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1.  Prevalence and risk factors for diabetes and diabetic retinopathy: results from the Nigeria national blindness and visual impairment survey 
BMC Public Health  2014;14(1):1299.
Background
In Nigeria, urbanisation and increasing life expectancy are likely to increase the incidence of non-communicable diseases. As the epidemic of diabetes matures, visual loss from diabetic retinopathy (DR) will increase unless mechanisms for early detection and treatment improve, and health systems respond to the growing burden of non-communicable diseases.
Methods
A nationally-representative population-based sample of 13,591 participants aged ≥40 years selected by multistage-stratified-cluster-random-sampling with probability-proportional-to-size procedures were examined in 305 clusters in Nigeria between January 2005 to June 2007. All were asked about history of diabetes and underwent basic eye examination. Visual acuity (VA) was measured using logMAR E-chart. Participants with VA<6/12 and/or DR detected underwent detailed eye examination including dilated retinal examination and retinal photography. Systematic sampling of 1-in-7 gave a subsample (n=1759) examined in detail regardless of VA; and had random blood glucose (RBG) testing. Images were graded by Moorfields Eye Hospital Reading Centre. Participants were defined as having diabetes if they were previously diagnosed or RBG>11.1mmol/l or had DR. Data in the subsample were used to estimate the prevalence and to analyse risk factors for diabetes and DR using multivariable logistic regression. Additional information on the types of DR was obtained from participants not in the subsample.
Results
In the subsample, 164 participants were excluded due to missing data; and 1,595 analysed. 52/1,595 had diabetes, a prevalence of 3.3% (95%CI 2.5-4.3%); and 25/52(48%) did not know. Media opacity in 8/52 precluded retinal examination. 9/44(20.5%) had DR. Higher prevalence of diabetes was associated with urban residence (Odds ratio [OR]1.87) and overweight/obesity (OR3.02/4.43 respectively). Although not statistically significant, DR was associated with hypertension (OR3.49) and RBG>15.0mmol/L (OR8.10). Persons with diabetes had 3 times greater odds of blindness. Of 11,832 other participants in the study sample, 175(1.5%) had history of diabetes; 28 had DR. Types of DR (total=37) included 10.8% proliferative, 51.4% macular oedema.
Conclusion
The age-adjusted prevalence of diabetes in Nigeria was 3.25% (95%CI 2.50-4.30) and over 10% of people with diabetes aged ≥40 years had sight-threatening-DR. These data will enable the development of better public health strategies for the control of diabetes and planning services for DR to prevent vision loss.
doi:10.1186/1471-2458-14-1299
PMCID: PMC4301086  PMID: 25523434
2.  The Heritability of the Ring-Like Distribution of Macular Pigment Assessed in a Twin Study 
Purpose.
It has been suggested that ring-like patterns of macular pigment, as measured with dual wavelength autofluorescence, are observed less frequently in subjects with age-related maculopathy. We explored relative contributions of genetic and environmental factors in macular pigment optical density (MPOD) distributions using a classic twin study.
Methods.
As part of a previous nutritional study, 322 healthy Caucasian female twins, aged 16 to 50 (mean 40) years, underwent measurement of MPOD optical density by two-wavelength fundus autofluorescence. In the present study, the right eye MPOD profile was assessed for the presence of a ring-like pattern by two graders independently, using common criteria, with a third grader arbitrating in cases of disagreement. Concordance was calculated as 2C/(2C + D), where C is the number of twin pairs concordant, and D the number discordant, for the ring-like pattern. Also, heritability was calculated using maximum-likelihood structural equation modeling.
Results.
Images and zygosity data were available for 314 twins (88 monozygotic [MZ] and 69 dizygotic [DZ] pairs). The overall prevalence of the ring pattern was 25.8%. Respective concordances for MZ and DZ twins were 0.75 and 0.22. Additive genetic factors were estimated to contribute to 84.0% of the total variance (95% confidence intervals, 63.7%–94.6%).
Conclusions.
Concordance for MZ twins was over three times that for DZ twins, with heritability estimated at 84%, indicating that genetic factors contribute to the development of the ring structure. Studies have suggested that ring-like patterns of macular pigment can affect risk for age-related maculopathy. In a classic twin study, we found that the presence of such a pattern was highly heritable.
doi:10.1167/iovs.13-13829
PMCID: PMC3979519  PMID: 24609627
macular pigment; heritability; lutein
3.  The role of heredity in determining central retinal thickness 
The British Journal of Ophthalmology  2007;91(9):1143-1147.
Aims
To examine the relative roles of genetic and environmental factors in central retinal thickness, by performing a classical twin study.
Methods
310 subjects were recruited from the TwinsUK adult registry at St Thomas' Hospital. Optical coherence tomography (Zeiss, stratus OCT3) was used to measure the average retinal thickness in the central 1 mm diameter area. The covariance of central retinal thickness (CRT), within MZ and DZ twin pairs, was compared and genetic modelling techniques were used to determine the relative contributions of genes and environment to the variation in CRT observed in this population.
Main outcome measure
CRT (average retinal thickness in the central 1 mm diameter area, centred on the fovea).
Results
The mean CRT of all subjects was 212.1 μm (range 165–277). CRT was statistically related to refractive error, with increasing myopia associated with a thinner CRT. CRT was more highly correlated within MZ twin pairs (r = 0.88) than with DZ twin pairs (r = 0.58), suggesting a genetic role. A model combining additive genetic and unique environmental factors provided the best fitting model and gave a heritability estimate of 0.90.
Conclusion
Genetic factors appear to play an important role in CRT, with a heritability estimate of 0.90.
doi:10.1136/bjo.2007.114215
PMCID: PMC1954930  PMID: 17360735
4.  The key informant method: a novel means of ascertaining blind children in Bangladesh 
Background
Most information on the causes of blindness has come from examining children in special education. To obtain a more representative population‐based sample of children, a novel method was developed for ascertaining severe visually impaired (SVI) or blind (BL) children by training local volunteers to act as key informants (KIs).
Objective
To compare the demography and cause of blindness in children recruited by KIs with other ascertainment methods.
Method
Children with SVI/BL were recruited in all 64 districts of Bangladesh. Three sources for case ascertainment were utilised: schools for the blind (SpEdu), community‐based rehabilitation (CBR) programmes and KIs. All data were recorded using the standard WHO/PBL Eye Examination Record.
Results
1935 children were recruited. Approximately 800 KIs were trained. The majority of the children were recruited by the KIs (64.3%). Children recruited by KIs were more likely to be female (odds ratio (OR) 1.6, p<0.001), of pre‐school age (OR 14.1, p<0.001), from rural areas (OR 5.9, p<0.001), be multiply impaired (OR 3.1, p = 0.005) and be suffering from treatable eye diseases (OR 1.3, p = 0.005) when compared with those in SpEdu. Overall a child with an avoidable causes of SVI/BL had 40% (adjusted CI 1.1 to 1.7, p = 0.015) and 30% (CI 1.0 to 1.7, p = 0.033) higher odds of being ascertained using the KIs compared with SpEdu and CBR methods, respectively.
