Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.

Quantized semiconductor nanoclusters of Bi2S3 are prepared in acetonitrile by reacting BiI3 with H2S or Na2S. Both preparation methods yield stable colloids with particle diameters of ≤5 nm. Excitation with a 355-nm laser pulse results in transient bleaching in the 400−500-nm region. This process is followed by the formation of S- surf with a difference absorption maximum around 540 nm. This we attribute to the chemical changes associated with the hole-trapping process. A composite thin film electrode comprised of SnO2/Bi2S3 nanocrystallites has been prepared by sequential deposition of SnO2 and Bi2S3 films onto an optically transparent electrode, and its photoelectrochemical behavior has been studied. The thin film is photoactive in the visible and near-IR and exhibits an incident photon to photocurrent efficiency (IPCE) of ∼15% at 400 nm.

SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1-6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1-2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2-3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9-3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality ). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.

We present 2 cases of toric intraocular lens implantation for keratoconus: A 55-year-old man with forme fruste keratoconus with a preoperative uncorrected distance visual acuity (UDVA) of 20/800 and a refraction of -6.50-3.00x135 and a 46-year-old man with a claw-shaped topographic pattern, a family history of keratoconus, and a UDVA of 20/800 with a refraction of -5.00-3.00x85. The refraction had been stable for at least 5 years in both patients. Phacoemulsification and implantation of an acrylic toric IOL were uneventful. One year postoperatively, the UDVA was 20/25 in both cases, with a refraction of -0.25-0.50x140 and 0.25-0.50x60, respectively. No progression and no IOL rotation were observed. Toric IOLs may provide excellent outcomes in patients with stable and nonprogressive corneal ectasia.

PURPOSE: To report the clinical features, management, and outcome of a patient who developed bilateral ectasia after photorefractive keratectomy (PRK). METHODS: Case report of a 35-year-old man who underwent bilateral PRK. Preoperative uncorrected visual acuity was 20/200 in the right eye and 20/100 in the left eye. The patient's history was unremarkable and he denied a family history of ocular disorders. RESULTS: Two weeks after surgery, the patient presented with loss of visual acuity in both eyes. Uncorrected visual acuity was 20/80 in the right eye and 20/200 in the left eye. Objective refraction could not be obtained. Slit-lamp microscopy showed corneal thinning in both eyes. After examining the patient's family, his sister was found to have clinical and topographic keratoconus. CONCLUSIONS: Ectasia is a rare complication of PRK. We report the occurrence of bilateral ectasia after PRK in a patient with asymmetric bowtie topographies. We recommend that refractive surgery, even surface techniques such as PRK, be avoided in patients with a family history of keratoconus. [J Refract Surg. 2007;23:941-943.]