Simulation of visual impairment in persons with normal vision for scientific research.

Simulation of visual impairment in healthy eyes has multiple applications in students' training, research and product development. However, due to the absence of an existing standard protocol, the method of simulation was left to the discretion of the researcher. This review aimed to outline the various methods of simulating visual impairment and categorising them. A scoping review of the relevant publications was conducted. Of the 1593 articles originally retrieved from the databases, 103 were included in the review. The characteristics of the participants, the method for simulation of the visual impairment in persons with normal vision and the level or type of visual impairment that was simulated were extracted from the papers. None of the methods of simulation can be judged as being superior to the others. However, electronic displays produced the most consistent form of visual impairment simulation.

Barriers and enablers to low vision care and rehabilitation in sub-Saharan Africa within a global context.

Low vision is an uncorrectable form of visual impairment that affect millions of people worldwide. Low vision care and rehabilitation are essential to improving the independence of affected individuals. Even though sub-Saharan Africa has one of the highest burdens of low vision globally, there are inadequate care and rehabilitation services in most countries and in some cases they are non-existent This scoping review aimed to identify the barriers and enablers to low vision care and rehabilitation in sub-Saharan Africa and assess these within the global context. The review was conducted using the five-step Arksey and O'Malley framework. Search terms were formulated based on the research questions and a search strategy was designed to search for eligible research articles from electronic databases; Pubmed, Ovid, Medline, and Embase. The data was screened by two members of the research team in accordance with set inclusion and exclusion criteria. Twenty-five out of 260 articles satisfied the inclusion criteria for the study. Inadequate low vision care infrastructure and supplies, non-standardised training of low vision care providers, health system failure and poor awareness of low vision care were the main barriers noted by eye care practitioners. Patients living with low vision cited the cost and availability of low vision aids, societal stigma, and poor awareness of services as the main barriers. No direct enablers were identified in sub-Saharan Africa; however, practitioners suggested improved training in low vision as a potential enabler. The barriers to low vision care and rehabilitation services identified were not unique to sub-Saharan Africa when viewed within a global context. Adopting and adapting solutions from other countries may therefore assist in improving low vision care and rehabilitation in sub-Saharan Africa.

Central contrast sensitivity perimetry discriminates between glaucomatous and non-glaucomatous eyes.

Background: Glaucoma is an optic neuropathy which causes irreversible vision loss. Standard perimetry, which is essential for glaucoma diagnosis, can only detect glaucomatous visual filed loss when considerable structural damage has occurred. Contrast sensitivity is one of the visual function tests that is reduced in eyes with glaucoma. It is known to be affected in pre-perimetric stages of glaucoma. Objective: The objective of this study was to investigate the discriminating ability of central contrast sensitivity perimetry in eyes with and without glaucoma. Design: The study employed a cross-sectional study design. Methods: The study participants were made of two groups; eyes diagnosed with glaucoma by an ophthalmologist based on visual field test and optical coherence tomography (OCT) and age- and sex-matched controls who were declared free from glaucoma. Static contrast sensitivity (CS) was measured in the central 10° of visual field using a custom psychophysical test. Results: There were 45 eyes with glaucoma and 45 age- and sex-matched controls in this study. The static CS in the glaucoma group was significantly reduced in 9 out of the 13 tested locations in the central 10° of the visual field. The mean static CS at 5°, 10°, superior hemifield and inferior hemifield were all significantly reduced in the glaucoma patients compared to the controls. Conclusion: Static CS measurement is a sensitive approach that can be utilized to aid in the detection of glaucoma. The use of static CS can be adopted in the development of a cost-effective yet sensitive screening tool for the detection of glaucoma.

Refractive error correction among urban and rural school children using two self-adjustable spectacles.

