Epilation for minor trachomatous trichiasis: four-year results of a randomised controlled trial

Background

Trachomatous trichiasis (TT) needs to be managed to reduce the risk of vision loss. The long-term impact of epilation (a common traditional practice of repeated plucking of lashes touching the eye) in preventing visual impairment and corneal opacity from TT is unknown. We conducted a randomized controlled trial of epilation versus surgery for the management of minor TT (fewer than six lashes touching the eye) in Ethiopia. Here we report the four-year outcome and the effect on vision and corneal opacity.

Methodology/ Principal Findings

1300 individuals with minor TT were recruited and randomly assigned to quality trichiasis surgery or repeated epilation using high quality epilation forceps by a trained person with good near vision. Participants were examined six-monthly for two-years, and then at four-years after randomisation. At two-years all epilation arm participants were offered free surgery. At four-years 1151 (88.5%) were re-examined: 572 (88%) and 579 (89%) from epilation and surgery arms, respectively. At that time, 21.1% of the surgery arm participants had recurrent TT; 189/572 (33%) of the epilation arm had received surgery, while 383 (67%) declined surgery and had continued epilating (“epilation-only”). Among the epilation-only group, 207 (54.1%) fully controlled their TT, 166 (43.3%) had minor TT and 10 (2.6%) had major TT (>5 lashes). There were no differences between participants in the epilation-only, epilation-to-surgery and surgery arm participants in changes in visual acuity and corneal opacity between baseline and four-years.

Conclusions/ Significance

Most minor TT participants randomised to the epilation arm continued epilating and controlled their TT. Change in vision and corneal opacity was comparable between surgery and epilation-only participants. This suggests that good quality epilation with regular follow-up is a reasonable second-line alternative to surgery for minor TT for individuals who either decline surgery or do not have immediate access to surgical treatment.

Trachoma causes visual impairment through the effect of in-turned eyelashes (trichiasis) on the surface of the eye. Epilation is a common traditional practice of intermittent plucking of lashes touching the eye, however, its long-term effectiveness in preventing visual impairment is unknown. We conducted a randomized controlled trial of epilation versus eyelid surgery (the main treatment option) in 1300 people with mild trichiasis in Ethiopia. We defined mild trichiasis as fewer than six lashes touching the eye. We have previously reported results to two years and have now re-assessed these individuals at four years. Overall, we found no difference between the epilation and surgery groups in terms of change in vision and corneal opacity between baseline and four years. Most mild trichiasis participants randomised to the epilation arm continued epilating and controlled their trichiasis. This suggests that good quality epilation is a reasonable second-line alternative to surgery for mild trichiasis for individuals who either decline surgery or do not have immediate access to surgical treatment.

Cataract surgery outcomes in bangladeshi children

PURPOSE

To measure visual acuity (VA) outcomes, complication rates, and the social impact of cataract surgery in a cohort who underwent surgery as children in Bangladesh.

DESIGN

Case series.

PARTICIPANTS

A total of 471 of 850 children from 6 Bangladeshi districts who had been identified as cataract blind using key informants (KIs) between 2004 and 2009 during the Bangladesh Childhood Cataract Campaign (BCCC) together with all those children not included in the BCCC database but in the Child Sight Foundation (CSF) database who had been identified as cataract blind.

METHODS

The subjects and families were contacted again by KIs and transported to local examination centers, where parents and subjects were administered a questionnaire and subjects underwent full ocular examination. Where operative data were available (15%), they were analyzed in conjunction with questionnaire and examination findings. Statistical analysis was performed using SPSS Statistics (IBM, Armonk, NY).

MAIN OUTCOME MEASURES

Presenting and best-corrected visual acuities (BCVAs), cause(s) of poor outcome, postoperative refraction, and school attendance.

