A multi-cohort genome-wide association study in African ancestry individuals reveals risk loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG), the leading cause of irreversible blindness worldwide, disproportionately affects individuals of African ancestry. We conducted a genome-wide association study (GWAS) for POAG in 11,275 individuals of African ancestry (6,003 cases; 5,272 controls). We detected 46 risk loci associated with POAG at genome-wide significance. Replication and post-GWAS analyses, including functionally informed fine-mapping, multiple trait co-localization, and in silico validation, implicated two previously undescribed variants (rs1666698 mapping to DBF4P2; rs34957764 mapping to ROCK1P1) and one previously associated variant (rs11824032 mapping to ARHGEF12) as likely causal. For individuals of African ancestry, a polygenic risk score (PRS) for POAG from our mega-analysis (African ancestry individuals) outperformed a PRS from summary statistics of a much larger GWAS derived from European ancestry individuals. This study quantifies the genetic architecture similarities and differences between African and non-African ancestry populations for this blinding disease.

Eyes of Africa: The Genetics of Blindness: Study Design and Methodology.

BACKGROUND: This report describes the design and methodology of the "Eyes of Africa: The Genetics of Blindness," a collaborative study funded through the Human Heredity and Health in Africa (H3Africa) program of the National Institute of Health. METHODS: This is a case control study that is collecting a large well phenotyped data set among glaucoma patients and controls for a genome wide association study. (GWAS). Multiplex families segregating Mendelian forms of early-onset glaucoma will also be collected for exome sequencing. DISCUSSION: A total of 4500 cases/controls have been recruited into the study at the end of the 3rd funded year of the study. All these participants have been appropriately phenotyped and blood samples have been received from these participants. Recent GWAS of POAG in African individuals demonstrated genome-wide significant association with the APBB2 locus which is an association that is unique to individuals of African ancestry. This study will add to the existing knowledge and understanding of POAG in the African population.

Exfoliation syndrome in sub-Saharan Africa.

The goal of this review is to estimate the burden of exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in sub-Saharan Africa and to identify the gaps in knowledge of disease prevalence in this region. PubMed, Medline, African Journals Online and Google engine search were carried out using the following terms "pseudoexfoliation" or "exfoliation syndrome Africa", "pseudoexfoliation" or "exfoliation syndrome" + "glaucoma Africa," "glaucoma prevalence Africa," "pattern of glaucoma presentation Africa," "pseudoexfoliation" or "exfoliation syndrome" + "cataract Africa," "ophthalmic conditions Africa." Studies were included if they described the proportion or prevalence/incidence of XFG and XFS in sub-Saharan Africa or if they investigated lysyl oxidase-like 1 (LOXL1) variants in XFS among Africans. 22 papers were identified and classified as clinic-based studies (n = 16) and population-based (n = 4) studies. Two other studies were considered important, and therefore, included in the review. Clinic-based studies demonstrate that XFS is a common cause of glaucoma, as is true in many other parts of the world. Furthermore, XFS often co-exists with cataract and climatic droplet keratopathy. Its prevalence ranged from 5.1 to 7.7 % in patients >40 years in population-based studies, a value that is considerably higher than that reported in African Americans. XFS was strongly associated with increasing age in the prevalence studies. The burden of XFS in sub-Saharan Africa is high. More investigation is needed to determine why clinic-based studies report virtually no XFS in some countries (Ghana and Tanzania), while nearby countries report greater proportions (Nigeria and Ethiopia).

Patients' Acceptance of Glaucoma Therapy in Sub-Saharan Africa.

