The aim of this study is to identify factors influencing the short-term prognosis of patients with proliferative diabetic retinopathy (PDR) after pars plana vitrectomy (PPV) using Lasso-Logistic regression analysis and construct a predictive model.

A total of 179 PDR patients (179 eyes) who underwent PPV in the Ophthalmology Department of Linfen People′s Hospital from January 2021 to February 2024 were selected as the study subjects. There were 83 female (83 eyes) and 96 male (96 eyes) with a mean age of (64.3±8.3) years (ranging from 29 to 81 years). Based on the degree of visual acuity after surgery 6 months decline compared to preoperative levels, patients were divided into the poor prognosis group with 33 cases (33 eyes) and the favorable prognosis group with 146 cases (146 eyes). Data collected included gender, age, eye involved, diabetes duration, medical history, PDR stage, diabetes treatment type, preoperative best-corrected visual acuity (BCVA), disease severity, treatment modality, intraocular pressure (IOP), blood pressure, blood glucose, blood lipids, blood cells, liver and kidney biochemistry, and postoperative complications. The age, diabetes duration, preoperative BCVA, number of retinal laser photocoagulations, preoperative IOP, blood pressure, fasting blood glucose, glycated hemoglobin (HbA1c), four lipid items, complete blood count, liver and kidney function indices. Data conforming to a normal distribution were expressed as ±s and compared between groups using independent samples t-test. Skewed measurement data including the diabetes duration and urinary albumin were expressed as M(P₂₅, P₇₅) and compared between groups using the rank-sum test. The gender, eye involved, medical history, PDR stage, diabetes treatment type, macular detachment, iris neovascularization/rubeosis, vitreous hemorrhage, preretinal hemorrhage, anti-vascular endothelial growth factor (anti-VEGF) treatment, combined cataract surgery, vitreous cavity tamponade, postoperative complications were expressed as number and percentage, and compared between groups using Pearson′s or continuity-adjusted chi-square test. Univariate analysis and Lasso regression were used to screen factors affecting short-term poor prognosis after PPV in PDR patients. Independent influencing factors were identified using multivariate Logistic regression analysis, and a nomogram prediction model was constructed based on these factors. The Hosmer-Lemeshow test was used for goodness-of-fit; the C-index was used to analyze discriminative ability; the accuracy was analyzed using calibration curves; the clinical utility was analyzed using decision curve analysis, and predictive efficacy was analyzed using receiver operating characteristic (ROC) curve analysis.

