Abstract:
Objective To investigate interexaminer reproducibility
of non-cycloplegic subjective refractions. Subjective
refractions are frequently determined, and it is important
to know whether differences in refractive state over time
constitute meaningful, non-random change.
Methods and analysis Fifty registered and
experienced (≥5 years) optometrists from a single
geographic region performed non-cycloplegic subjective
refractions for a participant with moderate left eye(OS) to
severe right eye (OD) ametropia. Subjective refractions
were transformed to power matrices for analysis with
stereopairs, distribution ellipsoids and polar profiles
of variance of dioptric power. Absolute 95% limits of
reproducibility (
1.96 (√2
)
(SD)) for excesses of subjective
refractions for the right and left eyes separately from mean
subjective refractions were determined.
Results Mean subjective refractions were −7.68–
4.50×10 and −4.59–1.85×178 for the right and left eyes,
respectively. The 95% absolute reproducibility limits for the
stigmatic coefficients (spherical equivalents) were ≤1.71 D
and ≤0.75 D for the right and left eyes, but corresponding
limits for astigmatic coefficients were smaller (≤0.69 D).
Conclusion Removal of possible outliers for OD and
OS, respectively, reduces the absolute 95% reproducibility
limits for the stigmatic and astigmatic coefficients
to ≤0.97 D and ≤0.49 D, thus improving interexaminer
reproducibility. However, these results suggest caution
with analysis of refractive data where subjective rather
than objective methods are applied for longitudinal and
epidemiological studies.
