Prevalence and systemic associations of retinal vascular occlusions in Sub-Saharan Africa.

Background: Retinal vascular occlusions are a common cause of visual impairment. Studies on retinal vascular occlusions in sub-Saharan Africa (SSA) have primarily been retrospective and on retinal vein occlusion (RVO) only. The aim of this study, therefore, was to determine the prevalence and pattern of retinal vascular occlusions and their systemic associations in SSA. Materials and Methods: This was a hospital-based, cross-sectional study involving all new patients presenting at the general ophthalmic and specialty retina clinics in four hospitals in Nigeria over a 1 year period. All the patients underwent a comprehensive eye examination. The demographic and clinical data of patients with retinal vascular occlusions were entered into an excel sheet and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 22.0. Statistical significance was indicated by P < 0.05. Results: A total of 8614 new patients were seen, and a diagnosis of retinal vascular occlusion was made in 90 eyes of 81 patients giving a disease prevalence of 0.9%. Eighty-one eyes of 72 (88.9%) patients had RVO, while 9 eyes of 9 (11.1%) patients had retinal artery occlusion (RAO). The mean age of patients with RVO and RAO was 59.5 years and 52.4 years, respectively. Increasing age, hypertension, and diabetes were the significant associations with retinal vascular occlusion with P < 0.0001. Conclusion: Retinal vascular occlusions are an increasing cause of retinal disease in SSA and tend to occur at an earlier age. They are associated with hypertension, diabetes, and increasing age. Further studies will, however, be required to establish the demographic and clinical profile of patients with RAO in the region.

Résumé Contexte: Les occlusions vasculaires rétiniennes sont une cause fréquente de la déficience visuelle. Les études sur les occlusions vasculaires rétiniennes en Afrique subsaharienne (SSA) ont été principalement rétrospectives et uniquemment sur l'occlusion veineuse rétinienne (RVO). Le but de cette étude était donc de determiner la prévalence et le schéma des occlusions vasculaires rétiniennes et leurs associations systémiques en Afrique subsaharienne. Matériels et méthodes: Il s'agissait d'une étude transversale hospitalière portant sur tous les nouveaux patients se présentant aux cliniques d'ophtalmologie générale et de rétine spécialisée dans quatre hôpitaux au Nigéria sur une période d'un an. Tous les patients ont subi un examen ophtalmologique complet. Les données démographiques et cliniques des patients avec des occlusions vasculaires rétiniennes ont été saisies dans une feuille excel et elles ont été analysées à l'aide du paquet statistique pour les sciences sociales (SPSS) logiciel version 22.0. La signification statistique était indiquée par P < 0,05. Résultats: Au total, 8614 nouveaux patients ont été vus et un diagnostic d'une occlusion vasculaire rétinienne a été réalisée dans 90 yeux de 81 patients donnant une prévalence de la maladie de 0,9 %. Quatre-vingt-un yeux de 72 (88,9 %) patients avaient RVO, tandis que 9 yeux de 9 (11,1%) patients avaient une occlusion de l'artère rétinienne (RAO). L'âge moyen des patients avec RVO et RAO était de 59,5 ans et 52,4 ans, respectivement. L'augmentation de l'âge, l'hypertension et le diabète étaient les associations significatives avec l'occlusion vasculaire rétinienne avec P < 0,0001. Conclusion: Les occlusions vasculaires rétiniennes sont une cause croissante de maladie rétinienne en Afrique subsaharienne et elles ont tendance à survenir à un âge plus précoce. Elles sont associées à l'hypertension, au diabète et à l'âge. D'autres études seront cependant nécessaires pour établir la démographie et le profil clinique des patients atteints de RAO dans la région. Mots-clés: Diabète, hypertension, occlusion artérielle rétinienne, occlusion veineuse rétinienne.

Tractional Retinal Detachment: Prevalence and Causes in Nigerians.