OBJECTIVE: Self-refracting spectacles (SRSs) have different optical and mechanical designs, which may affect the refractive outcome, depending on the experience of the end user. This study compared the performance of two SRS among children in Ghana. METHODS AND ANALYSIS: A cross-sectional study of two Alvarez variable-focus SRS designs was conducted. A total of 167 children (mean age 13.6±1.6 years) identified as having refractive error were recruited from 2465 students who underwent screening. Subjects completed self-refraction using FocusSpecs, and Adlens, autorefraction and cycloplegic subjective refraction (CSR) (gold standard). Wilcoxon signed-rank test was used to compare visual outcomes and accuracy of refraction and graphically illustrated using Bland-Altman plots. RESULTS: Eighty (47.9%) urban and 87 (52.1%) rural children were analysed and only about one-quarter 40 (24.0%) wore spectacles. The proportion who achieved visual acuity of ≥6/7.5 with FocusSpec, Adlens, autorefraction and CSR among urban schools were 92.6%, 92.4%, 60% and 92.6%, while those in rural schools were 81.6%, 86.2%, 54.0% and 95.4%, respectively. The mean±SD spherical equivalent errors for urban and rural schools using FocusSpec, Adlens and CSR were -1.05±0.61 D, -0.97±0.58 D and -0.78±0.53 D; and -0.47±0.51 D, -0.55±0.43 D and -0.27±0.11 D, respectively. The mean differences between the two self-refraction spectacles for urban and rural schools were not statistically different (p>0.00) but differed significantly when both were compared with the gold standard (CSR) (p<0.05). CONCLUSION: Background and refraction experience of school children did not significantly affect self-refraction.

The effect of filters and varying illumination on contrast sensitivity in eyes with moderate to severe visual impairment.

PURPOSE: To investigate the effect of filters and illumination on contrast sensitivity in persons with cataract, pseudophakia, maculopathy and glaucoma to provide a guide for eye care providers in low vision rehabilitation. MATERIALS AND METHODS: A within-subjects experimental design with a counter-balanced presentation technique was employed in this study. The contrast sensitivity of eyes with cataract, pseudophakia, maculopathy and glaucoma was measured with filters (no filter, yellow, pink and orange) combined with increasing illumination levels (100 lx, 300 lx, 700 lx and 1000 lx) using the SpotChecks™ contrast sensitivity chart. The data were analyzed using descriptive statistics and two-way repeated measures ANOVA. RESULTS: The yellow filter at 100 lx significantly improved contrast sensitivity in the maculopathy group. There were no significant improvements with either intervention in the rest of the groups. There was, however, a significant interaction between filters and illumination in the cataract group. CONCLUSION: There were small improvements in contrast sensitivity at low illumination levels with the yellow filter in the maculopathy group, and this could be considered in clinical practice and low vision rehabilitation. Overall, filters at most illumination levels did not benefit most groups.

Dry eye symptom questionnaires show adequate measurement precision and psychometric validity for clinical assessment of vision-related quality of life in glaucoma patients.

PURPOSE: To ascertain the presence of Dry Eye Syndrome (DES) in patients being treated for glaucoma, using subjective and objective methods and to examine DES impact on their quality of life (QOL). METHOD: A cross-sectional study was conducted by employing 156 glaucoma patients recruited from treatment centers in the Cape Coast Metropolis in Ghana. All the participants underwent dry eye examination and completed the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ), the Dry Eye-related Quality of Life Score (DEQS) and the Ocular Surface Disease Index (OSDI). Comparisons of the clinical tests, NEI VFQ-25 subscale item and composite scores and scores of DEQS and OSDI were made among subgroups divided according to the presence of dry eye symptoms or signs. Multivariate logistic regression analysis was performed to investigate the factors that influence DES related-QOL among the patients. RESULTS: The study involved 156 subjects with a mean age of 47.88 ± 16.0 years and made up of 81 (51.9%) females and 75 (48.1%) males. A One-Way ANOVA was conducted, and the F-statistic (F) indicated that there was a significant difference in the mean scores of the groups. There were significantly lower Tear break-up time (TBUT) values found in the group with definite dry compared with the group without DES and the group that was symptomatic with no signs DES in both eyes, [(F(3,151) = 13.703, p<0.001 (RE): (F(3,152) = 18.992, p<0.001 (LE)]. Similar results were found for Schirmer test (ST) [(F (3,151) = 28.895, p<0.001 (RE): (F (3,152) = 17.410, p<0.001 (LE)]. There was statistically significant difference in the mean composite score (64.93 ± 20.27) for the NEI VFQ-25 and sub-scale score of ocular pain, which was significantly lower in the group with definite dry as compared to other sub-groups (F(3,152) = 4.559, p = 0.004). OSDI scores of the group with definite dry eye (47.69-19.17) and the group that was symptomatic but with no signs (38.90-22.44) were significantly higher than those without dry eye and those that were asymptomatic but had a sign (F(3,152) = 17.896, p<0.001), with a similar trend occurring in the groups with relation to DEQS scores (F(3,152) = 8.775, p<0.001). There was a strong correlation between the DEQS and the OSDI questionnaires, and a weak correlation between the DEQS and the NEI VFQ-25 questionnaire after adjusting for all other factors (all p < 0.01). CONCLUSION: The study established a high presence of DES and consequently low DES related-QOL in glaucoma patients. Dry eye questionnaires are able to discriminate those who have definite dry eye from the other groups, showing its appropriateness for clinical use in glaucoma patients. Ocular surface evaluation should be conducted among glaucoma patients on topical anti-glaucoma therapy to ensure the timely detection and treatment of signs and symptoms of DES and improvement of dry-eye related QOL.

