The Assessment of Stereoacuity in Patients with Strabismus

Abstract

목적: 사시환자에서 입체시 검사법에 따른 입체시의 양상과 입체시에 영향을 미치는 인자를 알아보고자 하였다.

대상과 방법: 간헐외사시 또는 굴절조절내사시로 진단받은 사시환자를 대상으로 티트무스 검사, 티엔오 검사, 랑 II 검사를 이용하여 입체시를 측정하였다.

결과: 간헐외사시 환아 94명, 굴절조절내사시 환아 36명으로, 평균나이는 7.2세였다. 간헐외사시 환아에서 평균 입체시는 티트무스 검사, 티엔오 검사, 랑 II 검사에서 각각 143.1±207.9초, 130.2±103.7초, 200.0±0.0초였으며, 굴절조절내사시 환아에서는 각각 430.3±288.6초, 232.5±90.0초, 230.0±97.9초였다. 입체시를 보지 못한 빈도는 간헐외사시 환아보다 굴절조절내사시 환아에서 더 높았고, 두 환아군 모두 티엔오 검사에서 입체시를 보지 못한 비율이 가장 높았다. 입체시에 영향을 미치는 유의한 인자는 보이지 않았다.

결론: 입체시의 분포는 동일한 환아에서도 입체시 검사의 종류에 따라 다른 양상을 보였고, 굴절조절내사시 환아가 간헐외사시 환아보다 더 낮은 입체시를 보였다. 사시환자에서 입체시 저하를 발견하기 위해서는 티엔오 검사가 민감할 것으로 생각된다.

Purpose: To analyze stereoacuity in patients with strabismus using various stereotests.

Methods: Stereoacuity was assessed in children who were diagnosed with intermittent exotropia or refractive accommodative esotropia using the Titmus stereotest, TNO stereotest, and the Lang II stereotest. Patients with amblyopia or previous ocular surgery were excluded.

Results: Ninety-four patients with intermittent exotropia and 36 patients with refractive accommodative esotropia were included; the mean age was 7.2 years. The mean stereoacuity in intermittent exotropia was 143.1±207.9 seconds of arc with the Titmus stereotest, 130.2±103.7 seconds of arc with the TNO stereotest, and 200.0±0.0 seconds of arc with the Lang II stereotest. The mean stereoacuity in refractive accommodative esotropia was 430.3±288.6 seconds of arc, 232.5±90.0 seconds of arc, and 230.0±97.9 seconds of arc, respectively. The absence of stereoacuity was more frequent in patients with refractive accommodative esotropia than in patients with intermittent exotropia, and both groups of patients showed the largest proportion of absent stereopsis with the TNO stereotest. No factor was significant for stereopsis in patients with intermittent exotropia and patients with refractive accommodative esotropia.

Conclusions: Stereoacuity showed various seconds of arc according to the type of stereotest in the same patient. Patients with refractive accommodative esotropia showed lower stereoacuity in all stereotests than patients with intermittent exotropia. TNO stereotests are sensitive enough to detect the absence of stereopsis in patients with strabismus.