Clare Gilbert

Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010

Background:Retinopathy of prematurity (ROP) is a leading cause of potentially avoidable childhood blindness worldwide. We estimated ROP burden at the global and regional levels to inform screening and treatment programs, research, and data priorities.Methods:Systematic reviews and meta-analyses were undertaken to estimate the risk of ROP and subsequent visual impairment for surviving preterm babies by level of neonatal care, access to ROP screening, and treatment. A compartmental model was used to estimate ROP cases and numbers of visually impaired survivors.Results:In 2010, an estimated 184,700 (uncertainty range: 169,600–214,500) preterm babies developed any stage of ROP, 20,000 (15,500–27,200) of whom became blind or severely visually impaired from ROP, and a further 12,300 (8,300–18,400) developed mild/moderate visual impairment. Sixty-five percent of those visually impaired from ROP were born in middle-income regions; 6.2% (4.3–8.9%) of all ROP visually impaired infants were born at >32-wk gestation. Visual impairment from other conditions associated with preterm birth will affect larger numbers of survivors.Conclusion:Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP. Improved data tracking and coverage of locally adapted screening/treatment programs are urgently required.

An update on progress and the changing epidemiology of causes of childhood blindness worldwide

PURPOSEnTo summarize the available data on pediatric blinding disease worldwide and to present current information on childhood blindness in the United States.nnnMETHODSnA systematic search of world literature published since 1999 was conducted. Data also were solicited from each state school for the blind in the United States.nnnRESULTSnIn developing countries, 7% to 31% of childhood blindness and visual impairment is avoidable, 10% to 58% is treatable, and 3% to 28% is preventable. Corneal opacification is the leading cause of blindness in Africa, but the rate has decreased significantly from 56% in 1999 to 28% in 2012. There is no national registry of the blind in the United States, and most schools for the blind do not maintain data regarding the cause of blindness in their students. From those schools that do have such information, the top three causes are cortical visual impairment, optic nerve hypoplasia, and retinopathy of prematurity, which have not changed in past 10 years.nnnCONCLUSIONSnThere are marked regional differences in the causes of blindness in children, apparently based on socioeconomic factors that limit prevention and treatment schemes. In the United States, the 3 leading causes of childhood blindness appear to be cortical visual impairment, optic nerve hypoplasia, and retinopathy of prematurity; a national registry of the blind would allow accumulation of more complete and reliable data for accurate determination of the prevalence of each.

Epidemiology of childhood blindness

In this paper an attempt is made to define, quantify and determine the causes of childhood blindness in different parts of the world, with particular emphasis on blinding diseases which are detectable during the neonatal period.

Causes of severe visual impairment and blindness in children in schools for the blind in Ethiopia

Aims: To determine the causes of severe visual impairment and blindness in children in schools for the blind in Ethiopia, to aid in planning for the prevention and management of avoidable causes. Methods: Children attending three schools for the blind in Ethiopia were examined during April and May 2001 using the standard WHO/PBL eye examination record for children with blindness and low vision protocol. Data were analysed for those children aged less than 16 years using the epi-info-6 programme. Results: Among 360 pupils examined, 312 (96.7%) were aged <16 years. Of these children, 295 (94.5%) were blind or severely visually impaired. The major anatomical site of visual loss was cornea/phthisis (62.4%), followed by optic nerve lesions (9.8%), cataract/aphakia (9.2%), and lesions of the uvea (8.8%). The major aetiology was childhood factors (49.8%). The aetiology was unknown in 45.1% of cases. 68% of cases were considered to be potentially avoidable. Conclusions: Vitamin A deficiency and measles were the major causes of severe visual impairment/blindness in children in schools for the blind in Ethiopia. The majority of causes acquired during childhood could be avoided through provision of basic primary healthcare services.

Causes and temporal trends of blindness and severe visual impairment in children in schools for the blind in North India

Aims: To describe the causes of severe visual impairment and blindness (SVI/BL) in children in schools for the blind in north India, and explore temporal trends in the major causes. Methods: A total of 703 children were examined in 13 blind schools in Delhi. A modified WHO/PBL eye examination record for children with blindness and low vision which included sections on visual acuity, additional non-ocular disabilities, onset of visual loss, the most affected anatomical part of the eye concerning visual impairment, and the aetiological category of the child’s disorder based on the timing of insult leading to visual loss was administered in all children. Results: With best correction, 22 (3.1%) were severely visually impaired (visual acuity in the better eye of <6/60) and 628 (89.3%) children were blind (visual acuity in the better eye of <3/60). Anatomical sites of SVI/BL were whole globe in 27.4% children, cornea 21.7%, retina 15.1%, and lens 10.9%. The underlying cause of visual loss was undetermined in 56.5% children (mainly abnormality since birth 42.3% and cataract 8.3%), childhood disorders were responsible in 28.0% (mainly vitamin A deficiency/measles 20.5%), and hereditary factors were identified in 13.4%. Study of temporal trends of SVI/BL by comparing causes in children in three different age groups—5–8 years, 9–12 years, and 13–16 years—suggests that retinal disorders have become more important while childhood onset disorders (particularly vitamin A deficiency) have declined. Conclusions: Almost half of the children suffered from potentially preventable and/or treatable conditions, with vitamin A deficiency/measles and cataract the leading causes. Retinal disorders seem to be increasing in importance while childhood disorders have declined over a period of 10 years.

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 16u2009507 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.

Measuring the burden of childhood blindness

Globally, the prevalence of blindness among children is estimated to be approximately one tenth of that in adults, at around 0.7 per 1000.1-3 However, blindness in childhood has far reaching implications for the affected child and family, and throughout life profoundly influences educational, employment, personal, and social prospects.4 Thus, the control of childhood blindness has been identified as a priority of the World Health Organisation’s (WHO) global initiative for the elimination of avoidable blindness by the year 2020.5 nnMeasures of disease frequency alone, however, afford a limited understanding of the public health significance of childhood blindness. The global financial cost of blindness with an onset during childhood, in terms of loss of earning capacity (per capita GNP), is greater than the cost of adult blindness and has recently been estimated to be between US

Frailty in HIV-infected adults in South Africa.

6000 million and

Risk factors for retinopathy of prematurity in six neonatal intensive care units in Beijing, China

27u2009000 million.6 Most of this is accounted for by children living in high income countries, where the prevalence is less, but life expectancy and earning capacity greater, than in low income countries. These financial costs alone, however, provide only one perspective of the public health burden of blindness. Improved understanding and quantification require the application of indicators which measure the impact of blindness in terms of morbidity (years of disability suffered) as well as mortality (years of life lost through premature blindness associated death). Such indicators are useful in identifying those in the population in greatest need and for setting priorities in provision of health services. They are also important in the assessment of effectiveness of interventions and …

Changing pattern of childhood blindness in Maharashtra, India

Objectives:Some evidence suggests that HIV infection is associated with premature frailty—a syndrome typically viewed as being related to ageing. We determined the prevalence and predictors of frailty in a population of HIV-infected individuals in South Africa. Design:Case-control study of 504 adults more than the age of 30 years, composed of 248 HIV-infected adults and 256 age- and gender-matched, frequency-matched HIV-seronegative individuals. Methods:Frailty was defined by standardized assessment comprised of ≥3 of weight loss, low physical activity, exhaustion, weak grip strength, and slow walking time. Independent predictors of frailty were evaluated using multivariable logistic regression. Results:The mean ages of the HIV-infected and HIV-seronegative groups were 41.1 ± 7.9 years and 42.6 ± 9.6 years, respectively. Of the HIV-infected adults, 87.1% were receiving antiretroviral treatment (median duration, 58 months), their median CD4 count was 468 cells/&mgr;L (interquartile range = 325–607 cells/&mgr;L) and 84.3% had undetectable plasma viral load. HIV-infected adults were more likely to be frail than HIV-seronegative individuals (19.4% vs. 13.3%; P = 0.07), and this association persisted after adjustment for confounding variables [adjusted OR = 2.14; 95% confidence interval (95% CI): 1.16–3.92, P = 0.01]. Among HIV-infected individuals, older age was a strong predictor of frailty, especially among women (women: OR = 2.55 per 10-year age increase; men: OR = 1.29 per 10-year age increase, P-interaction = 0.01). Lower current CD4 count (<500 cells/&mgr;L) was also independently associated with frailty (OR = 2.84; 95% CI: 1.02 –7.92, P = 0.04). Conclusions:HIV infection is associated with premature development of frailty, especially in women. Since higher CD4 counts were associated with lower risk of frailty, earlier initiation of antiretroviral treatment may be protective.