PRESCHOOL VISION SCREENING - OUTCOME OF CHILDREN REFERRED TO THE HOSPITAL EYE SERVICE

Aims - To assess the outcome of children referred to the hospital eye service (HES) from an orthoptist based preschool vision screening prog ramme. Methods - A retrospective study was conducted of children refer red from screening during a 2 year period. Children were screened by c ommunity orthoptists at 31/2 years of age. The main outcome measures w ere (1) HES findings for children referred from screening, and (2) vis ual outcome for amblyopic children after completion of treatment. Resu lts - The attendance rate at screening was 79.3% (6794 children): 348 children (5.1% of those screened) were referred to the HES. The HES fi ndings were refractive error (32.9%), amblyopia (29.9%), false positiv e referral (20.1%), strabismus (13.2%), and other ocular disorders (3. 9%). The positive predictive value of screening was 79.9%. Screening d etected 48 children with straight eyed amblyopia and 43 children with strabismic amblyopia. A visual acuity of 6/9 or better in the amblyopi c eye was achieved by 87.2% of straight eyed amblyopes and 64.3% of st rabismic amblyopes (chi(2)=5.27, p=0.02). Residual amblyopia of 6/24 o r worse occurred in only 5.6% of amblyopic children. Conclusion - Most amblyopic children detected by preschool vision screening achieve a g ood visual outcome with treatment. While treatment earlier in the sens itive period might be expected to give improved results, it remains to be demonstrated that preschool screening results in a better outcome than screening at school entry. Preschool vision screening also detect s a significant number of children without amblyopia who have reduced vision due to refractive errors. This group of children must be includ ed in any analysis of the cost effectiveness of preschool vision scree ning.