Background: To study the effects of aerobic exercise (AE) on tear secretion and tear film stability in dry eye patients. Methods: This study consisted of two parts, each part included 3 groups, namely dry eye without AE group, dry eye with AE group and pre-clinical dry eye with AE group. In part 1, we studied the variations of Schirmer I test and six tear compositions before and after AE (34 eyes in each group). In part 2, we studied the variations of tear meniscus height, first and average non-invasive tear breakup time (F-NITBUT and A-NITBUT), lipid layer thickness, number of incomplete and complete blinks, partial blink rate (PBR) and visual acuity before and after AE (30 eyes in each group). Results: In dry eye with AE group, Schirmer I test at 0 min after AE increased significantly compared to baseline (P < 0.001), the oxidative stress marker 8-hydroxy-2′-deoxyguanosine after AE decreased significantly compared to baseline (P = 0.035, P = 0.045), F-NITBUT and A-NITBUT after AE prolonged significantly compared to baseline (P < 0.001, P = 0.007, P = 0.036; P < 0.001, P = 0.001, P = 0.044), number of incomplete blinks and PBR at 10 min after AE decreased significantly compared to baseline (P < 0.001; P < 0.001) while number of complete blinks increased significantly (P < 0.001). Besides, significant differences were also found between dry eye with AE group and dry eye without AE group at all above corresponding time point (P < 0.05). Conclusion: AE promotes tear secretion and improves tear film stability in dry eye patients. AE may be a potential treatment for dry eye. Trial registration: Chinese Clinical Trial Registry, ChiCTR2000038673. Registered 27 September 2020,

Background: To develop a model for predicting the risk of visual impairment in diabetic retinopathy (DR) by a nomogram. Methods: Patients with DR who underwent both optical coherence tomography angiography (OCTA) and fundus fluorescein angiography (FFA) were retrospectively enrolled. FFA was conducted for DR staging, swept-source optical coherence tomography (SS-OCT) of the macula and 3*3-mm blood flow imaging by OCTA to observe retinal structure and blood flow parameters. We defined a logarithm of the minimum angle of resolution visual acuity (LogMAR VA) ≥0.5 as visual impairment, and the characteristics correlated with VA were screened using binary logistic regression. The selected factors were then entered into a multivariate binary stepwise regression, and a nomogram was developed to predict visual impairment risk. Finally, the model was validated using the area under the receiver operating characteristic (ROC) curve (AUC), calibration plots, decision curve analysis (DCA), and clinical impact curve (CIC). Results: A total of 29 parameters were included in the analysis, and 13 characteristics were used to develop a nomogram model. Finally, diabetic macular ischaemia (DMI) grading, disorganization of the retinal inner layers (DRIL), outer layer disruption, and the vessel density of choriocapillaris layer inferior (SubVD) were found to be statistically significant (P < 0.05). The model was found to have good accuracy based on the ROC (AUC = 0.931) and calibration curves (C-index = 0.930). The DCA showed that risk threshold probabilities in the (3–91%) interval models can be used to guide clinical practice, and the proportion of people at risk at each threshold probability is illustrated by the CIC. Conclusion: The nomogram model for predicting visual impairment in DR patients demonstrated good accuracy and utility, and it can be used to guide clinical practice. Trial registration: Chinese Clinical Trial Registry, ChiCTR2200059835. Registered 12 May 2022, https://www.chictr.org.cn/edit.aspx?pid=169290&htm=4

Introduction: This study aimed to investigate the correlation between fundus blood flow parameters and the severity of pathological biopsy in patients with diabetic kidney disease (DKD). Methods: Data of patients with type 2 diabetes mellitus who completed renal pathology biopsies and optical coherence tomography angiography (OCTA) examinations, including renal function, 24-h urine protein quantification, and macular flow imaging, were collected. DKD pathology biopsies were graded as stages 1–4, and differences and correlations of the parameters were compared between groups. The grading was transformed into early (stage 1) and late (stages 2–4), and regression analyses were conducted to develop a model, draw a nomogram, and test efficacy. Results: This study included 157 eyes from 157 individuals in total. Urinary microalbumin and to urinary creatinine ratio (mALB/NCR) increased with pathological grading, whereas while glomerular filtration rate was decreased (p < 0.01). Corresponding retinal blood flow in superficial, deep, and full paracentral rings was decreased, which correlated with pathological grading (p < 0.01), with the highest blood flow density in the whole layer (r2 = −0.707). Meaningfully, in the early DKD model (area under the curve = 0.929 [0.889–0.970], p < 0.01), whole-layer blood flow density, mALB/NCR, and diabetes duration were statistically significant. Conclusions: The decrease in macular retinal blood flow density detected by OCTA is closely associated with the increase in pathological grading of DKD and can be used as a noninvasive parameter for monitoring early changes in DKD.