PURPOSE: To determine the frequency at which patients newly diagnosed with glaucoma in sub-Saharan Africa (SSA) decline recommended therapy and to characterize the reasons for declining therapy. METHODS: This was a multicenter, cross-sectional study conducted on adult patients at the time of glaucoma diagnosis at 27 centers in 10 countries in SSA. Data collected from the diagnostic encounter included demographics, clinical glaucoma characteristics, treatment recommendations, patient acceptance of therapy, and reasons for declining therapy. RESULTS: Among 2,282 eyes of 1,198 patients offered treatment for glaucoma, initially recommended treatment was accepted in 2,126 eyes (93.2%). Acceptance of therapy varied with the nature of treatment offered, with medical therapy accepted in 99.2% of eyes, laser therapy in 88.3%, and surgical therapy in 69.3%. The most common reasons cited for declining therapy were fear (42.9%) and cost (41.7%); cost was the primary reason for declining medical and laser therapy, while fear was the most common reason for declining surgical therapy. Most patients declining laser or surgical therapy accepted medical therapy as an alternate therapy (98.1%). CONCLUSIONS: Patients' acceptance of glaucoma therapy was high overall, but lower for surgery than for laser or medical therapy. Most patients who declined laser or surgical therapy accepted medical therapy as an alternate therapy when offered. Educational interventions, sustainable incentives, and other approaches are needed to enhance patient acceptance of glaucoma therapy in this setting, particularly surgery when needed.

Nigerian parents' perspectives on genetic testing in their children with genetic eye diseases.

The decision for genetic testing in children is usually taken by their parents or caregivers, and may be influenced by sociocultural and ethical concerns. This study evaluateds the perspectives of Nigerian parents towards genetic testing of their children with genetic eye diseases parental willingness for genetic testing in their children, and its determinants, in a hospital setting in Nigeria. This cross-sectional, hospital-based study was conducted at the Eye clinic, University College Hospital, Ibadan. The participants were 42 parents of children with genetic eye diseases purposively recruited from April to July 2021. The main variables of interest were overall willingness to test, and willingness to test given ten different scenarios. Summary statistics were performed, and determinants of willingness to test (parental sociodemographic and children's clinical characteristics) were assessed using Fischer's exact test. All the participants expressed willingness to test when presented with six of the ten scenarios.However, slightly fewer (83-95%) proportions were willing to test for the other four scenarios (out-of-pocket payment, if test will reveal a systemic association, if test may confirm a diagnosis with no current treatment, and prenatal testing). Willingness to test was not significantly associated with the determinants tested. Thirty-nine (93%) would join a support group, 38 (91%) would inform a family member at risk, and 28 (67%) would be unwilling to have more children if there wais a risk to future offspring. This study demonstrated a high degree of parental willingness for genetic testing of their children. This is important evidence that can guide policy and planning of ophthalmic genetics services.

Comparison of Ocular Biomery in Primary Open Angle Glaucoma and Non-glaucoma in South West Nigeria.

Background: Glaucoma is a public health problem in Nigeria. The number of individuals affected by glaucoma in Nigeria is much higher than the individuals known to have the disease. Ocular parameters such as intraocular pressure, central cornea thickness, axial length and refractive error have all been documented as risk factors of glaucoma especially among Caucasians and African Americans, with little documentation in Africa where there's an alarming rate of blindness. Aim and Objectives: To compare central cornea thickness (CCT), intraocular pressure (IOP), axial length (AL) and refractive state in participants with primary open angle glaucoma (POAG) and non-glaucoma in South-West Nigeria. Materials and Methods: This hospital-based case-control study was carried out among 184 newly diagnosed POAG and non-glaucoma adult participants attending the outpatient clinic of Eleta eye institute. The CCT, IOP, AL and refractive state were measured in each participant. Test of significance between proportions in categorical variables were assessed using chi square test (χ2) in both groups. The means were compared using independent t-test while correlation between parameters were analyzed using Pearson correlation coefficient. Results: The mean age of the POAG participants was 57.16 + 13.3 years and the mean age of the non-glaucoma participants was 54.15 + 13.4 years. The mean IOP in the POAG group was 30.2 + 8.9mmHg while non- glaucoma group was 14.2 + 2.6mmHg (P < 0.001), other ocular parameters were not significantly different in both groups. In the POAG group, decreased spherical equivalent refractive error (i.e increasing myopia) was significantly associated with increased axial length (r= -0.252, P = 0.01), but not significant in the non- glaucoma group. However, in the non-glaucoma group, central cornea thickness increased with increasing intraocular pressure (r= 0.305, P = 0.003), which was not significant in the glaucoma group. Conclusion: Patients with POAG had much higher IOP and thus, IOP remains a significant risk factor in its development. There was a significant relationship between refractive state and axial length in the POAG group while a significant relationship was identified between central cornea thickness and intraocular pressure in the non- glaucoma group.

