Objective:To evaluate the relationship between hemoglobin(Hb) level and the risk of diabetic retinopathy(DR) in patients with type 2 diabetes mellitus(T2DM).Methods:This study was a prospective cohort study. A total of 1 730 T2DM patients without DR, who received regular management at the Li′s Clinic in Taiwan, China starting from 2002, were selected as the study population. All patients underwent annual dilated fundus examination by professional ophthalmologists. General patient information and laboratory results were collected and analyzed. Based on the occurrence of DR during patient follow-up, patients were divided into the DR group and the non-DR(NDR) group. The impact of Hb levels on DR was explored using a generalized linear mixed model, and the relationship between Hb levels and DR was studied using Cox proportional hazards regression model.Results:After an average follow-up of 9.79 years, 481 patients with DR were detected. Compared with NDR group, DR group displayed a longer course of diabetes, higher rates of cataract, insulin use, and anemia, and higher systolic blood pressure, HbA 1C, and UACR as well as lower Hb. The results of the generalized linear mixed model showed a negative correlation between Hb and the occurrence of DR( β=-0.015, P<0.001). The Cox proportional hazards regression model showed that, after adjusting for confounding variables and based on quartiles of average Hb levels during follow-up, the risk of developing DR increased by 56.9% in the Q1 group(Hb≤127 g/L) compared to the Q4 group(Hb≥142 g/L). The cumulative risk plot showed that, after adjusting for confounding variables, the Q1 group had the highest cumulative risk of developing DR, and the difference was statistically significant( P<0.05). Conclusion:Hb was negatively correlated with DR, and the lower Hb levels were associated with the occurrence of DR, independent of other influencing factors.

The introduction of vitrectomy has solved a difficult and intractable problem in the ophthalmology community for the treatment of fundus oculi diseases. To date, minimally invasive vitrectomy(MIV)is the main surgery for the treatment of fundus oculi diseases. Clinically, patients develop dry eye symptoms after MIV, including lacrimation, foreign body sensation, and visual disturbances. We speculates that MIV may damage the conjunctival and corneal epithelium as well as related sensory nerves, disrupting the tear film and causing a local inflammation response, thereby further affecting the ocular surface microenvironment and inducing or aggravating dry eye symptoms. At present, there are few studies on the changes of ocular surface after MIV. This article aims to analyze the effects of different factors on the microenvironment of the ocular surface before, during and after MIV, and to provide preventive and curative measures that can be taken to guide the clinic to make good preparations for the operation, to choose the appropriate surgical procedure, and to reduce the risk of dry eye in the postoperative period.