Instruments for predicting visual acuity. A clinical comparison
R. C. Spurny, R. Zaldivar, C. D. Belcher 3rd and R. J. Simmons
A series of 54 eyes in 50 patients had preoperative predictions of
postoperative visual acuity, using both a white-light interferometer
(Lotmar Visometer) and a Snellen chart projector (Guyton-Minkowski
Potential Acuity Meter). The predicted vision by each instrument was
compared with the actual postoperative vision. Forty eyes in 36 of these
patients, 25 with concurrent eye disease, had cataract extraction with
intraocular lens implantation. Fifteen eyes in 15 patients, 11 with
concurrent eye disease, had neodymium-YAG laser posterior capsulotomy. The
Visometer gave more accurate predictions than the Potential Acuity Meter in
cataract patients with open angle glaucoma, even with glaucomatous visual
field loss, and in patients with a visual acuity of less than 20/400 due to
advanced cataract formation.
