The Incidence, Clinical features, and Management of Essential Infantile Esotropia in the United Kingdom. A British Ophthalmology Surveillance Unit (BOSU) study

Background: /Objectives A national study was undertaken through the British ophthalmology surveillance unit (BOSU) to determine the incidence presenting features and management of essential infantile esotropia (EIE) in the UK Methods Data from a prospective national observational study of newly diagnosed EIE presenting to clinicians in the United Kingdom over a 12-month period was collected. Cases with a confirmed diagnosis by a clinician of a constant, non-accommodative esotropia ≥ 20 prism dioptres (PD), presenting at ≤ 12months, with no neurological or ocular abnormalities were identified through BOSU. Follow up data was collected at 12 months. Results A total of 57 cases were reported giving an incidence of EIE of 1 in 12,828 live births. The mean age of diagnosis and intervention were 7.05 ± 2.6 months (range 2 to 12 months) and 14.7 ± 4.9 (range 6.5–28.1 months) respectively. Management was surgical in 59.6%, and botulinum toxin alone in 22.8%, 17.5% were observed. The preoperative angle of esotropia was smaller in the observation group (P = 0.04). The post-operative angle of esotropia was not statistically significant between botulinum toxin or surgery (P = 0.3) though the age of intervention was earlier in the botulinum group (P = 0.007). Early intervention did not influence the motor post intervention outcomes between 0–10 prism dioptres of esotropia (P = 0.78). Conclusions The incidence of EIE in the UK is considerably lower than reported in other population-based studies. The preferred method of treatment was surgical with earlier intervention in those treated with botulinum toxin. An early age of intervention did not influence motor outcomes.