From pathophysiology to rehabilitation: Addressing low vision in diabetic retinopathy
Maduabuchukwu I. Nkollo, Nnaemeka A. Onwukwe, Edafe O. Emurotu, Helen Lucky-Udi, Ayodeji E. Ige, Bobby I. Ebuehi, Franklin E. Kio, Anthony U. Megwas, Afe V. Dania, Canice C. Asonye
Abstract
Diabetic Retinopathy (DR) is a major microvascular complication of diabetes mellitus and one of the leading causes of low vision and blindness globally. As the prevalence of diabetes increases, DR-related visual impairment poses significant clinical and public health challenges. This review explores the pathophysiological mechanisms underlying DR, its contribution to low vision, and rehabilitation strategies to improve patient outcomes. Relevant peer-reviewed articles, guidelines, and reports from 1990 to 2024 were reviewed from databases including PubMed, Scopus, and Google Scholar. The focus was on studies addressing the pathogenesis of DR, the prevalence of DR-related low vision, and evidence-based rehabilitation interventions. The pathophysiology of DR involves chronic hyperglycemia, oxidative stress, microvascular damage, and breakdown of the blood-retinal barrier, leading to retinal ischemia, neovascularization, and irreversible vision loss. DR accounts for an estimated 4.8% of global blindness, with rising prevalence in low- and middle-income countries. While medical and surgical treatments, such as laser photocoagulation, intravitreal anti-VEGF therapy, and vitrectomy, slow disease progression, many patients develop irreversible visual impairment. Rehabilitation through optical aids, electronic devices, orientation and mobility training, and psychosocial support significantly enhances quality of life. Addressing low vision in DR requires a dual approach: early detection and intervention to prevent progression, and comprehensive rehabilitation services to optimize residual vision. Integrating low vision care into diabetes and ophthalmology services is essential to reduce disability and improve functional independence in affected individuals.
Keywords
References
- American Diabetes Association. Standards of medical care in diabetes-2023. Diabetes Care. 2023; 46(Suppl. 1), S1-S290. doi: 10.2337/dc23-SINT
- International Diabetes Federation. IDF Diabetes Atlas (10th ed.). 2023; IDF. https://diabetesatlas.org
- Cheung N, Mitchell P, Wong TY. Diabetic retinopathy. The Lancet. 2010; 376(9735): 124-136. doi: 10.1016/S0140-6736(09)62124-3
- Yau JWY, Rogers SL, Kawasaki R, Lamoureux EL, Kowalski JW, BekT, et al. Global prevalence and major risk factors of diabetic retinopathy. Diabetes Care. 2012; 35(3): 556-564. doi: 10.2337/dc11-1909
- World Health Organization. World report on vision. Geneva: WHO. 2019. https://www.who.int/publications/i/item/ world-report-on-vision
- Mwangi M, Gichuhi S, Rono H. Prevalence and risk factors for diabetic retinopathy in sub-Saharan Africa: A systematic review and meta-analysis. BMC Ophthalmology. 2020; 20(1): 283. doi: 10.1186/s12886-020-01568-8
- Khanna RC, Murthy GVS, Gilbert C. Low vision and blindness rehabilitation. Community Eye Health Journal. 2021; 34(112): 65-68. NIH: 301-402-0276.
