Diabetic Eye Disease

Diabetic Eye Disease Publications

Sobrin L, Susarla G, Stanwyck L, Rouhana JM, Li A, Pollack S, Igo RP, Jensen RA, Li X, Ng MCY, Smith AV, Kuo JZ, Taylor KD, Freedman BI, Bowden DW, Penman A, Chen CJ, Craig JE, Adler SG, Chew EY, Cotch MF, Yaspan B, Mitchell P, Wang JJ, Klein BEK, Wong TY, Rotter JI, Burdon KP, Iyengar SK, Segrè AV. Gene Set Enrichment Analyses Identify Pathways Involved in Genetic Risk for Diabetic Retinopathy. Am J Ophthalmol 2021;Abstract
PURPOSE: To identify functionally related genes associated with diabetic retinopathy (DR) risk using gene set enrichment analyses (GSEA) applied to genome-wide association study (GWAS) meta-analyses. METHODS: We analyzed DR GWAS meta-analyses performed on 3,246 Europeans and 2,611 African Americans with type 2 diabetes. Gene sets relevant to five key DR pathophysiology processes were investigated: tissue injury, vascular events, metabolic events and glial dysregulation, neuronal dysfunction, and inflammation. Keywords relevant to these processes were queried in four pathway and ontology databases. Two GSEA methods, Meta-Analysis Gene set Enrichment of variaNT Associations (MAGENTA) and Multi-marker Analysis of GenoMic Annotation (MAGMA) were used. Gene sets were defined to be enriched for gene associations with DR if the P value corrected for multiple testing (Pcorr) was <.05. RESULTS: Five gene sets were significantly enriched for multiple modest genetic associations with DR in one method (MAGENTA or MAGMA) and also at least nominally significant (uncorrected P <.05) in the other method. These pathways were regulation of the lipid catabolic process (2-fold enrichment, Pcorr=.014); nitric oxide biosynthesis (1.92-fold enrichment, Pcorr=.022); lipid digestion, mobilization and transport (1.6-fold enrichment, P=.032); apoptosis (1.53-fold enrichment, P=.041); and retinal ganglion cell degeneration (2-fold enrichment, Pcorr=.049). The interferon gamma (IFNG) gene, previously implicated in DR by protein-protein interactions in our GWAS, was among the top ranked genes in the nitric oxide pathway (best variant P=.0001). CONCLUSIONS: These GSEA indicate that variants in genes involved in oxidative stress, lipid transport and catabolism and cell degeneration are enriched for genes associated with DR risk.
Ashraf M, Rageh A, Gilbert M, Tolls D, Fleming A, Souka A, El-Baha S, Cavallerano JD, Sun JK, Aiello LP, Silva PS. Factors Affecting Predominantly Peripheral Lesion Identification and Grading. Transl Vis Sci Technol 2021;10(7):6.Abstract
Purpose: The purpose of this study was to determine factors affecting predominantly peripheral lesion (PPL) grading, such as qualitative versus quantitative assessment, device type, and severity of diabetic retinopathy (DR) in ultrawide field color images (UWF-CIs). Methods: Patients with DR had UWF-CI qualitatively graded for PPL using standardized techniques and had hemorrhages/microaneurysms (H/Mas) individually annotated for quantitative PPL grading on two different ultrawide field devices. Results: Among 791 eyes of 481 patients, 38.2% had mild nonproliferative DR (NPDR), 34.7% had moderate NPDR, and 27.1% had severe NPDR to proliferative DR (PDR). The overall agreement between qualitative and quantitative PPL grading was moderate (ĸ = 0.423, P < 0.001). Agreement rates were fair in eyes with mild NPDR (ĸ = 0.336, P < 0.001) but moderate in eyes with moderate NPDR (ĸ = 0.525, P < 0.001) and severe NPDR-PDR (ĸ = 0.409, P < 0.001). Increasing thresholds for quantitative PPL determination improved agreement rates, with peak agreements at H/Ma count differences of six for mild NPDR, five for moderate NPDR, and nine for severe NPDR-PDR. Based on ultrawide field device type (California = 412 eyes vs. 200Tx = 379 eyes), agreement between qualitative and quantitative PPL grading was moderate for all DR severities in both devices (ĸ = 0.369-0.526, P < 0.001) except for mild NPDR on the 200Tx, which had poor agreement (ĸ = 0.055, P = 0.478). Conclusions: Determination of PPL varies between standard qualitative and quantitative grading and is dependent on NPDR severity, device type, and magnitude of lesion differences used for quantitative assessment. Translational Relevance: Prior UWF studies have not accounted for imaging and grading factors that affect PPL, such factors need to be reviewed when assessing thresholds for DR progression rates.
