HandyRef-K: Comparison of the Latest Handheld Auto Refracto-keratometer with Retinomax and Plusoptix in Patients Younger than Three Years of Age

INTRODUCTION: The purpose of the study was to compare the refractive error measurements of pediatric patients performed with a Plusoptix A09 photorefractor (PO; Plusoptix AG, Nuremberg, Germany), a Retinomax K-plus 3 (RTX; Right Group, Tokyo, Japan), and the new handheld auto refracto-keratometer, the Nidek HandyRef-K (HDY; Nidek SA, Créteil, France), and to evaluate the intermethods agreement.
METHODS: A total of 194 eyes of 194 children were included in the study. All of the children underwent refraction measurement with the PO before cycloplegia and 2 autorefractors were used after cycloplegia: the RTX and the HDY.
RESULTS: The mean age of the patients was 16.65±10.04 months (range: 3-34 months). There were no statistically significant differences between the spherical values (SV) or cylindrical axis values (CAV) measured with the PO (SV: 1.61±1.79 diopters [D]; CAV: 94.25±72.47 D), the RTX (SV: 1.91±2.06 D; CAV: 94.3±73.44 D), and the HDY (SV: 1.89±2.04 D; CAV: 93.55±73.71 D) (p>0.05).There was a statistically significant difference in the cylindrical values (CV) assessed with the RTX (CV: -0.97±0.75 D) and the HDY (CV: -1.11±0.76 D) (p=0.003) and the HDY and the PO (CV: -0.92±0.68 D)(p=0.002), while there was no statistically significant difference between the values determined with the RTX and the PO (p>0.05). Statistically significant differences were demonstrated for spherical equivalent values (SEV) obtained with the RTX (SEV: 1.43±1.97 D) and the PO (SEV: 1.15±1.74 D) (p=0.02), and the HDY (SEV: 1.34±1.95 D) and the PO (p=0.03), but no significant difference was found between the RTX and the HDY values (p>0.05).
DISCUSSION AND CONCLUSION: No significant difference was found between the SEV measured by the RTX and the HDY, but the PO was significantly less hyperopic than the RTX and the HDY. The CV measured by HDY was higher than that of other devices. These devices can be used for screening in crowded pediatric ophthalmology clinics and may be an easier way of measuring refractive errors in children younger than 3 years of age, but high SEV and CV results should serve as an alert to physicians. It should also be kept in mind that cycloplegic retinoscopy is still the gold standard and these alternative methods can only be used for screening. The prescription of eyeglasses should not be made without cycloplegic retinoscopy.