Conclusion
Using this innovative approach has resulted in one of the largest studies of SVI/BL children to date. The findings indicate that KIs can recruit large numbers of children quickly, and that the children they recruit are more likely to be representative of all blind children in the community.
doi:10.1136/bjo.2006.108027
PMCID: PMC1954788  PMID: 17431019
5.  The Impact of Climatic Risk Factors on the Prevalence, Distribution, and Severity of Acute and Chronic Trachoma 
Background and Objectives
Trachoma is the most common cause of infectious blindness. Hot, dry climates, dust and water scarcity are thought to be associated with the distribution of trachoma but the evidence is unclear. The aim of this study was to evaluate the epidemiological evidence regarding the extent to which climatic factors explain the current prevalence, distribution, and severity of acute and chronic trachoma. Understanding the present relationship between climate and trachoma could help inform current and future disease elimination.
Methods
A systematic review of peer-reviewed literature was conducted to identify observational studies which quantified an association between climate factors and acute or chronic trachoma and which met the inclusion and exclusion criteria. Studies that assessed the association between climate types and trachoma prevalence were also reviewed.
Results
Only eight of the 1751 papers retrieved met the inclusion criteria, all undertaken in Africa. Several papers reported an association between trachoma prevalence and altitude in highly endemic areas, providing some evidence of a role for temperature in the transmission of acute disease. A robust mapping study found strong evidence of an association between low rainfall and active trachoma. There is also consistent but weak evidence that the prevalence of trachoma is higher in savannah-type ecological zones. There were no studies on the effect of climate in low endemic areas, nor on the effect of dust on trachoma.
Conclusion
Current evidence on the potential role of climate on trachoma distribution is limited, despite a wealth of anecdotal evidence. Temperature and rainfall appear to play a role in the transmission of acute trachoma, possibly mediated through reduced activity of flies at lower temperatures. Further research is needed on climate and other environmental and behavioural factors, particularly in arid and savannah areas. Many studies did not adequately control for socioeconomic or environmental confounders.
Author Summary
Trachoma – the leading cause of infectious blindness – is spread through contact with infected persons by hands and towels, and by ‘eye-seeking flies.’ Trachoma prevalence is high in areas characterised by poverty, inadequate water supply, and poor sanitation. Trachoma is controlled by the SAFE strategy: S = surgery to the upper eyelids; A = antibiotics for active infection; F = facial cleanliness; and E = environmental improvement. In this study we reviewed the scientific literature to assess the extent to which climatic factors (e.g., rainfall, heat, dust, altitude) influence trachoma distribution. A systematic review of the literature found eight papers that measured an association between a climatic factor and trachoma in children or adults. Several studies reported that trachoma is less common at higher altitudes, indicating that temperature may play a role in trachoma transmission. Some studies also reported that trachoma is higher in areas with low rainfall, which is consistent with anecdotal evidence that trachoma is associated with dry environments.
doi:10.1371/journal.pntd.0002513
PMCID: PMC3820701  PMID: 24244768
6.  Ocular parameters of biological ageing in HIV-infected individuals in South Africa: relationship with chronological age and systemic biomarkers of ageing 
Mechanisms of ageing and development  2013;134(9):10.1016/j.mad.2013.08.002.
HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two ‘cellular’ biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend=0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection.
doi:10.1016/j.mad.2013.08.002
PMCID: PMC3818088  PMID: 23994067
Telomeres; CDKN2A; lens density; retinal vessel calibre; HIV
7.  Prevalence and risk factors for hypertension and association with ethnicity in Nigeria: results from a national survey 
Cardiovascular Journal of Africa  2013;24(9):344-350.
Summary
Background
Non-communicable diseases are now a global priority. We report on the prevalence of hypertension and its risk factors, including ethnicity, in a nationally representative sample of Nigerian adults recruited to a survey of visual impairment.
Methods
A multi-stage, stratified, cluster random sample with probability proportional to size procedures was used to obtain a nationally representative sample of 13 591 subjects aged ≥ 40 years. Of these, 13 504 (99.4%) had a blood pressure measurement.
Results
The prevalence of hypertension was 44.9% [95% confidence interval (CI): 43.5–46.3%]. Increasing age, gender, urban residence and body mass index were independent risk factors (p < 0.001). The Kanuri ethnic group had the highest prevalence of hypertension (77.5%, 95% CI: 71.0–84.0%).
Conclusions
The high prevalence of hypertension in Nigeria is a cause for concern and suggests that it is inevitable that the impact of hypertension-related ill health is imminent, with the accompanying financial and societal costs to families and the state of Nigeria.
doi:10.5830/CVJA-2013-058
PMCID: PMC3896106  PMID: 24042732
hypertension; ethnicity; Nigeria; survey
8.  Candidate gene study of macular response to supplemental lutein and zeaxanthin☆ 
Experimental Eye Research  2013;115(100):172-177.
Supplementation with carotenoids is proposed to protect against age-related macular degeneration. There is, however, considerable variability in retinal macular pigment response, which may be due to underlying genetic variation. The purpose of this study was to determine whether genetic factors, which have been previously associated with cross-sectional macular pigment levels in the retina or serum lutein, also influence response to supplementation.
To this end we conducted an association study in 310 subjects from the TwinsUK cohort between variants in 8 candidate genes and serum lutein and retinal macular pigment optical density (MPOD) levels before and after supplementation. Four variants were associated with MPOD response to supplementation (p < 0.05): rs11057841 (SCARB1), rs4926339 (RPE65), rs1929841 (ABCA1) and rs174534 (FADS1). We also confirmed previous associations between rs6564851 near BMCO1 (p < 0.001) and rs11057841 within SCARB1 (p = 0.01) and baseline measures of serum lutein; while the latter was also associated with MPOD response, none of the BMCO1 variants were. Finally, there was evidence for association between variants near RPE65 and ELOVL2 and changes in lutein concentration after supplementation.
This study is the first to show association between genetic variants and response to carotenoids supplementation. Our findings suggest an important link between MP response and the biological processes of carotenoids transport and fatty acid metabolism.
Highlights
•Four variants were associated with macular pigment response to supplementation.•We replicated associations between BMCO1 variants and lutein at baseline.•Carotenoids transport may affect macular response to supplementation.•Lipid metabolism may affect macular response to supplementation.
doi:10.1016/j.exer.2013.07.020
PMCID: PMC3819993  PMID: 23891863
macular pigment; lutein; genetics; supplementation; macular degeneration; CAREDS, Carotenoids in Age Related Eye Disease Study; MP, macular pigment; L, lutein; MPOD, macular pigment optical density; LZ, lutein and zeaxanthin; Z, zeaxanthin
9.  Retinal Nerve Fibre Layer Thickness and Contrast Sensitivity in HIV-Infected Individuals in South Africa: A Case-Control Study 
PLoS ONE  2013;8(9):e73694.
Background
Antiretroviral treatment (ART) has altered the spectrum of HIV-related eye disease, resulting in a lower prevalence of retinal opportunistic infections (OIs). However, abnormalities in visual function have been reported in HIV-infected individuals despite effective viral suppression and the absence of retinal OIs. These changes may be mediated by an HIV-associated ‘neuroretinal disorder’, characterized by changes in the retinal nerve fibre layer (RNFL). HIV infection may also be associated with accelerated biological aging. The aim of this study was to investigate the relationships between contrast sensitivity, RNFL thickness, HIV infection and frailty in South African adults.
