http://hdl.handle.net/10386/1243 Journal articles Tue, 07 Apr 2026 07:16:03 GMT 2026-04-07T07:16:03Z http://hdl.handle.net/10386/4705 Review of the commonly used colour vision testing methods Mathebula, S. D . Colour is an extremely important component of the information that people gather with their eyes. Most people use colour so automatically that they fail to appreciate how important it is in daily activity. Colour vision is perceived through three types of cones in the retina which are sensitive to red, green and blue colours. The purpose of this paper is to review the available and significant clinical colour vision tests in light of the need in the clinical examination of both congenital and acquired colour vision deficiency (CVD) and colour blindness. The tests are grouped and described as pseudoisochromatic plates, arrangement or matching tests, the lantern test and the anomaloscope test. The performance of each test type is described. When an individual exhibits CVD, the ability to discriminate cones diminishes under specific circumstances that could involve limitations in career choices, early education, academic, and everyday activities. Clinicians should test the colour vision of all patients with the Ishihara test. Those shown to have CVD should be evaluated with the Farnsworth D-15 and/or anomaloscope. Although there are many colour vision tests, their performances are difficult to compare. Once the results are obtained, appropriate advice should be given to the patient. Journal article published in SA Ophthalmology Journal Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10386/4705 2022-01-01T00:00:00Z http://hdl.handle.net/10386/4704 Repurposing antiviral phytochemicals from the leaf extracts of Spondias mombin (Linn) towards the identifcation of potential SARSCOV‑2 inhibitors Boadu, Akwasi; Agoni, Clement; Karpoormath, Rajshekhar; Soliman, Mahmoud; Nlooto, Manimbulu Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a pneumonia-like disease with a pattern of acute respiratory symptoms, currently remains a significant public health concern causing tremendous human suffering. Although several approved vaccines exist, vaccine hesitancy, limited vaccine availability, high rate of viral mutation, and the absence of approved drugs account for the persistence of SARS-CoV-2 infections. The investigation of possibly repurposing of phytochemical compounds as therapeutic alternatives has gained momentum due to their reported affordability and minimal toxicity. This study investigated anti-viral phytochemical compounds from ethanolic leaf extracts of Spondias mombin L as potential inhibitor candidates against SARS-CoV-2. We identified Geraniin and 2-O-Cafeoyl-(+)-allohydroxycitric acid as potential SARS-CoV-2 inhibitor candidates targeting the SARS-CoV-2 RNA-dependent polymerase receptor-binding domain (RBD) of SARSCoV-2 viral S-protein and the 3C-like main protease (3CLpro). Geraniin exhibited binding free energy (ΔGbind) of − 25.87 kcal/mol and − 21.74 kcal/mol towards SARS-CoV-2 RNA-dependent polymerase and receptor-binding domain (RBD) of SARS-CoV-2 viral S-protein respectively, whereas 2-O-Cafeoyl(+)-allohydroxycitric acid exhibited a ΔGbind of − 32 kcal/mol towards 3CLpro. Molecular Dynamics simulations indicated a possible interference to the functioning of SARS-CoV-2 targets by the two identified inhibitors. However, further in vitro and in vivo evaluation of these potential SARS-CoV-2 therapeutic inhibitor candidates is needed. Journal article published in Scientific Reports | (2022) 12:10896 Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10386/4704 2022-01-01T00:00:00Z http://hdl.handle.net/10386/4703 Interexaminer reproducibility for subjective refractions for an ametropic participant Mathebula, Solani David; Rubin, Alan Objective To investigate interexaminer reproducibility of non-cycloplegic subjective refractions. Subjective refractions are frequently determined, and it is important to know whether differences in refractive state over time constitute meaningful, non-random change. Methods and analysis Fifty registered and experienced (≥5 years) optometrists from a single geographic region performed non-cycloplegic subjective refractions for a participant with moderate left eye(OS) to severe right eye (OD) ametropia. Subjective refractions were transformed to power matrices for analysis with stereopairs, distribution ellipsoids and polar profiles of variance of dioptric power. Absolute 95% limits of reproducibility (‍ 1.96 (√2 ) (SD)) for excesses of subjective refractions for the right and left eyes separately from mean subjective refractions were determined. Results Mean subjective refractions were −7.68– 4.50×10 and −4.59–1.85×178 for the right and left eyes, respectively. The 95% absolute reproducibility limits for the stigmatic coefficients (spherical equivalents) were ≤1.71 D and ≤0.75 D for the right and left eyes, but corresponding limits for astigmatic coefficients were smaller (≤0.69 D). Conclusion Removal of possible outliers for OD and OS, respectively, reduces the absolute 95% reproducibility limits for the stigmatic and astigmatic coefficients to ≤0.97 D and ≤0.49 D, thus improving interexaminer reproducibility. However, these results suggest caution with analysis of refractive data where subjective rather than objective methods are applied for longitudinal and epidemiological studies. Journal article published in BMJ Open Ophthalmology: 10.1136/bmjophth-2021-000954 Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10386/4703 2022-01-01T00:00:00Z http://hdl.handle.net/10386/4701 Latest developments on meibomian gland dysfunction: diagnosis, treatment and management Mathebula, Solani D Background: Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease and one of the most common ophthalmic conditions found in clinical practice. Meibomian gland dysfunction tends to be overlooked because its signs and symptoms do not cause blindness. Meibomian gland dysfunction is characterised by the obstruction of the meibomian gland terminal ducts resulting in tear film instability. Aim: The purpose of this article was to provide an update on MGD’s diagnosis and treatment. Method: A literature review was conducted using search engines such as Google Scholar, Medline and ScienceDirect databases. Keywords such as MGD diagnosis and management and treatment of MGD were used to search the databases. Results: A total of 44 relevant papers were reviewed. These papers were then curated to include only those concerning diagnosis of meibomian gland dysfunction, treatment of meibomian gland dysfunction and management options of meibomian gland dysfunction. The references of individual papers from the curated results were checked to yield a further 13 papers. Conclusion: Meibomian gland dysfunction is not a single entity but is multifactorial in origin; however, our understanding of the condition is evolving rapidly because of newer imaging technology. There is no gold standard treatment option for MGD, but many options are available that include medications and other procedures Journal article published in African Vision and Eye Health 2022;81(1), a713 Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10386/4701 2022-01-01T00:00:00Z