RESULTS

A total of 407 of the participants had undergone bilateral surgery as children, with a mean follow-up of 8.8 years. The mean age at examination was 16 years (range, 5-28 years; standard deviation [SD], 4.6 years); 63% of those examined were male; 22% had a binocular presenting VA of >20/60; and 53% were severely visually impaired or blind (VA <20/200). After refraction, 33% had VA >20/60 in their better eye and 33% had VA <20/200. Factors that predicted poor VA in multivariate logistic regression analysis were nystagmus (P < 0.001), longer delay in presentation (P < 0.001), and magnitude of absolute spherical equivalent refractive error (P<0.001). Some 50% had nystagmus, and 69% of those currently aged ≤16 years were attending school. Better acuity was associated with school attendance (P < 0.001), whereas gender was not.

CONCLUSIONS

Approximately one third of all participants had a BCVA of ≥20/60 in their better eye. Amblyopia and nystagmus limited visual outcome, indicating the need for earlier detection and treatment. This is the first study to show the link between pediatric cataract outcome and access to education, a millennium development goal.

Prevalence and risk factors for diabetes and diabetic retinopathy: results from the Nigeria national blindness and visual impairment survey

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.

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.

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.

Retinal nerve fibre layer thickness and contrast sensitivity in HIV-infected individuals in South Africa: a case-control study

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.

Prevalence and risk factors for hypertension and association with ethnicity in Nigeria: results from a national survey

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.

Ocular parameters of biological ageing in HIV-infected individuals in South Africa: relationship with chronological age and systemic biomarkers of ageing

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.

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.

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.

Setting up and improving retinopathy of prematurity programs: interaction of neonatology, nursing, and ophthalmology

Retinopathy of prematurity (ROP) programs require collaboration between neonatologists, ophthalmologists, nurses, and allied health personnel, together with parents. The concept of a ROP program will vary according to the setting. However, in every situation there should be 2 main aspects: primary prevention of ROP through better overall care, and secondary prevention through case detection (often called screening), treatment, and follow-up. ROP programs will have different content and emphasis according to whether the setting is in an economically advanced or developing country.

Assessment of candidate ocular biomarkers of ageing in a South African adult population: relationship with chronological age and systemic biomarkers

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.

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.

Are we there yet? Bevacizumab therapy for retinopathy of prematurity

The publication of the BEAT-ROP study of bevacizumab (Avastin) treatment for Zone I and II retinopathy of prematurity (ROP) has raised hopes that there might now be a simpler, cheaper and more effective treatment than laser therapy, the current standard of care. However, we would urge caution at this point in time. We review the scientific background to the use of intravitreal anti-vascular endothelial growth factor for ROP, highlight a number of design issues in the BEAT-ROP study and problems with interpretation of the results. For example, no visual outcomes were reported and the study was underpowered to assess longer term safety. Intravitreal bevacizumab leaks into the systemic circulation in animals and adult humans and there are real concerns of potential harm to the developing preterm infant because vascular growth factors play a critical role in organogenesis. We conclude that bevacizumab should be reserved for exceptional circumstances and compassionate use pending further studies. Laser remains the proven effective therapy for first line treatment of all forms of ROP with little systemic morbidity. Neonatology and ophthalmology have an impressive record of conducting collaborative multicentre studies and we urgently need further rigorously designed, adequately powered randomised trials of anti-VEGF agents that evaluate visual outcomes as well as short and long term ocular and systemic safety.

Corneal endothelial cells provide evidence of accelerated cellular senescence associated with HIV infection: a case-control study

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.

Retinal arterioles narrow with increasing duration of anti-retroviral therapy in HIV infection: a novel estimator of vascular risk in HIV?

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.

How to achieve universal coverage of cataract surgical services in developing countries: lessons from systematic reviews of other services

PURPOSE

Since the Declaration of Alma Ata, universal coverage has been at the heart of international health. The purpose of this study was to review the evidence on factors and interventions which are effective in promoting coverage and access to cataract and other health services, focusing on developing countries.

