Comparative efficacy evaluation of disinfectants against severe acute respiratory syndrome coronavirus-2.

BACKGROUND: Disinfection is one of the most effective ways to block the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Due to the prolonged coronavirus disease 2019 (COVID-19) pandemic, disinfectants have become crucial to prevent person-to-person transmission and decontaminate hands, clothes, facilities and equipment. However, there is a lack of accurate information on the virucidal activity of commercial disinfectants. AIM: To evaluate the virucidal efficacy of 72 commercially available disinfectants constituting 16 types of ingredients against SARS-CoV-2. METHODS: SARS-CoV-2 was tested with various concentrations of disinfectants at indicated exposure time points as recommended by the manufacturers. The 50% tissue culture infectious dose assay was used to calculate virus titre, and trypan blue staining and CCK-8 were used to assess cell viability after 3-5 days of SARS-CoV-2 infection. FINDINGS: This study found that disinfectants based on 83% ethanol, 60% propanol/ethanol, 0.00108-0.0011% sodium dichloroisocyanurate and 0.497% potassium peroxymonosulfate inactivated SARS-CoV-2 effectively and safely. Although disinfectants based on 0.05-0.4% benzalkonium chloride (BAC), 0.02-0.07% quaternary ammonium compound (QAC; 1:1), 0.4% BAC/didecyldimethylammonium chloride (DDAC), 0.28% benzethonium chloride concentrate/2-propanol, 0.0205-0.14% DDAC/polyhexamethylene biguanide hydrochloride (PHMB) and 0.5% hydrogen peroxide inactivated SARS-CoV-2 effectively, they exhibited cytotoxicity. Conversely, disinfectants based on 0.04-4% QAC (2:3), 0.00625% BAC/DDAC/PHMB, and 0.0205-0.14% and 0.0173% peracetic acid showed approximately 50% virucidal efficacy with no cytotoxicity. Citric acid (0.4%) did not inactivate SARS-CoV-2. CONCLUSION: These results indicate that most commercially available disinfectants exert a disinfectant effect against SARS-CoV-2. However, re-evaluation of the effective concentration and exposure time of certain disinfectants is needed, especially citric acid and peracetic acid.

Retinal sequelae of primary ocular blast injuries.

Primary ocular blast injury is an uncommon and disputed phenomenon. As personal ballistic protection of the head and torso improves for soldiers, increasing numbers of injuries to the unprotected areas such as the face and eyes may be expected; similarly the increase in the use of improvised explosive devices by insurgent terrorists in Iraq is increasing the number of primary blast injuries being seen by the Defence Medical Services. We report a rare case of primary blast injury to the eye and briefly discuss the literature on the subject.

Posterior embryotoxon may not be a forme fruste of Axenfeld-Rieger's Syndrome.

Axenfeld-Rieger Syndrome is a disorder of morphogenesis which is autosomal dominantly inherited. One of the main ocular features associated with Axenfeld-Rieger is posterior embryotoxon, which is a prominent anteriorly displaced Schwalbe's line. This can be found in up to 15% of normal eyes, without any clinical significance or may represent a forme fruste of an anterior segment dysgenesis. Many large case series studies of Axenfeld-Rieger had used the presence of posterior embryotoxon with iris strands extending from the peripheral iris to Schwalbe's line, as inclusion criterion for this condition. We report a case of Axenfeld-Rieger syndrome without posterior embryotoxon and the abnormalities of the angle, but with other features to support the diagnosis of Axenfeld-Rieger Syndrome.

Outcomes of corneal transplantation: a corneal surgeon vs the general ophthalmologist.

AIMS: The aim of this study was to examine the outcomes of corneal transplantation in cases performed by a group of general ophthalmologists and those performed by an ophthalmologist with a subspecialist interest in corneal surgery. METHODS: A retrospective analysis of the outcomes in corneal transplantation was carried out for a 4-year period in three separate units in South Wales. In addition to patient demographic details, the primary diagnosis, type of keratoplasty performed, and outcome of surgery were noted. The data were analysed statistically by the Mann-Whitney U-test (one-tailed). RESULTS: Group A (n=35) was defined as those patients whose surgery was performed by a general ophthalmologist. There were seven surgeons in this group with a mean of five procedures each over the study period. Group B (n=54) were all operated on by the same surgeon. The mean age in both groups was similar with group A comprising of 66% males with 50% males in group B. The commonest indication for surgery in both groups was endothelial cell failure In group A, graft clarity at 1 year was 83% for all aetiologies and 73% at 2 years. In group B, the results were 97 and 92%, respectively. In group A, overall 56% achieved 6/18 or better compared with 68% in group B. In group A 73% had an improvement of one or more lines compared with 84% in group B (P=0.085). Reasons for graft failure in both groups were similar. CONCLUSION: The success rate of corneal transplantation carried out by general ophthalmologists in this study is reduced when compared with cases performed by a corneal surgeon. The explanation for this is not clear, but is undoubtedly multifactorial.

