Mucormycosis

The zygomycoses are infections caused by fungi of the class zygomycetes, comprised of the orders Mucorales and Entomophthorales. Fungi ofthis order are causes of mucormycosis, an acute opportunistic infection occurring mostly in immunocompromised individuals, particularly in patients with diabetic ketoacidosis. The purpose of this paper is to present an academic perspective on the pathophysiology, presentation and management of mucormycosis. Possible management strategies are provided

Ocular manifestations of mitochondrial disease

Mitochondrial disease caused by mutations in mitochondrial DNA is recognized as one of the most common causes of inherited neurological disease. Neuro-ophthalmic manifestations are a common feature of mitochondrial disease.  Optic atrophy causing central visual loss is the dominant feature of mitochondrial DNA diseases. Nystagmus is also encountered in mitochondrial disease.Although optometrists are not involved with the management of mitochondrial disease, they are likely to see more patients with this disease. Oph-thalmic examination forms part of the clinical assessment of mitochondrial disease. Mitochondrial disease should be suspected in any patient with unexplained optic neuropathy, ophthalmoplegia, pigmentary retinopathy or retrochiasmal visual loss. Despite considerable advances in the under-standing of mitochondrial genetics and the patho-genesis of mtDNA diseases, no effective treatment options are currently available for patients withmitochondrial dysfunction. (S Afr Optom 201271(1) 46-50

Optical transferences and their application to ray tracing through the human cornea*

The purpose of this paper is two fold, firstly to describe aspects of the quantitative analysis of the linear optical character of the corneas of ten young and healthy subjects using the exp-mean-log-transference and secondly to illustrate how mean transference and ray vector fields or diagrams can be used to explain and understand the optical properties of corneas as thick optical systems.An Oculus Pentacam was used to obtain 43 successive measurements of the radii of curvature of the anterior and posterior corneal surfaces and the central corneal thicknesses of the right eyes of ten subjects. From these measurements 4×4 ray transferences were calculated. Mean transferences were obtained via multi-dimensional Hamiltonian space and these mean transferences were used to produce stereo-pairs of ray vector fields. The mean transferences are also important in understanding the behaviour of light through each of the corneas concerned. This paper provides the first order optical characters of corneas from the positions and inclinations of rays entering and leaving such systems. As anticipated, light rays through the cornea are deflected inwards when the refractive index of the cornea is greater than the index of the surrounding medium. The exp-mean-log transference for a specific cornea exists and is the optical transference of the averaged cornea of the sample of measurements for that cornea. Within the limitations of linear or paraxial optics, the corneas of the different eyes in this sample and their averages were found to be close to that of thin optical systems; but they were not truly thin and instead should be considered as being thick optical systems. (S Afr Optom 2011 70(4) 156-167

Ocular surface disorder among HIV and AIDS patients using antiretroviral drugs

Background: Ocular disorders occur in 50% – 80% of HIV and AIDS patients, and dry eye has been reported as one of the most common anterior segment manifestations in these patients. Aim: The aim of this study was to investigate ocular surface disorders (OSDs) or dry eye in people living with HIV and AIDS on antiretroviral (ARVs) in a controlled setting. Setting: Mankweng Hospital, ARV Clinic. Methods: This study included 130 HIV and AIDS participants attending an ART Clinic at Mankweng Hospital and 48 controls. Each participant had an anterior and posterior segment eye examination with a slit lamp and fundus camera, respectively. The dry eye or OSD was investigated with Schirmer’s test and invasive fluorescein tear breakup time (TBUT). Results: The means of the Schirmer’s test and TBUT were 6.7 mm ± 4.0 mm and 6.9 ± 4 seconds in HIV and AIDS participants, while the means in the control group were 13.5 mm ± 3 mm and 14.2 ± 3 s, respectively. The correlations between the severity of dry eye and the level of CD4 cell count were positive and significant. Conclusion: There was decreased tear production as measured by the Schirmer’s test and TBUT in our study participants. Statistically significant correlations were found between the severity of dry eye and the level of CD4 cell count. Although the entire pathogenesis of dry eye in HIV and AIDS patients remains unclear, it may be associated with lymphocytic infiltration and destruction of the lacrimal gland

Tuberculosis treatment intervention trials in Africa: A cross-sectional bibliographic study and spatial analysis