METHODS

A thorough literature search for systematic reviews was conducted. Information resources searched were Medline, The Cochrane Library and the Health System Evidence database. Medline was searched from January 1950 to June 2010. The Cochrane Library search consisted of identifying all systematic reviews produced by the Cochrane Eyes and Vision Group and the Cochrane Effective Practice and Organisation of Care. These reviews were assessed for potential inclusion in the review. The Health Systems Evidence database hosted by MacMaster University was searched to identify overviews of systematic reviews.

RESULTS

No reviews met the inclusion criteria for cataract surgery. The literature search on other health sectors identified 23 systematic reviews providing robust evidence on the main factors facilitating universal coverage. The main enabling factors influencing access to services in developing countries were peer education, the deployment of staff to rural areas, task shifting, integration of services, supervision of health staff, eliminating user fees and scaling up of health insurance schemes.

CONCLUSION

There are significant research gaps in eye care. There is a pressing need for further high quality primary research on health systems-related factors to understand how the delivery of eye care services and health systems' capacities are interrelated.

The impact of successful cataract surgery on quality of life, household income and social status in South India

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.

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.

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.

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

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

The prevalence of type 2 idiopathic macular telangiectasia in two African populations

PURPOSE

Type 2 idiopathic macular telangiectasia (MacTel) is a progressive retinal disease associated with a slow deterioration of visual acuity, starting in the fifth to seventh decades of life. The etiology and pathogenesis of the disease are little known, and no effective therapy is available. We aimed to estimate the prevalence and describe the phenotype of type 2 MacTel in two African populations.

METHODS

From two population-based cross-sectional surveys conducted nationally in Nigeria and in the Nakuru district of Kenya, patients with fundus features of type 2 MacTel were selected. Diagnosis was based on color fundus images, grading performed according to the MacTel Study protocol and staged using the Gass and Blodi system. Disease phenotype and clinical characteristics of affected participants were assessed.

RESULTS

Of 8599 total participants, five showed a phenotype compatible with type 2 MacTel. Prevalence was estimated as 0.06% (95% confidence interval [CI] 0.02-0.21%) in Kenya, 0.06% (95% CI 0.01-0.17%) in Nigeria, and overall at 0.06% (95% CI 0.02-0.14%). Mean age was 62 years (SD 5 years), four of five affected participants were female, and none had a history of diabetes. Median corrected visual acuity was 6/12 in the better eye and 6/69 in the worse eye.

CONCLUSIONS

The estimated prevalence and phenotype of type 2 MacTel in the African populations examined were similar to those in predominantly white populations. All data published so far are based on the analysis of color fundus images only and are thus likely to underestimate the true prevalence of this disease.

Anophthalmos, microphthalmos, and Coloboma in the United kingdom: clinical features, results of investigations, and early management

PURPOSE

To describe the clinical features of children with anophthalmos, microphthalmos, and typical coloboma (AMC).

DESIGN

Descriptive, observational, cross-sectional study of the United Kingdom.

PARTICIPANTS

A total of 135 children with AMC newly diagnosed over an 18-month period beginning in October 2006.

METHODS

Cases were identified using active surveillance through an established ophthalmic surveillance system. Eligible cases were followed up 6 months after first notification.

MAIN OUTCOME MEASURES

Phenotypic characteristics, both ocular and systemic, clinical investigations, causes, and interventions.

RESULTS

A total of 210 eyes (of 135 children) were affected by AMC, of which 153 had isolated coloboma or coloboma with microphthalmos. The most common colobomatous anomaly was a chorioretinal defect present in 109 eyes (71.2%). Some 44% of children were bilaterally visually impaired. Systemic abnormalities were present in 59.7% of children, with craniofacial anomalies being the most common. Children with bilateral disease had a 2.7 times higher odds (95% confidence interval, 1.3-5.5, P = 0.006) of having systemic involvement than unilaterally affected children. Neurologic imaging was the most frequent investigation (58.5%) performed. Less than one third (30.3%) of the children with microphthalmos had ocular axial lengths measured. Eight children had confirmed genetic mutations. Approximately half (49.2%) of the children required ocular intervention.