- Brownlee M. The pathobiology of diabetic complications: A unifying mechanism. Diabetes. 2005; 54(6): 1615-1625. doi: 10.2337/diabetes.54.6.1615
- Stitt AW, Curtis TM, Chen M, Medina RJ, McKay GJ, Jenkins A, et al. The progress in understanding and treatment of diabetic retinopathy. Progress in Retinal and Eye Research. 2016; 51: 156-186. doi: 10.1016/j.preteyeres. 2015.08.001
- Antonetti DA, Klein R, Gardner TW. Diabetic retinopathy. New England Journal of Medicine. 2012; 366(13): 1227-1239. doi: 10.1056/NEJMra1005073
- Cunha-Vaz J. Phenotypes and biomarkers of diabetic retinopathy. Progress in Retinal and Eye Research. 2014; 41: 90-111. doi: 10.1016/j.preteyeres.2014.03.003
- Aiello LP, Avery RL, Arrigg PG, Keyt BA, Jampel HD, Shah ST, et al. Vascular endothelial growth factor in ocular fluid of patients with diabetic retinopathy and other retinal disorders. New England Journal of Medicine. 1994; 331(22): 1480-1487. doi: 10.1056/NEJM199412013312203
- Campochiaro PA. Molecular pathogenesis of retinal and choroidal vascular diseases. Progress in Retinal and Eye Research. 2015; 49: 67-81. doi: 10.1016/j.preteyeres.2015.06.001
- Wong TY, Cheung CM, Larsen M, Sharma S, Sim R. Diabetic retinopathy. Nature Reviews Disease Primers. 2016; 2: 16012. doi: 10.1038/nrdp.2016.12
- World Health Organization. (2005). Prevention of blindness from diabetes mellitus. Geneva: WHO Press. ISBN: 9789241547123
- Teo ZL, Tham YC, Yu M, et al. Global prevalence of diabetic retinopathy and projection of burden through 2045: Systematic review and meta-analysis. Ophthalmology. 2021; 128(11): 1580-1591. doi: 10.1016/j.ophtha.2021. 04.027
- Saeedi P, Petersohn I, Salpea P, Malanda B, Karuranga S, Unwin N, et al. Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas, 9th edition. Diabetes Research and Clinical Practice. 2019; 157: 107843. doi: 10.1016/j.diabres.2019.107843
- Xie X, Xu L, Yang J. Global burden of vision loss due to diabetic retinopathy, 1990-2021: Findings from the Global Burden of Disease Study. BMJ Open Ophthalmology. 2024; 9(1): e002111. doi: 10.1136/bmjophth-2022-002111
- Times of India. Can’t turn a blind eye to diabetic retinopathy: India’s looming vision crisis. The Times of India. 2024. Updated: Nov 19, 2025, 14:22 IST
- Sabanayagam C, Banu R, Chee ML, Lee R, Wang YX, Tan G, et al. Incidence and progression of diabetic retinopathy: A systematic review. The Lancet. Diabetes and Endocrinology. 2019; 7(2): 140-149. doi: 10.1016/ S2213-8587(18)30128-1
- Lamoureux EL, Keeffe JE. The importance of measuring the impact of vision impairment for adults and children. Community Eye Health Journal. 2007; 20(63): 1-4. doi: Nil.
- Stelmack J. Quality of life of low-vision patients and outcomes of low-vision rehabilitation. Optometry and Vision Science. 2001; 78(5): 335-342. doi: 10.1097/00006324-200105000-00019
- Crossland MD, Silva RS, Macedo AF. Electronic vision enhancement systems for low vision rehabilitation: A systematic review. Ophthalmic and Physiological Optics. 2014; 34(2): 169-182. doi: 10.1111/opo.12106
- Binns AM, Bunce C, Dickinson C, Harper R, Tudor-Edwards R, Woodhouse M, et al. How effective is low vision service provision? A systematic review. Survey of Ophthalmology. 2012; 57(1): 34-65. doi: 0.1016/j.survophthal. 2011.06.006
- Jin B, Ai Z, Rasmussen ML, Yan J. Artificial intelligence applications for low vision and blindness: A systematic review. Translational Vision Science and Technology. 2021; 10(14): 1-12. doi: 10.1167/tvst.10.14.1
- Silver J, Gill J, Wolffsohn JS. The use of electronic vision enhancement systems (EVES) by people with vision impairment. Ophthalmic and Physiological Optics. 2018; 38(5): 513-528. doi: 10.1111/opo.12572
- Bourne RRA, Flaxman SR, Braithwaite T, Cicinelli MV, Das A, Jonas JB, et al. Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: A systematic review and meta-analysis. The Lancet Global Health. 2017; 5(9): e888-e897. doi: 10.1016/S2214-109X(17)30293-0
- Nathan DM, Genuth S, Lachin J, Cleary P, Crofford O, Davis M, et al. Intensive diabetes therapy and cardiovascular disease in type 1 diabetes. The New England Journal of Medicine. 2005; 353(25): 2643-2653. doi: 10.1056/ NEJMoa052187
- UK Prospective Diabetes Study (UKPDS) Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). The Lancet. 1998; 352(9131): 837-853. doi: 10.1016/S0140-6736(98)07019-6
- ETDRS Research Group. Early treatment diabetic retinopathy study report number 9. Ophthalmology. 1991; 98(5 Suppl): 766-785.PMID: 2062512.
