{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T07:47:30Z","timestamp":1782719250888,"version":"3.54.5"},"reference-count":37,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T00:00:00Z","timestamp":1782518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Foundation for Science and Technology","award":["UID\/04650\/2025"],"award-info":[{"award-number":["UID\/04650\/2025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vision"],"abstract":"<jats:p>Purpose: This study was conducted to assess retinal responses in myopic and non-myopic participants after exposure to repeated low-level red-light therapy (RLRT) of 3 min and 1 min duration to see if response differs with exposure time and refractive status using global flash multifocal electroretinogram (gf-mfERG). Methods: This was a prospective exploratory pilot study with a convenient sample of 20 participants of mean age of 25.5 years (18 to 39 years) who underwent 3 min therapy, followed by, 1 week after, 1 min therapy in each participant between February to May 2025. However, four participants who did not appear in 1 min therapy for measurements were excluded from the between-group comparison analysis. We measured retinal responses using gf-mfERG ring-wise implicit time (DCT, ICT) and amplitude (DCA, ICA), baseline, post-first and post-second RLRT. Data analysis included descriptives, repeated measures ANOVA, post hoc test, Bonferroni adjusted correction, and correlation with axial length (AL) and choroidal thickness (CT) in each group. The study was conducted at CEORLab, University of Minho, Portugal, and adhered to Ethical Committee approval and the tenets of the Declaration of Helsinki. Results: In 3 min RLRT exposure, no significant within-subject changes were observed across direct (DC) and induced (IC) gf-mfERG components across all rings (p &gt; 0.05). Statistically significant between-group differences in DC implicit time were noted in Ring 2 (p = 0.029) and Ring 3 (p = 0.012). IC amplitude showed significant within-subject changes in myopes (Ring 1: p = 0.030; Ring 4: p = 0.035) and non-myopes (Ring 1: p = 0.042; Ring 3: p = 0.001; Ring 4: p &lt; 0.001; Ring 5: p = 0.034), with no significant between-group differences (p &gt; 0.05). In contrast, 1 min RLRT showed no significant changes in DC, IC time or amplitudes ICA, DCA (all p &gt; 0.05). Correlation analysis after 3 min RLRT showed that in myopes, DCT positively correlated with AL in Ring 3 (r = 0.591, p = 0.006) and Ring 4 (r = 0.615, p = 0.004), ICT positively correlated with CT in Ring 2 (r = 0.601, p = 0.005) and Ring 3 (r = 0.573, p = 0.008), and ICA negatively correlated with AL in Rings 3\u20135 (all p &lt; 0.01). Non-myopes demonstrated limited correlations, including a negative association between ICT and axial length in Ring 4 (r = \u22120.619, p = 0.004). Similar but weaker patterns were observed following 1 min RLRT. Conclusions: 3-min RLRT induces localized inner retinal functional changes without significantly altering outer retinal responses, while 1-min exposure shows no measurable effect. Retinal ERG responses are primarily influenced by axial length, particularly in myopic eyes, highlighting a structure\u2013function relationship rather than a robust short-term therapeutic effect of RLRT.<\/jats:p>","DOI":"10.3390\/vision10030037","type":"journal-article","created":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T05:49:33Z","timestamp":1782712173000},"page":"37","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Retinal Response to Low-Level Red-Light Therapy in Myopic and Non-Myopic Eyes Assessed Using Global Flash Multifocal Electroretinogram"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5730-8722","authenticated-orcid":false,"given":"Muhammad","family":"Qasim","sequence":"first","affiliation":[{"name":"Physics Center for Universities of Minho and Porto (CF-UM-UP), School of Sciences, University of Minho, Gualtar Campus, 4710-057 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3921-6357","authenticated-orcid":false,"given":"Paulo","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Physics Center for Universities of Minho and Porto (CF-UM-UP), School of Sciences, University of Minho, Gualtar Campus, 4710-057 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4369-3332","authenticated-orcid":false,"given":"Jorge","family":"Jorge","sequence":"additional","affiliation":[{"name":"Physics Center for Universities of Minho and Porto (CF-UM-UP), School of Sciences, University of Minho, Gualtar Campus, 4710-057 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1097\/OPX.0000000000001367","article-title":"Myopia control: Why each diopter matters","volume":"96","author":"Bullimore","year":"2019","journal-title":"Optom. Vis. Sci."