Chen T, Jin L, Zhu W, Wang C, Zhang G, Wang X, Wang J, Yang K, Cochrane GM, Lamoureux EL, Friedman DS, Gilbert S, Lansingh VC, Resnikoff S, Zhao J, Xiao B, He M, Congdon N. Knowledge, attitudes and eye health-seeking behaviours in a population-based sample of people with diabetes in rural China. Br J Ophthalmol 2021;105(6):806-811.Abstract
AIMS: To assess knowledge of diabetes and acceptance of eye care among people with diabetes in rural China, to improve service uptake. METHODS: Population-based study of people in Guangdong, China, with glycosylated haemoglobin A1c≥6.5% and/or known history of diabetes. Between August and November 2014, participants answered a questionnaire (based on Delphi process/previous focus groups) on medical history, demographic characteristics, self-rated health and vision, knowledge about diabetes and diabetic retinopathy, quality of local healthcare, barriers to treatment, likely acceptance of eye exams and treatment, and interventions rated most likely to improve service uptake. Presenting visual acuity was assessed, fundus photography performed and images graded by trained graders. Potential predictors of accepting care were evaluated and confounders adjusted for using logistic regression. RESULTS: A total of 562 people (9.6% (256/5825), mean age 66.2±9.84 years, 207 (36.8%) men) had diabetes, 118 (22.3%) previously diagnosed. 'Very likely' or 'likely' acceptance of laser treatment (140/530=26.4%) was lower than for eye exams (317/530=59.8%, p<0.001). Predictors of accepting both exams and laser included younger age (p<.001) and prior awareness of diabetes diagnosis (p=0.004 and p=0.035, respectively). The leading barrier to receiving diabetes treatment was unawareness of diagnosis (409/454, 97.2%), while interventions rated most likely to improve acceptance of eye exams included reimbursement of travel costs (387/562, 73.0%), video or other health education (359/562, 67.7%) and phone call reminders (346/562, 65.3%). CONCLUSIONS: Improving diagnosis of diabetes, along with incentives, education and communication strategies, is most likely to enhance poor acceptance of diabetic eye care in this setting.
Chan CK, Mein CE, Glassman AR, Beaulieu WT, Calhoun CT, Jaffe GJ, Jampol LM, MacCumber MW, Maguire MG, Maturi RK, Salehi-Had H, Rofagha S, Sun JK, Martin DF, Martin DF. Pneumatic Vitreolysis with CF for Vitreomacular Traction with and without Macular Hole: DRCR Retina Network Protocols AG and AH. Ophthalmology 2021;Abstract
OBJECTIVE: To evaluate pneumatic vitreolysis (PVL) in eyes with vitreomacular traction (VMT) with and without full-thickness macular hole (FTMH). DESIGN: Two multi-center (28 sites) studies: one randomized clinical trial comparing PVL with observation (sham injection) for VMT without FTMH (Protocol AG), and a single-arm study assessing PVL for closure of FTMH (Protocol AH). PARTICIPANTS: Participants were adults with central VMT in which the vitreomacular adhesion was 3000 μm or less. In AG, visual acuity (VA) was 20/32 to 20/400. In AH, eyes had FTMH (≤250 μm at the narrowest point) and VA of 20/25 to 20/400. INTERVENTION: PVL using C3F8 gas. MAIN OUTCOME MEASURES: Central VMT release without rescue treatment at 24 weeks (AG). FTMH closure without rescue treatment at 8 weeks (AH). RESULTS: From October 2018 to February 2020, 46 participants were enrolled in AG and 35 eligible participants were enrolled in AH. Higher than expected rates of retinal detachments and tears resulted in early termination of both protocols. Combining studies, 7 of 59 (12% [95% CI, 6%-23%]; 2 in AG, 5 in AH) eyes that received PVL developed rhegmatogenous retinal detachment (6) or retinal tear (1). At 24 weeks in AG, 18 of 23 eyes in the PVL group (78%) versus 2 of 22 eyes in the sham group (9%) had central VMT release without rescue vitrectomy (adjusted risk difference = 66% [95% CI, 44%-88%], P<.001). The mean change in VA letter score from baseline at 24 weeks in AG was 6.7 in the PVL group and 6.1 in the sham group (adjusted difference = -0.8 [95% CI, -6.1 to 4.5], P=.77; negative values indicate greater improvement in sham group). In AH,10 of 35 eyes (29% [95% CI, 16%-45%]) had FTMH closure without rescue vitrectomy at 8 weeks. The mean change in VA from baseline at 8 weeks in AH was -1.5 letters (95% CI, -10.3 to 7.3). CONCLUSIONS: In most eyes with VMT, PVL induced hyaloid release. In eyes with FTMH, PVL resulted in hole closure in approximately one third of eyes. These studies were terminated early because of safety concerns related to retinal detachments and retinal tears.