Associations between personality traits and adherence to treatment in patients with primary open-angle glaucoma in an African population.

CLINICAL RELEVANCE: Inclusion of personality profile assessment and appropriate psychotherapeutic regimen in glaucoma diagnosis and management protocols could prove useful for enhanced medication adherence in patients living with glaucoma. BACKGROUND: There is poor adherence to medication among patients with glaucoma, especially in people of African ancestry. The present study assessed the influence of personality traits on adherence to glaucoma medication among patients living with primary open-angle glaucoma (POAG) from an African population. METHODS: A clinic-based cross-sectional study was conducted among patients with POAG attending a specialist eye-care facility. Adapted and validated questionnaires for personality trait (The Big Five Inventory) and medication adherence (Medication Adherence Report Scale 5) were used. RESULTS: Self-reported adherence to glaucoma medication was 60.8%. The personality traits conscientiousness and agreeableness significantly predicted medication adherence but accounted for only 30.3% and 13.3% of the variance, respectively. Non-adherence to glaucoma medication was significantly predicted by the personality profiles neuroticism, extraversion and openness which, respectively, accounted for 61.7%, 20.3% and 13.3% of the variance in the personality trait assessment. Old age and longer use of glaucoma medications were also significantly associated with non-adherence to glaucoma medication. CONCLUSIONS: Personality trait dimensions were significantly associated with glaucoma medication adherence in this at-risk population.

Case Series: Avoidable Blindness after Inappropriate Ophthalmic Self-medication in Ghana.

SIGNIFICANCE: Inappropriate ophthalmic self-medication continues to plague Sub-Saharan Africa because of lack of public health education and inaccessibility to eye care services. This case series describes three cases of blindness (two monocular, one binocular) in Ghana, because of self-treatment of ocular conditions using improper drugs or homemade herbal mixtures. The article highlights the consequences of misinterpretation of symptoms and use of traditional home remedies, leading to delayed professional eye care and avoidable blindness. PURPOSE: This case series aims to report three separate cases of avoidable blindness after inappropriate ophthalmic self-medication to draw attention to the need for intense public health education in Ghana. CASE REPORTS: Three men aged 25, 79, and 35 years, respectively, reported severe reduction in visual acuity in one eye for two cases and both eyes for one case. All patients reported ophthalmic self-medication either with an inappropriate drug bought from the drug store or a homemade herbal mixture made from leaves assumed to treat eye infections. Professional care did not yield any improvement in visual acuity because their corneas were already decompensated at the onset of management. The eye of one patient had to be enucleated. CONCLUSIONS: These cases highlight the importance of eye health promotion and education. It is recommended that intense sensitization is carried out at all levels.

Assessment of four validated questionnaires for screening of dry eye disease in an African cohort.

PURPOSE: To evaluate the 5-item dry eye questionnaire (DEQ-5) for measurement precision and unidimensionality, and assess the ability of Ocular Surface Disease Index (OSDI), McMonnies Dry Eye Questionnaire (MQ), Ocular Comfort Index questionnaires (OCI), and DEQ to predict clinical measures of DED in an African population. METHOD: Participants (n = 113; mean age 24.7 ± 5.4 years) completed all four questionnaires administered in a randomized order. Internal consistency and test-retest reliability of the instruments were assessed. A masked examiner performed clinical dry eye tests in both eyes of participants and the results used to classify into either "dry" or "non-dry" groups. The diagnostic criteria for dry eye disease were tear break up time (TBUT) < 10 s plus at least one of Schirmer <15 mm in 5 min., > 5 corneal staining spot, or > 9 conjunctival staining spots. Rasch analysis was performed to assess the DEQ for unidimensionality and measurement precision, and receiver operating characteristic curve (AUC) analysis was used to assess the ability of the four questionnaires to predict clinical measures of DED. RESULTS: The responses from the DEQ-5 met the Rasch analysis criterion of unidimensionality with infit and outfit values of between 0.74-1.43 mean-square and 0.69-1.49 mean-square, respectively, and measurement precision of 2.33. Internal consistency and test-retest reliability of each test was high, with Cronbach alpha >0.70 for the questionnaire and their respective subscales but internal consistency reliability of the MQ was poor (Cronbach's alpha = 0 .29-0 0.52). Each test segregated the "dry" and "non-dry" groups with moderate (all AUC 0.70-0.80) and similar accuracy (P > .05). CONCLUSION: The DEQ -5 demonstrated adequate measurement precision and unidimensionality. Each of the four questionnaires showed psychometric validity for clinical use in the African population, and modest and similar accuracy when screening for dry eye signs but the performance of the McMonnies questionnaire was limited in terms of internal consistency reliability.

Smartphone usage among people living with severe visual impairment and blindness.

Low vision care and rehabilitation is often limited by access to assistive devices, especially in low-resourced countries, due to their high cost and unavailability. Smartphones have the potential to serve as an alternative assistive device for people living with severe visual impairment and blindness (SVIB). This study aims to investigate the use of smartphones among people living with SVIB. The study was a cross-sectional study of 166 people living with SVIB in a low resourced setting. The participants were recruited from two tertiary institutions and four eye care facilities. A questionnaire was administered to all respondents and for those who could not read prints they were read out to them and their responses recorded. The majority of respondents (n = 88, 53.1%) either had no phone or used a basic phone. The prevalence of smartphone usage among people living with SVIB was found to be 46.90% (n = 78). Most respondents use their smartphones to interact on social media [n = 75 (96%)] and web browsing [n = 69,92%]. The most frequently demanded [n = 22 (44%)] smartphone functionality by the respondents was the image and color description feature. Most participants were unaware that 90% of their functionality demands already existed and were compatible with current smartphones. A significant number of people living with SVIB in this study used smartphones; however, most users are unaware of its full functionality and assistive capabilities.

Accuracy of Noncycloplegic Refraction for Detecting Refractive Errors in School-aged African Children.

SIGNIFICANCE: Cycloplegia is often restricted in screening settings. Previous studies have evaluated noncycloplegic refraction for screening, but their data are not fully applicable to school-aged African children. This article adds to the literature by investigating this in school-aged African children. PURPOSE: The purpose of this study was to evaluate the ability of noncycloplegic autorefraction (NCA) and noncycloplegic retinoscopy (NCR) to detect refractive errors in school-aged African children and quantify differences between noncycloplegic and cycloplegic refraction measures. METHODS: Autorefraction and retinoscopy were performed on 150 children aged 6 to 15 years before and after cyclopentolate cycloplegia. Subjective refraction was performed by the same examiner after cycloplegia. Noncycloplegic and cycloplegic measurements were compared, and the data were assessed with receiver operating characteristic curves and Bland-Altman plots. RESULTS: With the exception of cylindrical vector J0 (P = .17) and J45 (P = .08) obtained with NCR, all mean measures of NCA and NCR significantly differed from mean cycloplegic subjective refraction measurements by -0.71 ± 0.67 (P ≤ .001; 95% confidence interval, -2.02 to +0.60) and -0.75 ± 0.68 (P ≤ .001; 95% confidence interval, -2.08 to +0.58), respectively. Mean spherical power between the two tests did not differ (NCA -NCR, mean bias of -0.037 ± 0.675 and 95% limits of agreement of -1.36 to 1.286; P = .51). The sensitivities for detecting any refractive error for NCR and NCA were 86.8 and 82.9%, respectively, and the specificities were 82.0% for NCR and 82.4% for NCA. Performance of both tests was excellent for myopia (area under the curve, >0.90; sensitivity, ≥90%) and similar (P = .13), but the specificities for detecting hyperopia were 78.0% for NCR and 80.0% for NCA. CONCLUSIONS: Noncycloplegic refraction may accurately detect astigmatism and myopia in this population but may elicit higher myopic values and lower hyperopic values than using cycloplegic refraction.

