Clinical and Serological Characteristics of Ocular Toxoplasmosis in the Democratic Republic of Congo.

PURPOSE: To describe demographic data, clinical features, and serological profiles in a cohort of Congolese patients with ocular toxoplasmosis (OT). METHOD: Cross-sectional study, carried out between March 2020 and July 2021 in two ophthalmic clinics in Kinshasa. RESULTS: The study comprised 95 participants with OT. Fifty-three patients were male (55.8%). The mean age at presentation was 35.6 ± 14.1 years (range 8-69 years); 71 had active OT (74.7%), among them, 33 had primary OT (46.5%), and 38 had recurrences (53.5%). At presentation, 51 patients (53.7%) had visual impairment (VA < 6/18). Retinochoroidal lesions were located in the central retina in 60 patients (63.1%). Patients with primary OT tend to have higher IgG levels than those with recurrent OT (P = .01). CONCLUSION: We report the largest cohort of patients with OT in sub-Saharan Africa. In our setting, most patients had recurrent OT with multiple, extensive, and central retinochoroidal lesions.

Ophthalmic Ultrasonography in Sub-Saharan Africa-A Kinshasa Experience.

The aim of this study was to analyze the use of the diagnostic B-scan ultrasound. Should it be made accessible to all surgical centers in Sub-Saharan Africa in order to (i) avoid unnecessary cataract surgery and (ii) evaluate extraocular pathology? This study was conducted in Kinshasa from 2006 to 2019. Three hundred and twenty-three patients were included and separated into two groups. Group 1 included 262 patients with dense cataract. Group 2 consisted of 61 patients with pathologies of the ocular adnexa, and all were examined with a B-scan ultrasound. In group 1, there were 437 systematically screened eyes. Three hundred and ninety-eight eyes (91.08%) showed no abnormalities, 13 (2.97%) retinal detachments were identified, and 15 (3.43%) demonstrated a detached posterior hyaloid membrane. In the second group, 61 patients were examined (group 2). In 20 of them, surgery was performed for biopsy, tumor excision, mucoceles drainage, and palliative treatment. The need for routine B-scan examinations in dense cataract patients seems to be limited and can most likely be replaced by a thorough application of locally available examination techniques. B-scan application is recommended to manage orbital patients in the most cost-effective way.

Predictive value of retinal function by the Purkinje test in patients scheduled for cataract surgery in Kinshasa, DR Congo.

AIM: To assess the retinal function in patients with dense cataracts in resource poor settings in Kinshasa, DR Congo. METHODS: In a tertiary eye care center, the Purkinje entoptic test was performed as part of the ophthalmological examination in 98 eyes in patients with cataract, using a penlight. Totally 92 cataract patients including 86 patients suffered from unilateral and 6 from bilateral cataracts were included in the study. The investigator asked the patients about their perception of the vascular pattern most commonly described as a leafless or dead tree. Visual acuity≥6/60 was considered an indication of good visual function and visual acuity<6/60 of poor function. Following small incision cataract surgery, best corrected visual acuity (BCVA) was determined and compared with the preoperative findings. RESULTS: Out of 98 eyes, there were 80 (81.6%) where the Purkinje entoptic phenomenon was reported by the patients. After cataract surgery, out of the 80 eyes, there were 75 (93.8%) with a BCVA of better than 6/60, whereas in 5 eyes (6.2%), BCVA was 6/60 or less. Out of the 18 eyes (18.4%) where no Purkinje tree was recognized, there were 14 (77.8%) with BCVA of better than 6/60, whereas in 4 (22.2%) BCVA was 6/60 or less. CONCLUSION: The Purkinje entoptic test is successfully used for preoperative assessment of retinal function in patients with dense cataract. However, further investigation and refinement of the test is necessary to validate the method for use in sub-Saharan conditions.

Prevalence and patterns of childhood ocular morbidity in Kinshasa. A population-based study.

Context: Childhood ocular disorders can seriously impact on development and education, future employment opportunities and quality of life, their consequences are especially severe in low resource settings. There is a lack of data on pattern and prevalence of ocular morbidities among children in Democratic Republic of the Congo (DRC). Objective: The aim of this study was to determine the pattern and magnitude of childhood ocular disorders in children in Kinshasa, the capital city of DRC. Methods: A population-based cross-sectional study was conducted from July to August 2017. Children aged less than 16 years old were screened by volunteers in households and those with ocular pathologies were examined by two ophthalmologists. Prevalence and pattern of ocular diseases were determined. Results: A total of 4307 households were visited by the surveyors and 13,197 children were screened. Ocular pathologies were diagnosed among 399 children. Girls represented 50.7% of the children and the mean age ± SD was 9.2 ± 4.1 years. The overall prevalence of ocular morbidity in our population was 3.6% [95% CI 3.3-3.9]. Allergic conjunctivitis was the most frequent pathology (56.2%) followed by refractive errors (27.4%) and strabismus (5%). Age of children was the only risk factor with a significant impact on the frequency of ocular pathology. Forty-five percent of children had never benefited from any treatment, self-medication, and recourse to traditional treatments concerned respectively 18.%, and 2.3% of children. Conclusion: Childhood ocular morbidity in Kinshasa city was dominated by allergic conjunctivitis and refractive errors. The frequency of these conditions varies depending on the age of the children. Very few parents consult medical staff when their children have ocular problems, ignorance and limited financial resources are the principal barriers to consult.

Epidemiology of Childhood Blindness and Low Vision in Kinshasa-democratic Republic of the Congo.

Purpose: To determine the magnitude and causes of blindness and low vision in children in Kinshasa.Methods: A study was conducted to carry out a survey in 96 health areas in Kinshasa city. Children aged less than 16 years old with supposed visual problems (Visual acuity < 6/18) were identified by volunteers and surveyors in households and were thereafter examined by two ophthalmologists. Prevalence and causes of blindness and low vision were determined. For each child, anatomic sites of abnormality, etiologic factors and avoidable causes responsible for visual impairment were considered.Results: Thirty-six children with bilateral visual impairment were identified, including 10 cases of blindness and 26 cases of low vision. The prevalence of blindness and low vision was, respectively, 0.08% [95% CI 0.04-0.14] and 0.19% [95% CI 0.13-0.28].Optic nerve and whole globe were the main anatomical sites responsible for blindness in, respectively, in 30% and 20%. Optic nerve atrophy and glaucoma were the leading causes of childhood blindness. The globe apparently normal (50%), uvea (12%) and cornea (12%) were the most common anatomic site responsible for low vision with refractive errors (42%) and uveitis (12%) as the main causes. Childhood and hereditary factors accounted for, respectively, 16.7% and 13.9% of low vision cases. Visual impairment was due to avoidable causes in 69.4% of children.Conclusion: Damage to the optic nerve and refractive errors were respectively the maincauses of blindness and low vision among children in Kinshasa.

Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry.

Importance: Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders. Objectives: To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma. Design, Settings, and Participants: A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma. Exposures: Genetic variants associated with primary open-angle glaucoma. Main Outcomes and Measures: Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data. Results: A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-ß A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry. Conclusions and Relevance: In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies.