Challenges and Opportunities in the Genetic Analysis of Inherited Retinal Dystrophies in Africa, a Literature Review.

Inherited retinal dystrophies (IRDs) are a global problem that is largely unaddressed, especially in Africa. Black indigenous Africans are rarely represented in research that develops genetic tests and genetic therapies for IRDs, yet their genomes are more diverse. The aim of this literature review is to synthesize information on the IRD genetic research conducted among indigenous black Africans to identify challenges and opportunities for progress. PubMed was searched to identify empirical publications reporting the genetic analysis of IRDs among indigenous Africans. A total of 11 articles were selected for the review. Based on the information in the articles, the main genetic testing methods in use include next-generation, whole exome, and Sanger sequencing. The main IRDs characterized by the genetic tests include retinitis pigmentosa, Leber Congenital Amaurosis, Stagardt disease, and cone dystrophy. Examples of implicated genes include MERTK, GUCY2D, ABCA4, and KCNV2 for the four IRDs, respectively. Research activities on the genetics of IRDs are generally scanty in Africa. Even in South Africa and North Africa where some research activities were noted, only a few indigenous black Africans were included in the study cohorts. There is an urgent need for genetic research on IRDs, especially in East, Central, and West Africa.

Retinal Toxicity from Chronic Hydroxychloroquine use in Kenya.

Irreversible visual loss due to retinal toxicity is one of the side effects of hydroxychloroquine (HCQ) therapy. The recent outbreak of the novel coronavirus-19 (COVID 19) has seen HCQ proposed as a possible treatment and prophylactic drug, leading to its increased use. Many are unaware of its ocular side effects. We describe a case of HCQ-induced retinopathy in a 46-year-old female who was referred by a rheumatologist for routine eye review.

Résumé La perte de vision irréversible secondaire à la toxicité rétinienne est l'un des effets indésirables du traitement à l'hydroxychloroquine (HCQ). Nous décrivons un cas d'une patiente âgée de 46 ans, présentant une rétinopathie secondaire au traitement à l'HCQ référée par un Rhumathologue pour un examen ophtalmique. Mots-clés: Hydroxychloroquine, rétine toxicité rétinienne, rétinopathie.

Retinopathy of prematurity in Kenya: prevalence and risk factors in a hospital with advanced neonatal care.

INTRODUCTION: Increased survival of preterm babies in sub-saharan Africa has held to an increasing prevalence of Retinopathy of prematurity (ROP). This study was done to determine the ROP prevalence in a hospital with advanced neonatal care in urban Kenya. METHODS: A hospital-based retrospective review of the records of premature infants screened for ROP between January 2010 and December 2015. Records of all premature infants screened for ROP in the neonatal unit and outpatient eye clinic were extracted. Information on Birth weights, Gestational age, Maternal risk factors (mode of delivery, pre-eclampsia/eclampsia) and Neonatal risk factors (neonatal sepsis, days on oxygen, blood transfusion) was recorded in a questionnaire then analysed. RESULTS: 103 infants were included in the study. Mean gestational age was 29.9 ± 2.2 weeks and the mean birth weight was 1280.1 ± 333.0 grams. Forty-three infants were diagnosed with ROP, a prevalence of 41.7%. Majority of these had Stage 1 or 2 ROP in Zone II, which spontaneously regressed with follow up. Nine infants were diagnosed with vision-threatening ROP (any Zone I disease or Stage 2/3 disease in Zone II with plus disease), a prevalence of 20.9%. All of these underwent laser treatment in the neonatal unit. The most significant risk factor was low gestational age. Other risk factors identified were: low birth weight and blood transfusions. CONCLUSION: ROP prevalence in sub-saharan Africa will match those in middle-income and high income countries in neonatal units with advanced care and low mortality.

Rapid assessment of avoidable blindness in Nakuru district, Kenya.

OBJECTIVES: To estimate the prevalence of avoidable blindness in > or =50-year-olds in Nakuru district, Kenya, and to evaluate the Rapid Assessment for Avoidable Blindness (RAAB), a new methodology to measure the magnitude and causes of blindness. DESIGN: Cross-sectional population-based survey. PARTICIPANTS: Seventy-six clusters of 50 people 50 years or older were selected by probability proportionate to size sampling of clusters. Households within clusters were selected through compact segment sampling. Three thousand seven hundred eighty-four eligible subjects were selected, of whom 3503 (92.6%) were examined. METHODS: Participants underwent a comprehensive ophthalmic examination in their homes by an ophthalmologist, including measurement of visual acuity (VA) with a tumbling-E chart and the diagnosis of the principal cause of visual impairment. Those who had undergone cataract surgery were questioned about the details of the operation and their satisfaction with surgery. Those who were visually impaired from cataract were asked why they had not gone for surgery. MAIN OUTCOME MEASURES: Visual acuity and principal cause of VA<6/18. RESULTS: The prevalence of bilateral blindness (presenting VA < 3/60) was 2.0% (95% confidence interval [CI], 1.5%-2.4%), and prevalence of bilateral visual impairment (VA of <6/18-> or =6/60) was 5.8% (95% CI, 4.8%-6.8%) in the sample. Definite avoidable causes of blindness (i.e., cataract, refractive error, trachoma, and corneal scarring) were responsible for 69.6% of bilateral blindness and 74.9% of bilateral visual impairment. Cataract was the major cause of blindness (42.0%) and visual impairment (36.0%). The cataract surgical coverage was high, with 78% of those with bilateral cataract who needed surgery having had surgery at VA<3/60. The quality of surgery was of concern because 22% of the 222 eyes that had undergone cataract surgery had VA<6/60 with best correction. The main barriers to surgery were lack of awareness and cost. The RAAB methodology was easy to use, and each team could visit one cluster per day. CONCLUSIONS: The prevalence of blindness in > or =50-year-olds in Nakuru district was low, in part due to the high cataract surgical coverage. The RAAB is easy to use and inexpensive and provides information about the magnitude and causes of avoidable blindness that can be used for planning and monitoring eye care services.