ABSTRACT
AIM: This study aimed to differentiate moderate to high myopic astigmatism from forme fruste keratoconus using Pentacam parameters and develop a predictive model for early keratoconus detection. METHODS: We retrospectively analysed 196 eyes from 105 patients and compared Pentacam variables between myopic astigmatism (156 eyes) and forme fruste keratoconus (40 eyes) groups. Receiver operating characteristic curve analysis was used to determine the optimal cut-off values, and a logistic regression model was used to refine the diagnostic accuracy. RESULTS: Statistically significant differences were observed in most Pentacam variables between the groups (p < 0.05). Parameters such as the Index of Surface Variance (ISV), Keratoconus Index (KI), Belin/Ambrosio Deviation Display (BAD_D) and Back Elevation of the Thinnest Corneal Locale (B.Ele.Th) demonstrated promising discriminatory abilities, with BAD_D exhibiting the highest Area under the Curve. The logistic regression model achieved high sensitivity (92.5%), specificity (96.8%), accuracy (95.9%), and positive predictive value (88.1%). CONCLUSION: The simultaneous evaluation of BAD_D, ISV, B.Ele.Th, and KI aids in identifying forme fruste keratoconus cases. Optimal cut-off points demonstrate acceptable sensitivity and specificity, emphasizing their clinical utility pending further refinement and validation across diverse demographics.
Subject(s)
Corneal Topography , Keratoconus , Photography , ROC Curve , Humans , Keratoconus/diagnosis , Female , Male , Retrospective Studies , Adult , Ghana , Corneal Topography/methods , Photography/methods , Young Adult , Adolescent , Cornea/pathology , Cornea/diagnostic imaging , Middle Aged , Myopia/diagnosis , Astigmatism/diagnosis , Visual AcuityABSTRACT
BACKGROUND/OBJECTIVE: Describe vitreomacular interface abnormalities (VMIA) using spectral-domain optical coherence tomography (SD-OCT), and correlations with age-related macular degeneration (AMD) grade in Ghanaian Africans. SUBJECTS/METHODS: Prospective, cross-sectional study of adults aged ≥50 years recruited in Ghana AMD Study. Participant demographics, medical histories, ophthalmic examination, digital colour fundus photography (CFP) were obtained. High-resolution five-line raster OCT, Macular Cube 512 × 128 scans, and additional line scans in areas of clinical abnormality, were acquired. SD-OCT VMI features classified by International Vitreomacular Traction Study Group system and relationships to AMD grade were evaluated. OUTCOMES: VMIA prevalence, posterior vitreous detachment (PVD), vitreomacular adhesions (VMA), vitreomacular traction (VMT), epiretinal membranes (ERM), correlations with AMD grade. RESULTS: The full Ghana AMD cohort included 718 participants; 624 participants (1248 eyes) aged ≥50 years (range = 50-101, mean = 68.8), 68.9% female were included in this analysis. CFP with OCT scans were available for 776 eyes (397 participants); 707 (91.1%) had gradable CFP and OCT scans for both AMD and VMI grading forming the dataset for this report. PVD was absent in 504 (71.3%); partial and complete PVD occurred in 16.7% and 12.0% respectively. PVD did not increase with age (p = 0.720). VMIA without traction and macular holes were observed in 12.2% of eyes; 87.8% had no abnormalities. VMIA was not significantly correlated with AMD grade (p = 0.819). CONCLUSIONS: This provides the first assessment of VMIA in Ghanaian Africans. VMIA are common in Africans; PVD may be less common than in Caucasians. There was no significant association of AMD grade with VMIA.
Subject(s)
Eye Diseases , Macula Lutea , Macular Degeneration , Vitreous Detachment , Adult , Humans , Female , Male , Ghana/epidemiology , Vitreous Body , Prospective Studies , Cross-Sectional Studies , Vitreous Detachment/epidemiology , Tomography, Optical Coherence/methods , Retrospective StudiesABSTRACT
Purpose: To evaluate the thickness of the macular retina and central choroid in an indigenous population from Ghana, Africa and to compare them with those measured among individuals with European or African ancestry. Design: Cross-sectional study, systematic review, and meta-analyses. Participants: Forty-two healthy Ghanaians, 37 healthy individuals with European ancestry, and an additional 1427 healthy subjects with African ancestry from previously published studies. Methods: Macular retinal thickness in the fovea, parafovea, and perifovea and central choroidal thickness were extracted from OCT volume scans. Associations with ethnicity, age, and sex were assessed using mixed-effect regression models. Monte Carlo simulations were performed to determine the sensitivity of significant associations to additional potential confounders. Pooled estimates of retinal thickness among other groups with African ancestry were generated through systematic review and meta-analyses. Main Outcome Measures: Macular retinal thickness and central choroidal thickness and their association with ethnicity, age, and sex. Results: When adjusted for age and sex, the macular retina and central choroid of Ghanaians are significantly thinner as compared with subjects with European ancestry (P < 0.001). A reduction in retinal and choroidal thickness is observed with age, although this effect is independent of ethnicity. Meta-analyses indicate that retinal thickness among Ghanaians differs markedly from that of African Americans and other previously reported indigenous African populations. Conclusions: The thickness of the retina among Ghanaians differs not only from those measured among individuals with European ancestry, but also from those obtained from African Americans. Normative retinal and choroidal parameters determined among individuals with African or European ancestry may not be sufficient to describe indigenous African populations. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
ABSTRACT
OBJECTIVE: West African crystalline maculopathy (WACM) is characterized by the presence of macular hyperrefractile crystal-like deposits. Although the underlying pathophysiology has not been elucidated, a few biologic drivers have been proposed. We analyzed a large WACM case series to gain a more robust understanding of its features and etiology. DESIGN: Prospective, cross-sectional cohort study. SUBJECTS: Participants with WACM were selected from the large cohort recruited in the Ghana Age-Related Macular Degeneration Study. METHODS: Demographic and detailed medical histories, full ophthalmic examinations, digital color fundus photographs, and OCT images were obtained. All cases with WACM were evaluated by 3 retina experts. Crystal numbers, location, and distribution were determined. Associations between WACM and White age-related macular degeneration (AMD) risk variants were assessed using Firth's bias-reduced logistic regression, including age and sex as covariates. MAIN OUTCOME MEASURES: Phenotypic features of, and genetic associations with, WACM. RESULTS: West African crystalline maculopathy was identified in 106 eyes of 53 participants: 22 were bilateral and 24 were unilateral. Grading for AMD was not possible in 1 eye in 7 participants with WACM; therefore, laterality was not assessed in these subjects. Thirty-eight participants were women and were 14 men; sex was unrecorded for 1 participant. The mean age was 68.4 years (range, 45-101 years). Typical WACM crystals were demonstrated on OCT, which were more easily identified at high contrast and predominantly located at the inner limiting membrane. In eyes with copathology, crystals localized deeper in the inner retina, with wider retinal distribution over copathology lesions. There was no association with age or sex. A significant association was observed between the complement factor H (CFH) 402H risk variant and WACM. CONCLUSIONS: This study confirms the localization of crystals adjacent to the inner limiting membrane and distribution over lesions in eyes with copathology. The evaluation of OCT images under high contrast allows improved identification. West African crystalline maculopathy may be associated with the CFH-CFHR5 AMD risk locus identified among Whites; however, it is also possible that the combination of crystals and the CFH 402H allele increases the risk for developing late AMD. Further analyses using larger sample sizes are warranted to identify causalities between genotype and WACM phenotype.
