The short-term survival of penetrating corneal transplants is excellent, but the eventual attrition rate appears inexorable and many factors that influence graft survival significantly are not amenable to change. Most penetrating grafts are performed for visual improvement, and excellent acuity will be achieved by approximately half of all grafts.

ImportanceThere remains a lack of randomized trials investigating aspirin monotherapy for symptomatic venous thromboembolism (VTE) prophylaxis following total hip arthroplasty (THA) or total knee arthroplasty (TKA).ObjectiveTo determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE after THA or TKA.Design, Setting, and ParticipantsCluster-randomized, crossover, registry-nested trial across 31 hospitals in Australia. Clusters were hospitals performing greater than 250 THA or TKA procedures annually. Patients (aged ≥18 years) undergoing hip or knee arthroplasty procedures were enrolled at each hospital. Patients receiving preoperative anticoagulation or who had a medical contraindication to either study drug were excluded. A total of 9711 eligible patients were enrolled (5675 in the aspirin group and 4036 in the enoxaparin group) between April 20, 2019, and December 18, 2020. Final follow-up occurred on August 14, 2021.InterventionsHospitals were randomized to administer aspirin (100 mg/d) or enoxaparin (40 mg/d) for 35 days after THA and for 14 days after TKA. Crossover occurred after the patient enrollment target had been met for the first group. All 31 hospitals were initially randomized and 16 crossed over prior to trial cessation.Main Outcomes and MeasuresThe primary outcome was symptomatic VTE within 90 days, including pulmonary embolism and deep venous thrombosis (DVT) (above or below the knee). The noninferiority margin was 1%. Six secondary outcomes are reported, including death and major bleeding within 90 days. Analyses were performed by randomization group.ResultsEnrollment was stopped after an interim analysis determined the stopping rule was met, with 9711 patients (median age, 68 years; 56.8% female) of the prespecified 15 562 enrolled (62%). Of these, 9203 (95%) completed the trial. Within 90 days of surgery, symptomatic VTE occurred in 256 patients, including pulmonary embolism (79 cases), above-knee DVT (18 cases), and below-knee DVT (174 cases). The symptomatic VTE rate in the aspirin group was 3.45% and in the enoxaparin group was 1.82% (estimated difference, 1.97%; 95% CI, 0.54%-3.41%). This failed to meet the criterion for noninferiority for aspirin and was significantly superior for enoxaparin (P = .007). Of 6 secondary outcomes, none were significantly better in the enoxaparin group compared with the aspirin group.Conclusions and RelevanceAmong patients undergoing hip or knee arthroplasty for osteoarthritis, aspirin compared with enoxaparin resulted in a significantly higher rate of symptomatic VTE within 90 days, defined as below- or above-knee DVT or pulmonary embolism. These findings may be informed by a cost-effectiveness analysis.Trial RegistrationANZCTR Identifier: ACTRN12618001879257

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To determine factors influencing longterm graft survival and visual acuity in 4834 eyes of 4060 patients receiving their first penetrating corneal graft for keratoconus. Methods: A large cohort study was performed from a national register of corneal grafts in which data were recorded prospectively and analyzed retrospectively. Main outcome measures were graft survival and Snellen visual acuity. Follow-up extended up to 23 years. Results: Kaplan-Meier survival rates of first grafts for keratoconus were 89%, 49%, and 17% at 10, 20, and 23 years, respectively. After 15 years, the graft survival rate was no better than that of all other penetrating grafts (P=.36). Multivariate risk factors influencing failure of first grafts for keratoconus included time to suture removal, postgraft uveitis or microbial keratitis, corneal vascularization prior to or after graft, geographic location of surgery and follow-up (center effect), recipient age at graft, occurrence of rejection episodes, graft size, and surgeon workload. The timing of bilateral grafts made no difference to the risk of rejection. A Snellen visual acuity of 20/40 or better at the most recent follow-up was recorded in 74% of grafts. Conclusions: Penetrating grafts performed for keratoconus exhibited better visual outcome and graft survival than grafts performed for other indications. However, the Kaplan-Meier survival rate of first penetrating grafts for keratoconus was 17% at 23 years after graft and had not plateaued at this time, indicating that young patients are likely to need 1 or more repeated grafts during their lifetime.