Aim: To determine the causes of tractional retinal detachment (TRD) in Nigerians. Materials and Methods: A prospective, multicentre study evaluating eyes diagnosed to have TRD. History, clinical examination (including visual acuity, intraocular pressure measurement, anterior segment examination and dilated fundoscopy) and systemic evaluation (including previous diagnosis of diabetes, hypertension, sickle-cell disease and others) were performed in TRD eyes out of a cohort of retinal detachment eyes. Results: The prevalence of TRD of the 237 patients diagnosed with RD within a one-year study period was 25.7% (61 patients). Eighty eyes were diagnosed with TRD. Thirty-eight eyes of nineteen patients (31%) were bilateral, and 42 (69%) were unilateral. There were 38 male patients (62.3%) and 23 female patients (37.7%). The mean age was 52.3 ± 12.7 years (11-69 years). 88.5% of all TRD patients had an associated systemic disease, diabetes being the most common disease in 88.8% of them. Proliferative diabetic retinopathy was the most common cause of TRD (77.5%) and the most common cause of bilateral TRD. Both trauma and proliferative sickle-cell retinopathy occurred in 3.8% of the eyes. 68.8% of TRD eyes were blind at the presentation. However, the causes of TRD did not show any significant association with blindness (P = 0.819). Conclusion: Proliferative diabetic retinopathy poses a significant threat to vision, being the most common cause of TRD. Early detection and treatment of proliferative retinopathy in diabetes and sickle-cell disease, and trauma prevention will significantly reduce the burden of blindness due to TRD.

Exudative Retinal Detachment in Nigerians: Demographics and Causes.

Background: Exudative retinal detachment (ERD) is a rare type of retinal detachment (RD), and information on its causes and presentation in Nigerians and Black Africans is scarce. Aim: To report the prevalence, vision at presentation, and causes of ERD in a cohort of RD patients. Materials and Methods: A prospective, multicentre, hospital-based study. We examined consecutive eyes diagnosed with ERD in ophthalmic patients seen within 1 year in four ophthalmic hospitals in Nigeria. The patients had a complete eye examination, including visual acuity, intraocular pressure measurement, slit lamp examination of the anterior segment, dilated fundus examination, and other ancillary investigations. Statistical analysis was done using SPSS version 22.0. Results: Nine out of 237 patients were diagnosed with ERD, giving a hospital-based prevalence of 3.8% of RDs. The mean age of patients was 45.8 ± 21.6 years (6 months-80 years), male:female = 2:1. ERD was bilateral in one patient and unilateral in eight patients. There was no gender association (P = 0.84), but systemic disease was associated with a risk of ERD (P = 0.001). Five out of 9 (55.6%) patients had an associated systemic disease. The systemic diseases include two patients (40%) who had chronic renal failure, two patients (40%) who had systemic hypertension, and one patient (10%) who had lung cancer. Other ocular causes of ERD include post endophthalmitis, coats disease, and age-related macular degeneration in one eye each. 80 % of eyes were blind at presentation. Conclusion: ERD is a rare form of RD in Nigerians and is associated with systemic diseases. There are inflammatory, neoplastic, vascular, and degenerative causes of ERD. At presentation, most eyes are blind. Early presentation will be beneficial in salvaging vision. Also, awareness of the occurrence and causes of ERD should be created amongst eye care practitioners.

Prevalence and systemic associations of retinal vascular occlusions in Sub­Saharan Africa

Background: Retinal vascular occlusions are a common cause of visual impairment. Studies on retinal vascular occlusions in sub Saharan Africa (SSA) have primarily been retrospective and on retinal vein occlusion (RVO) only. The aim of this study, therefore, was to determine the prevalence and pattern of retinal vascular occlusions and their systemic associations in SSA. Materials and Methods: This was a hospital based, cross sectional study involving all new patients presenting at the general ophthalmic and specialty retina clinics in four hospitals in Nigeria over a 1 year period. All the patients underwent a comprehensive eye examination. The demographic and clinical data of patients with retinal vascular occlusions were entered into an excel sheet and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 22.0. Statistical significance was indicated by P < 0.05. Results: A total of 8614 new patients were seen, and a diagnosis of retinal vascular occlusion was made in 90 eyes of 81 patients giving a disease prevalence of 0.9%. Eighty one eyes of 72 (88.9%) patients had RVO, while 9 eyes of 9 (11.1%) patients had retinal artery occlusion (RAO). The mean age of patients with RVO and RAO was 59.5 years and 52.4 years, respectively. Increasing age, hypertension, and diabetes were the significant associations with retinal vascular occlusion with P < 0.0001. Conclusion: Retinal vascular occlusions are an increasing cause of retinal disease in SSA and tend to occur at an earlier age. They are associated with hypertension, diabetes, and increasing age. Further studies will, however, be required to establish the demographic and clinical profile of patients with RAO in the region

Optical Coherence Tomography Retinal Nerve Fibre Layer and Ganglion Cell Complex Measurements in Normal Southern Nigerian Eyes.