Burden and clinical profile of genetic eye diseases in children in Nigeria: a descriptive cross-sectional study.

Introduction: ophthalmic genetics is rapidly evolving globally but is still nascent in much of sub-Saharan Africa, with gaps in knowledge about the burden in the region. This study evaluated the burden and manifestations of genetic eye diseases in children in Ibadan, Nigeria. Methods: this was a hospital-based cross-sectional study in which new and follow-up paediatric eye clinic patients were recruited consecutively at the University College Hospital, Ibadan. Children with genetic eye diseases had comprehensive ocular and systemic examinations, and their pedigrees were charted to determine the probable modes of inheritance. The main outcome variables were the proportion of study participants with genetic eye diseases, the probable modes of inheritance, and the clinical diagnoses. Summary statistics were performed using means and standard deviations for numerical variables and proportions for categorical variables. Results: fifty-two (12%) of 444 children had genetic eye diseases, and their mean (SD) age was 88.8 ± 50.4 months. Thirteen different phenotypic diagnoses were made following the evaluation of the 52 children, including primary congenital glaucoma (13, 25%) and familial non-syndromic cataracts (8, 15%). The probable modes of inheritance were derived from the pedigree charts, and 30 (58%) conditions were presumed to be sporadic. Conclusion: this study demonstrated a significant burden and a wide range of paediatric genetic eye diseases in this tertiary referral centre in Nigeria. This information provides invaluable evidence for planning ophthalmic genetic services.

Amsler Grid Versus 10-2 Test in Primary Open Angle Glaucoma.

Background: Glaucoma is the leading cause of global irreversible blindness. The goal of management in glaucoma lies in its early detection and treatment to prevent further optic neuropathy. Available equipment for early glaucoma detection is not cost-effective or readily available in resource-scarce settings such as Nigeria. Thus, there is a need for a simple cost-effective tool to detect glaucomatous central visual field (CVF) defects in all the stages of glaucoma within the community in resource scarce-settings. Aims and Objectives: The aim of this article is to determine the validity of the Amsler grid in detecting central glaucomatous visual field defects in primary open angle glaucoma (POAG). Materials and Methods: This was a cross-sectional study of follow-up glaucoma patients at a secondary eye care hospital in Nigeria. All patients had detailed ophthalmic examination in addition to 24-2 and 10-2 CVF tests and Amsler grid test. POAG was classified using the Hodapp-Parrish-Anderson criteria into mild, moderate, and severe on 24-2 CVF. The diagnostic validity of the Amsler grid was calculated using the 10-2 CVF as a reference standard. Regression analyses were performed between the Amsler grid scotoma area and 10-2 CVF parameters [mean deviation (MD), scotoma extent (SE), and scotoma mean depth (SMD)]. Results: A total of 150 eyes of 150 patients were enrolled. The sensitivity, specificity, and positive predictive value and negative predictive value of the Amsler grid compared with the 10-2 CVF was 49.5%, 95.9%, 96.2%, and 47.9%, respectively, with an area under curve of 0.7. Sensitivity increased with increasing severity (P < 0.001) from 20.0%, 31.0%, and 76.6% in mild, moderate, and severe POAG, respectively. The Amsler grid scotoma area had the strongest relationship with the 10-2 MD, followed by 10-2 SE and 10-2 SMD with a quadratic R2 of 0.579, 0.370, and 0.307, respectively. Conclusion: The Amsler grid has a low sensitivity in mild-to-moderate POAG. However, it may serve as an adjunctive tool in resource-scarce settings for detection of severe POAG in the community by primary eye care providers.

