SUMMARY
Background:
Pupillary distance measurement (PD) is an important aspect in spectacle prescription. Being the best anatomical marker for aligning the optical centers of the corrective lenses, PD is essential to avoid lens decentrations which would produce prism effects. Aim of this study is to compare precision and reproducibility of four different methods of measuring PD.
Method:
The PD of 30 patients was determined by three examiners who used four procedures millimetric ruler (procedure I), auto-refractor with manual focusing (procedure II) auto-refractor with automatic focusing (procedure III), and a PD-meter aimed at the corneal reflex (procedure IV).
Results:
There were significant diferences among the four procedures. Measurements by every examiner after procedure II were greater than those after the other procedures. Comparison of the variability among the three examiners showed a significant difference concerning procedure I. No diferences among the three examiners were found concerning the other procedures.
Discussion:
Ali four procedures produced acceptable clinical results, although measurements from manual-focused auto-refractor were statistically greater. Reproducibility of the millimetric ruler was poor.
Key words:
Pupillary distance; Corrective lenses; Spectacles