title: [Fidelity of the potential acuity meter in the postoperative visual acuity of cataract surgery].
abstract: OBJECTIVE
  To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract.
  
  
  METHODS
  This is a prospective study performed at the Hospital Monumento Study Center. Sixty-three eyes of 45 patients submitted to phacoemulsification with intraocular lens implantation were enrolled in this study and 1 eye had been excluded. Besides the complete examination in the preoperative period, PAM was used and its results were compared with the VA at the third postoperative month and correlated with the dominant morphologic cataract classification. The result was called satisfactory when the variation was equal to or less than two lines at the Snellen chart. We transformed the AV into logMAR for comparison with the literature.
  
  
  RESULTS
  The mean age was 45.3 years with a mean VA of 0.64 logMAR by the PAM. At the third postoperative month, the mean best corrected visual acuity (BCVA) was 0.09 logMAR. The PAM overestimated the BCVA in 8 eyes (13%), underestimated it in 41 eyes (66%) and in 13 eyes (21%) the BCVA were the same. The satisfactory results regarding nuclear cataract were reduced in cases of higher density (1+/4 with 75.5% e 4+/4 with 33.3%) and increased in the posterior subcapsular cataracts (85.7%).
  
  
  CONCLUSIONS
  PAM revealed an underestimation or maintenance of the BCVA in most cases (87%). Its fidelity was inversely proportional in the nuclear cataracts (1+/4 with 75.5% e 4+/4 with 33.3%) and higher in the posterior subcapsular cataracts.
authors.affiliation: Hospital Monumento e Complexo Hospitalar Padre Bento - São Paulo (SP) - Brasil.
authors.forename: Brenda Biagio
authors.initials: BB
authors.lastname: Chiacchio
authors.forename: Ricardo Mitsuo
authors.initials: RM
authors.lastname: Sato
authors.forename: Roberta Bianca Peres
authors.initials: RB
authors.lastname: Siqueira
authors.forename: Frederico França
authors.initials: FF
authors.lastname: Marques
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000145:classification / Q000473:pathology*; D002387:Cataract Extraction / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies; D014787:Vision Tests / Q000295:instrumentation; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult