Optic neuritis: A South African hospital-based prospective study protocol.

BACKGROUND: Optic neuritis is a relatively common disease with an estimated lifetime risk of 0.6 per 1000; the estimated prevalence is 1-5 per 100 000/year. It occurs because of inflammation of the optic nerve from a variety of causes. The diagnosis of the disorder is established clinically and current literature is predominantly based on white patients from high-income countries. Optic neuritis presents differently in black patients compared to white patients. This study aims to assess the presentation and outcome of optic neuritis patients in a South African setting. METHODS: This is a prospective, hospital-based cohort study that will enrol patients with optic neuritis presenting to either the neurology department at Chris Hani Baragwanath Academic Hospital or the ophthalmology department at St John Eye Hospital, both in Johannesburg, South Africa. The specific aetiologies, clinical presentation and radiological findings will be studied, and the patient's course over one year will be documented in three-monthly follow-up visits. A specific group of patients with Neuromyelitis Optica Spectrum Disorders (NMOSD) and Myelin Oligodendrocyte Glycoprotein Associated Disorders (MOGAD) optic neuritis will be followed up for 5 years at yearly intervals. DISCUSSION: This study represents one of the few cohort studies in Sub-Saharan Africa that seeks to investigate optic neuritis. Our hope is that it will lead to better insights regarding the presentation, course and outcome of this condition. We will also analyse the data with a view of developing a predictive model for good visual outcome.

Response to botulinum neurotoxin injections in large-angle infantile esotropia: a post hoc analysis.

PURPOSE: To determine the anticipated reduction of baseline angle of esotropia and identify predictors of change following botulinum neurotoxin (BNT) injections in large-angle infantile esotropia. METHODS: This was a prospective, longitudinal study of children <10 years of age diagnosed with infantile esotropia of >30Δ and given either 1, 2, or 3 BNT injections. Post-injection change from baseline deviation was recorded, and predictors of reduction were analyzed. For this study, children were further divided into subgroups based on initial deviation of ≤60Δ (group 1) and >60Δ (group 2). The outcomes of subsequent surgeries in failed cases were analyzed. RESULTS: A total of 117 children were included, 55 in group 1 and 62 in group 2. Mean age was 30.3 ± 18.8 months. Mean baseline deviation was 62.5Δ ± 13.1Δ: 51.4Δ ± 8.4Δ in group 1 and 73Δ ± 7.5Δ in group 2. The mean number of injections was 2.2 ± 0.7. Success was achieved in 25.6% of patients (33.4% in group 1; 16.2% in group 2). The mean percentage reduction of deviation after BNT injection was 55.2% ± 26%, larger in group 1 than in group 2 (61.3% vs 51.1% [P = 0.001]). Five children reverted to baseline deviation. In multivariate analysis, adjusting for number of injections, younger age and larger baseline deviation were significant independent predictors of a larger absolute amount of reduction (P = 0.02, and 0.002, resp.). Thirty-two children had subsequent surgery; 22 were followed for a minimum of 6 months, and 20 were aligned within 10Δ of orthotropia. CONCLUSIONS: In large-angle esotropia there was a reduction of approximately 50% of baseline deviation, with greater relative reduction for smaller baseline deviations; the absolute change in angle was greater in younger children. Alignment after subsequent surgery appeared to remain stable and surgery required less recession than would have been needed for the original angle of esotropia.

Prevalence of complications in eyes with nanophthalmos or microphthalmos: protocol for a systematic review and meta-analysis.

INTRODUCTION: Microphthalmos and nanophthalmos are uncommon ocular conditions, whereby affected eyes have smaller dimensions compared to the normal population. Microphthalmos and nanophthalmos present several challenges to ophthalmologists; they have spontaneous and post-operative sequelae such as high hyperopia, angle-closure glaucoma, uveal effusion syndrome, and retinal detachment. This systematic review and meta-analysis intends to assess the prevalence of both the spontaneous complications associated with nanophthalmos and microphthalmos, as well as the post-surgical complications associated with nanophthalmos or microphthalmos. METHODS AND ANALYSIS: Articles will be searched for, on four online databases: PubMed, EMBASE, Scopus, and Web of Science. Two independent reviewers will identify the studies according to prespecified inclusion and exclusion criteria. All studies included with participants diagnosed with microphthalmos or nanophthalmos in one or both eyes, will be included if they have (i) more than 4 cases and (ii) defined microphthalmos/nanophthalmos as an axial length of < 21 mm or a high lens/eye volume ratio. Nanophthalmos may have an additional diagnostic criterion of posterior wall thickness greater than 1.7 mm. The prevalence of the following complications will be assessed: high hyperopia (spherical equivalent >3D), angle closure glaucoma, uveal effusion syndrome, retinal detachment, and chorioretinal folds. Studies that will be excluded are those that have not adequately defined the criteria for the diagnosis of nanophthalmos or microphthalmos, those studies that have less than five cases, studies with criteria not defined above, and deemed unsuitable, and studies in languages other than English with no published translation. Relevant data will be extracted and assessed for the risk of bias in each article using a modified Joanna Briggs Institute (JBI) assessment tool. The data will then be pooled to determine the prevalence of complications among patients with microphthalmos and nanophthalmos. If the data allows, subgroup analysis will be carried out according to axial length as well as subtype of microphthalmos/nanophthalmos (simple, complex, relative anterior, and posterior). DISCUSSION: Although nanophthalmos is an uncommon condition that affects the eye, its management and complications can be sight-threatening. Thus, it is important to counsel patients and their families correctly (in the case of children) upon diagnosis and prior to any surgical intervention. This can only be done if the overall prevalence of complications is known. REGISTRATION: PROSPERO CRD42021227847.

Cost comparison between botulinum neurotoxin and surgery in the treatment of infantile esotropia in a tertiary public hospital.

OBJECTIVE: To compare the cost implications of botulinum neurotoxin (BNT) injection to surgery in infantile esotropia (IE) in a public/government funded hospital. METHODS AND ANALYSIS: A simple costing comparison was undertaken for a randomised clinical trial in IE. Patients were randomised to receive either BNT or standard surgery. The participants in the BNT arm were further subdivided into subgroups based on their age in months and degree of esotropia in prism dioptres (PD) at presentation: G1 ≤60 PD/24 months, G2 ≤24 months/>60 PD, G3 >24 months/≤60 PD, G4 >24 months/>60 PD. The costs were calculated for each arm from primary treatment to eventual satisfactory outcome defined as orthophoria or microtropia (≤10 PD). A bottom-up costing analysis was done for single and multiple procedures for each arm. Comprehensive variable costs as well as fixed costs were calculated at each point of intervention and expressed in local currency ZAR (US$1=ZAR15.00). Costing was analysed for surgery and BNT subgroups (based on clinical success). RESULTS: There were 101 patients enrolled in the trial. 54 in the BNT arm and 47 in the surgery arm. Cost for single surgery and single BNT was ZAR 7743.04 and 1713.14, respectively. A favourable clinical outcome was achieved in 72% of surgery arm and 37% of BNT arm. The mean cost for eventual favourable outcome in BNT arm was ZAR9158.08 and in surgery arm ZAR9124.27 (p=0.26). Mean cost in G1 was ZAR6328.45, in G2 ZAR7197.45, in G3 ZAR11891.93 and G4 ZAR12882.44 (p=0.018). CONCLUSION: BNT has a cost-benefit in IE and is a viable option in the primary treatment of IE in resource constrained regions. Clinical outcomes and economic benefit in smaller angle of esotropia and younger patients are comparable to surgery.

Treatment Outcome of Tubercular Uveitis in a High TB and HIV Setting: A Prospective Cohort Study.

PURPOSE: To determine the time to resolution of inflammation in tubercular uveitis (TBU) cases on standard anti-tubercular treatment. Sub-analysis of time to resolution according to HIV status was also performed. PATIENTS AND METHODS: A prospective cohort study of presumed idiopathic uveitis cases >18 years underwent the tuberculin skin test, QuantiFERON-TB Gold test, and ocular tuberculosis (TB) polymerase chain reaction test. Adult TBU cases were treated with standard anti-tubercular therapy (and corticosteroids) for 9 months. Cases were followed-up for resolution of inflammation at 1.5, 3, 6, 9, 12 and 15 months post-diagnosis. Outcome measure was resolution of inflammation on ≤10 mg oral prednisone per day. RESULTS: Seventy-nine presumed idiopathic uveitis cases were enrolled in the study, 49 (62%) were diagnosed with TBU. The mean (SD) age of TBU cases at diagnosis was 41.8 (13.4) years. Using a multilevel mixed effects model, resolution was achieved at 6 months in the TBU cases (OR = 1.21; 95% CI, 1.03-1.41; P = 0.017). Using generalized estimating equations, resolution was also achieved at 6 months in the TBU cases (OR = 1.21; 95% CI, 1.05-1.39; P = 0.008). The HIV-positive cases (OR = 1.62; 95% CI, 1.13-2.31; P = 0.008) and the HIV-negative cases (OR = 1.25; 95% CI, 1.06-1.48; P = 0.009) achieved resolution at 9 months. CONCLUSION: Resolution of inflammation in TBU cases on anti-tubercular treatment with corticosteroids was achieved at 6 months and maintained throughout the study. Our study suggests a minimum of 6 months treatment is required for significant resolution. Resolution of inflammation in HIV-positive and HIV-negative TBU cases needs to be further explored.

Retinal nerve fibre layer thickness in a normal black South African population.

BACKGROUND: The measurement of retinal nerve fibre layer (RNFL) thickness on spectral domain OCT (SD-OCT) are compared with built-in age- and gender-matched European normative databases and this difference is used to assist with glaucoma diagnosis. However, there are differences in RNFL thickness between population groups. Therefore, using the built in European normative database as a comparison across all population groups could lead to erroneous results, due to the basic assumption that the normative values for non-European populations are the same as their European counterparts. METHODS: Cross-sectional study of RNFL thickness in normal black South African patients. RESULTS: One hundred and thirty-two eyes of 132 patients were enroled in this study. The mean (SD) age of patients in this study was 41.3 (12.5) years. Males comprised 40.9% (n = 54; p = 0.0367). All RNFL sectors except the temporal sector were significantly thicker than the reference database. The RNFL sectors measured as follows: global (108.7 µm, p < 0.001), superotemporal (152.4 µm, p < 0.001), superonasal (132.6 µm, p < 0.001), inferotemporal (150.1 µm, p < 0.001), inferonasal (129.2 µm, p < 0.001), nasal (77.7 µm, p < 0.001), temporal 74.8 µm, p = 0.9534). CONCLUSION: The RNFL thickness of normal black South Africans is significantly thicker than that of the European database on the Spectralis SD-OCT. This needs to be taken into account when performing RNFL thickness measurements on black patients.