Subject(s)
Macular Degeneration , Retinal Dystrophies , Cross-Sectional Studies , Female , Ghana/epidemiology , Humans , Macular Degeneration/diagnosis , Macular Degeneration/epidemiology , Macular Degeneration/genetics , Male , Prospective StudiesABSTRACT
Purpose: The purpose of this study was to characterize foveal pit morphology in an African (Ghanaian) population, to compare it to that of a Caucasian group and to determine if it varied with age in the two populations. Methods: The depth, diameter, slope, and volume of the foveal pit were interpolated from optical coherence tomography volume scans recorded in 84 Ghanaian and 37 Caucasian individuals. Their association with age, sex, and ethnicity was investigated using multilevel regression models. Results: The foveal pit differed significantly in width, slope, and volume between Ghanaian men and women (P < 0.001), but only in width and volume between Caucasian men and women (P < 0.01). In Ghanaians, age was associated with a narrowing of the foveal depression and a reduction of its volume. Overall, these changes were more pronounced in women as compared to men and were largely absent from the Caucasian group. When controlled for age, the foveal pit of Ghanaians was significantly wider and larger in volume as compared to the Caucasian group (P < 0.001). Conclusions: The morphology of the foveal pit differs between African and Caucasian individuals. These anatomic differences should be considered when examining differences in prevalence and clinical features of vitreoretinal disorders involving the fovea between the two populations. Translational Relevance: Differences in retinal anatomy may partly explain variations in the prevalence and clinical features of retinal diseases between Africans and Caucasians. Such differences should be adequately considered in diagnoses and monitoring of ocular diseases in patients with African ancestry.
Subject(s)
Fovea Centralis , White People , Female , Fovea Centralis/diagnostic imaging , Ghana/epidemiology , Humans , Male , Retina , Tomography, Optical CoherenceABSTRACT
BACKGROUND: Corneal transplantations are surgeries performed for irreparable corneal diseases and damage. However, there is a gap between the number of potential recipients and the number of donor corneas available. The main aim of the study was to determine the awareness and attitudes toward corneal donation among applicants and staff of DVLA, Kumasi-Ghana. METHODS: A descriptive cross-sectional study was conducted. One hundred participants were selected using convenient sampling method. A structured questionnaire was used to elicit responses from participants concerning awareness and attitudes toward corneal transplant. RESULTS: The mean ± SD age of the participants was 32.05 ± 11.48 years and age range, 18-67 years. Males were 66% whilst females constituted 34%. 32.7% of the participants were aware of corneal donation. Majority of the participants were Christians (83.1%) and Singles (63%). Television was the source of information with the highest preponderance (49.4%). 67.3% were willing to donate their corneas after death. 63.9% were willing to indicate their donor statuses on drivers' license form which had a significant association with willingness to donate cornea after death (p < 0.05, x2 = 12.187). CONCLUSION: There is a poor level of awareness (32.7%) of transplant and donation amongst the study population but a good level of willingness to donate organs (67%). Consent via driving license would seem to be a good potential mode of obtaining consent to supplement the harvesting of adequate tissues for transplant if adequate awareness is created.
Subject(s)
Corneal Transplantation , Health Knowledge, Attitudes, Practice , Tissue Donors/psychology , Tissue and Organ Procurement , Adolescent , Adult , Aged , Awareness , Cross-Sectional Studies , Female , Ghana , Humans , Male , Middle Aged , Young AdultABSTRACT
BACKGROUND: To determine the prevalence of diabetic retinopathy maculopathy and cataract amongst diabetics and the prevalence of visual impairment amongst diabetics attending the Komfo Anokye Teaching Hospital eye unit. There are no current data in the study area on the prevalence of visual impairment and blindness amongst diabetics. This data is required in planning for screening and prevention of blindness due to diabetics. METHODS: This was a hospital based cross sectional study. Subjects were diabetic patients attending the diabetic clinic. Simple random sampling was used. Demographic was taken. Visual acuity and refraction was done. Slit lamp examination was used to identify cataract. Maculopathy and retinopathy was determined using a 90D Volk lens and an indirect ophthalmoscope. RESULTS: Non -insulin dependent diabetics constituted 97.1% whilst 2.9% were insulin dependent diabetics. The prevalence of the outcomes measures was: Cataract (23.7%) mild and moderate retinopathy (13.7%) severe proliferative retinopathy (1.8%) maculopathy (6.8%). Prevalence of low vision and blindness was 18.4%. Amongst diabetics 59.1% had no previous eye evaluation. Impaired vision due to cataract was 24.0 % representing a 40% decline in a decade. CONCLUSION: The prevalence of visual impairment was high at 18.4%. The reduction in impaired vision due to cataract over a decade is suggestive of either an improved cataract surgical rate or improved diabetic care or both. Majority of the diabetic patients 59.1% had not received prior ocular evaluation. There is an urgent need to have a screening program in this area. FUNDING: None.
