J Med Assoc Thai 2009; 92 (6):806

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Accuracy of Noncycloplegic Refraction in Primary School Children in Southern Thailand
Funarunart P Mail, Tengtrisorn S , Sangsupawanich P , Siangyai P

Objective: To evaluate the accuracy of noncycloplegic refraction compared with cycloplegic refraction in
diagnosing refractive error in primary school children in southern Thailand.

Material and Method: This is a cross-sectional study. One hundred twenty children aged from 6-13 years who
had visual acuity of 20/40 or worse in at least one eye were included. All the children underwent autorefraction
using a Nikon model NRK-8000, retinoscopy and subjective refraction without cycloplegia followed by
cycloplegic refraction. The spherical power (SP), cylindrical power (CP), cylindrical axis (CA), and spherical
equivalence (SE) from each noncycloplegic technique were compared to cycloplegic refraction using the
mean difference. The authors also showed the percentage agreement between the data obtained from the three
noncycloplegic techniques with those from cycloplegic refraction.

Results: The SE mean difference of noncycloplegic autorefraction, retinoscopy and subjective refraction with
cycloplegic refraction were -0.85, -0.19, and -0.26, respectively (p < 0.0001). The data for the SP was similar.
The cylindrical power mean differences were -0.18, -0.13, and -0.02, respectively. The percentage agreements
of SE between noncycloplegic autorefraction, retinoscopy, and subjective refraction with cycloplegic
refraction within + 0.5 diopter (D) were 31.25%, 80.84%, and 81.66%, respectively. For the cylindrical
power, the percentages of patients who were within + 0.5 D were 87.50%, 94.58%, and 97.50%. The
percentages of patients who were within 10 degrees of the cylindrical axis were 73.46%, 96.91%, and 97.53%.

Conclusion: Noncycloplegic retinoscopy and subjective refraction are clinically accurate and can be applied
for refractive error screening in primary school children. Noncycloplegic autorefraction has a tendency
towards minus over-correction.

Keywords: Child, Refraction, Ocular, Refractive errors, Refractometry, Retinoscopy, Vision screening

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