Methods
Case-control study of 225 HIV-infected individuals without retinal OIs and 203 gender/age-matched HIV-seronegative individuals. Peri-papillary RNFL thickness was determined with spectral domain optical coherence tomography in four quadrants. CS was measured using a Pelli-Robson chart. Frailty was assessed using standard criteria. Multivariable linear and logistic regression were used to assess associations between HIV status and RNFL/CS and frailty.
Results
The median age of both groups was similar (41.2 vs. 41.9 years, p = 0.37). 88% of HIV-infected individuals were receiving ART and their median CD4 count was 468 cells/μl. Adjusted CS score was lower in HIV-infected participants compared to HIV-seronegative individuals (1.76 vs. 1.82, p = 0.002). Independent predictors of poor CS in the HIV-infected group were positive frailty status and current HIV viral load >2 log copies/ml. Lower CS score was also associated with thin temporal RNFL in HIV-infected individuals (p = 0.04). Superior quadrant RNFL thickness was greatest in ART-naïve participants relative to the HIV-uninfected group (p-trend = 0.04). Longer ART duration was associated with thinning of inferior and nasal RNFL quadrants (p-trend = 0.03 and 0.04, respectively).
Conclusions
Contrast sensitivity is reduced in HIV-infected individuals and functionally associated with frailty and unsuppressed viraemia. This may reflect structural changes in the RNFL that are evident despite the absence of OIs.
doi:10.1371/journal.pone.0073694
PMCID: PMC3777952  PMID: 24069225
10.  Ocular parameters of biological ageing in HIV-infected individuals in South Africa: Relationship with chronological age and systemic biomarkers of ageing☆ 
Highlights
•HIV is associated with age-related morbidity despite antiretroviral treatment.•Ocular age-related parameters may serve as biomarkers of ageing.•Lens density may have a role in the determination of biological age in HIV infection.
HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two ‘cellular’ biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend = 0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection.
doi:10.1016/j.mad.2013.08.002
PMCID: PMC3818088  PMID: 23994067
Telomeres; CDKN2A; Lens density; Retinal vessel calibre; HIV
11.  The Outcome of Trachomatous Trichiasis Surgery in Ethiopia: Risk Factors for Recurrence 
Background
Over 1.2 million people are blind from trachomatous trichiasis (TT). Lid rotation surgery is the mainstay of treatment, but recurrence rates can be high. We investigated the outcomes (recurrence rates and other complications) of posterior lamellar tarsal rotation (PLTR) surgery, one of the two most widely practised TT procedures in endemic settings.
Methodology/Principal Findings
We conducted a two-year follow-up study of 1300 participants who had PLTR surgery, conducted by one of five TT nurse surgeons. None had previously undergone TT surgery. All participants received a detailed trachoma eye examination at baseline and 6, 12, 18 and 24 months post-operatively. The study investigated the recurrence rates, other complications and factors associated with recurrence. Recurrence occurred in 207/635 (32.6%) and 108/641 (16.9%) of participants with pre-operative major (>5 trichiatic lashes) and minor (<5 lashes) TT respectively. Of the 315 recurrences, 42/315 (3.3% overall) had >5 lashes (major recurrence). Recurrence was greatest in the first six months after surgery: 172 cases (55%) occurring in this period. Recurrence was associated with major TT pre-operatively (OR 2.39, 95% CI 1.83–3.11), pre-operative entropic lashes compared to misdirected/metaplastic lashes (OR 1.99, 95% CI 1.23–3.20), age over 40 years (OR 1.59, 95% CI 1.14–2.20) and specific surgeons (surgeon recurrence risk range: 18%–53%). Granuloma occurred in 69 (5.7%) and notching in 156 (13.0%).
Conclusions/Significance
Risk of recurrence is high despite high volume, highly trained surgeons. However, the vast majority are minor recurrences, which may not have significant corneal or visual consequences. Inter-surgeon variation in recurrence is concerning; surgical technique, training and immediate post-operative lid position require further investigation.
Author Summary
Trachoma is the most common infectious cause of blindness worldwide. It causes trichiasis (inturning of the eyelashes to touch the eye), which can cause visual loss. Trachomatous trichiasis (TT) affects over eight million people, 1.2 of whom live in Ethiopia – the most affected country worldwide. Surgery is the mainstay of treatment for TT. However, results of surgery in the field are often very mixed. We investigated the surgical outcomes of one of the two most widely used surgical techniques (posterior lamellar rotation), in 1300 individuals in the Amhara Region of Ethiopia. We found that recurrence occurred frequently: 315/1276 (24.7%) participants. However, recurrence was rarely severe (greater than 5 lashes): 42 participants (3.3%). Recurrence occurred much more frequently in participants who had severe pre-operative disease and with specific surgeons. The high recurrence rates and inter-surgeon variation is concerning. Further research will be required to investigate factors such as surgical technique, surgeon training and immediate post-operative lid position, in order to improve surgical outcomes.
doi:10.1371/journal.pntd.0002392
PMCID: PMC3749971  PMID: 23991241
12.  Assessment of candidate ocular biomarkers of ageing in a South African adult population: Relationship with chronological age and systemic biomarkers☆ 
Mechanisms of Ageing and Development  2013;134(7-8):338-345.
Highlights
•Structural parameters of the eye change with increasing chronological age.•Ocular age-related parameters may serve as biomarkers of aging.•Relevant ocular parameters include retinal vessel calibre and lens density.
Certain anatomic and functional parameters of the eye change with increasing chronological age. They may, therefore, serve as potential biomarkers of ageing. We investigated associations between four such ocular parameters (lens density, retinal vessel calibre, corneal endothelial cells and retinal nerve fibre layer thickness) and two ‘cellular’ biomarkers of ageing (leukocyte telomere length and CDKN2A expression), with frailty (a clinical correlate of biological ageing) in a population of South African adults. All ocular parameters revealed an association with either telomere length or CDKN2A expression. However, lens density was most strongly correlated with age, increased CDKN2A expression, and with frailty (p = 0.05 and 0.03, respectively). Narrow retinal arteriolar diameter, associated with increased chronological age, was also associated with increased CDK2NA expression (0.42 vs. 0.31, p = 0.02) but not with frailty. Ocular parameters may aid in determining biological age, warranting investigation in longitudinal studies.
doi:10.1016/j.mad.2013.05.002
PMCID: PMC3710972  PMID: 23701820
Telomeres; CDKN2A; Lens density; Retinal vessel calibre; Corneal endothelium; Retinal nerve fibre layer; Frailty
13.  Epidemiology of Glaucoma in Sub-Saharan Africa: Prevalence, Incidence and Risk Factors 
Purpose:
The purpose of this study is to review the epidemiology of different types of glaucoma relevant to Sub-Saharan Africa (SSA) and to discuss the evidence regarding the risk factors for onset and progression of glaucoma, including risk factors for glaucoma blindness.
