Clinical Study
Eye (2006) 20, 1345–1351. doi:10.1038/sj.eye.6702106; published online 23 September 2005
A comparison of the potential acuity meter (PAM) and the illuminated near card (INC) in patients undergoing phacoemulsification
Meeting Presentation: Presented in part at the 2003 ARVO Annual Meeting, May 4, 2003, Ft. Lauderdale, Florida, USA (Poster Session)
Financial support: None
Proprietary interest: None
M A Chang1, S Airiani2, D Miele3 and R E Braunstein2
- 1Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- 2Department of Ophthalmology, Columbia University, College of Physicians and Surgeons, New York, NY, USA
- 3Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
Correspondence: RE Braunstein, Edward S Harkness Eye Institute, 635 W 165th Street, Box 39, New York, NY 10032, USA. Tel: +1 212 326 3320; Fax: +1 212 326 3313; E-mail: reb10@columbia.edu
Received 9 March 2005; Accepted 14 August 2005; Published online 23 September 2005.
Abstract
Purpose
To compare the accuracy of the potential acuity meter (PAM) and the illuminated near card (INC) in patients undergoing phacoemulsification.
Methods
During presurgical evaluations, both PAM and INC were tested on each study patient following dilation. Patients then rated the subjective ease of use of each test. Best spectacle-corrected visual acuity (BSCVA) was recorded at 4 and 12 weeks postoperatively. McNemar's 
2 test for paired associations was used to analyse categorical data; paired t-tests were used for continuous variables.
Results
Overall, the INC was more likely than the PAM to predict BSCVA within one Snellen line (P=0.002), but this difference decreased for accuracy within two lines. The PAM predicted BSCVA within one line in 87 (70.7%) eyes, as compared to 102 (82.9%) eyes by the INC. The PAM was accurate within two lines in 109 (88.6%) eyes; the INC was accurate in 115 (93.5%) eyes. The PAM was more likely to underpredict potential acuity (P<0.001), while the INC was more likely to overpredict (P=0.004) or give exact predictions of BSCVA (P<0.001). Accuracy of the INC declined in eyes with macular comorbidity. The PAM and INC were rated as 'easy' tests by 54 (45.4%) and 93 (78.2%) patients, respectively.
Conclusions
Both the PAM and the INC were useful for predicting BSCVA after phacoemulsification, but the PAM was more likely to underestimate potential acuity. The INC was easier for patients to use, and had better accuracy than the PAM in patients without macular comorbidity, but was more likely to overestimate potential acuity.
Keywords:
potential acuity, PAM, INC, cataract, phacoemulsification, cataract surgery
