Comparing the Potential Acuity Meter (PAM) and the Illuminated Near Card (INC) in Evaluating Potential Visual Acuity
Penny A Asbell, MD; Iris Krashin-Bishler, MD; Vilma Perez, MD; Clyde Schechter, MD; Patrick So, New York, New York.
Scientific Poster #253, American Academy of Ophthalmology, 1996.
Purpose: We compared the Potential Acuity Meter (PAM) and a new device, the Illuminated Near Card (INC), in evaluating potential visual acuity in patients with glaucomatous changes. Methods: Thirty-six eyes of 21 glaucoma patients were examined by both machines and compared to Snellen Visual Acuity. The length of time spent per eye was also compared. Results: INC produced the same results as the Snellen in nearly all patients (92%). The PAM has a strong tendency to underestimate the Snellen in the majority of patients (58%). Length of time needed for INC was shorter than for PAM (mean difference 70.6 seconds). Conclusion: Both devices produce results that correlate with Snellen Visual Acuity, but this tendency is significantly stronger for the INC.
Notes taken from the Poster Exhibit by A. J. Hofeldt, MD
Testing Times
PAM: 123.1 seconds (+/- 54.6 seconds)
INC (RAM): 52.6 seconds (+/- 29.0 seconds)
INC faster by 70.6 seconds
Visual Acuity Measurement
PAM underestimated 58% of patients
INC (RAM) = Snellen 92% of patients
Stronger correlation with the INC