Effectiveness of community outreach screening for glaucoma in improving equity and access to eye care in Nigeria.

PURPOSE: To determine the effectiveness of community outreach screening for glaucoma in improving equity and access to eye care in Nigeria. METHODOLOGY: This was a prospective study in which two cohort of participants were recruited in Nigeria: 1 from 24 outreach screenings and another from consecutive patients presenting spontaneously to a tertiary eye clinic in Nigeria. Sociodemographic and clinical data were obtained from participants and compared. RESULTS: Our sample consisted of 120 patients with glaucoma or suspected glaucoma (6.38% of 1881 screenees) recruited from the 24 outreach screenings, and another 123 patients with glaucoma who presented spontaneously at the eye clinic. Participants from the screenings were significantly older (p=0.012), less educated (p<0.001), had lower incomes (p<0.001), lower glaucoma knowledge scores and were less aware of their glaucoma (both p<0.001) and were more likely to be dependent on relations and children (p=0.002) compared with clinic participants. Of the 120 patients identified at the screenings and referred to the clinic for definitive care, 39 (32.5%) presented at the clinic within 3 months. Reasons for poor uptake of referral services were lack of a felt need and lack of money for transportation. Considering only patients who accepted referral, they were still less educated (p<0.001), poorer (p=0.001) and less knowledgeable about glaucoma (p=0.003) than spontaneous clinic presenters. CONCLUSION: Outreach screening improved equity of access but its effects were somewhat reduced by poor uptake of referral care. Interventions such as free transportation and educational efforts may improve the uptake of referral services and maximise equity gains.

Impact of a short online course on the accuracy of non-ophthalmic diabetic retinopathy graders in recognising glaucomatous optic nerves in Vietnam.

PURPOSE: To test an online training course for non-ophthalmic diabetic retinopathy (DR) graders for recognition of glaucomatous optic nerves in Vietnam. METHODS: This was an uncontrolled, experimental, before-and-after study in which 43 non-ophthalmic DR graders underwent baseline testing on a standard image set, completed a self-paced, online training course and were retested using the same photographs presented randomly. Twenty-nine local ophthalmologists completed the same test without the training course. DR graders then underwent additional one-to-one training by a glaucoma specialist and were retested. Test performance (% correct, compared with consensus grades from four fellowship-trained glaucoma experts), sensitivity, specificity, positive and negative predictive value, and area under the receiver operating (AUC) curve, were computed. RESULTS: Mean age of DR graders (32.6±5.5 years) did not differ from ophthalmologists (32.3±7.3 years, p=0.13). Online training required a mean of 297.9 (SD 144.6) minutes. Graders' mean baseline score (33.3%±14.3%) improved significantly after training (55.8%±12.6%, p<0.001), and post-training score did not differ from ophthalmologists (58.7±15.4%, p=0.384). Although grader sensitivity reduced before [85.5% (95% CI 83.5% to 87.3%)] versus after [80.4% (78.3% to 82.4%)] training, specificity improved significantly [47.8 (44.9 to 50.7) vs 79.8 (77.3 to 82.0), p<0.001]. Grader AUC also improved after training [66.6 (64.9 to 68.3)] to [80.1 (78.5 to 81.6), p<0.001]. Additional one-to-one grader training by a glaucoma specialist did not further improve grader scores. CONCLUSION: Non-ophthalmic DR graders can be trained to recognise glaucoma using a short online course in this setting, with no additional benefit from more expensive one-to-one training. After 5-hour online training in recognising glaucomatous optic nerve head, scores of non-ophthalmic DR graders doubled, and did not differ from local ophthalmologists. Intensive one-to-one training did not further improve performance.

Glaucoma Treatment Patterns in Sub-Saharan Africa.

