Clinical Analysis of Strabismus in Twin.

Yoon, Kyung Chul; Kim, Hyun Kyung; Park, Hong Young; Park, Yeoung Geol

Original Article

Journal of the Korean Ophthalmological Society 2003;44(7):1584-1591.
Published online July 1, 2003.

Clinical Analysis of Strabismus in Twin.

Kyung Chul Yoon, Hyun Kyung Kim, Hong Young Park, Yeoung Geol Park

Department of Ophthalmology, Chonnam University Medical School and Hospital, Gwang-Ju, Korea. ophyoon@hanmail.net

쌍둥이에서 발생한 사시의 임상적 분석

윤경철 ( Kyung Chul Yoon ) , 김현경 ( Hyun Kyung Kim ) , 박홍용 ( Hong Young Park ) , 박영걸 ( Yeoung Geol Park )

Abstract

PURPOSE
To evaluate the genetic factor in development of comitant strabismus. METHODS: We retrospectively reviewed 48 patients of 24 twins classified into monozygotic or dizygotic twin and analyzed gestational period and birth weight, refraction, phenotype and age of onset, amount of deviation, surgical history, and associated systemic or other ocular anomaly except strabismus. RESULTS: Seventeen of the 24 twins (70.8%) showed phenotypic concordance. The concordance was significantly higher in monozygotic twins (15 of the 18 pairs, 83.3%) than in dizygotic twins (2 of the 6 pairs, 33.3%) (p=0.038). Out of 15 twins with monozygosity who showed concordance, the predominant phenotype was intermittent exotropia (9 pairs, 60.0%). Concordance rate according to phenotype was high in refractive or nonrefractive accommodative esotropia (3 of the 3 pairs, 100.0%) and intermittent exotropia (9 of the 10 pairs, 90.0%). Most of concordant pairs showed similarity in age of onset and amount of deviation between first and second child. CONCLUSIONS: The concordance rate in monozygotic twin was high, especially in refractive or nonrefractive accommodative esotropia and intermittent exotropia, and therefore genetic factor can be responsible for the development of these types of strabismus.

Key Words: Concordance;Genetic factor;Strabismus;Twin