Comparison of the potential acuity meter and pinhole tests in predicting postoperative visual acuity after cataract surgery

Abstract

To compare the accuracy of potential acuity meter (PAM) and pinhole (PH) tests in predicting visual acuity after cataract surgery. Department of Ophthalmology and Visual Sciences, University of the Philippines, Philippine General Hospital, Manila, and Asian Eye Institute, Makati, Philippines. This prospective study comprised 64 eyes with mild to moderate cataract that had uneventful phacoemulsification. The PAM and PH tests were performed to predict postoperative visual acuity. Best corrected visual acuity (BCVA) 4 weeks after surgery was compared with the predicted visual acuity. The number of lines of inaccuracy was calculated by subtracting the BCVA from the predicted visual acuity. The variables analyzed were type of predictive test and preoperative BCVA. The eyes were divided according to preoperative BCVA as follows: Group 1, 20/20 to 20/50; Group 2, 20/60 to 20/100; Group 3, 20/200 or worse. The PH predicted visual acuity was correct in 5% of eyes and the PAM predicted acuity, in 17%. The PH predicted acuity was accurate within 1, 2, and 3 lines of BCVA in 23%, 40%, and 54% of eyes, respectively, and the PAM predicted acuity, in 64%, 81%, and 92% of eyes, respectively. The mean number of lines of inaccuracy was significantly less with the PH than with the PAM (3.47 lines +/- 2.42 [SD] and 1.60 +/- 1.55 lines, respectively) (P=.0005). The mean lines of inaccuracy in Group 1 were 2.49 +/- 1.52 for the PH and 1.14 +/- 0.99 for the PAM (P=.027); in Group 2, 3.17 +/- 1.99 PH and 1.65 +/- 1.80 PAM (P=.642); and in Group 3, 6.58 +/- 3.03 PH and 2.67 +/- 2.10 PAM (P=.240). The PAM was more accurate than the PH in predicting visual acuity after cataract surgery. The accuracy of both tests decreased in patients with poorer preoperative visual acuity.