Purchase this article with an account.
Y. Kitaguchi, J. Hosohata, H. Shimojyou, T. Fujikado; An Age Relation of the Myopic Shift in Phoria in Intermittent Exotropia . Invest. Ophthalmol. Vis. Sci. 2006;47(13):3676.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
In some eyes with intermittent exotropia (IXT), myopic shift with miosis is observed in binocular viewing condition. However an age relation of the myopic shift is not well investigated. In this study; we measured the amount of myopic shift and pupillary constriction in relation to age in patients with IXT.
A consecutive 36 patients with IXT who visited Osaka University Hospital in 2004 were studied. The age ranged from 4 to 43 years. 21 patients were aged under 9years (child group), 9 between 10 and 19 years (adolescent group), 6 between 20 and 43 years (adult group)). The angle of strabismus evaluated by alternating prism cover test was 2 to 50 (28±11)[[Unsupported Character – ⊿]] at 5m. Refraction and pupillary diameter were simultaneously measured by infrared video retinoscopy and pupillography (Powerref II, Plusoptix). Measurements were both in monocular and binocular condition under the mesoscopic light. The distance of measurement was set to 1 m and the results of 3 measurements were averaged. The statistic analysis was done in one eye of each patient.
The difference of refraction ([[Unsupported Character – ⊿]] R) and pupil diameter ([[Unsupported Character – ⊿]] P) between binocular and monocular condition was [[Unsupported Character – ⊿]]R = –0.45 ± 0.62D, [[Unsupported Character – ⊿]]P = –0.07 ± 0.69 mm in child group, [[Unsupported Character – ⊿]]R= –0.27 ± 0.36 D, [[Unsupported Character – ⊿]] P= –0.42± 0.74 mm in adolescent group, and [[Unsupported Character – ⊿]]R=–1.54 ± 1.18 D [[Unsupported Character – ⊿]] P = – 1.61 ± 1.19 mm in adult group. [[Unsupported Character – ⊿]] R and [[Unsupported Character – ⊿]] P were significantly larger in adult group than in child or adolescent group.
In IXT patients, a significant myopic shift under binocular condition occurred in a group beyond the age of 20 years, which accompanied the constriction of pupil. The aging of convergence– accommodation system may be responsible for this change.
This PDF is available to Subscribers Only