Research Articles (Opthalmology)

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Transorbital neuroendoscopy-assisted resection of a giant optic pathway glioma in a neonate
(Springer, 2023-09) Maseko, Rodney; Mabogo, Maanda; Lockhat, Zarina I.; Makunyane, P.S. (Priscilla); Ahmad, Samia; Bida, Meshack; Padayachy, Llewellyn; lc.padayachy@up.ac.za
Congenitalgiant orbital tumors in infancy are relatively rare, especially when the tumors are associated with significant intracranial extension. We describe the use of a transorbital neuroendoscopy-assisted resection of such a lesion. While this approach is increasingly gaining popularity for certain anterior and middle skullbase lesions in adults, this report represents the youngest patient reported on where this minimally invasive approach has been successfully used to resect the intracranial tumor. This surgical approach obviated the need for a separate craniotomy, with the additional benefit of minimizing blood loss.
Comparison of amplitude of accommodation in type 1 and type 2 diabetes mellitus
(New Media Publishing, 2021-03) Makunyane, P.S. (Priscilla); Mathebula, S.D.
BACKGROUND: The prevalence of diabetes is increasing exponentially due to increasing obesity and reduced physical activity levels. Diabetes affects all structures of the eye; the optics and biometry of the eye are also affected in diabetic patients. PURPOSE: To compare the amplitude of accommodation (AA) in type 1 and 2 diabetic patients with the age-matched controls. METHODS: One hundred individuals under the age of 40 years were examined. There were 22 subjects with type 1, 43 with type 2 diabetes and 35 age-matched controls. The AA was measured using the subjective push-up with the RAF rule (Royal Air Force rule). Descriptive statistics and regression analysis were used to analyse the data. RESULTS: The mean AA was 3.92±0.93, 4.93±1.05 and 7.26±1.30 dioptres (D) in type 1, type 2 and healthy subjects, respectively. There was a significant difference between the mean AA of all diabetic patients and the control subjects, p≤0.01. The t-test showed that there was significant difference between the AA measurements in type 1 and type 2, p≤0.01. CONCLUSION: The results of this study indicate that diabetes mellitus type 1 may have a major impact on the lens biometry and the AA measurements. The differences may indicate a fundamental difference in pathogenesis of reduced AA.
Ocular manifestations of HIV and AIDS patients on antiretroviral therapy in a tertiary hospital in South Africa
(AOSIS, 2021-09-21) Makunyane, P.S. (Priscilla); Mathebula, Solani D.
BACKGROUND : Human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) causes impairment to the immune system, which then leads to immunocompromised conditions, and allows for opportunistic infection to invade many organs of the human body. Ocular involvement is very common; the various ocular complications may be asymptomatic and they may be the initial manifestations of the underlying diseases. AIM : This study aimed to determine the prevalence and the type of ocular manifestations that occur in HIV and AIDS patients. SETTING : The study was conducted on ART (antiretroviral treatment) clinic patients in the Department of Ophthalmology at the Steve Biko Academic Hospital, Pretoria. METHODS : This descriptive, cross-sectional study was conducted on HIV and AIDS patients referred from the ART clinic for complete ophthalmological evaluation, irrespective of the immune system status and presence or absence of symptoms. All the participants underwent an ophthalmologic evaluation, which included case history and ocular examinations of both anterior and posterior segments. RESULTS : Out of the 177 participants, 72.3% had visual acuity of between 6/3 to 6/18, 10% had poor vision, 7% had lost one eye to ocular complications and 5% were blind. The most common anterior segment manifestations were uveitis and dry eye, whilst HIV-related retinopathy and papilledema were the most prevalent conditions in the posterior segment. Only three participants had third cranial nerve palsy. CONCLUSION : The prevalence of ocular manifestations was significantly higher with lower CD4+ cell counts, which could be regarded as predictors for the occurrence of ocular morbidity in HIV and AIDS patients.
Large discs with large cups : a diagnostic challenge in Black African patients
(New Media, 2020) Soma, Darshana; McLaren, G.D.; Carmichael, T.R.
