PATTERN OF PRESENTATION OF STRABISMUS AMONG PATIENTS OF THE EYE CLINIC OF UNIVERSITY COLLEGE HOSPITAL (UCH), IBADAN

Abstract

Strabismus is a misalignment of the visual axes of the eyes which results from deviation of one or both eyes. It has a worldwide distribution and is relatively common in children. Strabismus is a disorder of public health significance because of its psychosocial impact and negative social prejudice. However, there is paucity of information on the prevalence of the different types of strabismus and treatment outcome in Nigerian patients. Objective:To determine the pattern of presentation of strabismus among new patients of the Eye Clinic, University College Hospital (UCH) Ibadan, Nigeria between January 1999 and December 2008. Methods: This was a retrospective cross-sectional study with both descriptive and analytical components. The study was conducted on patients who presented for the first time to the Eye Clinic of UCH, Ibadan between 1999 and 2008. Patients with a diagnosis of strabismus were identified from the clinic registers and their case records were retrieved. Information on age, sex, cause and type of squint, associated ocular disease, treatment given, outcome of treatment as well as duration of follow up was collected and analysed with the use of SPSS 16. Analysis was considered to show significant association when the p value was less than 0.05 Results: A total of 240 patients had strabismus, giving a prevalence of 1.2%. Mean age of strabismus patients was 19.8 (±19.7) years while male to female ratio was 0.98:1. Esotropia occurred in 53.8% of patients while 44.2% had exotropia. The mean age of patients with esotropia was 12.8 years compared with 27.9 years for patients with exotropia. (p<0.001). About 72% of the patients had secondary strabismus and commonest cause of secondary strabismus was cataract in 29%. Sensory strabismus was the commonest subtype of strabismus, occurring in 83 (34.5%) patients; while accommodative esotropia was found in 5.8% patients. With regard to treatment 25.4% of patients were prescribed spectacles, two (0.8%) patients had strabismus surgery, while 65.4% of patients did not receive any active treatment. Only 49.6% of the patients kept follow up appointments. Majority (64.7°/o) of them did not have any realignment of the eyes (unfavourable outcome) at follow up. A favourable outcome was more likely in patients with secondary strabismus (p=0.005) and among those who received active treatment (p=0.003). Conclusion: The prevalence of strabismus in this study is fairly similar to other reports from Nigeria and Africa. Strabismus prevalence is lower in Africans compared to Caucasians. Esotropia was more common than exotropia and majority of patients had secondary strabismus. Sensory strabismus was the commonest subtype of strabismus while accommodative esotropia appears to occur less commonly when compared to Caucasians. A larger proportion of the patients did not receive any active treatment for strabismus and strabismus surgery was performed infrequently. The follow up rate was suboptimal and outcome of treatment was favourable in less than half of the patients studied. Secondary strabismus and receiving some form of treatment were associated with a better outcome. There is a need for more ophthalmologists in UCH Ibadan to undergo subspecialty training in the evaluation and management of strabismus.