Methods:
Electronic databases (PubMed, MedLine, African Journals Online- AJOL) were searched using the full text, Medical Subject Headings (MeSH) terms, author(s) and title to identify publications since 1982 in the following areas: population-based glaucoma prevalence and incidence studies in SSA and in African-derived black populations outside Africa; population-based prevalence and incidence of blindness and visual impairment studies in SSA including rapid assessment methods, which elucidate the glaucoma-specific blindness prevalence; studies of risk factors for glaucoma; and publications that discussed public health approaches for the control of glaucoma in Africa.
Results:
Studies highlighted that glaucoma in SSA is a public health problem and predominantly open-angle glaucoma. It is the second-leading cause of blindness, has a high prevalence, an early onset and progresses more rapidly than in Caucasians. These factors are further compounded by poor awareness and low knowledge about glaucoma even by persons affected by the condition.
Conclusion:
Glaucoma care needs to be given high priority in Vision 2020 programs in Africa. Many questions remain unanswered and there is a need for further research in glaucoma in SSA in all aspects especially epidemiology and clinical care and outcomes involving randomized controlled trials. Genetic and genome-wide association studies may aid identification of high-risk groups. Social sciences and qualitative studies, health economics and health systems research will also enhance public health approaches for the prevention of blindness due to glaucoma.
doi:10.4103/0974-9233.110605
PMCID: PMC3669488  PMID: 23741130
Africa; Epidemiology; Glaucoma prevalence; Glaucoma risk factors; Open-angle glaucoma; Sub-Saharan Africa
14.  Corneal Endothelial Cells Provide Evidence of Accelerated Cellular Senescence Associated with HIV Infection: A Case-Control Study 
PLoS ONE  2013;8(2):e57422.
Background
Cellular senescence may be a key factor in HIV-related premature biological aging. We assessed features of the corneal endothelium that are known to be associated with biological aging, and cellular senescence markers in HIV-infected adults.
Methods
Case-control study of 242 HIV-infected adults and 249 matched controls. Using specular microscopy, the corneal endothelium was assessed for features of aging (low endothelial cell density [ECD], high variation in cell size, and low hexagonality index). Data were analysed by multivariable regression. CDKN2A expression (a cell senescence mediator) was measured in peripheral blood leukocytes and 8-hydroxy-2′-deoxyguanosine (8-OHDG; an oxidative DNA damage marker) levels were measured in plasma.
Results
The median age of both groups was 40 years. Among HIV-infected adults, 88% were receiving antiretroviral therapy (ART); their median CD4 count was 468 cells/µL. HIV infection was associated with increased odds of variation in cell size (OR = 1.67; 95% CI: 1.00–2.78, p = 0.04). Among HIV-infected participants, low ECD was independently associated with current CD4 count <200 cells/µL (OR = 2.77; 95%CI: 1.12–6.81, p = 0.03). In participants on ART with undetectable viral load, CDKN2A expression and 8-OHDG levels were higher in those with accelerated aging, as reflected by lower ECD.
Conclusions
The corneal endothelium shows features consistent with HIV-related accelerated senescence, especially among those with poor immune recovery.
doi:10.1371/journal.pone.0057422
PMCID: PMC3584030  PMID: 23460854
15.  The Heritability of Macular Response to Supplemental Lutein and Zeaxanthin: A Classic Twin Study 
Purpose.
Antioxidant supplements may reduce age-related macular degeneration (AMD) progression. The macular carotenoids are of particular interest because of their biochemical, optical, and anatomic properties. This classic twin study was designed to determine the heritability of macular pigment (MP) augmentation in response to supplemental lutein (L) and zeaxanthin (Z).
Methods.
A total of 322 healthy female twin volunteers, aged 16–50 years (mean 40 ± 8.7) was enrolled in a prospective, nonrandomized supplement study. Macular pigment optical density (MPOD) measurements using two techniques (2-wavelength fundus autofluorescence [AF] and heterochromatic flicker photometry [HFP]), and serum concentrations of L and Z, were recorded at baseline, and at 3 and 6 months following daily supplementation with 18 mg L and 2.4 mg Z for a study period of 6 months.
Results.
At baseline, mean MPOD was 0.44 density units (SD 0.21, range 0.04–1.25) using HFP, and 0.41 density units (SD 0.15) using AF. Serum L and Z levels were raised significantly from baseline following 3 months' supplementation (mean increase 223% and 633%, respectively, P < 0.0001 for both), with no MPOD increase. After 6 months' supplementation, a small increase in MPOD was seen (mean increase 0.025 ± 0.16, P = 0.02, using HFP). Subdivision of baseline MPOD into quartiles revealed that baseline levels made no difference to the treatment effect. Genetic factors explained 27% (95% confidence interval [CI] 7–45) of the variation in MPOD response. Distribution profiles of macular pigment did not change in response to supplementation.
Conclusions.
MPOD response to supplemental L and Z for a period of 6 months was small (an increase over baseline of 5.7% and 3.7%, measured using HFP and AF, respectively), and was moderately heritable. Further study is indicated to investigate the functional and clinical impact of supplementation with the macular carotenoids.
A classical twin study of 322 twins determined the heritability of macular pigment augmentation in response to 6 months' supplemental lutein and zeaxanthin. There was a small increase in macular pigment optical density, which was moderately heritable; genetic factors explained 27% of variance.
doi:10.1167/iovs.12-9618
PMCID: PMC3410678  PMID: 22700713
16.  Retinal Arterioles Narrow with Increasing Duration of Anti-Retroviral Therapy in HIV Infection: A Novel Estimator of Vascular Risk in HIV? 
PLoS ONE  2012;7(12):e51405.
Objectives
HIV infection is associated with an increased risk of age-related morbidity mediated by immune dysfunction, atherosclerosis and inflammation. Changes in retinal vessel calibre may reflect cumulative structural damage arising from these mechanisms. The relationship of retinal vessel calibre with clinical and demographic characteristics was investigated in a population of HIV-infected individuals in South Africa.
Methods
Case-control study of 491 adults ≥30 years, composed of 242 HIV-infected adults and 249 age- and gender-matched HIV-negative controls. Retinal vessel calibre was measured using computer-assisted techniques to determine mean arteriolar and venular diameters of each eye.
Results
The median age was 40 years (IQR: 35–48 years). Among HIV-infected adults, 87.1% were receiving highly active antiretroviral therapy (HAART) (median duration, 58 months), their median CD4 count was 468 cells/µL, and 84.3% had undetectable plasma viral load. Unadjusted mean retinal arteriolar diameters were 163.67±17.69 µm in cases and 161.34±17.38 µm in controls (p = 0.15). Unadjusted mean venular diameters were 267.77±18.21 µm in cases and 270.81±18.98 µm in controls (p = 0.07). Age modified the effect of retinal arteriolar and venular diameters in relation to HIV status, with a tendency towards narrower retinal diameters in HIV cases but not in controls. Among cases, retinal arteriolar diameters narrowed with increasing duration of HAART, independently of age (167.83 µm <3 years of HAART vs. 158.89 µm >6 years, p-trend = 0.02), and with a HIV viral load >10,000 copies/mL while on HAART (p = 0.05). HIV-related venular changes were not detected.
