Ophthalmology

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Browsing Ophthalmology by browse.metadata.advisor "Smit, Derrick"

Now showing 1 - 4 of 4
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    Biomarker concentrations in serum and urine of patients with Ocular Tuberculosis – a prospective descriptive study.
    (Stellenbosch : Stellenbosch University, 2022-03) Van der Colff, Frederich James; Smit, Derrick; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Ophthalmology
    ENGLISH ABSTRACT: Purpose: To describe biomarker concentrations in serum and urine of South African patients with ocular tuberculosis (OTB). Methods: A prospective study to compare 29 urine and serum biomarkers in 14 OTB patients at a tertiary eye clinic. Results: Median age of participants (7 male and 7 female) was 38.5 years (range 25‐73). Most biomarker concentrations were significantly higher in serum than in urine (p < 0.01). Only two (IL‐1RA and IL‐2) showed higher concentrations in urine than serum (p < 0.01). Three biomarkers (sIL‐2Ra, sTNFRI and IFNγ) showed no difference in concentration between urine and serum (p > 0.05). Conclusions: Most biomarkers tested showed significant differences in concentration between serum and urine and therefore these 2 biofluids cannot be used interchangeably when studying biomarker profiles. One notable exception is IFNγ, as its concentration did not differ between serum and urine.
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    Clinical and laboratory characteristics of ocular syphilis and neurosyphilis among individuals with and without HIV infection
    (Stellenbosch : Stellenbosch University, 2022) Mathew, Dony Korah; Smit, Derrick; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Ophthalmology.
    ENGLISH ABSTRACT: BACKGROUND/AIMS: In the era of increasing incidence of syphilis globally, ocular syphilis is re-emerging as an important cause of uveitis. The aim of this study was to determine the clinical and laboratory characteristics of ocular- and neurosyphilis among individuals with and without HIV infection. METHODS: Retrospective analysis of patients diagnosed with ocular syphilis presenting to Tygerberg Hospital, South Africa, over a 5-year period ending December 2018. RESULTS: Two-hundred-and-fifteen eyes of 146 patients were included. HIV co-infection was present in 52.1% of the patients, with 23.7% of these patients being newly diagnosed on presentation. The median age was 36.5 + 9.8 years. Bilateral involvement occurred in 47.3%; with 68.1% of these patients being HIV positive. The most frequent form of intraocular inflammation was posterior uveitis (40.9%), followed by panuveitis (38.1%); both of which were more predominant in HIV-positive eyes. Seventy-four percent of all eyes had a visual acuity < 20/50 and 40% < 20/200 at presentation. A lumbar puncture was performed in 113 patients (77.4%). Sixteen patients had confirmed neurosyphilis and 27 probable neurosyphilis according to the UpToDate algorithms. CONCLUSION: This study included the largest number of ocular syphilis cases with the largest proportion of HIV infection to date. Forty-three of 146 patients (29.5%) had neurosyphilis. HIV status must be determined in all patients with ocular syphilis since almost ¼ of patients were newly diagnosed with HIV infection by doing so.
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    CXCL13, CXCL10 and CXCL8 as indicators of ocular and neurological involvement in patients with ocular syphilis: an observational descriptive study
    (Stellenbosch : Stellenbosch University, 2022) Van der Merwe, Laurie Wiid; Smit, Derrick; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Ophthalmology.
    ENGLISH ABSTRACT: Aim To investigate the role of the chemokines CXCL13, CXCL10 and CXCL8 in the diagnosis of ocular‐ and neurosyphilis by examining the serum, aqueous humour (AH) and cerebrospinal fluid (CSF) of patients with ocular syphilis. Methods An observational descriptive study was performed prospectively at Tygerberg Academic Hospital in Cape Town, South Africa from 1 February 2018 till 31 January 2021 which enrolled 23 participants. Upon diagnosis of ocular syphilis, the HIV status of each patient was determined, and 3 samples (AH, serum and CSF) were collected to measure the levels of CXCL13, CXCL10 and CXCL8 in each. Results The mean concentrations of all 3 biomarkers were higher in the AH and CSF than in the serum. The mean concentrations of the 3 measured biomarkers were markedly different when comparing both AH and CSF levels to serum levels. The level of CXCL13 measured in the AH correlated well with the concentrations found in the CSF of patients with neurosyphilis. In patients with neurosyphilis, mean AH levels of CXCL13 and CXCL10 were markedly higher than in serum while mean CSF levels of CXCL10 were also markedly higher than in serum. Also, the AH/serum ratio of CXCL13 and CXCL10, as well as the CSF/serum ratio of CXCL10, was much higher in patients with neurosyphilis than without. In patients with HIV infection, mean AH CXCL13 levels were much higher than in patients without HIV infection. Conclusion The levels of CXCL13, CXCL10 and CXCL8 in the AH of patients with neurosyphilis are similar to previously reported levels in the CSF of patients with neurosyphilis and can potentially be an adjunct in the diagnosis of ocular syphilis. Patients with ocular syphilis who tested negative for neurosyphilis with conventional CSF testing showed features of neurosyphilis when analysing the CSF chemokines.
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    The efficacy and safety of diode laser cycloablation in the treatment of refractory glaucoma in a South African population
    (Stellenbosch : Stellenbosch University, 2022-04) Thomas, Jason Peter; Smit, Derrick; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Ophthalmology
    ENGLISH SUMMARY: The development of a safe and effective protocol for trans-scleral cyclophotocoagulation in a Southern African population presenting with refractory glaucoma to a tertiary eye care centre. prospective, non-randomised, observational study of patients attending the Eye Clinic at Tygerberg Hospital, Cape Town, South Africa between March 2018 and January 2020. 119 eyes of 105 eligible patients were treated during the study period. The mean laser power was 1766 ± 187 milliwatt per burn for a mean of 15.6 ± 2.9 burns per eye. Mean total delivered energy per eye was 55.28 ± 12.61 Joule. 64% of the patients who followed up for the entire six-month period had an intraocular pressure reduction of ≥ 30% and 42.2% of those followed up had an IOP of ≤ 22 mmHg. The pain scores reported by patients decreased significantly between pre-operatively and three months (coefficient -1.752, p<0.001) and between pre-operatively and six months (coefficient -1.498, p=0.002). There was not a statistically significant effect on the change in topical medication from pre-operatively to three months (coefficient = -0.089, p=0.186), nor from pre-operatively to six months (coefficient = -0.003, p=0.946). Oral acetazolamide use decreased from 50.4% of patients at the date of their initial cyclophotocoagulation treatment to 9.3% at three months and further to 7.8% at six months. One eye had a scleral perforation at the time of initial treatment; no further complications arose. An individualized, “pop-titrated” cyclophotocoagulation protocol is safe and effective for use in a Southern African population. Retreatment should be considered at three months if intraocular pressure is not adequately controlled.