Socio-demographic factors modify awareness, knowledge, and perceived risk of glaucoma in rural and urban residents in Ghana: a population-based survey.

PURPOSE: To evaluate the awareness, knowledge and the perception of risks of glaucoma among rural and urban dwellers in Ghana, a high prevalent country, in order to provide information for health promotion planning. METHOD: In a population-based descriptive cross-sectional survey, 1200 adults were selected from household settings, using a two-stage cluster and simple systematic random sampling. Quantitative data collection, using interviewer-administered questionnaire, was employed. Descriptive statistics were performed using chi-square, ordinal univariate, multinomial and multivariate logistic regression models used to calculate odds ratio with 95% confidence interval (CI) to identify predictive factors. RESULTS: Overall, only 326 (27.2%, 95% CI = 24.6-29.7) indicated they were aware of glaucoma, whereas 331 (27.6%, 95% CI = 24.6-29.7) had ever undergone an eye screening. Low knowledge was demonstrated in 152 (46.6%, 95% CI = 41.2-52.0) and high knowledge in 99 (30.4%, 95% CI = 25.4-35.4) glaucoma-aware participants. Only 238 (19.8%, 95% CI = 17.6-22.1) of respondents presumed themselves to be at risk of developing glaucoma. Having eye examination (within the last 6 months) was positively associated with knowledge (adjusted odds ratio (AOR) = 1.413; 95% CI = 0.9-1.896) and awareness (AOR = 1.13; 95% CI = 0.938-2.449). Three levels of education (no education (AOR = 0.041; 95% CI = 0.016-0.11), primary (AOR = 0.057; 95% CI = 0.018-0.179), and middle school (AOR = 0.254; 95% CI = 0.127-0.51)) were associated with low knowledge while all levels of education were inversely associated with awareness. Perceived risk of glaucoma was also influenced by area of residence (rural (AOR = 0.344; 95% CI = 0.21-0.57)), being young (18-24 years (AOR = 4.308; 95% CI = 2.36-7.88)) and having previously undergone screening for glaucoma (AOR = 13.200; 95% CI = 5.318-32.764). CONCLUSION: The main modifiers of glaucoma awareness and knowledge were education and previous eye examination, but awareness had additional factor of area of residence. Perceived risk of glaucoma was influenced by being young and living in urban areas.

Ocular Symptoms of SARS-CoV-2: Indication of Possible Ocular Transmission or Viral Shedding.

The recently identified novel coronavirus (CoV), the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), causes the coronavirus disease 2019 (COVID-19). While published data about other highly infectious human COVs [that is, the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV)] provide helpful information about the infectivity of SARS-CoV-2, there is limited understanding surrounding knowledge of ocular manifestation of the virus. This paper reviews published data which reveal the presence of SARS-CoV-2 RNA in tears and conjunctival scrappings of some COVID-19 patients by real-time-polymerase chain reaction assay, although the detection rate is low compared to samples from respiratory sites. Nevertheless, the ocular complications from SARS-CoV-2 infection are uncommon. The evidence partly supports the eye as a portal of entry for SARS-CoV-2 to infect respiratory cells or viral shedding from respiratory cells via the nasolacrimal duct unto the ocular surface. The possibility of ocular secretions as source for SARS-CoV-2 to spread externally has substantial public health implications.

Oral consumption of Garcinia kola(Bitter kola) lowers intraocular pressure.

PURPOSE: Garcinia kola (bitter kola) is locally ingested across the West African subregion. It has ocular hypotensive effects similar to some commonly used glaucoma medications when administered topically. The study assessed the effect of oral ingestion of G. kola on intraocular pressure (IOP). METHOD: A randomized, single-blind, placebo-controlled, cross-over design was used in this study. Forty-six healthy subjects, aged between 19 and 27 years were recruited and randomized into two groups (A and B). Subjects in group A ingested 100 mg/kg body weight bitter kola in a 200 ml solution on their first visit and group B ingested 200 ml of water. On the second visit, the order of treatment was reversed, IOP was measured at baseline and every 45 min interval for 135 min. The mean difference between the baseline and post-treatment IOP measurements were tested for statistical significance using repeated-measures analysis of variance (95% confidence intervals [CIs]). RESULTS: Mean IOP measurements decreased by 7.9, 18.2 and 20.6% at 45, 90 and 135 min, respectively, after G. kola treatment. The reduction, though variable across subjects, was statistically significant (F [2.13, 95.62] = 90.35, p < 0.0001) across the respective time points. Repetition of an identical protocol without G. kola caused clinically negligible changes in IOP. There was no statistically significant influence of gender or age in G. kola effect on IOP reading. CONCLUSION: Oral ingestion of G. kola lowered the intraocular pressure of healthy young adults by 21%. Such an effect may be of therapeutic benefit to patients with POAG or ocular hypertension in low-income settings.

Normative Values of Retinal Nerve Fibre Layer Thickness and Optic Nerve Head Parameters and Their Association with Visual Function in an African Population.

PURPOSE: To determine normative values of retinal nerve fibre layer thickness (RNFL) and optic nerve head (ONH) parameters and their association with routine clinical tests such as refractive error (RE), stereoacuity (SA), and contrast sensitivity (CS) in an African population. METHODS: In a cross-sectional observational study, 100 normal subjects aged 20 to 78 years were evaluated using the Cirrus HD-OCT 5000 and matched with 200 glaucoma patients. RESULTS: Average (±SD) RNFL thickness for normal subjects was found to be 102.37 ± 7.45 (range, 82-119 microns) compared with 90.74 ± 14.50 found for glaucoma subjects. Females had higher average RNFL values (104.84 ± 6.90) compared with males (99.80 ± 7.18). Significant associations were calculated between quadrant RNFL thickness and SA, SE, and CS (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40-59 age group (2.01 ± 0.41) and then 20-39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40-59 age group (2.01 ± 0.41) and then 20-39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all p < 0.05). The mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean optic disc area (DA) was 2.08 mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by 40-59 age group (2.01 ± 0.41) and then 20-39 age group (2.19 ± 0.41). Significant associations were calculated between SA and ONH parameters, except rim area (all. CONCLUSION: RNFL thickness in healthy black Ghanaian population was significantly higher than that reported in other races. The values and associations reported in this study can inform clinical decision on the normal variation in RNFL and optic disc parameters.

Inter-regional trends in causes of childhood blindness and low vision in Ghana.

BACKGROUND: Inter-regional trends of visual loss in most developing countries remain largely unknown. We compared the causes of childhood blindness among children attending blind schools in the northern (one school) and southern (two schools) regions of Ghana and assessed their need for spectacles and low-vision devices. METHODS: Using a standardised methodology, children were examined by an ophthalmologist and optometrists in each location. Causes of visual loss were classified anatomically and by time of onset, and avoidable causes identified. Children identified with functional low vision were assessed and provided with low-vision devices. RESULTS: A total of 252 children under 16 years of age were examined in the schools. The overall prevalence of total blindness was 73 (29.0 per cent), with similar proportions (p = 0.87) in the north (29 [28.4 per cent]) and south (44 [29.3 per cent]); 92 (36.5 per cent) had functional low vision. Two children improved with spectacles and 35 benefited from low-vision devices. Corneal scarring was significantly (p = 0.045) more prevalent in southern Ghana (n = 150) than in the north (n = 102), responsible for visual loss in 36 (24.0 per cent, 95% CI 17.2-30.8 per cent) and 14 (13.7 per cent, 95% CI 7.0-20.4 per cent) cases, respectively. No significant difference (p = 0.321) was observed in the prevalence of cataract between northern (28: 27.5 per cent, 95% CI 18.3-36.2 per cent) and southern Ghana (33: 22.0 per cent, 95% CI 15.4-28.6 per cent). Over 87 per cent of children had 'avoidable' causes of visual loss, with a higher proportion being treatable (124: 49.2 per cent) than preventable (96: 38 per cent). CONCLUSION: Cataract was the major cause of visual loss in the overall population. The south had a higher proportion of corneal scarring and late-onset blindness compared with the north. More than one-third of blindness in blind schools in Ghana could have been prevented by primary care interventions and nearly half could have been treated surgically to prevent visual loss. Two in five children in blind schools in Ghana could benefit from optical intervention.

Comparative evaluation of a novel solar powered low-cost ophthalmoscope (Arclight) by eye healthcare workers in Malawi.

This study compared a novel low-cost solar powered direct ophthalmoscope called the Arclight with a traditional direct ophthalmoscope (TDO). After appropriate training, 25 Malawian eye healthcare workers were asked to examine 12 retinal images placed in a teaching manikin head with both the Arclight ophthalmoscope and a traditional direct ophthalmoscope (Keeler Professional V.2.8). Participants were scored on their ability to identify clinical signs, to make a diagnosis and how long they took to make a diagnosis. They were also asked to score each ophthalmoscope for 'ease of use'. Statistically significant differences were found in favour of the Arclight in the number of clinical signs identified, correct diagnoses made and ease of use. The ophthalmoscopes were equally effective as a screening tool for diabetic retinopathy, and there was no statistically difference in time to diagnosis. The authors conclude that the Arclight offers an easy to use, low cost alternative to the traditional direct ophthalmoscope to meet the demands for screening and diagnosis of visually impairing eye disorders in low-income and middle-income countries.

Self-refraction accuracy with adjustable spectacles among children in Ghana.

PURPOSE: To determine the accuracy of self-refraction (SR) in myopic teenagers, we compared visual and refractive outcomes of self-refracting spectacles (FocusSpecs) with those obtained using cycloplegic subjective refraction (CSR) as a gold standard. METHODS: A total of 203 eligible schoolchildren (mean [±SD] age, 13.8 [±1.0] years; 59.1% were female) completed an examination consisting of SR with FocusSpecs adjustable spectacles, visual acuity with the logMAR (logarithm of the minimum angle of resolution) chart, cycloplegic retinoscopy, and CSR. Examiners were masked to the SR findings. Wilcoxon signed rank test and paired Student t test were used to compare measures across refraction methods (95% confidence intervals [CIs]). RESULTS: The mean (±SD) spherical equivalent refractive error measured by CSR and SR was -1.22 (±0.49) diopters (D) and -1.66 (±0.73) D, respectively, a statistically significant difference of -0.44 D (p < 0.001, t = 15.517). The greatest proportion of participants was correctable to visual acuity greater than or equal to 6/7.5 (logMAR 0.1) in the better eye by CSR (99.0%; 95% CI, 96.5 to 99.7%), followed by cycloplegic retinoscopy (94.1%; 95% CI, 90.0 to 96.6%) and SR (85.2%; 95% CI, 79.7 to 89.5%). These proportions differed significantly from each other (p < 0.001, Wilcoxon signed rank test). Myopic inaccuracy of greater than 0.50 D and greater than or equal to -1.00 D was present in 29 (15.3%) and 16 (8.4%) right eyes, respectively, with SR. In logistic regression models, failure to achieve visual acuity greater than or equal to 6/7.5 in right eyes with SR was significantly associated with age (odds ratio, 1.92; 95% CI, 1.12 to 3.28; p = 0.017) and spherical power (odds ratio, 0.017; 95% CI, 0.005 to 0.056; p < 0.001). CONCLUSIONS: Self-refraction offers acceptable visual and refractive results for young people in a rural setting in Ghana, although myopic inaccuracy in the more negative direction occurred in some children.

Awareness, knowledge and self-care practices toward glaucoma among final year health science university students in Ghana.

BACKGROUND: In the absence of adequate services, patients have to rely on the few health professionals that they do come into contact with to advise them on their treatment options. The aim of this study was to determine the level of awareness and knowledge of glaucoma, and the association between these factors and self-care practices among final year health science university students in Ghana. METHOD: A cross-sectional survey involving the use of a structured questionnaire was conducted among 273 final year students (67 per cent) studying at any one of eight health science programs in three selected public universities in Ghana. RESULTS: All 273 respondents were aware of glaucoma but only 37.7 per cent had knowledge of it. The majority (65.9 per cent) defined glaucoma as raised intraocular pressure, and confused glaucoma with ocular hypertension. Over half (56.8 per cent) had acquired their knowledge of glaucoma during the course of their training. The media also played a major role in glaucoma awareness; however, it played a limited role in impacting on the knowledge of glaucoma. Only 28.6 per cent of respondents had previously undergone glaucoma screening. CONCLUSION: Although all respondents were aware of glaucoma, their level of knowledge of glaucoma was low. Self-care practices were also generally poor among the respondents. This information may be useful for glaucoma health education in Ghana.