Glassman AR, Beaulieu WT, Maguire MG, Antoszyk AN, Chow CC, Elman MJ, Jampol LM, Salehi-Had H, Sun JK, Sun JK. Visual Acuity, Vitreous Hemorrhage, and Other Ocular Outcomes After Vitrectomy vs Aflibercept for Vitreous Hemorrhage Due to Diabetic Retinopathy: A Secondary Analysis of a Randomized Clinical Trial. JAMA Ophthalmol 2021;Abstract
Importance: Although there were no differences in mean visual acuity (VA) over 24 weeks after vitrectomy with panretinal photocoagulation (PRP) vs aflibercept in a randomized clinical trial among eyes with vitreous hemorrhage due to proliferative diabetic retinopathy (PDR), post hoc analyses may influence treatment choices. Objective: To compare exploratory outcomes between treatment groups that may affect treatment choices for patients with vitreous hemorrhage due to PDR. Design, Setting, and Participants: This post hoc analysis of a randomized clinical trial conducted at 39 DRCR Retina Network sites included adults with vision loss due to PDR-related vitreous hemorrhage for whom vitrectomy was considered. Data were collected from November 2016 to January 2020. Interventions: Random assignment to 4 monthly injections of aflibercept vs vitrectomy with PRP. Both groups could receive aflibercept or vitrectomy during follow-up based on protocol-specific criteria. Main Outcomes and Measures: Visual acuity area under the curve (adjusted for baseline VA) and clearance of vitreous hemorrhage. Results: A total of 205 eyes were included in the analysis (115 male [56%] and 90 [44%] female participants; mean [SD] age, 57 [11] years). Among 89 eyes with a baseline VA of 20/32 to 20/160 (47 receiving aflibercept, including 4 [9%] that had undergone vitrectomy; 42 undergoing vitrectomy, including 3 [7%] that had received aflibercept), the adjusted mean difference in VA letter score over 24 weeks between the aflibercept and vitrectomy groups was -4.3 (95% CI, -10.6 to 1.9) compared with -16.7 (95% CI, -24.4 to -9.1) among 59 eyes with baseline VA worse than 20/800 (P = .02 for interaction; 26 in the aflibercept group, including 6 [23%] that had undergone vitrectomy; 33 in the vitrectomy group, including 8 [24%] that had received aflibercept). In the full cohort, the median time to clearance of the initial vitreous hemorrhage was 36 (interquartile range [IQR], 24-52) weeks in the aflibercept group vs 4 (IQR, 4-4) weeks in the vitrectomy group (difference, 32 [95% CI, 20-32] weeks; P < .001). Conclusions and Relevance: Both initial aflibercept and vitrectomy with PRP are viable treatment approaches for PDR-related vitreous hemorrhage. Although this study did not find a significant difference between groups in the primary outcome of mean VA over 24 weeks of follow-up, eyes receiving initial vitrectomy with PRP had faster recovery of vision over 24 weeks when baseline VA was worse than 20/800 and faster vitreous hemorrhage clearance. Approximately one-third of the eyes in each group received the alternative treatment (aflibercept or vitrectomy with PRP). These factors may influence treatment decisions for patients initiating therapy for PDR-related vitreous hemorrhage. Trial Registration: ClinicalTrials.gov Identifier: NCT02858076.