- Diabetic Retinopathy Clinical Research Network; Elman MJ, Aiello LP, Beck RW, Bressler NM, Bressler SB, Edwards AR, et al. Randomized trial evaluating ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic macular edema. Ophthalmology. 2010; 117(6): 1064-1077. doi: 10.1016/j.ophtha. 2010.02.031
- Hariprasad SM, Mieler WF, Grassi M, Green JL, Jager RD, Miller L. Vision-related quality of life in patients with diabetic macular edema. British Journal of Ophthalmology. 2008; 92(1): 89-92. doi: 10.1136/bjo.2007.122416
- Owsley C, Sekuler R, Siemsen D. Contrast sensitivity throughout adulthood. Vision Research. 2001; 21(5): 859-868. doi: 10.1016/0042-6989(83)90210-9
- Ismail GM, Whitaker D. Early detection of changes in visual function in diabetes mellitus. Ophthalmic and Physiological Optics. 1998; 18(1): 3-12. PMID: 9666905.
- Bressler NM, Varma R, Doan QV, Gleeson M, Danese M, Bower JK, et al. Underuse of eye care in diabetes. Archives of Ophthalmology. 2010; 128(9): 1206-1213. doi: 10.1001/archophthalmol.2010.191
- Rees G, Xie J, Fenwick EK, Lamoureux EL. Vision-specific distress and depressive symptoms in people with vision impairment. Investigative Ophthalmology and Visual Science. 2010; 51(6): 28912896. doi: 10.1167/iovs.09-5080
- Ferris FL, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. American Journal of Ophthalmology. 1982; 94(1): 91-96. PMID: 7091289.
- Elliott DB, Sanderson K., Conkey A. The reliability of the Pelli-Robson contrast sensitivity chart. Ophthalmic and Physiological Optics. 1990; 10(1): 21-24. PMID: 2330208.
- Raasch TW, Bailey IL, Bullimore MA. Repeatability of visual field measurements in normal and low vision patients. Optometry and Vision Science. 1993; 70(2): 97-104. doi: 10.1097/00006324-199805000-00024
- Hee MR, Puliafito CA, Wong C, Duker JS, Reichel E, Schuman JS, et al. Optical coherence tomography of macular holes. Ophthalmology. 1995; 102(5): 748-756. doi: 10.1016/s0161-6420(95)30959-1
- Nahar N, Chowdhury H, Madzuki IN, Das P, Jamaludin MI, Sharma K, Ghosh R, Azad A. Bibliometric analysis of diabetic retinopathy research using optical coherence tomography (2020-2025): A VOSviewer study. Mediterranean Journal of Medical Research. 2025; 2(4): 239-258. doi: 10.5281/zenodo.17682969
- Brown DM, Schmidt-Erfurth U, Do DV, Holz FG, Boyer DS, Midena E, et al. Intravitreal aflibercept for diabetic macular edema: 100-week results from the VIVID and VISTA studies. Ophthalmology. 2015; 122(10): 2044-2052. doi: 10.1016/j.ophtha.2015.06.017
- Diabetic Retinopathy Vitrectomy Study (DRVS) Research Group. Early vitrectomy for severe vitreous hemorrhage in diabetic retinopathy. Archives of Ophthalmology. 1985; 92(4): 492-506. PMID: 2865943.
- DCCT Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications. The New England Journal of Medicine. 1993; 329(14): 977-986. doi: 10.1056/NEJM1 99309303291401
- ACCORD Eye Study Group. Effects of medical therapies on retinopathy progression in type 2 diabetes. The New England Journal of Medicine. 2010; 363(3): 233-244. doi: 10.1056/NEJMoa1001288
- Abràmoff MD, Lavin PT, Birch M, Shah N, Folk JC. Pivotal trial of an autonomous AI-based diagnostic system for the detection of diabetic retinopathy in primary care offices. NPJ Digital Medicine. 2018; 1(1): 39. doi: 10.1038/s 41746-018-0040-6
- Whittaker SG, Lovie-Kitchin J. Visual requirements for reading. Optometry and Vision Science. 1993; 70(1): 54-65. doi: 10.1097/00006324-199301000-00010
- Corn AL, Erin JN. Foundations of low vision: Clinical and functional perspectives (2nd ed.). 2021; American Foundation for the Blind Press. ISBN: 9780891288831.
- Kumar P, Bandyopadhyay S, Singh JP. Low vision aids and training: Improving visual functioning in patients with low vision. Indian Journal of Ophthalmology. 2014; 62(6): 629-634.Bookshelf ID: NBK585124. PMID: 36256771.