},{"key":"ref_2","first-page":"CD004916","article-title":"Interventions to slow progression of myopia in children","volume":"1","author":"Walline","year":"2020","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/j.ophtha.2011.07.031","article-title":"Atropine for the Treatment of Childhood Myopia: Safety and Efficacy of 0.5%, 0.1%, and 0.01% Doses (Atropine for the Treatment of Myopia 2)","volume":"119","author":"Chia","year":"2012","journal-title":"Ophthalmology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1167\/iovs.62.5.3","article-title":"IMI risk factors for myopia","volume":"62","author":"Morgan","year":"2021","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1016\/j.ophtha.2021.11.023","article-title":"Effect of repeated low-level red-light therapy for myopia control in children: A multicenter randomized controlled trial","volume":"129","author":"Jiang","year":"2022","journal-title":"Ophthalmology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10633-012-9353-y","article-title":"ISCEV standard for clinical pattern electroretinography (PERG): 2012 update","volume":"126","author":"Bach","year":"2013","journal-title":"Doc. Ophthalmol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/0002-9394(54)90012-4","article-title":"The origin of the electroretinogram","volume":"38","author":"Noell","year":"1954","journal-title":"Am. J. Ophthalmol."},{"key":"ref_8","unstructured":"Kolb, H., Fernandez, E., and Nelson, R. (2005). Simple anatomy and physiology of the retina. Webvision: The Organization of the Retina and Visual System, University of Utah Health Sciences Center."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1007\/s10633-022-09872-0","article-title":"ISCEV Standard for full-field clinical electroretinography (2022 update)","volume":"144","author":"Robson","year":"2022","journal-title":"Doc. Ophthalmol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1023\/A:1022591317907","article-title":"International Society for Clinical Electrophysiology of Vision. Guidelines for basic multifocal electroretinography (mfERG)","volume":"106","author":"Marmor","year":"2003","journal-title":"Doc. Ophthalmol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1016\/S1350-9462(00)00030-6","article-title":"Pattern electroretinography (PERG) and an integrated approach to visual pathway diagnosis","volume":"20","author":"Holder","year":"2001","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10633-011-9296-8","article-title":"ISCEV standard for clinical multifocal electroretinography (mfERG) (2011 edition)","volume":"124","author":"Hood","year":"2012","journal-title":"Doc. Ophthalmol."},{"key":"ref_13","first-page":"2586","article-title":"Mapping of retinal function in diabetic retinopathy using the multifocal electroretinogram","volume":"38","author":"Palmowski","year":"1997","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3413","DOI":"10.1016\/j.visres.2006.03.013","article-title":"Retinal adaptation responses revealed by global flash multifocal electroretinogram are dependent on the degree of myopic refractive error","volume":"46","author":"Chen","year":"2006","journal-title":"Vis. Res."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Yu, M., Creel, D., and Iannaccone, A. (2019). Electroretinography. Handbook of Clinical Electrophysiology of Vision, Springer.","DOI":"10.1007\/978-3-030-30417-1"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1111\/cxo.12527","article-title":"Relationship between functional and structural retinal changes in myopic eyes","volume":"100","author":"Ismael","year":"2017","journal-title":"Clin. Exp. Optom."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s10633-013-9375-0","article-title":"Evaluation of structural and functional changes in non-pathologic myopic fundus using multifocal electroretinogram and optical coherence tomography","volume":"126","author":"Park","year":"2013","journal-title":"Doc. Ophthalmol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"658","DOI":"10.1111\/opo.12159","article-title":"Correlation of structural and electrophysiological changes in the retina of young high myopes","volume":"34","author":"Koh","year":"2014","journal-title":"Ophthalmic Physiol. Opt."},{"key":"ref_19","first-page":"286","article-title":"Multifocal electroretinogram in non-pathological myopic subjects: Correlation with optical coherence tomography","volume":"9","author":"Song","year":"2016","journal-title":"Int. J. Ophthalmol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1016\/j.preteyeres.2009.12.002","article-title":"The multifunctional choroid","volume":"29","author":"Nickla","year":"2010","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1167\/tvst.13.10.29","article-title":"The effect of repeated low-level red-light therapy on myopia control and choroid","volume":"13","author":"Liu","year":"2024","journal-title":"Transl. Vis. Sci. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1363","DOI":"10.7150\/ijms.85746","article-title":"Repeated low-level red-light therapy for controlling onset and progression of myopia\u2014A review","volume":"20","author":"Zhu","year":"2023","journal-title":"Int. J. Med. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.exer.2005.08.009","article-title":"The sclera and myopia","volume":"82","author":"Rada","year":"2006","journal-title":"Exp. Eye Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1007\/s10633-021-09857-5","article-title":"Electroretinogram responses in myopia: A review","volume":"145","author":"Gupta","year":"2022","journal-title":"Doc. Ophthalmol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.sjopt.2011.08.002","article-title":"Electrophysiological study of myopia","volume":"26","author":"Kader","year":"2012","journal-title":"Saudi J. Ophthalmol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1111\/opo.12656","article-title":"Global-flash mfERG responses to local differences in spherical and astigmatic defocus across the human retina","volume":"40","author":"Turnbull","year":"2020","journal-title":"Ophthalmic Physiol. Opt."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"6262","DOI":"10.1167\/iovs.10-5457","article-title":"Human optical axial length and defocus","volume":"51","author":"Read","year":"2010","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1186\/s40942-024-00527-7","article-title":"Correlation between multifocal electroretinogram and optical coherence tomography findings with visual acuity after vitrectomy surgery for retinal detachment: An observational study","volume":"10","author":"Hassan","year":"2024","journal-title":"Int. J. Retin. Vitr."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Begum, R., Powner, M.B., Hudson, N., Hogg, C., and Jeffery, G. (2013). Treatment with 670 nm light upregulates cytochrome C oxidase expression and reduces inflammation in an age-related macular degeneration model. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0057828"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"104412","DOI":"10.1016\/j.pdpdt.2024.104412","article-title":"Impact of repeated low-level red-light exposure on choroidal thickness and blood flow in pediatric patients: A SS-OCTA study","volume":"50","author":"Wang","year":"2025","journal-title":"Photodiagnosis Photodyn. Ther."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"26773","DOI":"10.1038\/s41598-024-78300-x","article-title":"Retinal \u201csweet spot\u201d for myopia treatment","volume":"14","author":"Swiatczak","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4679","DOI":"10.1167\/iovs.08-2135","article-title":"Individual variations in human cone photoreceptor packing density: Variations with refractive error","volume":"49","author":"Chui","year":"2008","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3103","DOI":"10.1167\/iovs.15-16446","article-title":"Longitudinal changes in choroidal thickness and eye growth in childhood","volume":"56","author":"Read","year":"2015","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1221","DOI":"10.1016\/j.visres.2005.06.030","article-title":"Delayed mfERG responses in myopia","volume":"46","author":"Chen","year":"2006","journal-title":"Vis. Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1097\/01.APO.0000578944.25956.8b","article-title":"Myopia: Anatomic changes and consequences for its etiology","volume":"8","author":"Jonas","year":"2019","journal-title":"Asia-Pac. J. Ophthalmol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Zhang, W., Yang, F., Chen, S., and Shi, T. (2024). Peripheral and posterior pole retinal changes in highly myopic Chinese children and adolescents. BMC Ophthalmol., 24.","DOI":"10.1186\/s12886-024-03328-6"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1016\/j.ajo.2012.07.015","article-title":"The relationship between axial length and choroidal thickness in eyes with high myopia","volume":"155","author":"Lugo","year":"2013","journal-title":"Am. J. Ophthalmol."}],"container-title":["Vision"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2411-5150\/10\/3\/37\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T07:19:19Z","timestamp":1782717559000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2411-5150\/10\/3\/37"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,27]]},"references-count":37,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["vision10030037"],"URL":"https:\/\/doi.org\/10.3390\/vision10030037","relation":{},"ISSN":["2411-5150"],"issn-type":[{"value":"2411-5150","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,27]]}}}