Hutton DW, Glassman AR, Stein JD, Bressler NM, Sun JK, Sun JK. Costs of Managing Diabetic Macular Edema with Good Visual Acuity with Aflibercept, Laser or Observation: DRCR Retina Network Protocol V. Am J Ophthalmol 2021;Abstract
PURPOSE: Since eyes with center-involved diabetic macular edema (CI-DME) and good baseline visual acuity (VA) showed no difference in VA loss when managed initially with observation, laser, or aflibercept, understanding the estimated costs of these strategies to the US population is relevant for health care planning. DESIGN: Pre-planned subgroup analysis from a randomized controlled trial METHODS, SETTING, AND PARTICIPANTS: Total costs for managing participants with CI-DME and good baseline VA assigned to aflibercept (n= 236), laser (n=240), or observation (n = 236) during the 2-year trial were calculated. Using epidemiological data and extrapolating costs, 10-year costs for caring for persons with CI-DME and good baseline VA throughout the US was estimated. INTERVENTIONS: Observation or laser groups initiated aflibercept if VA decreased. Aflibercept group received injections up to every 4 weeks. MAIN OUTCOMES AND MEASURES: Estimated 10-year U.S. population costs to manage CI-DME with good VA. RESULTS: Assuming all patients in the US with CI-DME and good baseline VA received aflibercept initially, 10-year costs were projected to be $28.80 billion compared with $14.42 billion if initially receiving laser treatment or $15.70 billion if initially observed, with aflibercept added if VA worsened in the laser or observation arms. CONCLUSIONS AND RELEVANCE: Similar VA outcomes on average are obtained by initially managing CI-DME and good baseline VA with laser or observation strategies instead of immediately using aflibercept. While any one of these three strategies might be warranted depending on an individual's specific circumstances, on a societal level, cost savings might be achieved with these first two approaches. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01909791.
Jacoba CMP, Celi LA, Silva PS. Biomarkers for Progression in Diabetic Retinopathy: Expanding Personalized Medicine through Integration of AI with Electronic Health Records. Semin Ophthalmol 2021;36(4):250-257.Abstract
The goal of personalized diabetes eye care is to accurately predict in real-time the risk of diabetic retinopathy (DR) progression and visual loss. The use of electronic health records (EHR) provides a platform for artificial intelligence (AI) algorithms that predict DR progression to be incorporated into clinical decision-making. By implementing an algorithm on data points from each patient, their risk for retinopathy progression and visual loss can be modeled, allowing them to receive timely treatment. Data can guide algorithms to create models for disease and treatment that may pave the way for more personalized care. Currently, there exist numerous challenges that need to be addressed before reliably building and deploying AI algorithms, including issues with data quality, privacy, intellectual property, and informed consent.
Maturi RK, Glassman AR, Josic K, Antoszyk AN, Blodi BA, Jampol LM, Marcus DM, Martin DF, Melia M, Salehi-Had H, Stockdale CR, Punjabi OS, Sun JK, Sun JK. Effect of Intravitreous Anti-Vascular Endothelial Growth Factor vs Sham Treatment for Prevention of Vision-Threatening Complications of Diabetic Retinopathy: The Protocol W Randomized Clinical Trial. JAMA Ophthalmol 2021;Abstract
Importance: The role of anti-vascular endothelial growth factor injections for the management of nonproliferative diabetic retinopathy (NPDR) without center-involved diabetic macular edema (CI-DME) has not been clearly established. Objective: To determine the efficacy of intravitreous aflibercept injections compared with sham treatment in preventing potentially vision-threatening complications in eyes with moderate to severe NPDR. Design, Setting, and Participants: Data for this study were collected between January 15, 2016, and May 28, 2020, from the ongoing DRCR Retina Network Protocol W randomized clinical trial, conducted at 64 US and Canadian sites among 328 adults (399 eyes) with moderate to severe NPDR (Early Treatment Diabetic Retinopathy Study severity level, 43-53), without CI-DME. Analyses followed the intent-to-treat principle. Interventions: Eyes were randomly assigned to 2.0 mg of aflibercept injections (n = 200) or sham (n = 199) given at baseline; 1, 2, and 4 months; and every 4 months through 2 years. Between 2 and 4 years, treatment was deferred if the eye had mild NPDR or better. Aflibercept was administered in both groups if CI-DME with vision loss (≥10 letters at 1 visit or 5-9 letters at 2 consecutive visits) or high-risk proliferative diabetic retinopathy (PDR) developed. Main Outcomes and Measures: Development of CI-DME with vision loss or PDR through May 2020, when the last 2-year visit was completed. Results: Among the 328 participants (57.6% men [230 of 399 eyes]; mean [SD] age, 56 [11] years), the 2-year cumulative probability of developing CI-DME with vision loss or PDR was 16.3% with aflibercept vs 43.5% with sham. The overall hazard ratio for either outcome was 0.32 (97.5% CI, 0.21-0.50; P < .001), favoring aflibercept. The 2-year cumulative probability of developing PDR was 13.5% in the aflibercept group vs 33.2% in the sham group, and the 2-year cumulative probability of developing CI-DME with vision loss was 4.1% in the aflibercept group vs 14.8% in the sham group. The mean (SD) change in visual acuity from baseline to 2 years was -0.9 (5.8) letters with aflibercept and -2.0 (6.1) letters with sham (adjusted mean difference, 0.5 letters [97.5% CI, -1.0 to 1.9 letters]; P = .47). Conclusions and Relevance: In this randomized clinical trial, among eyes with moderate to severe NPDR, the proportion of eyes that developed PDR or vision-reducing CI-DME was lower with periodic aflibercept compared with sham treatment. However, through 2 years, preventive treatment did not confer visual acuity benefit compared with observation plus treatment with aflibercept only after development of PDR or vision-reducing CI-DME. The 4-year results will be important to assess longer-term visual acuity outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02634333.