Background Mycobacterium Tuberculosis (TB) poses a substantial burden in sub-Saharan Africa and is the leading cause of death amongst infectious diseases. Randomised controlled trials (RCTs) are regarded as the gold standard for evaluating the effectiveness of interventions. We aimed to describe published TB treatment trials conducted in Africa. Methods This is a cross-sectional study of published TB trials conducted in at least one African country. In November 2019, we searched three databases using the validated Africa search filter and Cochrane’s sensitive trial string. Published RCTs conducted in at least one African country were included for analysis. Records were screened for eligibility. Co-reviewers assisted with duplicate data extraction. Extracted data included: the country where studies were conducted, publication dates, ethics statement, trial registration number, participant’s age range. We used Cochrane’s Risk of Bias criteria to assess methodological quality. Results We identified 10,495 records; 175 trials were eligible for inclusion. RCTs were published between 1952 and 2019. The median sample size was 206 participants (interquartile range: 73–657). Most trials were conducted in South Africa (n = 83) and were drug therapy trials (n = 130). First authors were from 30 countries globally. South Africa had the most first authors (n = 55); followed by the United States of America (USA) (n = 28) and Great Britain (n = 14) with fewer other African countries contributing to the first author tally. Children under 13 years of age eligible to participate in the trials made up 17/175 trials (9.71%). International governments (n = 29) were the most prevalent funders. Ninety-four trials provided CONSORT flow diagrams. Methodological quality such as allocation concealment and blinding were poorly reported or unclear in most trials. Conclusions By mapping African TB trials, we were able to identify potential research gaps. Many of the global north’s researchers were found to be the lead authors in these African trials. Few trials tested behavioural interventions compared to drugs, and far fewer tested interventions on children compared to adults to improve TB outcomes. Lastly, funders and researchers should ensure better methodological quality reporting of trials

Repeated Assessments of Informed Consent Comprehension among HIV-Infected Participants of a Three-Year Clinical Trial in Botswana

Informed consent (IC) has been an international standard for decades for the ethical conduct of clinical trials. Yet frequently study participants have incomplete understanding of key issues, a problem exacerbated by language barriers or lack of familiarity with research concepts. Few investigators measure participant comprehension of IC, while even fewer conduct interim assessments once a trial is underway.We assessed comprehension of IC using a 20-question true/false quiz administered in 6-month intervals in the context of a placebo-controlled, randomized trial for the prevention of tuberculosis among HIV-infected adults in Botswana (2004-2009). Quizzes were offered in both Setswana and English. To enroll in the TB trial, participants were required to have ≥ 16/20 correct responses. We examined concepts understood and the degree to which understanding changed over three-years. We analyzed 5,555 quizzes from 1,835 participants. The participants' highest education levels were: 28% primary, 59% secondary, 9% tertiary and 7% no formal education. Eighty percent of participants passed the enrollment quiz (Quiz1) on their first attempt and the remainder passed on their second attempt. Those having higher than primary education and those who took the quiz in English were more likely to receive a passing score on their first attempt (adjusted odds ratios and 95% confidence intervals, 3.1 (2.4-4.0) and 1.5 (1.2, 1.9), respectively). The trial's purpose or procedures were understood by 90-100% of participants, while 44-77% understood randomization, placebos, or risks. Participants who failed Quiz1 on their initial attempt were more likely to fail quizzes later in the trial. Pass rates improved with quiz re-administration in subsequent years.Administration of a comprehension quiz at enrollment and during follow-up was feasible in a large, international collaboration and efficiently determined IC comprehension by trial participants. Strategies to improve understanding of concepts like placebos and randomization are needed. Comprehension assessments throughout a study may reinforce key concepts

A review of ocular genetics and inherited eye diseases

During the past twenty years, there has been an exponential increase in the knowledge and under-standing of ocular genetic diseases and syndromes. The number of human eye diseases that have a known genetic or hereditary component continues to increase. In addition, genetic diseases are the most common cause of blindness in infants and children in developed countries. Optometrists are likely to encounter patients with inherited eye disorders. They may be the first clinician the patient consults. Inherited eye diseases may be isolated (only affecting the eye) or part of a complicated syndrome. Both isolated eye diseases and genetic syndromes can have identifiable gene mutation known to cause the disease. Knowledge of the clinical and molecular features of ocular genetics and inherited eye diseases is important for appropriate diagnosis and patient management. This article reviews the current information on ocular genetics and inherited eye diseases.The ocular conditions described in the review have significant visual impairment and blindness consequences. Therefore, optometrists (as the mostly likely first line of consultation) should be able todiagnose the condition appropriately first before they could make any management, care or referralplan. Visual aids are, of course, one of the management options for such patients with visual impairment. (S Afr Optom 2012 71(4) 178-189

Quantitative analysis of the linear optical character of the anterior segment of the eye*

No abstract availabl

Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam*

The purpose of this study was to investigate short-term variation and intra-subject repeatabil-ity of  human central corneal thickness (CCT) and axial anterior chamber depth (AACD) measure-ments obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anteriorsegment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were ob-tained from these images and means, standard deviations,variances and repeatability of the measurements were investigated. Both parameters (CCTand AACD) showed small variation with good orexcellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 ±0.05 millimeters (or 555 ± 50 microns) and 3.206± 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young,normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more com- plicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue

Carotid cavernous fistula

No abstract availabl