Conclusions
Narrowing of retinal arteriolar diameters is associated with HAART duration and viral load, and may reflect heightened inflammatory and pro-atherogenic states of the systemic vasculature. Measurement of retinal vascular calibre could be an innovative non-invasive method of estimating vascular risk in HIV-infected individuals.
doi:10.1371/journal.pone.0051405
PMCID: PMC3519635  PMID: 23251521
17.  The Impact of Successful Cataract Surgery on Quality of Life, Household Income and Social Status in South India 
PLoS ONE  2012;7(8):e44268.
Background
To explore the hypothesis that sight restoring cataract surgery provided to impoverished rural communities will improve not only visual acuity and vision-related quality of life (VRQoL) but also poverty and social status.
Methods
Participants were recruited at outreach camps in Tamil Nadu, South India, and underwent free routine manual small incision cataract surgery (SICS) with intra-ocular lens (IOL) implantation, and were followed up one year later. Poverty was measured as monthly household income, being engaged in income generating activities and number of working household members. Social status was measured as rates of re-marriage amongst widowed participants. VRQoL was measured using the IND-VFQ-33. Associations were explored using logistic regression (SPSS 19).
Results
Of the 294 participants, mean age ± standard deviation (SD) 60±8 years, 54% men, only 11% remained vision impaired at follow up (67% at baseline; p<0.001). At one year, more participants were engaged in income generating activities (44.7% to 77.7%; p<0.001) and the proportion of households with a monthly income <1000 Rps. decreased from 50.5% to 20.5% (p<0.05). Overall VRQoL improved (p<0.001). Participants who had successful cataract surgery were less likely to remain in the lower categories of monthly household income (OR 0.05–0.22; p<0.02) and more likely to be engaged in income earning activities one year after surgery (OR 3.28; p = 0.006). Participants widowed at baseline who had successful cataract surgery were less likely to remain widowed at one year (OR 0.02; p = 0.008).
Conclusion
These findings indicate the broad positive impact of sight restoring cataract surgery on the recipients’ as well as their families’ lives. Providing free high quality cataract surgery to marginalized rural communities will not only alleviate avoidable blindness but also - to some extent - poverty in the long run.
doi:10.1371/journal.pone.0044268
PMCID: PMC3432104  PMID: 22952945
18.  Why Do People Not Attend for Treatment for Trachomatous Trichiasis in Ethiopia? A Study of Barriers to Surgery 
Background
Trachomatous trichiasis (TT) surgery is provided free or subsidised in most trachoma endemic settings. However, only 18–66% of TT patients attend for surgery. This study analyses barriers to attendance among TT patients in Ethiopia, the country with the highest prevalence of TT in the world.
Methodology/Principal Findings
Participants with previously un-operated TT were recruited at 17 surgical outreach campaigns in Amhara Region, Ethiopia. An interview was conducted to ascertain why they had not attended for surgery previously. A trachoma eye examination was performed by an ophthalmologist. 2591 consecutive individuals were interviewed. The most frequently cited barriers to previous attendance for surgery were lack of time (45.3%), financial constraints (42.9%) and lack of an escort (35.5% in females, 19.6% in males). Women were more likely to report a fear of surgery (7.7% vs 3.2%, p<0.001) or be unaware of how to access services (4.5% vs 1.0% p<0.001); men were more frequently asymptomatic (19.6% vs 10.1%, p<0.001). Women were also less likely to have been previously offered TT surgery than men (OR = 0.70, 95%CI 0.53–0.94).
Conclusions/Significance
The major barriers to accessing surgery from the patients' perspective are the direct and indirect costs of surgery. These can to a large extent be reduced or overcome through the provision of free or low cost surgery at the community level.
Trial Registration
ClinicalTrials.gov NCT00522860 and NCT00522912
Author Summary
Trachoma is the commonest infectious cause of blindness worldwide. It causes trichiasis (inturning of the eyelashes to touch the eye), which can cause visual loss. Trachomatous trichiasis (TT) affects over eight million people, of whom 1.2 million live in Ethiopia – the most affected country worldwide. Surgery is the mainstay of treatment for TT. Despite the provision of free surgery in many areas, attendance rates are frequently low. An understanding of these barriers is fundamental for instituting measures to increase surgical uptake. In this study we interviewed 2591 people with TT in Ethiopia about their reasons for not having previously attended for surgery. The major barriers to attendance were lack of time, financial constraints and lack of an escort. TT is more prevalent in women and the elderly. Some barriers were particularly frequent in these high risk groups: lack of escort, fear of surgery and not knowing the surgical location impeded women more frequently than men, while financial constraints, transport difficulties and lack of escort affected more of those aged over fifty years than younger participants. It is likely that providing surgery closer to the patients would lessen many of these barriers.
doi:10.1371/journal.pntd.0001766
PMCID: PMC3429389  PMID: 22953007
19.  Capacity building of nurses providing neonatal care in Rio de Janeiro, Brazil: methods for the POINTS of care project to enhance nursing education and reduce adverse neonatal outcomes 
BMC Nursing  2012;11:3.
Background
Increased survival of preterm infants in developing countries has often been accompanied by increased morbidity. A previous study found rates of severe retinopathy of prematurity varied widely between different neonatal units in Rio de Janeiro. Nurses have a key role in the care of high-risk infants but often do not have access to ongoing education programmes. We set out to design a quality improvement project that would provide nurses with the training and tools to decrease neonatal mortality and morbidity. The purpose of this report is to describe the methods and make the teaching package (POINTS of care--six modules addressing Pain control; optimal Oxygenation; Infection control; Nutrition interventions; Temperature control; Supportive care) available to others.
Methods/Design
Six neonatal units, caring for 40% of preterm infants in Rio de Janeiro were invited to participate. In Phase 1 of the study multidisciplinary workshops were held in each neonatal unit to identify the neonatal morbidities of interest and to plan for data collection. In Phase 2 the teaching package was developed and tested. Phase 3 consisted of 12 months data collection utilizing a simple tick-sheet for recording. In Phase 4 (the Intervention) all nurses were asked to complete all six modules of the POINTS of care package, which was supplemented by practical demonstrations. Phase 5 consisted of a further 12 months data collection. In Phase 1 it was agreed to include inborn infants with birthweight ≤ 1500 g or gestational age of ≤ 34 weeks. The primary outcome was death before discharge and secondary outcomes included retinopathy of prematurity and bronchopulmonary dysplasia. Assuming 400-450 infants in both pre- and post-intervention periods the study had 80% power at p = < 0.05 to detect an increase in survival from 68% to 80%; a reduction in need for supplementary oxygen at 36 weeks post menstrual age from 11% to 5.5% and a reduction in retinopathy of prematurity requiring treatment from 7% to 2.5%.
Discussion
The results of the POINTS of Care intervention will be presented in a separate publication.
Trial registration
Current Controlled Trials: ISRCTN83110114
doi:10.1186/1472-6955-11-3
PMCID: PMC3395837  PMID: 22409747
Brazil; Neonatal care; Neonatal nursing; Quality improvement; Neonatal mortality; Premature infant; Retinopathy of prematurity; Education; Continual professional development
20.  Epilation for Trachomatous Trichiasis and the Risk of Corneal Opacification 
Ophthalmology  2012;119(1):84-89.