Introduction Glaucoma is the leading cause of irreversible blindness worldwide. It is more severe in people with African heritage, and intraocular pressure remains the only modifiable risk factor in managing glaucoma. Attempts to improve the diagnosis and monitoring of glaucoma are ongoing. One of those attempts is the development of optical coherence tomography (OCT). However, there is a theoretical possibility of a delayed or wrong diagnosis of glaucoma using the OCT because of racial, age, and sex differences in the RNFL (retina nerve fibre layer), GCL (ganglion cell layer), and GCL+IPL (ganglion cell layer and inner plexiform layer) thickness. Objective This study aims to provide the measurements of RNFL, GCL, and GCL+IPL in normal eyes of southern Nigerian patients and specifically to evaluate the relationship of these measurements to gender, age, intra-eye variability, and the Topcon SD-OCT normative database. Method Three hundred and four eyes of 152 patients who had normal OCT scans using the 6x6 RNFL (four sectors) and Macula scans of the Topcon OCT-1 3D Maestro OCT machine were included for analysis. Parametric tests were used to interrogate the relationship between normally distributed parameters and gender, age, and the Topcon reference database. Non-parametric tests were used for non-normally distributed data. Results The male-to-female ratio was 1:1, and ages ranged between 18 and 71 for both genders. The average RNFL values were 111.49 ± 10.44 (right eye - RE) and 111.96 ± 9.66 (left eye - LE). For the GCL, average values were 66.23 ± 4.4 (RE) and 66.34 ± 4.19 (LE). GCL+IPL values were 104.02 ± 6.71 (RE) and 103.89 ± 6.66 (LE). There was no difference between genders (X2 = 56.467; df = 46; p = 0.160), and RNFL, GCL, and GCL+IPL values showed a significant reduction as the age of the respondents increased. There was a significant difference between RNFL, GCL, and GCL+IPL values and the Topcon reference database, p < 0.001. Conclusion Significant differences exist between the Southern Nigerian eyes' RNFL, GCL, and GCL+ IPL values and the Topcon OCT-1 3D Maestro reference database. While randomised control trials and extensive multi-centre studies have not been conducted to determine the possible effects of these differences between measured values and reference databases of the OCTs, they need to be considered while diagnosing and managing glaucoma with the OCT.

Profile, Visual Presentation and Burden of Retinal Diseases Seen in Ophthalmic Clinics in Sub-Saharan Africa.

PURPOSE: To determine the burden of retinal diseases and the degree of visual impairment associated with each disease, amongst Nigerians. PATIENTS AND METHODS: This was a hospital-based multicenter, prospective, cross-sectional, non-comparative study conducted from January to December 2018. Data was obtained from consecutive patients with a retinal diagnosis presenting at the general ophthalmic and specialty retina clinics in four hospitals (three public, and one private teaching eye department) in Nigeria. Biodata, visual acuity and refraction, intraocular pressure, findings on dilated retinal examination, diagnosis and systemic diseases were noted. Degree of monocular and bilateral visual loss associated with each diagnosed retinal disease was summarized and p value was calculated using chi-square test. P < 0.05 was considered significant. RESULTS: Eight hundred seventy-six of 8614 patients had a retinal diagnosis; establishing a hospital-based retinal disease prevalence of 9.8%. Male:female ratio was 1.1:1. The mean age of study patients was 49.97 (standard deviation 17.64 years). Mean symptom duration was 21.63 months (standard deviation 41.94). The mean intraocular pressure was 13.87 mmHg. Forty-three different retinal diseases were diagnosed. The most common was retinal complications of diabetes, i.e., diabetic retinopathy (DR) alone, diabetic macular edema (DME) alone and a combination of DR and DME, which accounted for 13.7%, 5.6% and 9.3%, respectively (contributed 28.6% of the entire diagnosis). This was followed by retinal detachment (RD), in 219 eyes (15.4%), dry age-related macular degeneration (AMD) in 124 eyes (8.7%). Nearly half of the eyes were blind or severely visually impaired. Blindness occurred in 34.1% of eyes; severe visual impairment in 8.2% of eyes and 29.7% had normal vision. There were 469 patients who had systemic diseases. The common systemic diseases were hypertension in 169 patients (19.3% of the total number of patients), hypertension and diabetes in 156 patients (18%), and diabetes alone in 98 patients (11.1%). Sickle cell disease was present in 1.5%. CONCLUSION: There is need to invest in infrastructure, local training and development of systems for early detection and treatment of several retinal diseases in sub-Saharan Africa; DR and DME having the largest burden. Collaborative physician care and management of hypertension and diabetes could significantly reduce the burden of DR and DME.