In the poor prognosis group with 33 cases (33 eyes), the diabetes duration median and urinary albumin were 11.00 (9.00, 13.50) years and 42.37 (36.41, 48.46) mg/L, respectively; there were 13 with hyperlipidemia, 14 with coronary heart disease, 6 with hypertension, accounting for 39.39%, 42.42% and 18.18%, respectively; 6 cases (6 eyes) with PDR stage Ⅳ, 15 cases (15 eyes) with stage Ⅴ, 12 cases (12 eyes) with stage Ⅵ, accounting for 18.18%, 45.45% and 36.36%, respectively; 6 with oral medications of diabetes treatment type, 17 with insulin injections, 10 with insulin combined with oral medications, accounting for 18.18%, 51.52% and 30.30%, respectively; 14 with macular detachment, 4 with iris rubeosis, 31 with vitreous hemorrhage, 13 with preretinal hemorrhage, accounting for 42.42%, 12.12%, 93.94% and 39.39% respectively; 11 not used anti-VEGF treatment, 18 used preoperativly, 4 used intraoperativly, accounting for 33.33%, 54.55% and 12.12% respectively; 17 combined with cataract surgery, accounting for 51.52%; 2 with C3F8 for vitreous cavity tamponade, 27 with silicone oil, 4 with balanced saline solution, accounting for 6.06%, 81.82% and 12.12% respectively; 18 with postoperative complications accounting for 54.55%. In the good prognosis groups with 146 cases (146 eyes), the diabetes duration median were 9.00 (7.00, 11.00) years; urinary albumin 41.76 (37.10, 46.09) mg/L; 37 with hyperlipidemia, 42 with coronary heart disease, 27 with hypertension, accounting for 25.34%, 28.77% and 18.49% respectively; PDR stage: 44 cases (44 eyes) with Ⅳ stage, 85 cases (85 eyes) with Ⅴ stage, 17 cases (17 eyes) with Ⅵ stage, accounting for 30.14%, 58.22% and 11.64% respectively; diabetes treatment type: 37 used by oral medications, 70 used by insulin injections, 39 used by insulin combined with oral medications, accounting for 25.34%, 47.95% and 26.71% respectively; 16 with macular detachment, 3 with iris rubeosis, 127 with vitreous hemorrhage, 52 with preretinal hemorrhage, accounting for 10.96%, 2.05%, 86.99% and 35.62% respectively; 35 not used anti-VEGF treatment, 94 preoperative, 17 intraoperative, accounting for 23.97%, 64.38% and 11.65% respectively; 58 with combined cataract surgery, accounting for 39.73%; 38 with C3F8 after vitreous cavity tamponade, 90 with silicone oil, 18 with balanced saline solution, accounting for 90.41%, 61.64% and 12.33% respectively; 32 with postoperative complications, accounting for 21.92%. The mean preoperative BCVA, number of retinal laser spots, preoperative IOP, systolic blood pressure, diastolic blood pressure, fasting blood glucose, HbA1c, total cholesterol, triglycerides, high density lipoprotein, low density lipoprotein, neutrophil count, lymphocyte count, platelet count, white blood cell count, alanine aminotransferase, aspartate transaminase, glutamyl transpeptidase, serum creatinine were (1.97±0.60) logarithm of the minimum angle of resolution (logMAR), (652.06±381.20)spots, (19.12±4.30)mmHg (1 mmHg=0.133 kPa), (153.97±20.86)mmHg, (93.85±10.03)mmHg, (10.22±1.41)mmol/L, (7.71±1.72)%, (5.33±0.33)mmol/L, (1.84±0.39)mmol/L, (1.05±0.07)mmol/L, (3.20±0.54)mmol/L, (3.90±1.14) ×10⁹/L, (1.60±0.45) ×10⁹/L, (254.93±54.14) ×10⁹/L, (8.47±2.62) ×10⁹/L, (26.92±8.18)U/L, (24.34±8.70)U/L, (36.60±11.12)U/L, (123.39±16.96)μmol/L, respectively; while those of good prognosis group were (1.62±0.47) logMAR, (1055.26±433.68) spots, (17.40±5.08) mmHg, (149.12±20.14) mmHg, (89.84±11.11) mmHg, (9.71±1.35) mmol/L, (6.99±1.40)%, (5.20±0.51) mmol/L, (1.78±0.34) mmol/L, (1.06±0.13) mmol/L, (3.00±0.55) mmol/L, (3.72±1.26) ×10⁹/L, (1.76±0.59) ×10⁹/L, (254.40±69.00) ×10⁹/L, (8.33±2.49) ×10⁹/L, (24.80±8.82) U/L, (22.52±7.54) U/L, (33.36±10.23) U/L, (119.65±18.23) μmol/L, respectively. There was a statistically significant difference in diabetes duration(Z=-3.316, P<0.05); macular detachment, iris rubeosis, vitreous cavity tamponade, and postoperative complications (χ²=19.102, 4.827, 6.479, 14.234; P<0.05); preoperative BCVA, number of retinal laser spots, and HbA1c (t=3.667, 4.926, 2.573; P<0.05). Lasso regression identified five variables with non-zero features: PDR stage, preoperative BCVA, macular detachment, number of retinal lasers, and postoperative complications. Multivariate logistic regression analysis showed that PDR Ⅴ, Ⅵ stages, preoperative BCVA, macular detachment, and postoperative complications were independent risk factors for short-term poor prognosis in PDR patients after PPV (OR=3.630, 10.296, 3.082, 3.806, 2.920; 95%CI: 1.088 to 12.110, 2.630 to 40.303, 1.074 to 8.845, 1.260 to 11.499, 1.075 to 7.930; P<0.05), while the number of retinal lasers was an independent protective factor (OR=0.784, 95%CI: 0.685~0.897; P<0.05). A column chart prediction model was constructed based on independent influencing factors of short-term poor prognosis in PDR patients undergoing PPV Logit (P)=-3.233+ 1.289×PDR stage Ⅴ+ 2.332×PDR stage Ⅵ+ 1.125×preoperative BCVA+ 1.337×macular detachment -0.002×number of retinal lasers+ 1.071×postoperative complications. The prediction model was well, and C index of 0.885 (95%CI: 0.876 to 0.895, P>0.05). The predicted probability of the column chart prediction model after the calibration curve and decision curve was close to the ideal curve, and the net profit range was relatively large. ROC curve analysis showed that the area under the curve of the line chart prediction model for predicting short-term poor prognosis in PDR patients after PPV was 0.885 (95%CI: 0.828 to 0.927), with a sensitivity of 84.85%, specificity of 78.77%, and a Youden index of 0.6362.

PDR staging, preoperative BCVA, macular detachment, number of retinal lasers, and postoperative complications are independent factors affecting the short-term poor prognosis of PDR patients after PPV. The column chart prediction model constructed based on these factors has high predictive efficiency for the short-term poor prognosis of PDR patients after PPV.