Trachoma control:the SAFE strategy

As a contagious bacterial infection that affects the conjunctival covering of the eye, the cornea and the eyelids, trachoma is controlled by an endorsed integrated strategy consisting of surgery for trichiasis, antibiotic therapy, facial cleanliness and environmental improvement, namely, the SAFE strategy developed by World Health Organization. Developed based on evidence from previous field trials and constantly modified in practice, SAFE strategy has greatly boosted the progress in trachoma control. Regardless of the fact that there are still many pending questions, national program coordinators are convinced that trachoma control initiative based on SAFE strategy would be effective.

Current state of active trachoma among elementary school students in the context of ambitious national growth plan: The case of Ethiopia

Trachoma is a classical disease of poverty. It is still the second leading cause of blindness in Ethiopia. Cognizant of the poor living condition of its people, every effort of the current government of Ethiopia is geared towards eradication of extreme poverty. The main aim of this study was to assess the current status and correlates of active trachoma among elementary school students. A cross sectional school-based study was conducted in Dangla town administration in the month of March 2012. Multistage sampling technique was employed. Pre-tested structured questionnaire and eye examination were data collection tools. The data were collected by health professionals especially trained for eye care. The data were analyzed using SPSS version 16 for windows. Possible associations, and statistical significance between, and among variables were measured using odds ratio at 95% confidence interval. The study indicated that overall prevalence of active trachoma was 12%. The multi-variate analysis revealed that those children with unclean face were seven times more likely to develop active trachoma than those with clean face (AOR = 7.07, 95% CI: 3.36-14.96). Moreover, children who didn’t use soap to wash their face were two times more likely to develop active trachoma than those who claimed to use soap to wash their face (AOR = 2.03, 95% CI 1.72-3.01). In short, the prevalence of trachoma is lower than the figures in previous survey reports in the region and at national levels;however, the risk factors remain the same. The struggle to eradicate extreme poverty should continue in a sustainable manner so that diseases of poverty including trachoma could be eliminated altogether.

Blinding trachoma among refugees:complicating social disaster

Objective:To determine the prevalence of blinding trachoma among refugees in South Western Ethiopia.Methods:A cross-sectional outreach clinic based descriptive study was conducted on 1054 refugees in Southwest Ethiopia.A basic eyelid and cornea examination for signs of trachoma was done by using 2.5× binocular magnifying loupe.The findings were classified by using the World Health Digitization simplified trachoma grading system and data were analyzed by using SPSS version 16.0.Results:A total of 1054 refugee patients were examined for trachoma.179(16.98%) of them had clinical signs of trachoma.About 6(3.35%) patients had active trachoma with trachomatous trichiasis(TT),47(26.26%) patients had TT only and the rest 126(70.39%)patients had TT with trachomatous corneal opacity.All of the trachoma patients had blinding trachoma(TT with or without trachomatous corneal opacity),and about 60.89% of them had visual impairment.Blinding trachoma was significantly more common among females.patients in age group of 16-59 years,married patients,illiterates and Fugnido camp settlers(P<0.05).Conclusions:There is a very high burden of blinding trachoma among refugees.Urgent surgical intervention is needed to prevent blindness and low vision in the study subjects,and targeted regular outreach-based eye care service should be commenced.

Scaling up of trachoma mapping in Salima District, Central Malawi

Background: A number of suspected endemic districts with Trachoma have not been mapped in Malawi, and this contributes to delays for scaling up trachoma control activities. Objectives: To determine the prevalence of trachoma and associated risk factors in one of the suspected endemic districts (Salima District) in central Malawi and to generate information to guide policy decisions. Methods: A population-based survey conducted in randomly selected clusters in Salima District (population 418,672), centralMalawi. Children aged 1-9 years and adults aged 15 and above were assessed for clinical signs of trachoma. Results: In total, 884 households were enumerated within 36 clusters. A total of 2765 persons were examined for ocular signs of trachoma. The prevalence of trachomatous inflammation, follicular (TF) among children aged 1-9 years was 17.1% (95% CI 14.9-19.4). The prevalence of trachoma trichiasis (TT) in women aged 15 years and above was 1.3% (CI 0.7-2.3), while the prevalence in men was zero. The presence of a dirty face and lack of sanitation were significantly associated with trachoma follicular (P < 0.001). Conclusion: Prevalence rate of trachoma follicles (TF) in Central Malawi exceeds the WHO guidelines for the intervention with mass antibiotic distribution (TF > 10%), and warrants the trachoma SAFE (Surgery, Antibiotics, Face washing and Environmental hygiene) control strategy to be undertaken in Salima District.

Active trachoma prevalence and its associated factors among children aged 1-9 years in rural residents of Lare District, Southwest Ethiopia

AIM:To determine the prevalence of active trachoma and its associated factors among children in Lare District,Southwest Ethiopia,2019.METHODS:A community-based cross-sectional study was conducted.A total of 620 participants were recruited using a multi-stage sampling technique.A structured questionnaire,torch,and magnifying loupes were used for data collection.The data was entered into epidemiological information and exported to statistical package for social science version 20 for analysis.The bi-variable and multivariable Logistic regression analysis model was fitted to identify factors associated with active trachoma.Odds ratio with a 95%CI was used to show the direction and strength of association between independent and outcome variables.RESULTS:A total of 610 children participated in this study with a response rate of 98.39%.The prevalence of active trachoma was 132(21.60%;95%CI:18.40-24.70).Family size being 6-9(AOR=2.34;95%CI:1.14-5.02),presence of more than two preschool children in a house(AOR=2.04;95%CI:1.12-3.70),open field waste disposal system(AOR=2.62;95%CI:1.00-6.80)and type of latrine being uncovered(AOR=4.12;95%CI:2.00-8.51)were positively associated with active trachoma.On the other side,water consumption being 40-60 liters per day was a protective factor for active trachoma.CONCLUSION:The prevalence of active trachoma is high among children aged 1-9 y in Lare District.Uncovered latrine,open field waste disposal system,family sizes of 6-9,and the presence of more than two preschool children in a house are associated with the occurrence of active trachoma.On the other side,water consumption of 40-60 liters is a protective factor.

Exploring multi-level risk factors and post-war burdens of trachomatous trichiasis among displaced population in Raya Kobo districts, implication for urgent action

AIM:To estimate post-war burdens of trachomatous trichiasis(TT)and multi-level risk factors among displaced population in Raya Kobo districts,implication for urgent action.METHODS:A community-based cross-sectional study was conducted among 603 participants from randomly selected 14 displaced slums in the Raya Kobo district.The data was collected from February 16th to March 30th,2023.Study participants were selected using the multistage sampling technique.A structured questionnaire and ophthalmic loupe with×2.5 magnificence were used to collect from participants.Multi-level binary logistic regression was used to determine associated factors with TT infection.Adjusted odds ratio(AOR)with 95%confidence interval(CI)were claimed for the strength of association at P<0.05.RESULTS:We recruited 602(99.9%)participants for the final analysis.From the total,126(20.9%)and 98(16.3%,95%CI:13.5%-19.4%)participants were diagnosed with active trachoma&TT infection,respectively.Being age≥45y(AOR=7.9,95%CI:2.4-25.3),having multiple eye infections(AOR=2.73,95%CI:1.47-5.29),poor wealth index(AOR=9.2;95%CI:2.7-23.7)and twice face washing per day(AOR=0.082,95%CI:0.03-0.21)has identified as individual as factors for TT infection.Whereas,distance between clean water source≥10 km(AOR=6.5,95%CI:3.9-31.3),and latrine availability(AOR=0.35,95%CI:0.21-0.58)were the two community-level factors associated with TT infections.CONCLUSION:The high prevalence of TT infection post-war throughout the study districts indicates a need for urgent clinical intervention in addition to rapid scaling up surgery,antibiotics,facial cleanliness,and environmental improvement(SAFE)strategies,strategy for high-risk population.Age≥45y,distance from the clean water source,poor wealth indexes,and eye infection are identified to be risk factors for TT infection.Furthermore,community-level preventative factors for TT infection are found as latrine availability and face washing practice.