CONCLUSIONS

Colobomatous defects were the most common phenotype within this spectrum of anomalies in the United Kingdom. The high frequency of posterior segment colobomatous involvement means that a dilated fundal examination should be made in all cases. The significant visual and systemic morbidity in affected children underlines the importance of a multidisciplinary approach to management.

Absorbable versus silk sutures for surgical treatment of trachomatous trichiasis in Ethiopia: a randomised controlled trial

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.

The clinical phenotype of trachomatous trichiasis in Ethiopia: not all trichiasis is due to entropion

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.

Epilation for trachomatous trichiasis and the risk of corneal opacification

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.

Preoperative visual acuity among cataract surgery patients and countries' state of development: a global study

OBJECTIVE

To describe the preoperative surgical case mix among patients undergoing cataract extraction and explore associations between case mix, country level of development (as measured by the Human Development Index, HDI) and cataract surgery rates (CSRs).

METHODS

Ophthalmologists in 50 countries were invited to join the newly-established International Eye Research Network and asked to complete a web-based questionnaire about their eye hospitals. Those who complied received a data collection form for recording demographic and clinical data on 100 consecutive patients about to undergo cataract surgery. Countries were ranked into five HDI categories and multivariable regression was used to explore associations.

FINDINGS

Ophthalmologists at 112 eye hospitals (54% of them nongovernmental) in 50 countries provided data on 11,048 cataract procedures over 9 months in 2008. Patients whose visual acuity (VA) before surgery was < 6/60 in the better eye comprised 47% of the total case mix in poorly developed countries and 1% in developed countries (P < 0.001). Overall, 72% of the eyes undergoing surgery had a VA < 6/60. Very low VA before cataract surgery was strongly associated with poor development at the country level and inversely associated with national CSR.

CONCLUSION

The proportion of patients with very poor preoperative VA is a simple indicator that can be easily measured periodically to monitor progress in ophthalmological services. Additionally, the internet can be an effective tool for developing and supporting an ophthalmological research network capable of providing a global snapshot of service activity, particularly in developing countries.

Prevalence, causes, and risk factors for functional low vision in Nigeria: results from the national survey of blindness and visual impairment

PURPOSE

To estimate prevalence and describe causes of functional low vision (FLV) among a nationally representative sample of Nigerian adults, assess socioeconomic risk factors, and estimate the number of adults in Nigeria who might benefit from low vision assessment or rehabilitation services.

METHODS

Multistage, stratified, cluster random sampling with probability proportional to size procedures were used to identify a nationally representative sample of 15,027 persons aged 40 years or older. Distance vision was measured using a reduced logMAR tumbling E-chart. All participants with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause. FLV was defined as best corrected vision <6/18 in the better eye, after excluding those with no light perception in both eyes and those with treatable causes. Analysis took account of the clustered design.

RESULTS

In all, 13,591 individuals were examined in 305 clusters (response rate, 89.9%). The crude prevalence of FLV was 3.5% (95% confidence interval, 3.1-3.9%). This was lower than the prevalence of blindness, which was 4.2%. Glaucoma was the most common cause and age the most important risk factor. There are estimated to be approximately 5000 adults with FLV per million population and 340 who are totally blind. Only 9.3% of those with FLV were of working age and literate.

CONCLUSIONS

These are the first data on the prevalence, causes, and risk factors for FLV from Africa. Results support studies from Asia that the prevalence of FLV is lower than previously thought. Because the majority of adults with FLV in Nigeria live in rural areas and are elderly and not literate, further research is required to assess the nature of the interventions required and who might best deliver them.

Anophthalmos, microphthalmos, and typical coloboma in the United Kingdom: a prospective study of incidence and risk

PURPOSE

Anophthalmos, microphthalmos, and typical coloboma (AMC) form an interrelated spectrum of congenital eye anomalies that can cause significant visual loss and cosmetic disfigurement in children. This prospective study of children born in the United Kingdom was undertaken to determine the incidence of AMC diagnosed by ophthalmologists and to explore sociodemographic risks.