- Lovie-Kitchin JE, Devereaux J, Wells S, Sculpher K. Multi-disciplinary low vision rehabilitation. Clinical and Experimental Optometry. 2001; 84(4): 165-170. doi: 10.1111/j.1444-0938.2001.tb04961.x
- Lamoureux EL, Pallant JF, Pesudovs K, Rees G, Hassell JB, Keeffe JE. The effectiveness of low-vision rehabilitation on participation in daily living and quality of life. Investigative Ophthalmology and Visual Science. 2007; 48(4): 1476-1482. doi: 10.1167/iovs.06-0610
- Goodrich GL, Kirby J, Cardenas D, Smith C. A visual skills workbook for individuals with low vision. Journal of Visual Impairment and Blindness. 2004; 98(10): 579-590. doi: Nil.
- Markowitz SN. Principles of modern low vision rehabilitation. Canadian Journal of Ophthalmology. 2006; 41(3): 289-312. PMID: 16767184.
- Leat SJ, Fryer A, Rumney NJ. Outcome of low vision aid provision: The effectiveness of a low vision clinic. Optometry and Vision Science. 1994; 71(3): 199-206. doi: 10.1097/00006324-199403000-00009
- Crossland MD, Silver J. Thirty years in low vision: Rehabilitation in 2018. Eye. 2018; 32: 873-880. doi: Nil.
- Van der Aa HPA, Comijs HC, Penninx BW, van Rens GH, van Nispen RM. Major depressive and anxiety disorders in visually impaired older adults. Investigative Ophthalmology and Visual Science. 2015; 56(2): 849-854. doi: 10.1167/iovs.14-15848
- Lamoureux EL, Fenwick E, Moore K, Klaic M, Borschmann K, Hill K. Impact of low vision on participation in daily living activities and quality of life. Investigative Ophthalmology and Visual Science. 2018; 59(14): 5284-5290. doi: 10.1167/iovs.18-24148
- International Diabetes Federation. (2021). IDF Diabetes Atlas (10th ed.). Brussels: IDF. ISBN: 978-2-930229-98-0
- Resnikoff S, et al. Vision impairment and blindness in 2020 and trends over 30 years. The Lancet Global Health. 2020; 8(3): e317-e328. doi: 10.1016/S2214-109X(19)30411-2
- Resnikoff S. Vision impairment and blindness in 2020 and trends over 30 years. The Lancet Global Health. 2020; 8(3): e317-e328. doi: 10.1016/S2214-109X(19)30411-2
- Bourne RRA, Steinmetz JD, Flaxman S, Briant PS, Taylor HR, Resnikoff S, Casson RJ, et al. Trends in prevalence of blindness and distance and near vision impairment over 30 years. The Lancet Global Health. 2021; 9(2): e130-e143. doi: 10.1016/S2214-109X(20)30425-3
- Finger RP, Fenwick E, Marella M, Dirani M, Holz FG, Chiang PP, Lamoureux EL. The impact of vision impairment on vision-specific quality of life in low- and middle-income countries. Investigative Ophthalmology and Visual Science. 2021; 62(8): 6. doi: 10.1167/iovs.62.8.6
- Furtado JM, Lansingh VC, Winthrop KL, Spivey B. Training of an ophthalmologist in concepts and practice of community eye health. Indian Journal of Ophthalmology. 2012; 60(5): 365-367. doi: 10.4103/0301-4738.100528
- Wong TY, Sabanayagam C. Strategies to tackle the global burden of diabetic retinopathy: From epidemiology to artificial intelligence. Ophthalmologica. 2020; 243(1): 9-20. doi: 10.1159/000502387
- Rahman N. Ethical and legal challenges of AI-based medical diagnostics: A perspective. Mediterranean Journal of Medicine and Medical Sciences. 2026; 2(1): 51-58. doi: 10.5281/zenodo.18772947
- Nizamuddin SFS, Ikramuddin M, Dhore NS. Artificial Intelligence in pharmaceutical sciences: Transforming drug discovery, formulation, and manufacturing. Mediterranean Journal of Medical Research. 2025; 2(4): 269-275. doi: 10.5281/zenodo.17945149
- Awulu I. Predictive launch architecture: Leveraging AI-driven market intelligence to de-risk pharmaceutical brand entry in emerging markets. Mediterranean Journal of Medicine and Medical Sciences. 2026; 2(2): 55-76. doi: 10.5281/zenodo.20435527
- Ting DSW, Pasquale LR, Peng L, Campbell JP, Lee AY, Raman R, et al. Artificial intelligence and deep learning in ophthalmology. British Journal of Ophthalmology. 2019; 103(2): 167-175. doi: 10.1136/bjophthalmol-2018-313173
Submitted date:
04/20/2026
Reviewed date:
06/01/2026
Accepted date:
06/10/2026
Publication date:
06/10/2026