Biological Effects of Chlamydiaphage phi CPG1 Capsid Protein Vp1 on Chlamydia Trachomatis In Vitro and In Vivo

The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis（Ct）. We investigated the biological effect of chlamydiaphage phi CPG1 capsid protein Vp1 on Ct both in Mc Coy cells and genital tract of mice. Different concentrations of Vp1 were co-incubated with Ct E serotype strain in Mc Coy cells. Female BALB/c mice were used to establish Ct E strain-induced urogenital infection model. They were randomly divided into five groups and given different treatments on the fifth day after Ct inoculation. Animals in groups 1 and 2 were given 30 μL different concentrations of Vp1 in the genital tract respectively, those in group 3 were intramuscularly injected with 30 μL Vp1, those in the infected group did not receive any intervention, and those in the control group received 30 μL PBS in the genital tract. The vaginal discharge was collected to identify the live chlamydia by cell culture and gene fragment by real time PCR different days after infection. Inhibition rate of 100 μg/m L and 50 μg/m L Vp1 proteins against Ct E strain in the Mc Coy cell cultures was 91% and 79% respectively. The number of intracellular Ct inclusion in the Mc Coy cells co-cultured with vaginal discharge of group 1 and group 2 was less than in the infected group, and that in group 1 was less than in group 2, on the 7th day after Ct inoculation. Real-time PCR showed that chlamydia concentration of the vaginal discharge in group 2 was lower than in the infected group, and that in group 1 was lower than in group 2 on the 10 th day. It was suggested that Vp1 capsid proteins had inhibitory effect on the proliferation of Ct serovar E strain in cell culture and mouse genital tract.

No blinding trachoma in Guangxi,China

In 2005,Boost and Cho reported a high incidence of trachoma in rural areas of Guangxi,China(1).Ten years later,active trachoma has been controlled in this province in southern China.Trachoma is the major cause leading to infectious blindness worldwide(2,3).The risk factors of the

Trachoma rapid assessment in Shandong province of China

Background This research aims at identifying relative interventions on trachoma and testing the effectiveness of control measures adopted by assessing its prevalence and related risk factors in Shandong province of China. Methods Trachoma rapid assessment （TRA） was conducted in 6 sub-districts selected from Shandong province based on primary high risk assessment. Active trachoma in children aged 1-9 years and environmental risk factors of trachoma （unclean faces, absence of running water, and absence of flush toilets） were assessed （TRA 1）. Control measures were taken in endemic areas. A second TRA （TRA 2） was conducted after 12 months in the same 6 districts and findings of the two TRAs were compared. Results In TRA 1, we found trachoma in 3 sub-districts and the detection rate was 4% （95% CI： 0.39%-11.12%）, 6% （95% CI： 1.18%-14.17%）, and 6% （95% CI： 1.18%-14.17%） respectively. We could not find trachoma cases in TRA 2. Research data supports that children living with environmental risk factors face an increased risk to active trachoma. However, we could not find statistical evidence for this association, which may be caused by the limited data on prevalence. Conclusions This research indicates that the TRA methodology is easy to assess trachoma and its related risk factors. Based on the results of this study, we have already achieved the goal of ＂elimination of trachoma＂ in Shandong province, as the detection rate of trachomatous infiamation follicular/trachomatous inflammation intense in 1-9-year-old children was less than 5%. Chln Med J 2014;127（14）：2668-2671

Etiology of trachoma:a great success in isolating and cultivating chlamydia trachomatis

