Grating acuity cardsによる視力検査

Visual acuity measurement with grating acuity cards

　生直後からの視力測定のため，一窓式縞視力カードを製作し，69人（男38人，女31人）の新生児，未熟児に対する縞視力を検査した．

　発育のよい40週数の児では，20／1200（0.0167）〜20／800（0.025）程度の縞視力が得られ，発育週数とともに視力の向上がみられた．縞視力検査の成功率は約80％で，両眼縞視力の測定時間は，平均4分47秒であった．

　早期の自発眼球運動や誘発運動の観察は，困難とされていたが，縞視力検査時の眼球運動をelectrooculographyにて記録することができた．

　以上の検査は早期の視覚障害，眼球運動障害，中枢神経系疾患に対する早期診断に有用である．

We employed a new version of one-hole grating acuity cards to test the visual acuity in 69 babies includ-ing premature ones. The measurement succeeded in about 80% of the cases. A single measurement could be completed, in average, in 4 minutes 47 seconds. Typi-cally, the visual acuity of a healthy baby at the ges-tational age of 40 weeks ranged from 0.0167 to 0.026, or 20/1200-20/800.

Contrary to the common assumption that the record-ing of voluntary and evoked eye movements are diffi-cult in babies, we could document the eye movement in our procedure by means of electrooculography. The present method promises to be of clinical value in the early diagnosis of visual disturbances, ocular motor palsies and central nervous diseases in newborn babies and in infants.