Effect of short-term exposure of red light on axial length, anterior chamber depth and visual acuity among young myopes

Purpose: evaluation of the effects of red-light exposure on vision and ocular measurements after a 3-minute exposure.

Material and methods. A Quasi experimental study was conducted. The non-random purposive sampling technique was used. The study included 41 patients with myopia. Both genders were included where the female were 90.24% while male were 9.76%. The mean age for females was 23.15 ± 1.58 (range: 19–24 years) and for males was 23 ± 2.16 (range: 20–25 years). Patient’s visual acuity (VA) was assessed with ETDRS chart while axial length (AL), anterior chamber depth (ACD), non-cylcloplegic spherical equivalent refraction (SER), keratometry readings were recorded using IOL Master before and after exposure. To provide exposure an Android mobile application called “SCREEN FLASH” was used in a dark room. The patient was exposed to the Red Screen utilizing 650 nm red light for 3 minutes. SPSS 26 was used for statistical analysis.

Results. Significant changes were observed in preand post biometric readings. The mean value of VA increased from 0.68 ± 0.33 to 0.58 ± 0.31 log MAR, (p-value < 0.001), AL decreased from 24.54 ± 1.05 to 24.53 ± 1.05 mm (p-value = 0.001), SER decreases from 4.5 ± 0.85 to 4.47 ± 0.97 D (p-value < 0.001) and ACD decreased from 3.64 ± 0.26 to 3.63 ± 0.25 mm (p-value < 0.001) after exposure. For keratometry values, results were insignificant.

Conclusion. A notable improvement in VA was found on exposure to red light in young myopic patients and significant reduction in AL, SER and ACD was observed.

1. Khan SA, Shah M, Sharif A, et al. Association of central corneal thickness among myopic and emmetropic patients visiting ophthalmology department of a tertiary care hospital in Islamabad. Journal of Rawalpindi Medical College. 2023 Apr 1; 27 (1). https://doi.org/10.37939/jrmc.v27i1.2033

2. Ekdawi N. Refractive development. Am Acad Ophthalmol. 2018. https://www.aao.org/education/disease-review/refractive-development

3. Shah M, Ullah S, Khan SA, Naroo SA. Myopia progression during COVID19 pandemic at a tertiary care hospital. Malaysian Journal of Medical Research (MJMR). 2022; 6 (3): 19–29. https://doi.org/10.31674/mjmr.2022.v6i03.003

4. Holden BA, Wilson DA, Jong M, et al. Myopia: a growing global problem with sight-threatening complications. Community eye health. 2015; 28 (90): 35. PMID: 26692649.

5. Read SA, Collins MJ, Vincent SJ. Light exposure and eye growth in childhood. Invest Ophthalmol Vis Sci. 2015 Oct; 56 (11): 6779–87. doi: 10.1167/iovs.14-15978

6. Dong J, Zhu Z, Xu H, He M. Myopia control effect of repeated low-level red-light therapy in chinese children: A Randomized, double-blind, controlled clinical trial. Ophthalmology. 2023 Feb; 130 (2): 198–204. doi: 10.1016/j.ophtha.2022.08.024

7. Saif Ullah, Mutahir Shah, Sadaf Qayyum, Sufian Ali Khan, Maryam Firdous. Myopia onset during COVID-19 pandemic: A global public health concern. Journal of Clinical and Community Ophthalmology. 2024; 2 (01): 7–12. https://www.jcco.pico.org.pk/index.php/jcco/article/view/47

8. Ullah Saif, Umer Muhammad F, Chandran Suriyakala P. Violet light transmission through eyeglasses and its effects on myopic children: A systematic review and meta-analysis. Saudi Journal of Ophthalmology. Jul–Sep 2024; 38 (3):235–42. doi: 10.4103/sjopt.sjopt_146_24

9. Singh H, Singh H, Latief U, et al. Myopia, its prevalence, current therapeutic strategy and recent developments: A review. Indian J Ophthalmol. 2022 Aug; 70 (8): 2788–99. doi: 10.4103/ijo.IJO_2415_21

10. Jiang Y, Zhu Z, Tan X, et al. Effect of repeated low-level red-light therapy for myopia control in children: A multicenter randomized controlled trial. Ophthalmology. 2022 May; 129 (5): 509–19. doi: 10.1016/j.ophtha.2021.11.023

11. He X, Wang J, Zhu Z, et al. Effect of repeated low-level red light on myopia prevention among children in China with premyopia: A randomized clinical trial. JAMA Netw Open. 2023 Apr 3; 6 (4): e239612. doi: 10.1001/jamanetworkopen.2023.9612

12. Tian L, Cao K, Ma DL, et al. Investigation of the efficacy and safety of 650 nm low-level red light for myopia control in children: A randomized controlled trial. Ophthalmol Ther. 2022 Dec; 11 (6): 2259–70. doi: 10.1007/s40123-022-00585-w

13. Tang J, Liao Y, Yan N, et al. Efficacy of Repeated low-level red-light therapy for slowing the progression of childhood myopia: A systematic review and meta-analysis. Am J Ophthalmol. 2023 Aug; 252: 153–63. doi: 10.1016/j.ajo.2023.03.036

14. Wang W, Jiang Y, Zhu Z, et al. Clinically significant axial shortening in myopic children after repeated low-level red light therapy: A retrospective multicenter analysis. Ophthalmol Ther. 2023 Apr; 12 (2): 999–1011. doi: 10.1007/s40123-022-00644-2

15. Chen Y, Xiong R, Chen X, et al. Efficacy comparison of repeated low-level red light and low-dose atropine for myopia control: A randomized controlled trial. Transl Vis Sci Technol. 2022 Oct 3; 11 (10): 33. doi: 10.1167/tvst.11.10.33

16. Liu G, Li B, Rong H, et al. Axial length shortening and choroid thickening in myopic adults treated with repeated low-level red light. J Clin Med. 2022 Dec 17; 11 (24): 7498. doi: 10.3390/jcm11247498

17. Chen H, Wang W, Liao Y, et al. Low-intensity red-light therapy in slowing myopic progression and the rebound effect after its cessation in Chinese children: a randomized controlled trial. Graefes Arch Clin Exp Ophthalmol. 2023 Feb; 261 (2): 575–84. doi: 10.1007/s00417-022-05794-4

18. Ullah S, Umer MF, Chandran SP. Long-term effect of repeated low-level redlight therapy on myopia control: A systematic review and meta-analysis. Eur J Ophthalmol. 2025 Jul; 35 (4): 1432–44. doi: 10.1177/11206721251314541