Myopia onset and role of peripheral refraction

Abstract

Background

To determine the peripheral refraction characteristics related to 18-month changes in refraction in Caucasian (Mediterranean) children.

Methods

Non-cycloplegic peripheral refraction at 10° intervals over the central ±30° of horizontal visual field over 18 months (baseline, 12 months, and 18 months of follow-up) was conducted in 50 healthy children who were 8 years old. Axial length (AL) was also recorded. Relative peripheral refraction (RPR) was calculated and eyes were divided into three study groups: non-myopic eyes, myopic eyes, and eyes that develop myopia.

Results

Myopic eyes showed hyperopic RPR and emetropic and hyperopic eyes showed myopic RPR. Univariate analysis of variance did not find any statistically significant effect of peripheral refraction (F₃₆=0.13; P=1.00) and RPR (F₃₆=0.79; P=0.80) on myopia onset (eyes that developed myopia along the study). All the studied groups showed an increase of AL, without statistically significant differences between the studied groups (F₆=0.09; P=0.99).

Conclusion

Hyperopic relative peripheral shift change in eyes that develop myopia has been found with differences in RPR between myopic (hyperopic RPR) and hyperopic or emmetropic eyes (with myopic RPR). The results suggest that RPR cannot predict development or progression of myopia in Caucasian (Mediterranean) children and the efficacy in slowing myopia progression obtained with treatments that manipulate the peripheral refraction is not just driven with RPR.

Keywords:

• myopia
• refractive errors
• myopia onset
• peripheral refraction
• relative peripheral hyperopia

Acknowledgments

The authors thank Elena Rubino for his assistance in providing the IOL Master instrument. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Disclosure

The authors report no conflicts of interest in this work.