METHODS

Recruitment was achieved though an established active surveillance system of U.K. ophthalmologists supported by a new research network of interested specialists, the Surveillance of Eye Anomalies (SEA-UK) Special Interest Group. It started October 1, 2006, and continued over 18 months.

RESULTS

One hundred thirty-five children were newly diagnosed with AMC. Typical colobomatous defects were the commonest phenotype, and anophthalmos was rare (n = 7). Both eyes were affected in 55.5% of the children. The cumulative incidence of AMC by age 16 years was 11.9 per 100,000 (95% CI, 10.9-15.4). Of the children examined, 41.5% had not seen an ophthalmologist by 3 months of age. The incidence in Scotland was nearly double that in England and Wales. The children of Pakistani ethnicity had a 3.7 (95% CI, 1.9-7.5) times higher risk of AMC than did white children. There was some evidence to suggest a higher incidence in the more socioeconomically deprived. The sibling risk ratio was 210 (95% CI, 25-722).

CONCLUSIONS

This is the first prospective study of AMC, and it establishes the frequency across the United Kingdom. Comparisons with data quoted in the literature are difficult because study methodologies differ, but the frequency appears to be lower than that quoted for other developed countries. There are geographic and ethnic variations in incidence that warrant further investigation.

Couching in Nigeria: prevalence, risk factors and visual acuity outcomes

PURPOSE

Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria.

METHODS

Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging.

RESULTS

Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60).

CONCLUSIONS

Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.

Outcome of cataract surgery in Nigeria: visual acuity, autorefraction, and optimal intraocular lens powers--results from the Nigeria national survey

OBJECTIVE

To describe presenting and corrected visual acuities after cataract surgery in a nationally representative sample of adults. Another objective was to describe refractive errors in operated eyes and to determine the optimal range of intraocular lens (IOL) powers for this population.

DESIGN

Cross-sectional, population-based survey.

PARTICIPANTS

Adults aged 40 years and more were selected using multistage stratified sampling and proportional to size procedures. A sample size of 15027 was calculated, and clusters were selected from all states.

METHODS

Individuals who had undergone cataract surgery were identified from interview and examination. All had their presenting visual acuity (VA) measured using a reduced logarithm of the minimum angle of resolution chart and underwent autorefraction. Corrected VAs were assessed using the autorefraction results in a trial set. An ophthalmologist conducted all examinations, including slit-lamp and dilated fundus examination. Causes of visual loss were determined for all eyes with a presenting VA <6/12 using the World Health Organization recommendations. Biometry data were derived from 20449 phakic eyes using the SRK-T formula after excluding those with poor VA or corneal opacities.

MAIN OUTCOME MEASURES

Presenting and corrected visual acuities in pseudo/aphakic individuals and autorefraction findings; biometry profile of Nigerian adults.

RESULTS

Data from 288 eyes of 217 participants were analyzed. Only 39.5% of eyes had undergone IOL implantation at surgery. Only 29.9% of eyes had a good outcome (i.e., ≥6/18) at presentation, increasing to 55.9% with correction. Use of an IOL was the only factor associated with a good outcome at presentation (odds ratio 9.0; 95% confidence interval, 4.3-18.9; P=0.001). Eyes undergoing cataract surgery had a higher prevalence and degree of astigmatism than phakic eyes. Biometry data reveal that posterior chamber IOL powers of 20, 21, and 22 diopters (D) (A constant 118.0) will give a postoperative refraction range of -2.0 D to emmetropia in 71.4% of eyes, which increases to 82.6% if 19 D is also included.

CONCLUSIONS

Postoperative astigmatism needs to be reduced through better surgical techniques and training, and use of biometry should be standard of care.

Retinopathy of prematurity in 7 neonatal units in Rio de Janeiro: screening criteria and workload implications

OBJECTIVES

The goals were to determine optimal screening criteria for retinopathy of prematurity (ROP) in 7 neonatal units in Rio de Janeiro, Brazil, and to explore the workload implications of applying different criteria.