BACKGROUND : The study was undertaken in order to determine in patients with large optic discs and large optic cups, the proportion with physiologic cupping (normal eyes) misdiagnosed as glaucomatous; and further, to evaluate the possible relationship between optic disc size and central corneal thickness. METHOD AND DESIGN : A case series of 69 Black African patients with large discs (vertical disc height measuring >1.8 mm) and large cups (vertical cup to disc ratio ≥0.6) was evaluated to determine what proportion had glaucoma. Patients categorised as normal were further evaluated to determine what proportion were previously misdiagnosed and treated for glaucoma. Patients with a suspected diagnosis of glaucoma, normal tension glaucoma or primary open angle glaucoma were recruited from the glaucoma clinic at St John’s Eye Hospital, Soweto, South Africa. Outcome measures included corrected vertical disc height (VDH), vertical cup to disc ratio (CDR), intraocular pressure (IOP), central corneal thickness (CCT), retinal nerve fibre layer (RNFL) analysis and visual fields. RESULTS : Sixty-nine Black African patients (138 eyes) with large discs and large cups were evaluated. Forty-one patients (59%) were females and 28 (41%) were males. The mean age was 56 years. Of the 69 patients, 51 (74%) had physiologic cupping (normal eyes) and 18 (26%) patients were glaucomatous. Of the group of 51 patients with physiologic cupping, there were nine patients who were previously misdiagnosed with glaucoma and who had received treatment. VDH ranged between 1.9 and 3.2 mm (mean±SD, 2.3±0.26 mm). The distribution analysis of VDH measurements noted the largest cluster around 2.3 mm. CCT ranged between 454 μm and 618 μm (mean±SD, 516±37μm). Of the 138 eyes, 107 (77.5%) had CCT<544 μm. CONCLUSION : Large CDR in relation to large disc size may be normal physiological cupping. It can be misdiagnosed as glaucomatous if objective RNFL analysis is not carried out. In this study, nine (18%) patients from a group of 51 patients with physiologic cupping were misdiagnosed as glaucomatous. There was no linear correlation between CCT and VDH in this study (Pearson’s correlation coefficient was 0.13). The majority of eyes (77.5%) had thin corneas (CCT<544 μm).
Ocular surface disorder among HIV and AIDS patients using antiretroviral drugs
(AOSIS Open Journals, 2019-01-31) Mathebula, Solani D.; Makunyane, P.S. (Priscilla)
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.
Intraocular pressure measurements following intravitreal anti-vascular endothelial growth factor injections with and without the use of a Honan balloon : a randomised open label clinical trial
(New Media Publishing, 2018) Tayob, Hamza; Ally, N.
OBJECTIVE : To assess whether ocular compression preintravitreal bevacizumab injection is beneficial in reducing the post-intravitreal injection intraocular pressure (IOP). METHOD : A prospective randomised, two-arm parallel control trial, at a secondary care ophthalmology clinic (Witbank Provincial Hospital) was conducted. Fifty-six patients receiving intravitreal injections of 0.1 ml bevacizumab (Avastin, Genentech, Roche, Basel, Switzerland) were randomised to either receive no intraocular pressure-lowering intervention pre-injection, or to receive intraocular pressure-lowering intervention pre-injection with the application of a Honan balloon inflated to 20–30 mmHg and applied over the eye for 15 minutes. After the administration of intravitreal injection in either group, the patients’ intraocular pressures were measured at 5-, 10- and 30-minute intervals using the Goldmann applanation tonometer. RESULTS : Twenty-eight patients were enrolled in each of the intervention and control arms of the study. The median baseline IOPs were 14 mmHg (IQR: 11–18 mmHg) and 14 mmHg (IQR: 12–16.5 mmHg) (p=0.914) in the control and intervention group respectively. The median IOPs in the control and intervention groups at 5-, 10- and 30-minutes respectively were 36 mmHg (IQR: 33–38 mmHg) and 18 mmHg (IQR: 16–24 mmHg) (p<0.001); 29 mmHg (26–30 mmHg) and 18 mmHg (14–20 mmHg) (p<0.001); and 24 mmHg (20–26 mmHg) and 18 (12–18 mmHg) (p<0.001). CONCLUSION : The results demonstrate a significant reduction in the post-injection IOP rise with the use of a Honan balloon to reduce IOP prior to the administration of intravitreal injections. Based on the findings of this study it is recommended that the Honan balloon be used prior to intravitreal injections in patients with normal pre-injection IOPs.