To review the studies on the etiology of trachoma and to honor Professor Tang Feifan (Prof FF Tang) He is the first scientist who was successful in isolating and cultivating chlamydia trachomatis in 1946 Data sources The principal literatures are cited from Tang's papers published from the 1930s to the 1950s Earlier literatures concerning early hypotheses for trachoma pathogenic agent are also studied Study selection and data extraction Only important and conclusive breakthroughs in Tang's papers are selected and extracted Results and conclusions In the 1930s Tang was intending to repeat Noguchi's experiments in isolating bacterium granulosis from cases of trachoma in China and to employ bacterium granulosis isolated by Noguchi in 1928 for reproducing experimental trachomatous human clinical manifestations in China Both experiments showed negative results In the 1950s, before isolated chlamydia trachomtas, Tang and his colleagues had finished two fundamental studies: (1) the histological nature of trachoma, their relationship to etiological agent as well as to the host cells; and (2) the clinical manifestations and the morphological pictures of trachoma in monkeys Eventually chlamydia trachomatis was isolated successfully and cultivated continuously

Association between water related factors and active trachoma in Hai district, Northern Tanzania

Background:Trachoma is widely distributed in sub-Saharan Africa and is mainly associated with poor water accessibility.However,these associations have never been demonstrated in some of the communities,especially in northern Tanzania.To cover that gap,the present case control study was conducted to assess the association of water related factors,general hygiene and active trachoma among preschool and school age children in Hai district,northern Tanzania.Results:Families reported to use>60 litres of water per day were less likely to have active disease(OR=0.4,95%CI:0.1-0.3;P<0.001)compared to households collecting≤60 litres.The risk of having trachoma increased with increase in distance to the water point(OR=6.5,95%CI;1.8-16.7;P=0.003).Households members who reported to use<2 liters of water for face washing were more likely to be trachomatous(OR=5.12,95%CI:1.87-14.6,P=0.001).Increased number of preschool children in the household was also associated with increased risk of active trachoma by 2.46 folds.Conclusions:Improving water supply near the households and providing public health education focusing on improving households socio-economic status and individual hygiene especially in pre-school children in part will help to reduce the prevalence of the disease.In addition,integrating public health education with other interventions such as medical interventions remains important.

A review of trachoma history in China: research, prevention, and control

Trachoma is one of the most widespread blinding eye diseases, which is harmful to human visual health. The efforts to prevent and control trachoma in China can be divided into three periods, i.e., highly epidemic period, research on pathogenesis and control of trachoma, and blinding trachoma elimination and epidemiological evaluation. In 1956, Prof. Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis, which clarified the cause of trachoma, and kick-started a fresh chapter in trachoma research, prevention, and control around the world. Although, the prevalence of trachoma differed in different areas, the average prevalence once exceeded 50% and was as high as 90% in some areas before and at early liberation of China. Therefore, the government-led efforts were made to comprehensively prevent and control trachoma, including development of National Plan for the Prevention and Control of Trachoma, nationwide screening and treatment of trachoma, implementation of National Patriotic Health Campaign and improvement of water supply and lavatories. After decades of effort, China reached the goal of eliminating blinding trachoma in 2015. China has gained remarkable achievements in the prevention and treatment of trachoma, making outstanding contributions toward the goal of eliminating trachoma worldwide. The research, prevention, and control of trachoma in China were reviewed in this paper.

