Chen, Zhengxi

ABSTRACT Purpose Substantial endothelial cell loss (∼80%) occurs after keratoplasty. Corneal rigid and scleral lenses are frequently prescribed to manage irregular astigmatism and high refractive error, but lens wear may contribute to hypoxic stress. The relationship between various lens wear and corneal stress after penetrating keratoplasty remains unclear. This study characterizes cell density distribution in post‐keratoplasty corneas and evaluates its influence on swelling during lens wear. Methods Participants ≥5 years post‐surgery, with or without habitual lens wear, were enrolled. Specular microscopy measured endothelial cell density in central, superior, inferior, superotemporal, and superonasal corneal quadrants (@3 mm). Baseline corneal thickness maps (>2 h after waking without lens wear) were acquired using Scheimpflug imaging (Pentacam). Wearers applied habitual lenses and all participants returned 6–8 h later for imaging. Nonparametric tests assessed cell density variation by quadrant and lens designs. Linear mixed models evaluated associations between endothelial parameters and corneal swelling while accounting for within‐subject correlation, repeated measures, lens type, location, and interactions. Results Twenty‐five participants (31 eyes) from three centers were included; 90% had keratoconus preoperatively. Four wore large‐diameter scleral lenses (13%), nine wore small‐diameter scleral lenses (29%), 12 wore corneal rigid lenses (39%), and six did not wear lenses (19%). Cell density across quadrants averaged 780 ± 240 cells/mm 2 . Central thickness decreased slightly in non‐lens‐wearing eyes (−0.3%) but increased in lens‐wearing eyes (1.9% ± 3.1%). Central cell density showed a weak negative correlation with swelling ( r = −0.39, p = 0.03). Compared with non‐lens wearers, corneal rigid ( p = 0.02) and large diameter scleral lenses ( p = 0.05) generated greater swelling; smaller diameter scleral lenses did not. Conclusions Although all eyes fitted with various lens designs were clear, lower central cell density correlated with increased swelling during lens wear, except when smaller diameter scleral lenses were worn. Clinically, however, cell density does not seem to be a robust predictor of corneal swelling induced by lens wear post‐keratoplasty.

Abstract Background: Clostridioides difficile infection (CDI) requiring colectomy carries substantial mortality risk, with optimal timing of surgery remaining poorly defined. We examined temporal trends in colectomy among inpatients with CDI, identified predictors of surgical intervention and postoperative mortality, and evaluated the association between surgical timing and patient outcomes. Methods: A retrospective cohort study was conducted using the National Inpatient Sample database from 2018 to 2022. We compared patients undergoing colectomy with those managed medically. To minimize confounding by hospital-onset cases, the analysis of surgical timing and mortality was restricted to patients undergoing colectomy within 8 days of admission. Predictors were identified using survey-weighted logistic regression and LASSO regression models. Results: Among 240,564 CDI hospitalizations (representing 1,207,995 weighted nationally), 717 patients underwent colectomy (3,585 weighted). CDI prevalence declined from 0.99% (2018) to 0.76% (2022), while colectomy rates increased from 0.28% to 0.34%. Peritonitis (OR 5.42; 95% CI, 4.46–6.59), coagulopathy (OR 4.96; 95% CI, 3.76–6.55), and sepsis/septic shock (OR 3.89; 95% CI, 3.39–4.47) were the strongest predictors of colectomy. Among patients undergoing colectomy within 8 days (2,830 weighted), in-hospital mortality was 26.5% overall, increasing from 21.0% (2018) to 30.7% (2022). Sepsis/septic shock (OR 8.20; 95% CI 2.92–23.07) and coagulopathy (OR 7.27; 95% CI 3.31–15.97) predicted mortality. Each additional day from admission to colectomy was associated with a 16% (OR 1.16; 95% CI 1.04–1.28) increased mortality risk. Conclusions: In this nationally representative cohort, surgical timing was an independent and modifiable determinant of survival in patients with CDI requiring colectomy. Our findings underscore the importance of early surgical consultation for CDI patients with peritonitis, sepsis, and coagulopathy.