Does macular laser alter the refraction in a diabetic with maculopathy? A pilot study.

PURPOSE: To determine whether macular photocoagulation has any effect on refraction in diabetics. METHODS: This was a prospective study of 12 eyes of 12 diabetics with refraction at 2 weeks before and at 4 weeks and 4 months after argon laser. This was combined with a questionnaire survey of attitude among ophthalmologists on prescribing spectacles for diabetics awaiting macular laser. The main outcome measure was the spherical equivalents (SEQ) before and after treatment. RESULTS: Only 36% of ophthalmologists surveyed would prescribe corrective lenses in patients waiting for macular photocoagulation. The median change in magnitude of SEQ at 4-6 weeks post-laser compared to pre-laser was 0.36 D (interquartile range 0.18-0.50 D). The median change in SEQ at 4 months was 0.25 D (interquartile range 0.12-0.56 D). These changes in SEQ from pretreatment values were not statistically significant on Wilcoxon signed-rank test (p = 0.17 and 0.10, respectively). The correlation coefficient between difference and average SEQ was 0.02 (95% CI -0.14 to 0.19, p = 0.75) at 4 weeks and 0.11 (95% CI -0.06 to 0.275, p = 0.17) at 4 months, indicating no tendency for change in refraction with increasing ametropia. CONCLUSION: This pilot study implies that argon laser photocoagulation in diabetic maculopathy does not alter refraction. Prescription of corrective lenses can be performed prior to laser therapy, if required.

Ultrasound with graded compression in the evaluation of acute appendicitis.

Acute appendicitis is the most common diagnosis made (in the Western world) in patients with an "acute abdomen." Although the mortality rate has been vastly reduced, the diagnostic inaccuracy rate of 15% to 20% has remained unchanged in the past 100 years. In this article, the authors report the ultrasonographic findings in 80 patients examined using a small linear-array transducer, which enables direct visualization of the inflamed appendix. During 22 months, 80 patients (28 males and 52 females; age range, 3 to 81 years; mean, 32.3 years) with equivocal clinical signs and symptoms of acute appendicitis were examined sonographically. Of the 29 patients whose appendicitis was verified at surgery, ultrasonography was positive in 26, with an overall sensitivity of 90%. Of the 51 patients who did not have appendicitis, ultrasonography was negative in all, with a specificity of 100%. The authors concur with reports in the literature that ultrasonography is helpful in diagnosing appendicitis.

The utilization of cross-sectional anatomy in a surgical residency training program.

The education of students and residents in a surgical department involves a thorough knowledge of three-dimensional anatomical relationships in the body. In addition, the advances in new imaging modalities demand an in-depth study of cross-sectional anatomy by both students and residents. Traditionally, surgical training incorporated dissections of cadavers and the progressive involvement of the resident in the surgical theater. At the King/Drew Medical Center cross-sectional anatomy has been incorporated into the teaching program. The central focus of this instructional program utilizes problem-solving learning modules that emphasize important surgical and anatomical principles.LEARNING MODULES FOR EACH MAJOR REGION OF THE BODY WERE ESTABLISHED AND INCLUDE THE FOLLOWING: (1) serial cross sections, corresponding computerized tomographic scans and roentgenograms; (2) an atlas (cross sections), case histories, and examination questions; and (3) audiovisual presentation of the normal anatomy, the surgical principles involved, and a discussion of the examination questions. The serial cross sections were prepared at the King/Drew Medical Center.A selected case study is used to illustrate how the knowledge of three-dimensional anatomy can be critical in the evaluation and surgical plan of a patient. Entire learning modules of the thorax and abdomen were used.