Etiological characteristics of chlamydia trachoma conjunctivitis of Primary Boarding School students in the Qinghai Tibetan area

The aim of this study was to investigate the etiological characteristics of Chlamydia trachomatis conjunctivitis among resident students at primary schools in the Qinghai Tibetan area in order to understand the distribution of C. trachomatis and other pathogenic microorganisms, to detect the isolation rate of infectious pathogens, and to provide an evidence for further targeted efforts in the prevent of sporadic trachoma efforts. From two primary schools in Qinghai Province, ocular samples from 35 students who were clinically diagnosed as trachoma cases and 60 normal controls were obtained by swabbing their upper eyelids and lower conjunctival sacs. Samples were preserved at 4°C and airlifted to Beijing Tongren Hospital within 24 h. Real-time polymerase chain reaction(RT-PCR) was used to screen for C. trachomatis, and nested PCR was used to amplify a fragment of the omp A gene for serotype confirmation. Bacterial cultivation and sensitivity tests were conducted based on the 2015 version of the Clinical and Laboratory Standards Institute. Adenovirus, herpes simplex virus, cytomegalovirus, and Epstein-Barr virus were screened by RT-PCR. Among the 35 students with trachoma, 8 came from the Jianshetang Primary School and 27 came from the Central Primary School. Two novel C. trachomatis B serotypes(Gen Bank accession numbers KU737520 and KU737521) were detected based on a sequence analysis of the omp A gene. Single C. trachomatis infections accounted for 42.86%(9/21) of the cases, and infections with multiple bacteria, particularly Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, and Streptococcus pneumoniae, accounted for the remaining 57.14%(12/21). Of the 14 C. trachomatis-negative samples, one was positive for adenoviral infection(serotype D) and 13 were positive for bacterial infections(H. influenzae, M. catarrhalis, S. pneumoniae, S. aureus, streptococci other than S. pneumoniae, Staphylococcus epidermidis, Corynebacterium, and Arthrobacterium). In addition to C. trachomatis, the other bacteria and virus that were detected in the boarding students of primary schools in the Qinghai Tibetan area should be emphasized in trachoma prevention and control.

Effectiveness of azithromycin mass drug administration on trachoma:a systematic review

Backgrounds:Azithromycin mass drug administration(MDA)is a key part of the strategy for controlling trachoma.This systematic review aimed to comprehensively summarize the present studies of azithromycin MDA on trachoma;provide an overview of the impact of azithromycin MDA on trachoma in different districts;and explore the possible methods to enhance the effectiveness of azithromycin MDA in hyperendemic districts.Methods:PubMed,Embase,the Cochrane Central Register of Controlled Trials,Web of Science,and ClinicalTrials.gov were searched up to February 2021 with no language restriction.Studies reporting the effect of azithromycin MDA on trachoma were included.Mathematical modeling studies,animal studies,case reports,and reviews were excluded.The trachomatous inflammation-follicular(TF)<5.0%was used to judge the effect of azithromycin MDA on eliminating trachoma as a public health problem.Two researchers independently conducted the selection process and risk of bias assessment.Results:A total of 1543 studies were screened,of which 67 studies including 13 cluster-randomized controlled trials and 54 non-randomized studies were included.The effect of azithromycin MDA on trachoma was closely related to the baseline prevalence in districts.For the districts with baseline prevalence between 5.0%and 9.9%,a single round of MDA achieved a TF<5.0%.For the districts with baseline between 10.0%and 29.9%,annual MDA for 3 to 5 years reduced TF<5.0%.However,for the districts with high level of baseline prevalence(TF>30.0%),especially with baseline TF>50.0%,annual MDA was unable to achieve the TF<5.0%even after 5 to 7 years of treatment.Quarterly MDA is more effective in controlling trachoma in these hyperendemic districts.Conclusions:Azithromycin MDA for controlling trachoma depends on the baseline prevalence.The recommendation by the World Health Organization that annual MDA for 3 to 5 years in the districts with TF baseline>10.0%is not appropriate for all eligible districts.

Enlightenment of blinding trachoma elimination in China

Trachoma is a blinding eye disease caused by Chlamydia trachomatis infection.Trachoma was pandemic in the 19th century and rampant around the world,and was a widely prevalent infectious eye disease.