PRCIS: Physicians were most likely to recommend primary medical therapy upon diagnosis of glaucoma. Laser therapy was underutilized where they were available. Physicians were more likely to recommend surgery in severe glaucoma, laser therapy in mild glaucoma, while recommendation of medical therapy did not depend on glaucoma severity. PURPOSE: To characterize treatment patterns for newly diagnosed glaucoma in sub-Saharan Africa (SSA). METHODS: This was a multicenter cross-sectional study of adults newly diagnosed with glaucoma at 27 eye care centers in 10 African countries. In addition to demographic and clinical data, physician treatment recommendations (medication, laser, surgery, or no treatment) were recorded. Statistical analyses were performed using STATA version 14.0. RESULTS: Data from 1201 patients were analyzed. Physicians were most likely to recommend primary medical therapy upon diagnosis of glaucoma (69.4%), with laser (13.2%), surgery (14.9%), and no treatment (2.5%) recommended to the remaining patients. All sites had medical therapy available and most (25/27, 92.6%) could provide surgical treatment; only 16/27 (59.3%) sites offered laser, and at these sites, 30.8% of eyes were recommended to undergo primary laser procedures. As glaucoma severity increased, the laser was recommended less, surgery more, and medications unchanged. Patient acceptance of medical therapy was 99.1%, laser 88.3%, and surgery 69.3%. CONCLUSIONS: Medical therapy for first-line glaucoma management is preferred by most physicians in SSA (69%). Laser therapy may be underutilized at centers where it is available. These findings underscore the need for comparative studies of glaucoma treatments in SSA to inform the development of evidence-based treatment guidelines and of programs to reduce glaucoma blindness in SSA. Strategic approaches to glaucoma therapy in SSA must address the question of whether medical therapy is the most optimal first-line approach in this setting.

The social construction of genomics and genetic analysis in ocular diseases in Ibadan, South-western Nigeria.

Genomics, an emerging field to improve public health practice, has potential benefits to understanding ocular diseases. This study explored the social construction of genomics in ocular diseases in the blind community in Ibadan, Nigeria, through two focus group discussions and twelve in-depth interview sessions conducted among people living with ocular disorders. The data were thematic and content-analysed. Although the participants had limited knowledge about ocular diseases, genomics, and their nexus, they maintained a positive attitude toward its potential benefits. This informed their willingness to participate in genomics testing for ocular diseases. The participants preferred saliva-based sample collection over blood-based, and expressed concern for the procedure and accrued benefits of genomics studies. Thus, public sensitisation about ocular diseases and client-centred genomics testing procedures should be engendered.

A Review to Populate A Proposed Cost-Effectiveness Analysis of Glaucoma Screening in Sub-Saharan Africa.

To populate a proposed cost-effectiveness analysis of glaucoma screening in Sub-Saharan Africa (SSA).A complete search was conducted on PubMed, Medline and African Journals Online (AJOL) to obtain relevant published articles, which were included in this review. All relevant articles on prevalence of glaucoma in SSA and among other African-derived populations, severity of glaucoma, cost of diagnosis and management, clinical effectiveness of glaucoma screening and treatment and the different glaucoma screening strategies in SSA were reviewed.Population screening interventions for glaucoma may be considered as follows: standalone screening for glaucoma, screening for glaucoma during cataract outreach, and screening incorporated with diabetic retinopathy image review using tele-ophthalmology. Our review suggests that cost of glaucoma treatment is relatively low with cost of medical treatment ranging from USD 273 to USD 480 per year/patient and surgical treatment cost of USD 283 per patient as with other developing countries. Compliance with medication is moderate to good in about 50% of glaucoma patients. Prevalence of glaucoma is much higher in SSA and almost 50% of glaucoma patients are blind in at least one eye at presentation in clinics (without outreach screening). Our review suggests a moderate sensitivity and specificity in identifying glaucoma with basic equipment (direct ophthalmoscope, contact tonometer and frequency doubling technology) during outreach screening although about a third or fewer take up glaucoma services in clinics.Our review provides the necessary information to conduct a cost-effective analysis of glaucoma screening in SSA using the decision Markov model.

Clinical Characteristics and Stage at Presentation of Glaucoma Patients in Sub-Saharan Africa.

