First-finder-related Clinical Features of Intermittent Exotropia

Abstract

Purpose: To determine whether the clinical features of intermittent exotropia (IXT) needing muscle surgery were different in the ophthalmologist-detected and non-specialist-detected groups (including parents).Methods: Medical records of 218 children (mean age: 5.9 ± 1.4 years) with IXT of ≥ 20 prism diopters (PD) were reviewed retrospectively. The angles of deviation were measured using the prism and alternate cover test and assessed by two ophthalmologists using photographs with a translucent occluder (photographic angle). The IXT subtype, fusional control, stereopsis, suppression, and spherical equivalent (SE) were compared between the ophthalmologist-detected and non-specialist-detected groups.Results: Mean 25.8 ± 6.8 PD of distant angle of IXT was first detected by the ophthalmologist in 41 patients (18.8%) and the non-specialists in 177 patients (81.2%). The deviated eye was more myopic in the ophthalmologist-detected than non-specialist- detected group (-0.77 ± 1.59 diopters [D] vs. -0.19 ± 1.48 D, <i>p</i> = 0.03). There were no other differences between the two groups. A comparison of 39 age- and non-dominant eye SE-matched pairs demonstrated that the measured angles for distant and near fixation were smaller in the ophthalmologist-detected than non-specialist-detected group (24.0 ± 6.8 PD vs. 28.5 ± 6.4 PD and 26.9 ± 6.6 PD vs. 31.0 ± 6.4 PD, respectively, <i>p</i> < 0.01), while the remaining characteristics, including the photographic angle, were similar.Conclusions: In cases with small angles of deviation or myopia, IXT with angles requiring surgical correction were commonly first detected by ophthalmologists during examinations.