Purpose
Eight million people have trachomatous trichiasis (TT). The World Health Organization (WHO) recommends entropion surgery for TT regardless of severity. However, epilation is widely practiced for treating minor TT (1–5 lashes touching the globe). We report the frequency and effectiveness of patient-initiated epilation and its relationship to corneal opacity.
Design
Cross-sectional baseline data of individuals recruited to 2 randomized, clinical trials.
Participants
We included 2556 individuals (4310 eyes) with previously unoperated TT in ≥1 eye.
Methods
A single ophthalmologist examined all participants for signs of trachoma using WHO grading systems with additional assessment of entropion grading, location and number of trichiatic lashes, and evidence of epilation. A questionnaire enquired about epilation practices.
Main Outcome Measures
The association between epilation and degree of corneal opacity. Epilation practices of TT patients.
Results
Central corneal scarring was present in 1436 (33%) eyes. Entropion was absent/mild in 2328 (54%) eyes, moderate in 1259 (29.2%), and severe in 723 (16.8%). The median number of lashes touching the eye was 2 (interquartile range, 1–5; range, 0–133). There was clinical evidence of epilation in 3018 (70%) eyes, of which 738 (24%) were successfully epilated (no lashes touching globe). Epilation was performed frequently (at least monthly in 3311 [76.8%] eyes), by someone other than the patient (92.8%), and using locally made forceps (88.9%). Controlling for age and degree of entropion, successful epilation was associated with less corneal opacity (odds ratio [OR], 0.61; 95% confidence interval [CI]. 0.43–0.88; P = 0.007). The association was only significant in patients with severe entropion (OR, 0.07; 95% CI, 0.02–0.25; P<0.005).
Conclusions
We found an association between successful epilation and less central corneal opacity. This indicates the importance of preventing eyelashes from touching the cornea, particularly in individuals with severe entropion. This is a cross-sectional study; therefore, a causative relationship cannot be concluded. However, the results suggest that among patients who decline or are unable to access surgery, and perhaps in minor TT where the management remains controversial, the provision of high-quality forceps and epilation training may be beneficial.
Financial Disclosure(s)
The authors have no proprietary or commercial interest in any of the materials discussed in this article.
doi:10.1016/j.ophtha.2011.06.045
PMCID: PMC3694301  PMID: 21975041
21.  Absorbable Versus Silk Sutures for Surgical Treatment of Trachomatous Trichiasis in Ethiopia: A Randomised Controlled Trial 
PLoS Medicine  2011;8(12):e1001137.
In this randomized trial, Saul Rajak et al. compare silk sutures (removed at 7–10 days) or absorbable sutures (left in place) during surgery for the management of trachomatous trichiasis.
Background
Trachoma causes blindness through an anatomical abnormality called trichiasis (lashes touching the eye). Trichiasis can recur after corrective surgery. We tested the hypothesis that using absorbable sutures instead of silk sutures might reduce the risk of recurrent disease among patients with major trichiasis in a randomised trial.
Methods and Findings
1,300 individuals with major trichiasis from rural villages in the Amhara Region of Ethiopia were recruited and assigned (1∶1) by computer-generated randomisation sequence to receive trichiasis surgery using either an absorbable suture (polyglactin-910) or silk sutures (removed at 7–10 days) in an otherwise identical surgical technique. Participants were examined every 6 months for 2 years by clinicians masked to allocation. The primary outcome measure was recurrent trichiasis (≥one lash touching the eye) at 1 year. There was no difference in prevalence of recurrent trichiasis at 1 year (114 [18.2%] in the absorbable suture group versus 120 [19.7%] in the silk suture group; odds ratio = 0.90, 95% CI 0.68–1.20). The two groups also did not differ in terms of corneal opacification, visual acuity, conjunctival inflammation, and surgical complications.
Conclusions
There was no evidence that use of absorbable polyglactin-910 sutures was associated with a lower prevalence of trichiasis recurrence at 1 year postsurgery than silk sutures. However, from a programmatic perspective, polyglactin-910 offers the major advantage that patients do not have to be seen soon after surgery for suture removal. The postoperative review after surgery using absorbable polyglactin-910 sutures can be delayed for 3–6 months, which might allow us to better determine whether a patient needs additional surgery.
Trial registration
ClinicalTrials.gov NCT00522860
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Globally, around 40 million people—mostly people living in rural areas in developing countries where there are water shortages, poor personal hygiene, and crowded living conditions—have active trachoma, an infectious eye disease that is caused by Chlamydia trachomatis. This bacterium is spread through contact with infected eye secretions or with contaminated towels or clothes, and by flies. Recurrent infections with C. trachomatis during early childhood cause inflammation of the tissue lining the eye lid (chronic conjunctival inflammation), which can lead to conjunctival scarring. If this scarring is severe, the eyelids turn inwards (entropion) and the lashes rub across the eye's surface (the cornea). This condition—trachomatous trichiasis—is extremely painful and, if not treated with surgery, can lead to irreversible corneal opacities and visual impairment by middle age. It is estimated that 8 million people have trichiasis and that an additional 8 million people are blind or visually impaired as a result of the condition.
Why Was This Study Done?
Surgery for trichiasis, antibiotics for infection, and facial cleanliness and environmental improvements to reduce transmission together constitute the SAFE strategy for the control of blinding trachoma. Unfortunately, trichiasis recurs in nearly two-thirds of patients within 3 years of surgery, often within the first year. How the surgery is performed, its quality, and the severity of entropion and conjunctival scarring at the time of surgery all contribute to trichiasis recurrence. In this randomized trial (a study in which randomly chosen groups of patients receive different treatments for a disease and are followed to compare the outcomes of these interventions), the researchers investigate whether using absorbable sutures instead of silk sutures reduces the risk of recurrent disease among patients with major trichiasis (more than five lashes touching the cornea). Sutures are used to sew up surgical incisions. Silk sutures, which are used routinely during trichiasis surgery, have to be removed 7–10 days after surgery when the incision may not have stably healed. Absorbable sutures might provide more stable fixation of the eye tissue while healing is taking place and might, therefore, reduce the recurrence of trichiasis after surgery.
What Did the Researchers Do and Find?
The researchers randomly assigned 1,300 people living in Ethiopia (the country with the highest rates of trachoma and trichiasis) to receive trichiasis surgery using silk sutures (removed at 7–10 days) or absorbable sutures (left in place); the other details of the surgery were identical for all the patients. The trial's primary outcome was recurrent trichiasis (one or more lash touching the eye) at 1 year. Secondary outcomes included the rate of recurrence, visual acuity, corneal opacity, and conjunctival inflammation at 2 years, and surgical complications. At 1 year, 18.2% of the patients in the absorbable suture group and 19.7% in the silk suture group had developed recurrent trichiasis. That is, the prevalence of recurrence in the two groups was similar. There was also no difference in the rate of trichiasis recurrence between the groups 2 years after surgery. Moreover, the two groups did not differ in terms of corneal opacity and visual acuity, conjunctival inflammation, or surgical complications.
What Do These Findings Mean?
