Development of manifest strabismus and reduced visual acuity following initial normal orthoptic examination/pseudo-strabismus under the age of 30 months

摘要

Aim: To evaluate the incidence of manifest strabismus and the visual acuity found at 5-year vision screening in those who were referred with concerns of strabismus under the age of 30 months and were initially diagnosed by an orthoptist with either pseudo-strabismus or "no abnormality detected" (NAD). Method: Data were collected for children who were seen between April 2007 and March 2008 and diagnosed as above. Notes were retrieved and the database of visual acuity at screening was examined. Results: 248 children were diagnosed as NAD or pseudo-squint on their first visit. 82 were discharged at their first appointment and 166 were offered follow-up. Notes were retrieved for 208 (84%). Of those followed up, 4 (1.9%) were later found to have a heterotropia (2 esotropes, 2 exotropes). Vision screening results were available for 207 (83.5%). Of these, 172 (83%) passed and 35 (17%) failed vision screening. 2 were found to have microtropia and 1 was esotropic. There was no statistically significant difference in the rate of referral from visual screening between the general population and those who were seen and discharged on their first visit (x2=1.76, p=0.67 risk ratio=0.98 [95% CI 0.89 to 1.08]). Conclusion: The incidence of undiagnosed esotropia in this group is between 2.4% and 3.4%. The risk of failing visual screening is the same as the general population.