PRCIS: The initial presentation of glaucoma varies meaningfully across SSA. A comprehensive strategy with regional customization based on local differences is needed to reduce glaucoma blindness in SSA. PURPOSE: To explore regional variations in the presentation of newly diagnosed glaucoma in Sub Saharan Africa (SSA). METHODOLOGY: This was a multicenter, cross-sectional study in which newly diagnosed, consecutive, glaucoma patients aged older than or equal to 18 years were recruited from 27 eye clinics in 10 countries throughout SSA. Demographic and ophthalmic examination data were collected. Glaucoma severity was based on optic nerve head and visual field assessment. Statistical analyses were performed using STATA version 14.0. RESULTS: Among 1214 enrolled patients with newly diagnosed glaucoma from Western, Eastern, and Southern Africa, the overall mean (SD) age was 59.9 (17.1) years. More than half of all patients (716/1178; 60.8%) presented with severe glaucoma in the worse eye, and one-third (36.9%) had severe glaucoma in both eyes. Primary open angle glaucoma was the commonest form of glaucoma in all regions (77.4%). A family history of blindness (260/1204, 21.6%) was common. Patients from Western Africa had lower mean presenting intraocular pressure (26.4 [11.1] mm Hg, P <0.001), but had worse glaucoma in the better eye based on mean cup-disc ratio (0.8; P <0.001) and mean visual field mean deviation [10.4 (8.4)] dB, P =0.016) compared with other regions. Exfoliation glaucoma was more common in Eastern Africa (30/170=17.7%, P <0.001) compared with other regions. CONCLUSION: The initial presentation of glaucoma varies meaningfully across SSA. A comprehensive strategy with regional customization based on local differences is needed to reduce glaucoma blindness in SSA.

The Effect of Direct Health Education on the Uptake of Screening by First Degree Relatives of Glaucoma Patients in Nigeria.

PRCIS: First degree relatives (FDRs) of glaucoma patients are more likely to present for screening when they are directly contacted and educated by health workers on the phone compared with when they are only invited by their relative with glaucoma. OBJECTIVE: The aim was to determine the effect of direct health education by phone calls on the uptake of glaucoma screening among FDRs of primary open angle glaucoma patients as a glaucoma blindness control strategy in an asymptomatic high-risk African population. METHODS: This was a randomized clinical trial in which 102 primary open angle glaucoma patients (probands) were randomized into control and intervention groups. Both proband groups were educated about glaucoma and requested by the investigator to invite their adult FDR to attend a screening clinic within 1 month. In addition, the FDRs in the intervention group were directly contacted, educated, and invited for examination by phone calls. A total of 560 FDRs were enumerated by the probands. The main outcome measure was proportion of FDR that presented for screening. RESULTS: A total of 218 (38.9%) FDRs took up glaucoma screening services. Eighty-nine (30.1%) of the 296 FDRs in the control group and 129 (48.9%) of the 264 FDRs in the intervention group presented for examination. After multivariate analysis, FDRs in the phone call group were 2.506 times [95% confidence interval (CI): 1.695-3.706] more likely to present than FDRs in the no phone call group. Young FDRs were more likely to present [odds ratio (OR)=3.593; 95% CI: 1.613-8.007] than the elderly FDRs, while FDRs living within 200 km of the hospital were also more likely to present (OR=5.200; 95% CI: 2.860-9.456) than those living far (>200 km) away. Probands with moderate to severe visual impairment were significantly more likely (OR=3.073; 95% CI: 1.845-4.352) to have their FDRs present than probands with mild or no visual impairment. CONCLUSION: Direct contact and health education of FDRs through phone calls had a significant positive effect on the uptake of glaucoma screening by FDRs. We recommend direct contact and education of the FDRs of glaucoma patients.

Genome-wide meta-analysis identifies 127 open-angle glaucoma loci with consistent effect across ancestries.