These findings provide no evidence to suggest that the use of absorbable sutures during trichiasis surgery is clinically better than the use of silk sutures. However, the researchers note that the use of absorbable sutures would eliminate the need for patients to return to the clinic soon after their operation to have their sutures removed. In remote rural settings, it can be difficult for patients, who are often elderly and poor, to attend clinics. Thus, it might be better for trachoma services to concentrate on encouraging patients to return 3–6 months after surgery when the need for additional surgery can be determined rather than trying to encourage them to come back after 7–10 days for suture removal. The use of absorbable sutures would also avoid any complications arising from patients failing to come back to have their stitches removed. The researchers suggest, therefore, that trachoma control programs should now consider the potential logistical advantages of using absorbable sutures rather than silk sutures during trichiasis surgery despite the lack of any apparent clinical difference between the two suture types.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001137.
An accompanying PLoS Medicine Research Article by Saul Rajak et al. describes another randomized trial undertaken by these researchers that compares surgery and epilation (eyelash removal) for the treatment of trichiasis in Ethiopia
The World Health Organization has information on trachoma (in several languages), including details of the Alliance for Global Elimination of Trachoma by the year 2020 (GET 2020) and a personal story about blinding trachoma
The UK National Health Service Choices website also provide information on trachoma
Orbis, an international nonprofit organization devoted to blindness prevention and treatment in developing countries, provides information about trachoma
The International Trachoma Initiative provides detailed information about trachoma and a personal story about trichiasis surgery in Ethiopia
The Global Atlas of Trachoma is an open-access resource on the geographical distribution of trachoma
Light for the World is a nonprofit organization dedicated to ensuring the rights of persons with disabilities in developing countries, including people in Ethiopia with trachoma
doi:10.1371/journal.pmed.1001137
PMCID: PMC3236737  PMID: 22180732
22.  Surgery Versus Epilation for the Treatment of Minor Trichiasis in Ethiopia: A Randomised Controlled Noninferiority Trial 
PLoS Medicine  2011;8(12):e1001136.
In this randomized, non-inferiority trial, Saul Rajak et al compare epilation and surgery for the management of minor trichiasis in Ethiopia, the country with the most cases of trachomatous trichiasis.
Background
Trachomatous trichiasis can cause corneal damage and visual impairment. WHO recommends surgery for all cases. However, in many regions surgical provision is inadequate and patients frequently decline. Self-epilation is common and was associated with comparable outcomes to surgery in nonrandomised studies for minor trichiasis (
Methods and Findings
1,300 individuals with minor trichiasis from Amhara Regional State, Ethiopia were recruited and randomly assigned (1∶1) to receive trichiasis surgery or epilation. The epilation group were given new forceps and epilation training. The surgical group received trichiasis surgery. Participants were examined every 6 months for 2 years by clinicians masked to allocation, with 93.5% follow-up at 24 months. The primary outcome measure (“failure”) was ≥five lashes touching the eye or receiving trichiasis surgery during 24 months of follow-up, and was assessed for noninferiority with a 10% prespecified noninferiority margin. Secondary outcomes included number of lashes touching, time to failure, and changes in visual acuity and corneal opacity.
Cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group (risk difference = 11%). The 95% confidence interval (8.1%–13.9%) includes the 10% noninferiority margin. Mean number of lashes touching the eye was greater in the epilation group than the surgery group (at 24 months 0.95 versus 0.09, respectively; p<0.001); there was no difference in change in visual acuity or corneal opacity between the two groups.
Conclusions
This trial was inconclusive regarding inferiority of epilation to surgery for the treatment of minor trichiasis, relative to the prespecified margin. Epilation had a comparable effect to surgery on visual acuity and corneal outcomes. We suggest that surgery be performed whenever possible but epilation be used for treatment of minor trichiasis patients without access to or declining surgery.
Trial registration
ClinicalTrials.gov NCT00522912
Please see later in the article for the Editors' Summary
Editors' Summary
Background
About 40 million people are affected at any one time by active trachoma, an infectious eye disease caused by the bacterium Chlamydia trachomatis. Trachoma, which is responsible for more than 3% of the world's blindness, mostly affects people living in rural areas in developing countries where there are water shortages, poor personal hygiene, and crowded living conditions. C. trachomatis is spread through contact with infected eye secretions or with contaminated towels or clothes, and by flies. Recurrent infections with C. trachomatis during childhood cause inflammation of the lining of the eye lid (chronic conjunctival inflammation), which can lead to conjunctival scarring. If this scarring is severe, the eyelids turn inwards and the eye lashes rub across the eye's surface (the cornea). This condition—trachomatous trichiasis—is extremely painful. Patients describe the pain like having thorns scraping their eyes when they blink. If left untreated, trichiasis can lead to irreversible corneal opacities and visual impairment.
Why Was This Study Done?
The SAFE strategy—surgery for trichiasis, antibiotics for infection, and facial cleanliness and environmental improvements to reduce transmission—aims to control trachoma in countries where it is common. Unfortunately, current surgical activity is only keeping up with new cases of trichiasis; it is not clearing the backlog. The reasons for this treatment gap are complex but in many regions surgical provision is inadequate. Moreover, although the World Health Organization recommends surgery for all cases of trachomatous trichiasis, people with minor trichiasis (only a few eyelashes touching the cornea) often decline surgery, preferring to pull out their eyelashes (epilation), an intervention that has to be repeated when the eyelashes regrow. In this randomized, noninferiority trial, the researchers compare epilation and surgery for the management of minor trichiasis in Ethiopia, the country with the most cases of trachomatous trichiasis. In a randomized trial, randomly chosen groups of patients are given different treatments for a disease and then followed to compare the outcomes of these interventions. A noninferiority trial investigates whether one treatment is not worse than another treatment.
What Did the Researchers Do and Find?
The researchers randomly assigned 1,300 Ethiopians with minor trichiasis to receive surgery or to be given epilation training and good quality epilation forceps. The primary trial outcome was “failure”—five or more lashes touching the eye or receiving trichiasis surgery during the 24-month follow-up period. The researchers decided in advance that epilation would be deemed noninferior to surgery if its failure rate was less than 10% greater than that of surgery (a noninferiority margin of 10%). Secondary outcomes included the number of lashes touching the eye and changes in visual acuity and corneal opacity. The cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group, a difference of 11%. The 95% confidence interval for this difference was 8.1%–13.9%. That is, there was a 95% probability that the true failure rate lay within this range. The mean number of lashes touching the eye at 24 months was 0.95 and 0.09 in the epilation and surgery groups, respectively, a significant difference (that is, a difference unlikely to have occurred by chance). Finally, the changes in visual acuity or corneal opacity during the trial were similar in the two groups.
What Do These Findings Mean?
Because the 95% confidence interval for the difference in failure rate of the two interventions included the preset inferiority margin, these findings provide no evidence that epilation is noninferior to surgery for the management of minor trichiasis. That is, statistically speaking, this trial is inconclusive. Thus, if one were to consider only the primary clinical outcome when deciding whether to include epilation in the management of mild trichiasis, one would reject it because this trial indicates that surgery is better than epilation at preventing lashes touching the eye. However, epilation had a comparable effect to surgery on visual acuity and corneal opacity changes and, importantly, in real life, surgical services are likely to remain unacceptable, unavailable, inaccessible, or prohibitively expensive for many people with trachomatous trichiasis in the medium term. The researchers suggest, therefore, that surgery should be performed for minor trachomatous trichiasis whenever possible but that epilation should be considered when surgery is not available or is declined by the patient.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/ 10.1371/journal.pmed.1001136.
