Browsing by Author "Tinley, Christopher"

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    Corneal donations in South Africa: a 15-year review
    (2018) York, Nicholas; Tinley, Christopher
    Background: Corneal pathology is one of the leading causes of preventible blindness in South Africa. A corneal transplant procedure can restore, or significantly improve vision in most of these patients. In current South African clinical practice however, there is a gross shortage of corneal tissue available to ophthalmologists to perform these procedures. There is little published data on corneal donations in South Africa describing the magnitude of the current problem. Objectives: To describe trends in the number of corneal donors per year, the number of corneal transplants performed each year, the origin of corneal donors, the allocation of corneas to the public or private sector and the demographics of corneal donors in South Africa. Methods: A retrospective review of all corneal donations made to South African eye banks during a 15-year study period from 1 January 2002 to 31 December 2016. Results: A progressive year-on-year decline in corneal donors was found over the study period, from 565 donors per year in 2002 to 89 donors in 2016. As a direct result, there has been an 85.5% decrease in the number of corneal transplants performed per year using locally donated corneas, from 1049 in 2002 to 152 in 2016. 48.8% of donors originated from mortuaries, 39% from private hospitals and 12.2% from government hospitals. Donors originating from mortuaries showed the most significant declines over the 15 year period, decreasing by 94.8%. 79.3% of donated corneas were allocated to the private sector while 21.7% were allocated to the public sector. Demographic data showed that 69.1% of donors were male, while 30.9% were female. 77.2% were white, 14.0% coloured, 6.3% black and 2.5% Indian/Asian. Age of donors demonstrated a bimodal peak, at 25 and 55 years. Conclusion: The number of corneal donations in South Africa has markedly declined, causing the burden of corneal disease requiring corneal transplantation to continually rise. This study describes the magnitude and trends of the current problem in South Africa. The demographic data has identified certain low donor rate groups within the South African population, where there are possible cultural and other objections to corneal donation. These should serve as a major focus of future research and initiatives aimed at reversing the current trends.
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    Duane's retraction syndrome in a cohort of South African children a 20 year clinic based review
    (2019) Steyn, Anna; Tinley, Christopher
    OBJECTIVES: To describe the clinical features of Duane’s retraction syndrome in a cohort of South African children and analyse subtypes for ethnic differences. METHODS: Retrospective case series of 120 patients seen in the period from 1997 to 2017 at the Red Cross War Memorial Children’s Hospital. RESULTS: Of the 120 patients, Type 1 was present in 76 (64%) of cases, with Type 2 in 27 (23%) and Type 3 in 16 (13%).Type 2 was most common in black children (54%), while Type 1 predominated in mixed race (68%) and white children (94%). A female predominance was seen in white children (69%) and mixed race children (59%), while there was a male predominance amongst black children (62.5%) Left involvement was the most common (44%), followed by right (41%) and bilateral involvement (14%).The average age of presentation was 2,85 years. A positive family history of squints or Duane’s was present in 6 (0,5%). Congenital systemic abnormalities were present in 12 (1%) and congenital ocular abnormalities in 2 (0.4%). Squint in primary position was present in 57 (46%), of which 39% had esotropia and 61% exotropia. Squint was more common in black children (71%) than in mixed race (39.4%) and white children (41%). An abnormal head position was present in 59 (50%) and was most common in Type 2 (67%). Up and downshoots were seen in 58 (48.3%). Ametropia was found in 94 (79%), and of these 88 (93,6%) were hyperopic and 6 (6.4%) myopic. Amblyopia was present in 15 (12.5%). Surgery was performed in 41(34%). CONCLUSION: This study is the first to provide robust data on the profile of paediatric DRS in the 3 main South African ethnic groups, and shows clear ethnic differences in DRS. In black patients, males are more often affected, the proportion with Type 2 DRS is more frequent, and surgery is required more often. Further population-based studies on the epidemiology of DRS in children are needed to clarify the role of race as a potential risk factor.
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    Is the Adams D-15 colour vision test a sensitive screening tool for ethambutol- and linezolid-induced optic neuropathy? A retrospective case series
    (2021) Van der Merwe, Pieter Jacobus Stephanus; Tinley, Christopher
    Background: Ethambutol hydrochloride and linezolid are commonly used anti-tuberculous agents. Both agents can cause potentially blinding toxic optic neuropathy. Currently there is no low-cost, sensitive screening tool to detect early toxicity before permanent vision loss has occurred. Purpose: To evaluate the ability of the Adams D-15 colour vision test to detect early ethambutol- and linezolid-induced optic neuropathy. Methods: This was a retrospective case series of 15 patients who were screened for ethambutol- and linezolid-induced toxic optic neuropathy. At screening and follow-up visits, a detailed clinical history was taken, a standard of care examination performed and a battery of side-room investigations conducted, including: Farnsworth Munsell D15 (FM D15) and Adams D15 colour vision tests, retinal nerve fiber layer optical coherence tomography (RNFL-OCT) and a Humphrey visual field 24-2 (HVF 24-2). According to the results of these tests, the patients were classified into 3 groups: “No toxicity”, “Uncertain toxicity” or “Confirmed toxicity”. Results: Six patients were classified as “No toxicity”, 3 were “Uncertain toxicity” and 6 were classified as “Confirmed toxicity”. The Adams D15 showed a sensitivity of 100% for detecting a toxic optic neuropathy. Conclusion: The Adams D15 is a sensitive screening tool for the detection of early ethambutol- and linezolid-induced optic neuropathy.