Primary open-angle glaucoma (POAG), is a heritable common cause of blindness world-wide. To identify risk loci, we conduct a large multi-ethnic meta-analysis of genome-wide association studies on a total of 34,179 cases and 349,321 controls, identifying 44 previously unreported risk loci and confirming 83 loci that were previously known. The majority of loci have broadly consistent effects across European, Asian and African ancestries. Cross-ancestry data improve fine-mapping of causal variants for several loci. Integration of multiple lines of genetic evidence support the functional relevance of the identified POAG risk loci and highlight potential contributions of several genes to POAG pathogenesis, including SVEP1, RERE, VCAM1, ZNF638, CLIC5, SLC2A12, YAP1, MXRA5, and SMAD6. Several drug compounds targeting POAG risk genes may be potential glaucoma therapeutic candidates.

Correlation and Agreement Between Water Drinking Test and Modified Diurnal Tension Curve in Untreated Glaucoma Patients in Nigeria.

PURPOSE: To determine the correlation and agreement between intraocular pressure (IOP) parameters evaluated by the modified diurnal tension curve (mDTC) and the water drinking test (WDT) in primary open-angle glaucoma (POAG) in an indigenous African population. MATERIALS AND METHODS: This was a prospective, interventional, comparative study of 50 newly diagnosed, previously untreated primary open-angle glaucoma patients at the out-patient clinic of the Eleta Eye Institute, Ibadan. A series of IOP measurements were taken 2 hourly (from 7:00 AM to 3:00 PM) for the mDTC, using Goldmann applanation tonometer. The WDT was performed thereafter. The patients drank 800 mL of water within 5 minutes, and another series of IOP measurements were taken every 15 minutes for a duration of 1 hour from the moment water was fully ingested. Both the mDTC and the WDT were performed on the same day. IOP peak, mean, and IOP fluctuations were estimated from the data collected. Comparison between the mDTC and the WDT was performed using the paired Student T test for means, Pearson correlation analysis for correlation, and Bland-Altman analysis for agreement. RESULTS: Estimated IOP parameters were significantly higher for the WDT than for the mDTC. The average peak IOP was 27.8±4.0 mm Hg during the WDT and 24.9±3.1 mm Hg during the mDTC (P<0.001). The average mean IOP was 25.8±3.6 mm Hg during the WDT and 22.3±2.4 mm Hg during the mDTC (P<0.001). The average IOP fluctuation was higher (6.6±2.9 mm Hg) during the WDT compared with 4.7±2.0 mm Hg during the mDTC. The mean and peak IOPs were strongly correlated between the mDTC (r=0.729, P<0.001) and the WDT (r=0.658, P<0.001). IOP fluctuation, however, showed weak correlation between the mDTC and the WDT (r=0.258, P=0.709). CONCLUSIONS: There is a strong positive correlation between IOP parameters (peak and mean IOP) estimated from the WDT and the mDTC. The peak and mean IOP can be estimated from the WDT, which is quicker, compared with the mDTC. This is more relevant in low resource settings with limited personnel, time, and resource constraints. In addition, higher IOP values were obtained from the WDT compared with the mDTC, and therefore could serve as a useful practical way to determine target peak in order to optimize IOP control in glaucoma patients.

Eye Care Practices, Knowledge, and Attitude of Glaucoma Patients at Community Eye Outreach Screening in Nigeria.