Rageh A, Ashraf M, Fleming A, Silva PS. Automated Microaneurysm Counts on Ultrawide Field Color and Fluorescein Angiography Images. Semin Ophthalmol 2021;36(4):315-321.Abstract
BACKGROUND: The severity and extent of microaneurysms (MAs) have been used to determine diabetic retinopathy (DR) severity and estimate the risk of DR progression over time. The recent introduction of ultrawide field (UWF) imaging has allowed ophthalmologists to readily image nearly the entire retina. Manual counting of MAs, especially on UWF images, is laborious and time-consuming, limiting its potential use in clinical settings. Automated MA counting techniques are potentially more accurate and reproducible compared to manual methods. METHOD: Review of available literature on current techniques of automated MA counting techniques on both ultrawide field (UWF) color images (CI) and fluorescein angiography (FA) images. RESULTS: Automated MA counting techniques on UWF images are still in the early phases of development with UWF-FA counts being further along. Early studies have demonstrated that these techniques are accurate and reproducible. CONCLUSION: Automated techniques may be an appropriate option for detecting and quantifying MAs on UWF images, especially in eyes with earlier DR severity. Larger studies are needed to appropriately validate these techniques and determine if they add substantially to clinical practice compared to standard DR grading.
Wang M, Garg I, Miller JB. Wide Field Swept Source Optical Coherence Tomography Angiography for the Evaluation of Proliferative Diabetic Retinopathy and Associated Lesions: A Review. Semin Ophthalmol 2021;36(4):162-167.Abstract
Retinal imaging remains the mainstay for monitoring and grading diabetic retinopathy. The gold standard for detecting proliferative diabetic retinopathy (PDR) requiring treatment has long been the seven-field stereoscopic fundus photography and fluorescein angiography. In the past decade, ultra-wide field fluorescein angiography (UWF-FA) has become more commonly used in clinical practice for the evaluation of more advanced diabetic retinopathy. Since its invention, optical coherence tomography (OCT) has been an important tool for the assessment of diabetic macular edema; however, OCT offered little in the assessment of neovascular changes associated with PDR until OCT-A became available. More recently, swept source OCT allowed larger field of view scans to assess a variety of DR lesions with wide field swept source optical coherence tomography (WF-SS-OCTA). This paper reviews the role of WF-SS-OCTA in detecting neovascularization of the disc (NVD), and elsewhere (NVE), microaneurysms, changes of the foveal avascular zone (FAZ), intraretinal microvascular abnormalities (IRMA), and capillary non-perfusion, as well as limitations of this evolving technology.
