Comparison of near visual acuity and reading metrics in presbyopia correction.

PURPOSE: To provide a consistent standard for the evaluation of different types of presbyopic correction.

SETTING

Eye Clinic, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom.

METHODS

Presbyopic corrections examined were accommodating intraocular lenses (IOLs), simultaneous multifocal and monovision contact lenses, and varifocal spectacles. Binocular near visual acuity measured with different optotypes (uppercase letters, lowercase letters, and words) and reading metrics assessed with the Minnesota Near Reading chart (reading acuity, critical print size [CPS], CPS reading speed) were intercorrelated (Pearson product moment correlations) and assessed for concordance (intraclass correlation coefficients [ICC]) and agreement (Bland-Altman analysis) for indication of clinical usefulness.

RESULTS

Nineteen accommodating IOL cases, 40 simultaneous contact lens cases, and 38 varifocal spectacle cases were evaluated. Other than CPS reading speed, all near visual acuity and reading metrics correlated well with each other (r>0.70, P<.001). Near visual acuity measured with uppercase letters was highly concordant (ICC, 0.78) and in close agreement with lowercase letters (+/-0.17 logMAR). Near word acuity agreed well with reading acuity (+/-0.16 logMAR), which in turn agreed well with near visual acuity measured with uppercase letters (+/-0.16 logMAR). Concordance (ICC, 0.18 to 0.46) and agreement (+/-0.24 to 0.30 logMAR) of CPS with the other near metrics was moderate.

CONCLUSION

Measurement of near visual ability in presbyopia should be standardized to include assessment of near visual acuity with logMAR uppercase-letter optotypes, smallest logMAR print size that maintains maximum reading speed (CPS), and reading speed.