A comparison of the potential acuity meter (PAM) and the illuminated near card (INC) in patients undergoing phacoemulsification

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 v 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 ¼ 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 (Po0.001), while the INC was more likely to overpredict (P ¼ 0.004) or give exact predictions of BSCVA (Po0.001). 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.

Disparities Between Ambient, Standard Lighting and Retinal Acuities in Community‐Dwelling Older People: Implications for Disability

“…In this study of 299 community‐dwelling older people, 45% had the potential of seeing better by three or more lines of letters. If this sample is representative, then perhaps 4.5 million elderly Americans living independently could see appreciatively better with improved lighting and ophthalmic care 21,22 …”

“…As noted for aging and cataractogenesis, 5 the human lens severely attenuates light, although the light intensity of the RAM is sufficient to penetrate a cataract that attenuates up to 97% of light. RAM technology has been shown to measure retinal acuity at statistically significant levels in eyes with maculopathy, glaucoma, opaque posterior capsule, and cataract associated with vision loss to the 20/200 level 16,18–21 …”

“…The difference between standard lighting acuity and retinal acuity is vision loss attributable to ocular conditions 16–21 such as uncorrected refractive error, corneal conditions, cataract, and other opacities in the ocular media and is termed the “ocular component of visual reserve.” For measurement of standard lighting acuity and retinal acuity, each eye was tested separately. The standard lighting acuity of the better eye was compared with the retinal acuity of the same eye (although correlations between right and left eye acuity were large: correlation coefficient (r) =0.63 for standard lighting vision and r =0.66 for retinal acuity, P <.001).…”

“…RAM technology has been shown to measure retinal acuity at statistically significant levels in eyes with maculopathy, glaucoma, opaque posterior capsule, and cataract associated with vision loss to the 20/200 level. 16,[18][19][20][21] The difference between standard lighting acuity and retinal acuity is vision loss attributable to ocular conditions [16][17][18][19][20][21] such as uncorrected refractive error, corneal conditions, cataract, and other opacities in the ocular media and is termed the ''ocular component of visual reserve.'' For measurement of standard lighting acuity and retinal acuity, each eye was tested separately.…”

Cataract surgery after pars plana vitrectomy

“…Reviewing the patients' charts and their best-corrected visual acuity (BCVA) before developing the cataract together with the thorough ophthalmic examination will help the surgeon to decide. Additionally, tests such as the potential acuity pinhole test, the potential acuity meter, the retinal acuity meter, the illuminated near card and laser interferometer and Amsler grid have been shown to be valuable to predict postsurgical visual acuity and thus could help with the decision to proceed to cataract surgery [13,14].…”