Rodríguez-Valdés PJ, Rehak M, Zur D, Sala-Puigdollers A, Fraser-Bell S, Lupidi M, Chhablani J, Cebeci Z, Laíns I, Chaikitmongkol V, Fung AT, Okada M, Unterlauft JD, Smadar L, Loewenstein A, Iglicki M, Busch C. GRAding of functional and anatomical response to DExamethasone implant in patients with Diabetic Macular Edema: GRADE-DME Study. Sci Rep 2021;11(1):4738.Abstract
To analyze functional and anatomical response patterns to dexamethasone (DEX) implant in diabetic macular edema (DME), to describe proportion of responders and non-responders, and to propose a new DME grading system. Retrospective, multicenter, observational cohort study. Naïve and non-naïve DME patients were treated with DEX, with visual acuity (VA) ≥ 0.2 logMAR and central subfield thickness (CST) of ≥ 300 µm. Functional and anatomical responses were graded after 2 and 4 months, and categorized as early and stable improvement, early and progressive improvement, pendular response, delayed improvement, and persistent non-response. 417 eyes were included (175 treatment naïve eyes). Compared to non-naïve eyes, naïve eyes showed a very good functional response (VA gain ≥ 10 letters) more frequently after 2 and 4 months (56% and 57% [naïve] vs. 33% and 28% [non-naïve], p < 0.001). A VA gain < 5 letters (non-response) after 2 and 4 months was seen in 18% and 16% of naïve eyes, and in 49% and 53% of non-naïve eyes (p < 0.001). A lack of anatomical response was rare in both groups, but more frequently in non-naïve eyes (12% vs. 4%, p = 0.003). Functionally and anatomically, naïve eyes showed most frequently an early and stable improvement (functionally: 77/175 44%; anatomically: 123/175 eyes, 70%). Most non-naïve eyes experienced no significant improvement functionally (97/242 eyes, 40%), despite a mostly early and stable improvement anatomical response pattern (102/242 eyes, 42%). Functional but not anatomical response patterns were influenced by baseline VA. Naïve and non-naïve eyes show different functional and anatomical response patterns to DEX implant. Functional non-responders are rare in naïve eyes, whereas anatomical non-response is unusual in both groups.
Imamura M, Takahashi A, Matsunami M, Horikoshi M, Iwata M, Araki S-I, Toyoda M, Susarla G, Ahn J, Park KH, Kong J, Moon S, Sobrin L, and (iDRAGON) IDRGCON, Yamauchi T, Tobe K, Maegawa H, Kadowaki T, Maeda S. Genome-wide association studies identify two novel loci conferring susceptibility to diabetic retinopathy in Japanese patients with type 2 diabetes. Hum Mol Genet 2021;30(8):716-726.Abstract
Several reports have suggested that genetic susceptibility contributes to the development and progression of diabetic retinopathy. We aimed to identify genetic loci that confer susceptibility to diabetic retinopathy in Japanese patients with type 2 diabetes. We analysed 5 790 508 single nucleotide polymorphisms (SNPs) in 8880 Japanese patients with type 2 diabetes, 4839 retinopathy cases and 4041 controls, as well as 2217 independent Japanese patients with type 2 diabetes, 693 retinopathy cases and 1524 controls. The results of these two genome-wide association studies (GWAS) were combined with an inverse variance meta-analysis (Stage-1), followed by de novo genotyping for the candidate SNP loci (P < 1.0 × 10-4) in an independent case-control study (Stage-2, 2260 cases and 723 controls). After combining the association data (Stages 1 and 2) using meta-analysis, the associations of two loci reached a genome-wide significance level: rs12630354 near STT3B on chromosome 3, P = 1.62 × 10-9, odds ratio (OR) = 1.17, 95% confidence interval (CI) 1.11-1.23, and rs140508424 within PALM2 on chromosome 9, P = 4.19 × 10-8, OR = 1.61, 95% CI 1.36-1.91. However, the association of these two loci was not replicated in Korean, European or African American populations. Gene-based analysis using Stage-1 GWAS data identified a gene-level association of EHD3 with susceptibility to diabetic retinopathy (P = 2.17 × 10-6). In conclusion, we identified two novel SNP loci, STT3B and PALM2, and a novel gene, EHD3, that confers susceptibility to diabetic retinopathy; however, further replication studies are required to validate these associations.
Antonetti DA, Silva PS, Stitt AW. Current understanding of the molecular and cellular pathology of diabetic retinopathy. Nat Rev Endocrinol 2021;17(4):195-206.Abstract
Diabetes mellitus has profound effects on multiple organ systems; however, the loss of vision caused by diabetic retinopathy might be one of the most impactful in a patient's life. The retina is a highly metabolically active tissue that requires a complex interaction of cells, spanning light sensing photoreceptors to neurons that transfer the electrochemical signal to the brain with support by glia and vascular tissue. Neuronal function depends on a complex inter-dependency of retinal cells that includes the formation of a blood-retinal barrier. This dynamic system is negatively affected by diabetes mellitus, which alters normal cell-cell interactions and leads to profound vascular abnormalities, loss of the blood-retinal barrier and impaired neuronal function. Understanding the normal cell signalling interactions and how they are altered by diabetes mellitus has already led to novel therapies that have improved visual outcomes in many patients. Research highlighted in this Review has led to a new understanding of retinal pathophysiology during diabetes mellitus and has uncovered potential new therapeutic avenues to treat this debilitating disease.