Objective: To determine whether a modified Snellen eye chart could be
used to accurately assess visual acuity (VA) in the supine position, M
ethod: This was a prospective study involving ED staff volunteers comp
aring VA on a standard Snellen eye chart with VA on a size-reduced cei
ling-mounted modified Snellen eye chart, Results: Fifty-six volunteers
participated. VA ranged from 20/10 to 20/200 on both of the charts, b
ut 87% of the volunteers had VA of 20/50 or better. The VA results for
the 2 charts were highly correlated; right eye r = 0.931 and left eye
r = 0.953, Weighted Ks showed substantial agreement for both eyes; ka
ppa = 0.63 and 0.79 for the right and left eyes, respectively. In only
4 of 112 paired measurements did the VA recorded with the ceiling cha
rt differ by >1 line from that recorded on the Snellen chart. Conclusi
on: There is an excellent correlation between VAs determined in the er
ect and the supine positions using the standard Snellen eye chart and
the modified ceiling-mounted version. Substantial agreement exists bet
ween readings using the 2 charts. Although additional testing is warra
nted in an ophthalmologically diverse patient population, use of this
chart for the assessment of VA in the supine ED patient may allow for
earlier VA evaluation.