Browsing by Author "Steffen, Jonel"

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    Characteristic distribution of peripapillary retinal nerve fibre layer oedema in acute methanol-induced optic neuropathy
    (2025) Maritz, Francois; Steffen, Jonel; Van der Merwe, Junet
    Aims: To describe a characteristic distribution of peripapillary retinal nerve fibre layer oedema in acute methanol-induced optic neuropathy (Me-ION). Methods: This retrospective case series study included four adult patients with acute Me-ION treated at Groote Schuur hospital in Cape Town during the national alcohol ban amid the COVID-19 pandemic from 27 March 2020 to 31 May 2020. Clinical examination included a best corrected visual acuity, pupillary light reflex assessment, anterior segment slit-lamp examination, and dilated fundoscopy. Fundus photography and retinal nerve fibre layer (RNFL) thickness by optical coherence tomography (OCT) was performed. Results: All patients were examined during the acute phase of Me-ION, with a mean interval of 5.5 days between methanol exposure and ocular examination. Fundoscopy showed peripapillary retinal nerve fibre layer whitening and oedema, which extended superiorly and inferiorly from the optic disc and followed the vascular arcades but spared the nasal and temporal areas. In three cases, this correlated with a distinctive pattern of superior and inferior quadrant RNFL thickening on OCT with relative sparing of the nasal and temporal quadrants. Conclusion: Our study is the first to associate this fundoscopic finding with the distinctive superior and inferior quadrant RNFL oedema on OCT during the acute phase of Me-ION. Recognition of this pattern can aid in early diagnosis and timely initiation of life-saving treatment, particularly in cases where patients may be unaware of their methanol exposure.
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    Open Access
    Co-Infection in HIV positive patients with retinitis: A case series of dual positive intraocular fluid polymerase chain reaction
    (2020) Hayes, Morgan; Steffen, Jonel
    Objective To report 10 cases of dual-positive intraocular fluid PCR results in infectious retinitis where both pathogens may be clinically relevant. Methods A retrospective observational case series including 10 patients with infectious retinitis who demonstrated more than 1 positive result on PCR testing over a 10-year period at a single referral centre. Results Of 619 patients who underwent intraocular fluid PCR testing for infectious retinitis, we identified 10 patients (1.62%) where 2 organisms were isolated. All 10 patients were HIV positive with profound immunosuppression (mean CD4 count 67cells/mm3) and extensive retinitis. CMV was identified in all 10 cases whilst the additional pathogen was VZV in 6 cases, Toxoplasma gondii in 3 cases and HSV in 1 case. Conclusions PCR analysis of ocular fluids is important in this clinical scenario since more than one pathogen may be present and clinically relevant. Clinicians should be aware of this rare phenomenon to ensure that, when it does occur, consideration be given to adjusting treatment to cover both organisms.
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    Feasibility of an automated AI-based screening tool for diabetic retinopathy at an endocrine outpatient clinic in SA
    (2024) Roux, Margaretha Magdalena; Steffen, Jonel
    INTRODUCTION: Diabetic retinopathy (DR) is a worsening global pandemic and a leading cause of blindness. Screening is paramount. In the South African public health sector, screening initiatives have faced significant challenges and leveraging new screening technologies may prove useful. This study aimed at evaluating the feasibility of an autonomous AI-based diagnostic tool in an endocrine outpatient clinic at Groote Schuur Hospital. METHODS: Patients identified as referable DR (moderate NPDR or worse) by autonomous AI screening, as well as patients with ungradable images, were referred to an ophthalmologist. We assessed the time it took to do screening, number of patients requiring dilation, number of ungradable images and their potential causes, referral burden, and number of patients requiring treatment. RESULTS: A total of 62 patients underwent screening, with a median AI screening time of 11.7 minutes. Of these, 55 (88.7%) required referral to ophthalmology. This included 36 patients (58.1%) with referable DR according to AI grading (of which 19 patients (30.6%) had vision-threatening DR) and 19 (30.6%) with ungradable images despite dilatation. Nine patients (14.5%) were lost to follow-up between AI screening and ophthalmology assessment, and 8 patients (12.9%) required treatment for vision-threatening DR according to ophthalmology human grading. Cataracts were the most important cause for ungradable images. . CONCLUSION: This study showed that screening for diabetic retinopathy using autonomous AI is feasible in terms of time. However, the significant burden of referrals and high number of ungradable images may be problematic within a resource-constrained public healthcare system.