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    Outcomes of uveitic cataract surgery in a cohort of South African children
    (2023) Kennedy, Clare; Tinley, Christopher; Steffen Jonel
    BACKGROUND: Cataract formation is a common and potentially blinding complication of paediatric uveitis. Surgical management approach remains a point of controversy. The purpose of this study was to determine the peri- and postoperative outcomes of uveitic cataract surgery in a cohort of South African children. METHODS: Retrospective case-series of paediatric patients with uveitis who underwent cataract surgery between 01/01/2010 to 31/12/2020. The main outcome measures were postoperative best corrected visual acuity (BCVA), intra- and postoperative complications, and immunosuppressive requirements. RESULTS: The study included 18 eyes from 14 patients. Fifteen eyes underwent a pars plana vitrectomy, lensectomy with capsulectomy and were left aphakic. Three eyes had an anterior approach lensectomy with insertion of a posterior chamber intraocular lens (PCIOL). All eyes had improvement in BCVA, with a mean gain of 5 lines. BCVA equal to or better than 6/12 was achieved in 68.8% of eyes with 62.5% seeing 6/9 or 6/6. The most common post operative complication was cystoid macular oedema (CMO). Of the 3 eyes that had PCIOLs inserted, 2 required removal.
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    Paediatric non-infectious uveitis in Cape Town, South Africa: a retrospective review of disease characteristics and outcomes on immunomodulating treatment
    (2021-04-01) Slamang, Waheba; Tinley, Christopher; Brice, Nicola; Scott, Christiaan
    Background Non-infectious uveitis is a well-reported cause of blindness in more developed countries, however data from sub-Saharan Africa is lacking. Here we aim to describe the diseases associated with paediatric non-infectious uveitis and the effect of currently available treatment in this setting. Methods A retrospective observational analysis of children with non-infectious uveitis from January 2010 to December 2017, attending the tertiary paediatric rheumatology and ophthalmology referral units in Cape Town was conducted. Statistical analysis utilising STATA13 software was performed with p < 0.05 considered significant. Results Twenty-nine children were identified: median age at first visit of 74 months (IQR 49–86 months), female to male ratio of 0.9:1, predominantly of mixed ancestry (72.4%). Juvenile idiopathic arthritis associated uveitis (JIAU) (48.3%), idiopathic uveitis (41.4%), sarcoidosis (6.9%) and Behcet’s disease (3.5%) were diagnosed. Chronic anterior uveitis (72.4%) was the most frequent finding. Fifty-five percent had complications at presentation and all children with idiopathic uveitis presented with cataracts. Only 6.5% of the JIA cohort had JIAU. All JIA children had chronic anterior uveitis. There were no differences between JIA children with uveitis and those without uveitis, for sex (p = 0.68) and race (p = 0.58). Significantly, children with uveitis presented at an overall younger age (p = 0.008), had oligo-articular JIA (p = 0.01) and were antinuclear antibody positive (p < 0.001). Children with idiopathic uveitis were predominantly male (66.6%) with chronic anterior uveitis (41.7%). Nineteen children (65.5%) in the cohort had inactive disease on treatment at 12 months from diagnosis, which included 10 on topical corticosteroid therapy. At the last clinical visit 17 (58.6%) on standard initial therapy, 8 (27.6%) on tumour necrosis factor inhibitors and 2 on additional DMARDs were in remission. Five of these children still required topical corticosteroids. Surgery was performed in 41.4%, primarily in the idiopathic group. Visual acuity improved or was maintained on treatment. Conclusion Current practice seems to detect children with potentially sight-threatening disease but the high rate of complications and the low percentage of children with JIAU raises concerns of delayed healthcare intervention. Tumour necrosis factor inhibitors have improved outcomes in refractory cases in this cohort, however further studies are needed.
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    TEDI 1 Week 4 - Types of Visual Impairment
    (2019) Tinley, Christopher
    This week discusses how to make the curriculum accessible for all - particularly focusing on those with severe to profound disabilities. This includes understanding some of the causes of specific impairments (hearing, visual and intellectual) and their impacts on learning. We also have the pleasure of learning from experts who outline which principles and approaches can be adopted to best support learners with these specific impairments. This is video 3/8 in week 4 of the Disability Inclusion in Education: Building Systems of Support course.