Loss of amplitude of accommodation in pre-presbyopic HIV and AIDS patients under treatment with antiretrovirals
(AOSIS Open Journals, 2017-12-01) Mathebula, Solani D.; Makunyane, P.S. (Priscilla)
BACKGROUND : The prevalence of HIV and AIDS is causing an enormous public health burden. Its manifestations spare no organ. Ocular complications are mainly attributed to various opportunistic infections which are directly or indirectly caused by immune deficiency. Purpose and aim: The purpose of this study was to determine the effect of HIV and AIDS on subjective amplitude of accommodation of patients under treatment with antiretrovirals and then to compare their results to those of control subjects. METHODS : The study took place over a period of 10 months. A quantitative study was carried out on 58 subjects (29 ± 5.5 years) with HIV and AIDS and 35 (28.67 ± 4.6 years) controls of similar age. Amplitude of accommodation was measured using the subjective Royal Air Force push-up method. The influence of CD4+ cell count was also recorded. Results: People with HIV and AIDS had lower mean amplitude of accommodation (5.69 ± 0.88 D) compared to controls (8.53 ± 1.2 D). The decrease in amplitude of accommodation did not show any correlation with the CD4+ cell count. Lower amplitude of accommodation exists in people living with HIV and AIDS when compared with age-related healthy people. CONCLUSION : The results suggest that patients with HIV and AIDS on antiretroviral drugs (ARVs) have reduced amplitude of accommodation and might experience presbyopia earlier in life than participants without HIV and AIDS. The reduced amplitude of accommodation could be the initial presentation of HIV infection before the systemic manifestation. The possible causes could be the direct neuronal infection by HIV-1, ARVs use, pathological changes of the lens and ciliary muscle or the sensory component of the visual system. It is unknown whether the reduced amplitude of accommodation occurred prior to antiretroviral therapy or represents an ongoing injury to the eye and visual system by the HIV.
Update on ocular toxicity of ethambutol
(AOSIS Open Journals, 2016-08-30) Makunyane, P.S. (Priscilla); Mathebula, Solani D.; prisilla.makunyane@up.ac.za
The purpose of this review is to update clinicians on available literature on the ocular toxicity of ethambutol and the type of eye care to be provided to patients treated with these medications. Ethambutol is a commonly used first-line anti-tuberculosis drug. Since its first use in the 1960s, ocular toxicity is described as related to dose and duration, and it is reversible on therapy discontinuation. However, the reversibility of the toxic optic neuropathy remains controversial. The mechanism of ocular toxicity owing to ethambutol is still under investigation. Other than discontinuing the drug, no specific treatment is available for the optic neuropathy caused by ethambutol. Doctors prescribing ethambutol should be aware of the ocular toxicity, and the drug should be used with proper patient education and ophthalmic monitoring.
An update on diagnostic tests for colour vision defects in individuals working in the aviation industry
(South African Society of Occupational Medicine (SASOM), 2016-05) Makunyane, P.S. (Priscilla); prisilla.makunyane@up.ac.za
BACKGROUND : Colour vision is a function of the visual system and is important in visually-demanding environments such as aviation. There is no international consensus on minimum colour vision standards or on colour vision assessment protocols for use in aviation. OBJECTIVE : To provide an update on colour-vision tests approved by the International Civil Aviation Organization and to highlight the importance of choosing appropriate colour-vision tests that can be used with confidence to detect colour-vision deficiency, to classify the type of deficiency involved, and to quantify the severity of loss. METHODS : Available English literature was reviewed. The articles reviewed focused on the colour-vision tests recommended by the International Civil Aviation Organization. FINDINGS : Comparisons of conventional colour-vision tests revealed the enormous variability and inconsistency of outcomes. Novel techniques of colour-vision assessment referred to as precision tests provide more description of the class and severity of colour vision loss. These techniques go a long way towards establishment of an objective and less variable colour-vision assessment within aviation. CONCLUSION : There is a clear need for the development of an internationally recognised system of colour-vision assessment that is less variable and can be used to accurately classify the class of colour deficiency and severity of loss of vision. There is an even greater need to establish the level of residual colour vision that can be classed as safe within well-defined working environments to ensure that applicants who can carry out safety-critical, colour-related tasks, as well as normal trichomats, are not discriminated against on the basis of their colour deficiency.

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