Establishment and Validation of a Risk Prediction Model for Long-term Low Vision After Vitrectomy in PDR Patients

Study Overview
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Brief Summary
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Diabetic retinopathy (DR) is the main cause of blindness among working-age adults in the world. Proliferative diabetic retinopathy (PDR) is the severe stage of DR, which is characterized by neovascularization of the retina. Vitreous hemorrhage and traction retinal detachment caused by PDR often require vitrectomy. The purpose of vitrectomy is to remove vitreous hemorrhage, peel off the preretinal proliferative membrane and help restore the retina. With the deepening of people's understanding of diabetes and the development and application of various hypoglycemic drugs, the life expectancy of patients with diabetes continues to prolong. Therefore, the goal of vitrectomy in patients with DR is not only to prevent blindness, but also to maintain good vision for a long time. The purpose of this study is to analyze the risk factors related to the occurrence of long-term low vision postoperatively and establish a risk prediction model, which can help patients adjust their psychological expectations reasonably and promote communication between doctors and patients.

Official Title
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Establishment and Validation of a Risk Prediction Model for Long-term Low Vision After Vitrectomy in Proliferative Diabetic Retinopathy Patients

Conditions
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Pars Plana Vitrectomy, Proliferative Diabetic Retinopathy, Risk Prediction Model

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Voluntary and able to sign an informed consent form Age ≥18 years Documented diagnosis of diabetes mellitus (type I or type II diabetes) defined by the American Diabetes Association or World Health Organization criteria. Unabsorbed vitreous hemorrhage lasted for more than 2 weeks, with or without tractional retinal detachment examen by slit lamp, B-ultrasound and fundus color photography. Exclusion Criteria: Patients with less than 12 months of follow-up Previous intraocular surgery (eg. corneal transplantation, glaucoma filtering, vitrectomy, except cataract surgery) Complicated with other retinal diseases Underwent surgery (eg. intravitreal injection, cataract surgery) of the study eye within 3 months Lack of medical records.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best corrected visual acuity at the last follow-up | Standard logarithmic visual acuity scale | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The occurrence of re-vitrectomy | The occurrence and indication of re-vitrectomy during the follow-up period | 1 year | 
| The occurrence of neovascular glaucoma | Non-contact computerized tonometer (CT-1, Topcon, Japan) and slit-lamp biomicroscopy | 1 year | 
| The occurrence of vitrectomy for the fellow eye | The occurrence of vitrectomy for the fellow eye during the follow-up period | 1 year |