An accompanying PLoS Medicine Research Article by Saul Rajak et al. describes another randomized trial undertaken by these researchers that compares the use of absorbable and silk sutures for the surgical treatment of trachomatous trichiasis in Ethiopia
The World Health Organization has information on trachoma (in several languages), including details of the Alliance for Global Elimination of Trachoma by the year 2020 (GET 2020) and a personal story about blinding trachoma
The UK National Health Service Choices web site also provides information on trachoma
Orbis, an international nonprofit organization devoted to blindness prevention and treatment in developing countries, provides information about trachoma
The International Trachoma Initiative provides detailed personal story about trichiasis surgery in Ethiopia information about trachoma and a personal story about trichiasis surgery in Ethiopia
The Global Atlas of Trachoma is an open-access resource on the geographical distribution of trachoma
Light for the World is a nonprofit organization dedicated to ensuring the rights of persons with disabilities in developing countries, including people in Ethiopia with trachoma
doi:10.1371/journal.pmed.1001136
PMCID: PMC3236738  PMID: 22180731
This study found that many patients with trachomatous trichiasis have minimal or no entropion, but rather the trichiasis is frequently due to metaplastic or misdirected eyelashes. The World Health Organization recommends entropion surgery for all. The results of tarsal rotation surgery in patients without manifest entropion should be investigated and alternative treatment strategies evaluated.
Purpose.
Trachomatous trichiasis (TT) is usually described as a cicatricial entropion of the upper lid; however, other forms of trichiasis have been reported. This variation in clinical phenotype is potentially important for treatment guidelines. Therefore, this study was conducted to investigate the range of disease type and severity encompassed by TT.
Methods.
Individuals presenting with TT to surgical treatment campaigns were examined by a single ophthalmologist using the Detailed WHO Trachoma Grading System. Additional features were graded, including type of trichiatic lashes (metaplastic, misdirected, and entropic), lower lid trichiasis, entropion severity, and lid margin mucocutaneous junction (MCJ) position.
Results.
Recruited were 2556 individuals with previously unoperated TT in at least one eye (4310 eyes). The median number of lashes touching the eye was 2 (range, 0 [epilating]–133). Entropion was absent or mild in 2328 (54.0%) eyes, moderate in 1259 (29.2%) eyes, and severe in 723 (16.8%) eyes. Trichiatic lashes were predominantly metaplastic or misdirected (80.2%), rather than secondary to entropion; 4204 (97.7%) had anteroplacement of the MCJ; and lower lid trichiasis was present in 494 (11.5%). Entropion was more severe among those with a low BMI, those who were female, those aged less than 50 years, and those with moderate to severe conjunctival inflammation, central corneal opacity, and severe conjunctival scarring.
Conclusions.
Many patients with TT have minimal or no entropion. The trichiasis is frequently attributable to metaplastic or misdirected eyelashes. The results of tarsal rotation surgery in TT patients without manifest entropion should be investigated and potentially alternative treatment strategies evaluated.
doi:10.1167/iovs.11-7880
PMCID: PMC3219424  PMID: 21896855
BMC Ophthalmology  2008;8:17.
Background
Despite having the largest population in Africa, Nigeria has no accurate population based data to plan and evaluate eye care services. A national survey was undertaken to estimate the prevalence and determine the major causes of blindness and low vision. This paper presents the detailed methodology used during the survey.
Methods
A nationally representative sample of persons aged 40 years and above was selected. Children aged 10–15 years and individuals aged <10 or 16–39 years with visual impairment were also included if they lived in households with an eligible adult. All participants had their height, weight, and blood pressure measured followed by assessment of presenting visual acuity, refractokeratomery, A-scan ultrasonography, visual fields and best corrected visual acuity. Anterior and posterior segments of each eye were examined with a torch and direct ophthalmoscope. Participants with visual acuity of < = 6/12 in one or both eyes underwent detailed examination including applanation tonometry, dilated slit lamp biomicroscopy, lens grading and fundus photography. All those who had undergone cataract surgery were refracted and best corrected vision recorded. Causes of visual impairment by eye and for the individual were determined using a clinical algorithm recommended by the World Health Organization. In addition, 1 in 7 adults also underwent a complete work up as described for those with vision < = 6/12 for constructing a normative data base for Nigerians.
Discussion
The field work for the study was completed in 30 months over the period 2005–2007 and covered 305 clusters across the entire country. Concurrently persons 40+ years were examined to form a normative data base. Analysis of the data is currently underway.
Conclusion
The methodology used was robust and adequate to provide estimates on the prevalence and causes of blindness in Nigeria. The survey would also provide information on barriers to accessing services, quality of life of visually impaired individuals and also provide normative data for Nigerian eyes.
doi:10.1186/1471-2415-8-17
PMCID: PMC2572038  PMID: 18808712
BMJ : British Medical Journal  2007;336(7634):29-32.
Objective To explore the association between blindness and deprivation in a nationally representative sample of adults in Pakistan.
Design Cross sectional population based survey.
Setting 221 rural and urban clusters selected randomly throughout Pakistan.
Participants Nationally representative sample of 16 507 adults aged 30 or above (95.3% response rate).
Main outcome measures Associations between visual impairment and poverty assessed by a cluster level deprivation index and a household level poverty indicator; prevalence and causes of blindness; measures of the rate of uptake and quality of eye care services.
Results 561 blind participants (<3/60 in the better eye) were identified during the survey. Clusters in urban Sindh province were the most affluent, whereas rural areas in Balochistan were the poorest. The prevalence of blindness in adults living in affluent clusters was 2.2%, compared with 3.7% in medium clusters and 3.9% in poor clusters (P<0.001 for affluent v poor). The highest prevalence of blindness was found in rural Balochistan (5.2%). The prevalence of total blindness (bilateral no light perception) was more than three times higher in poor clusters than in affluent clusters (0.24% v 0.07%, P<0.001). The prevalences of blindness caused by cataract, glaucoma, and corneal opacity were lower in affluent clusters and households. Reflecting access to eye care services, cataract surgical coverage was higher in affluent clusters (80.6%) than in medium (76.8%) and poor areas (75.1%). Intraocular lens implantation rates were significantly lower in participants from poorer households. 10.2% of adults living in affluent clusters presented to the examination station wearing spectacles, compared with 6.7% in medium clusters and 4.4% in poor cluster areas. Spectacle coverage in affluent areas was more than double that in poor clusters (23.5% v 11.1%, P<0.001).
Conclusion Blindness is associated with poverty in Pakistan; lower access to eye care services was one contributory factor. To reduce blindness, strategies targeting poor people will be needed. These interventions may have an impact on deprivation in Pakistan.
doi:10.1136/bmj.39395.500046.AE
PMCID: PMC2174750  PMID: 18087076

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