METHODS

Infants with birth weights of < or = 2000 g or gestational age of <37 weeks were examined by 3 ophthalmologists in 7 of the largest units in Rio de Janeiro, during a 34-month period. ROP was classified by using the international classification, and laser treatment was given to infants developing type 1 ROP.

RESULTS

A total of 3437 (87%) of 3953 eligible infants were examined, of whom 124 (3.6% [range: 2.1%-7.8%]) were treated. Eleven infants were treated for aggressive posterior ROP. Appropriate screening criteria for the 2 NICUs with high survival rates (ie, > or =80% among infants with birth weights of <1500 g) would be < or =1500 g or <32 weeks. For NICUs with low survival rates (ie, <80%), appropriate criteria would be < or =1500 g or < or =35 weeks. UK, US, and previous Brazilian criteria would all miss infants needing treatment.

CONCLUSIONS

ROP programs in Brazil should use the wider criteria of < or =1500 g or < or =35 weeks until further evidence-based criteria become available, although this would mean a slight increase in workload across the city, compared with use of the narrower criteria in the better units. Whether survival rates can be used as a proxy to indicate screening criteria requires further investigation.

Randomised controlled trial of screening and prophylactic treatment to prevent primary angle closure glaucoma

AIMS

To determine if screening with an ultrasound A-scan and prophylactic treatment of primary angle closure (PAC) with laser peripheral iridotomy (LPI) can reduce the incidence of primary angle closure glaucoma (PACG) in Mongolia.

METHODS

A single-masked randomised controlled trial was initiated in 1999. 4725 volunteer Mongolian participants ≥ 50 years old from the capital Ulaanbaatar or the rural province of Bayankhongor were recruited, of which 128 were excluded with glaucoma. 4597 were randomly allocated to the control, no-screening arm or screening with ultrasound central anterior chamber depth (cACD), with the cut-off set at < 2.53 mm. 685 screen-positive participants were examined and angle closure was identified by gonioscopy in 160, of which 156 were treated with prophylactic LPI. Primary outcome of incident PACG was determined using both structural and functional evidence from objective grading of paired disc photographs from baseline and follow-up, objective grading of follow-up visual fields and clinical examination.

RESULTS

Six years later, 801 (17.42%) participants were known to have died, and a further 2047 (53.92%) were traced and underwent full ophthalmic examination. In an intention to treat analysis using available data, PACG was diagnosed in 33 participants (1.61%, 95% CI 1.11% to 2.25%), of which 19 were in the screened group and 14 in the non-screened group (OR 1.29, 95% CI 0.65 to 2.60, p = 0.47), indicating no difference between groups.

CONCLUSIONS

We were not able to identify a reduction in the 6 year incidence of PACG after screening with cACD < 2.53 mm and prophylactic treatment of PAC.

Prevalence of blindness and visual impairment in Nigeria: the National Blindness and Visual Impairment Study

PURPOSE

To determine the prevalence of blindness and visual impairment among adults aged > or = 40 years in Nigeria.

METHODS

Multistage, stratified, cluster random sampling with probability proportional to size procedures was used to identify a cross-sectional nationally representative sample of 15,027 persons > or = 40 years of age from all 36 states in Nigeria and the Federal Capital Territory. Distance visual acuity (VA) was measured with a reduced logMAR tumbling-E chart at 4 and 1 m. Presenting and best corrected visual acuities were recorded. Autorefraction was performed in all examined adults. Clinical evaluations included examination under dilation for those with presenting vision < 6/12 in either eye.

RESULTS

In the study, 15,122 persons aged > or = 40 years were enumerated and 13,599 (89.9%) examined. Prevalence of blindness (< 20/400 in the better eye) and severe visual impairment (< 20/200-20/400; presenting vision) was 4.2% (95% confidence interval [CI]: 3.8%-4.6%) and 1.5% (95% CI: 1.3%-1.7%), respectively. Blindness was associated with increasing age, being female, poor literacy, and residence in the North. Participants residing in the South West had the lowest prevalence while those in the North East had the highest prevalence of blindness. It is estimated that 4.25 million adults aged > or = 40 years have moderate to severe visual impairment or blindness (< 20/63 in the better eye).

