Discussion
PDR, TRD, death, CKD, postoperative recurrent detachment, diabetic vitrectomy, kidney failure, NVG, hypertension, diabetes
MICROINVASIVE, LOW VISION, KIDNEY FAILURE, HYPERTENSION, COMPLICATIONS, DIABETES
For serious PDR complications, vitrectomy may be the only approach to improve visual acuity. Microinvasive vitreous surgery and an optimized vitrectomy platform with fluid and pressure control have greatly reduced the complications of PPV; however, some patients cannot fully achieve their ideal visual function long-term after diabetic vitrectomy. The estimated incidences of long-term postoperative BCVA<0.3 and<0.1 are 40% and 20%, respectively (In this study, TRD, symptom duration, preoperative BCVA measurement, and hypertension were identified as independent risk factors for long-term low vision after diabetic vitrectomy. With an AUC value of 0.764, along with 0.747 and 0.755 in the internal and external validation cohorts, the risk prediction model based on the four parameters demonstrated good discrimination. The nomogram provided a graphical representation of mathematical formulas, facilitating understanding and application. The factors in this model are easily obtainable, allowing doctors to make a preliminary evaluation of long-term functional outcomes through routine examinations and have good preoperative communication with patients.In this model, TRD involving or threatening the macular was regarded as the greatest risk factor. Patients with TRD had a 4.235 times increased incidence of postoperative long-term low vision than individuals without TRD. Although the final retinal reattachment rates have been reported to range from 95–100% (In addition to the four independent risk factors identified in this study, other factors have also been thought to affect visual acuity after diabetic vitrectomy. The progression of PDR is thought to be considerably influenced by the age at diabetes onset. Younger patients usually present with more severe anatomical features and have a higher rate of NVG and postoperative recurrent detachment (CKD is also a concern for researchers; for instance, kidney failure was regarded as the most frequent cause of death in patients who underwent diabetic vitrectomy (Although previous studies have explored the prognostic factors of long-term visual acuity after diabetic vitrectomy (Postoperative long-term visual acuity is the most concerning issue for patients with PDR. In this study, a BCVA measurement of 0.3 was selected as the cutoff value according to the WHO 2015 standard. In clinical practice, we also found a BCVA measurement of 0.3 to be the critical value of subjective feeling for patients with PDR. Additionally, in this study, the surgical procedures were performed by one surgeon, eliminating the impact of skill level and treatment habits on the prognosis.Nevertheless, this study had some limitations. First, confounding variables and bias are present owing to its retrospective nature. Second, we could not obtain comprehensive preoperative and follow-up data. Finally, this study did not consider the difference between 23-gauge and 25-gauge vitrectomy systems because previous studies have proved that the differences of these systems in terms of visual prognosis are negligible (In conclusion, TRD, symptom duration, preoperative BCVA measurement, and hypertension are independent risk factors of long-term low vision after diabetic vitrectomy. The risk prediction model based on these four risk factors exhibited good predictive value. This prognostic nomogram could help clinicians make better surgical decisions, assist patients with PDR in adjusting their psychological expectations, and foster better patient-doctor communication.