Subject(s)
Cataract/epidemiology , Diabetes Complications/epidemiology , Diabetic Retinopathy/epidemiology , Macular Degeneration/epidemiology , Vision Disorders/epidemiology , Aged , Ambulatory Care Facilities/statistics & numerical data , Blindness/epidemiology , Blindness/etiology , Cataract/etiology , Cross-Sectional Studies , Female , Ghana/epidemiology , Humans , Macular Degeneration/etiology , Male , Middle Aged , Prevalence , Tertiary Care Centers/statistics & numerical data , Vision Disorders/etiology , Vision Tests , Visual AcuityABSTRACT
BACKGROUND: There seems a preponderance of hospital-based studies on the prevalence of Allergic Conjunctivitis (AC) compared to community-based ones, particularly among children in Ghana and Africa as a whole. Meanwhile, literature supports the possibility of underdiagnosing AC in the hospital setting; exponentially so when males generally have poor hospital-attending behavior. This may lead to underestimation of the true burden of AC. Consequently, the purpose of the current community-based study was to determine the prevalence of AC among basic school children in the Kumasi Metropolis, while identifying its associated symptoms. METHODS: A cross-sectional community-based study involving 1571 students from 11 basic schools (Primary and JHS) participated in the study. Data collection started in November 2011 and was completed in March 2014. After history taking, subjects underwent a battery of tests; visual acuity, objective refraction, anterior and posterior segments examination with a slit-lamp and a direct ophthalmoscope respectively. RESULTS: The prevalence of AC was 39.9 %. The mean (± SD) age of participants was 8 ± 0.65 years. AC was significantly associated with gender (p < 0.05), but not with age (p > 0.05). A total of 70 % of the students with AC never had any form of treatment. CONCLUSIONS: AC is an endemic ocular disease among basic schools in the Kumasi metropolis and therefore calls for pragmatic and proactive measures to reduce its burden and effects on its victims. Public health measures may be required to help reduce the burden associated with this condition.
Subject(s)
Conjunctivitis, Allergic/epidemiology , Adolescent , Age Distribution , Child , Child, Preschool , Community Health Services , Conjunctivitis, Allergic/diagnosis , Cross-Sectional Studies , Female , Ghana/epidemiology , Humans , Male , Prevalence , Schools , Sex DistributionABSTRACT
PURPOSE: To assess the prevalence of refractive error and visual impairment in private school children in Ghana. METHODS: A random selection of geographically defined classes in clusters was used to identify a sample of school children aged 12 to 15 years in the Ashanti Region. Children in 60 clusters were enumerated and examined in classrooms. The examination included visual acuity, retinoscopy, autorefraction under cycloplegia, and examination of anterior segment, media, and fundus. For quality assurance, a random sample of children with reduced and normal vision were selected and re-examined independently. RESULTS: A total of 2454 children attending 53 private schools were enumerated, and of these, 2435 (99.2%) were examined. Prevalence of uncorrected, presenting, and best visual acuity of 20/40 or worse in the better eye was 3.7, 3.5, and 0.4%, respectively. Refractive error was the cause of reduced vision in 71.7% of 152 eyes, amblyopia in 9.9%, retinal disorders in 5.9%, and corneal opacity in 4.6%. Exterior and anterior segment abnormalities occurred in 43 (1.8%) children. Myopia (at least -0.50 D) in one or both eyes was present in 3.2% of children when measured with retinoscopy and in 3.4% measured with autorefraction. Myopia was not significantly associated with gender (P = 0.82). Hyperopia (+2.00 D or more) in at least one eye was present in 0.3% of children with retinoscopy and autorefraction. CONCLUSIONS: The prevalence of reduced vision in Ghanaian private school children due to uncorrected refractive error was low. However, the prevalence of amblyopia, retinal disorders, and corneal opacities indicate the need for early interventions.