Background: Community eye outreach (CEO) screening is an important model which has been widely employed to detect eye conditions such as cataract and glaucoma in high-risk groups. There is a dearth of data on the eye care practices of glaucoma patients identified using this model in South West Nigeria. Objectives: The aim of this article is to assess the eye care practices, knowledge, and attitudes of glaucoma patients/suspects identified at CEO screenings in Nigeria. Design of the Study: This was a mixed method study with quantitative and qualitative approaches. Setting in Which the Study Took Place: The study was carried out at 24 outreach screening centres in communities in Oyo and Osun states. Materials and Methods: The quantitative component of this study was a cross-sectional survey of patients with suspected glaucoma identified at routine CEO in South West Nigeria. Surveys were administered by trained personnel and gathered information on knowledge and attitudes towards glaucoma. The qualitative component consisted of structured interviews with providers to assess their knowledge and perspectives of glaucoma patients' attitudes and behaviours. Results: A total of 1881 patients were screened at 24 outreach screenings in South West Nigeria, among which 120 glaucoma cases/suspects were identified. Fifty-six (46.7%) of the glaucoma patients were aware of glaucoma, but only 39 (32.5%) patients could answer at least one knowledge question correctly. Predictors of awareness of glaucoma were minimum of secondary school education [adjusted odds ratio (OR) 8.76; 95% confidence interval (CI) 3.18-24.13] and having had an eye check-up in the past (adjusted OR 5.87; 95% CI 1.92 - 17.92). Patients said cost and 'not knowing the disease was serious' were reasons for not following up at the main hospital. Health workers interviewed said that cost and poor knowledge were the main reasons glaucoma patients frequently attended free outreach screening events rather than seeking definitive care. Conclusion: Although CEO screenings improve access to eye care, provision of appropriate health education programs and strengthening of the health insurance scheme are needed to improve its impact in glaucoma care.

Exfoliation syndrome in Northern Nigeria.

PURPOSE: To estimate the frequency of exfoliation syndrome (XFS) and its association with ocular diseases in Northern Nigeria. MATERIALS AND METHODS: Consecutive patients who presented to the outpatient department of ECWA Eye Hospital Kano from February 2015 to May 2015 were included in the study. Each patient had a complete ophthalmic examination. The anterior segment examination included tonometry, gonioscopy, and detailed slit-lamp examination to assess for the presence or absence of exfoliation material, inflammatory cells, and other abnormal findings. Patients with exfoliation material on the anterior lens surface and/or pupillary margin in either or both eyes were considered to have XFS. Statistical analysis was performed using the Statistical Package for the Social Sciences version 16.0. RESULTS: A total of 620 patients living in Northern Nigeria from the 6 geopolitical zones were examined. The majority of them (34.5%) were indigenous Hausas. There was a male preponderance of 56.6%, while the mean age at presentation for examination in all age groups was 55.7±13.7 years. There were 9 patients with XFS; the frequency was 1.5%, with most of the patients being 70-80 years old. In patients who were ≥50 years, the frequency was 2.5%. Patients with XFS had a higher mean age of 68±4.9 years. The frequency of XFS among glaucoma patients was 4.4%, while among cataract patients it was 3.7%. No other associated ocular disease was found in the patients with XFS. CONCLUSION: This study shows that XFS does exist in Northern Nigeria, as was found in the South. The prevalence of XFS was, however, not reported in the Nigerian National Blindness and Visual Impairment Survey. Therefore, a population-based study is still needed to determine the true prevalence of XFS in Northern Nigeria.

The Rationale for Selective Laser Trabeculoplasty in Africa.

Glaucoma is the leading cause of irreversible blindness in Africa. The condition is treatable but not curable. There are numerous obstacles to glaucoma care in Africa, including availability, accessibility and affordability of treatments, as well as medication nonadherence among patients. Medical therapy is costly relative to the average income in Africa and it requires daily self-dosing by patients. Surgery is of limited availability in many regions in Africa, and a high proportion of patients refuse surgery because it is expensive. Selective laser trabeculoplasty (SLT) proves to be a favorable alternative to medical or surgical care, as it is highly effective and safe in people of African descent, more cost-effective than medical therapy, quick and easy to perform, and portable. The procedure also requires no postoperative care, thus obviates the issue of nonadherence. In uncontrolled studies, SLT has a high response rate and it lowers intraocular pressure by 30% to 40%, which exceeds the goal in international guidelines for initial therapies. The African Glaucoma Consortium (AGC), a member-driven stakeholder collective, has been formed in part to develop the infrastructure for continent-wide improvements in glaucoma care. It embraces SLT as a potential key tool in their development plans. The mission of AGC includes improving clinical care by educating existing and new health care professionals to expand the provider network, by conducting trials to identify optimal care strategies for glaucoma in Africa, and by facilitating the development of an integrated network of Centers of Excellence to bring SLT and other crucial glaucoma therapies to communities throughout Africa.