Effect of Low-Level Laser Irradiation on Accommodation and Visual Fatigue

Abstract

Purpose

This study used low-level laser irradiation on auricular points for the eyes of junior college teenagers with myopia to observe the changes in refractive errors and eye accommodation. According to the Sterner’s study, we used the relationship between the amplitude and subjective symptoms to assess the degree of improvement in visual fatigue caused by changes in accommodation.

Methods

Participants were 49 healthy junior college teenagers, with an average age of 16.04±0.80 years old, and the refractive errors of both eyes were between −1.50 D and −5.00 D. All participants underwent refractive error tests before and after class and after a 30-min break. In a 30-min break, all participants underwent two tests of with (experimental group) and without (control group) low-level laser irradiation on the auricular points. Then, refractive error tests were conducted to evaluate the participants’ eye accommodation.

Results

The results revealed that with treatment of the auricular points with and without low-level laser irradiation, the refractive error of the participants’ binocular left and right eyes decreased by −0.12 D (−0.18 D) in the experimental grou and by −0.05 D (−0.02D) in the control group. For the amplitudes of accommodation (AA) examination, the AA of the participants’ binocular in the experimental group became 7.98 ± 1.35 D (7.65 ± 1.37 D). The AA of participants’ binocular can recover to the level before the class.

Conclusion

The results indicated that low-level laser irradiation at auricular points restored the eye accommodation faster than did natural closing of the eyes.

Keywords:

• low-level laser irradiation
• myopia
• teenager
• accommodation
• auricular point

Ethical Approval

All the authors’ institutions have not established the Institutional Review Board. According to Chapter 2 Article 5 of the Taiwan Human Body Research Act, prior to conducting a research, the principal investigator shall submit the research protocol for review and approval by the Institutional Review Board (hereinafter “IRB”). The review in the preceding Paragraph shall be conducted by the research entity’s IRB. Where an entity does not have an established IRB, the review may be conducted by IRB of other entity. In this study, all procedures performed were in accordance with the ethical standards of the Human Research Ethics Committee at National Cheng Kung University (Approval No. NCKU HREC-E-107-337-2) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed Consent

Informed consent was obtained from all patients. The person in Figure 2 is one of authors and provided written informed consent for the image to be published.

Disclosure

The authors declare that they have no competing interests.

Additional information

Funding

No external funding sources to declare.