CONCLUSIONS

There is a high prevalence of blindness and severe visual impairment among those aged > or = 40 years in Nigeria. Significant differences exist between the geopolitical zones and emphasis should be on ensuring eye services across Nigeria, which means that planning at the regional level is necessary.

The Nigerian national blindness and visual impairment survey: Rationale, objectives and detailed methodology

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.

Prevalence and causes of functional low vision and implications for services: the Pakistan National Blindness and Visual Impairment Survey

PURPOSE

To determine the prevalence and causes of functional low vision (FLV) and total blindness and to estimate the assessment needs for low-vision services in Pakistan.

METHODS

Multistage, cluster random sampling was used to select a nationally representative sample of adults (age, > or =30 years). Participants underwent visual acuity measurement and detailed ophthalmic examination. Functional low vision was defined as a corrected visual acuity in the better eye of less than 6/18 to more than no perception of light (NPL) in individuals with untreatable causes of visual loss. Total blindness was defined as NPL in both eyes. Needs assessments were categorized into three groups: optical services, nonoptical/environmental interventions, and rehabilitation.

RESULTS

A sample of 16,507 adults (95.3% response rate) was examined. The standardized prevalence of FLV and total blindness were 1.7% (95% CI: 1.5%-1.9%) and 0.2% (95% CI: 0.1%-0.2%), respectively. More than 90% of those with FLV were illiterate and 35.3% were of working age (i.e., <60 years). An estimated 727,000 (586,000-891,000) adults in Pakistan had FLV. Retinal conditions were the commonest cause in urban populations (39.8% vs. 26.5% rural) compared with corneal opacity in rural areas (38.0% vs. 25.5% urban). It was estimated that 565,000 adults require assessment for optical services, 735,000 for nonoptical interventions, and 424,000 for rehabilitation.

CONCLUSIONS

As VISION 2020 enters its second 5-year phase, the provision of low-vision services and their integration into national eyecare programs is a priority. In Pakistan, planning must take account of the magnitude along with the demographic and educational characteristics of those affected.

Prevalence and causes of functional low vision in school-age children: results from standardized population surveys in Asia, Africa, and Latin America

PURPOSE

Data on the prevalence and causes of functional low vision (FLV) in adults and children are lacking but are important for planning low-vision services. This study was conducted to determine the prevalence and causes of FLV among children recruited in eight population-based prevalence surveys of visual impairment and refractive error from six countries (India [2 locations]; China [2 locations]; Malaysia, Chile, Nepal, and South Africa).

METHODS

Using the same protocol, 4082 to 6527 children aged 5 (or 7) to 15 years were examined at each site. Uncorrected and presenting visual acuities were successfully measured with retroilluminated logMAR tumbling-E charts in 3997 to 5949 children; cycloplegic autorefraction was performed and best corrected acuities assessed. All children were examined by an ophthalmologist and a cause of visual loss assigned to eyes with uncorrected acuity < or =6/12. The prevalence of FLV was determined overall and by site; associations with gender, age, parental education and urban/rural location were assessed with logistic regression.

RESULTS

The prevalence of FLV ranged from 0.65 to 2.75 in 1000 children, with wide confidence intervals. The overall prevalence was 1.52 in 1000 children (95% CI 1.16-1.95). FLV was significantly associated with age (odds ratio [OR] 1.13 for each year, P = 0.01), and parental education was protective (OR 0.75 for each of five levels of education, P = 0.017). Retinal lesions and amblyopia were the commonest causes.

CONCLUSIONS

More studies are needed to determine the prevalence and causes of FLV in children so that services can be planned that promote independence, improve quality of life, and increase access to education.

Poverty and blindness in Pakistan: results from the Pakistan national blindness and visual impairment survey

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.