with a small discrepancy of vision between the eyes (0.1 to 0.5 logMAR) there was no progressive worsening of vision during the period of observation and 50% of patients improved spontaneously, although two patients were lost to follow up. In the subgroup (n = 10 at 6 weeks) with a large discrepancy between the eyes (> 0.5 logMAR), all patients ultimately required occlusion, and there was minimal improvement in only three patients. Conclusion: Recorded vision at 6 weeks is more informative for making treatment decisions than that recorded at presentation. The 14 week review confers no benefit to those with reliable and improving visual acuity. Those patients presenting with a large discrepancy in visual acuity do not improve after 14 weeks and we feel that these patients could be occluded at 6 weeks. We propose a new algorithm for the treatment of this patient group.