Prevalence and determinants of active trachoma among preschool-aged children in Dembia District,Northwest Ethiopia

Background:Trachoma is an infectious eye disease caused by Chlamydia trachomatis,which is the leading infectious cause of blindness worldwide.In areas where trachoma is endemic,active trachoma is common among preschool-aged children,with varying magnitude.This study aimed to estimate the prevalence of active trachoma and associated risk factors among preschool-aged children in Dembia District,northwest Ethiopia.Methods:A community-based cross-sectional survey was conducted among preschool-aged children of northwest Ethiopia.Multistage systematic random sampling was used to select 695 subjects.Trained clinical optometrists subjected each child to an ocular examination and assessed the presence of active trachoma.Face to face interview using pretested and structured questionnaire were conducted to collect data on possible risk factors.Trachoma cases were graded following a World Health Organization simplified grading scheme.All statistical analysis was carried out using the SPSS software version 20.Adjusted odds ratios(aORs)with 95%confidence intervals(CIs)were used to identify factors associated with active trachoma.Results:Of the 681 preschool-aged children studied,18%(95%CI:15.4%-21.1%)had a prevalence of active trachoma.Children who had clean faces(absence of nasal and ocular discharges)had a lower chance of having active trachoma[aOR=0.55,95%CI:0.37-0.82].The odds of having active trachoma decreased with an increase in the distance to a water point[aOR=0.51,95%CI:0.33-0.78].Similarly,no or poor utilization of liquid waste disposal in the child’s household was associated with an increased chance of having active trachoma[aOR=3.83,95%CI:1.26-11.61].Conclusion:The prevalence of active trachoma in these preschool-aged children was found to be high and needs special interventions that focus on educating families about proper face washing,liquid waste disposal,and improving safe water supply near the households.

Elimination of blinding trachoma in China: why is further study necessary?

Sixty years ago,Prof.Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis,a finding that clarified the cause of trachoma and marked the beginning of a fresh chapter on trachoma research,prevention,and control worldwide（Tang et al.,1956;Tang et al.,1957a;Tang et al.,1957b）.

Operational adaptations of the trachoma pre-validation surveillance strategy employed in Ghana:a qualitative assessment of successes and challenges

Background:In 2009 Ghana began to design a trachoma pre-validation surveillance plan,based on then-current WHO recommendations.The plan aimed to identify active trachoma resurgence and identify and manage trichiasis cases,through both active and passive surveillance approaches.This paper outlines and reviews the adaptations made by Ghana between 2011 and 2016.The assessment will provide a learning opportunity for a number of countries as they progress towards elimination status.Methods:A mixed methods approach was taken,comprising in-depth interviews and documents review.Between January and April 2016,20 in-depth interviews were conducted with persons involved in the operationalisation of the trachoma surveillance system from across all levels of the health system.A three-tier thematic coding framework was developed using a primarily inductive approach but also allowed for a more iterative approach,which drew on aspects of grounded theory.Results:During the operationalisation of the Ghana surveillance plan there were a number of adaptations(as compared to the WHO recommendations),these included:(i)Inclusion of surveillance of active trachoma in the passive surveillance approach,as compared to trichiasis alone.Issues with case identification,challenges in implementation coverage and a non-specific reporting structure hampered effectiveness;(ii)Random selection and increase in number of sites selected for the active surveillance component.This likely lacked the spatiotemporal power to be able to identify recrudescence in a timely manner;(iii)Targeted trichiasis door-to-door case searches,led by ophthalmic nurses.An effective methodology to identify trichiasis cases but resource intensive;(iv)A buddy system between ophthalmic nurses to support technical skills in an elimination setting where it is difficult to attain diagnostic and surgical skills,due to a lack of cases.The strategy did not take into account the loss of proficiency within experienced personnel.Conclusions:Ghana developed a comprehensive surveillance system that exceeded the WHO recommendations but issues with sensitivity and specificity likely led to an inefficient use of resources.Improved targeted surveillance strategies for identification of recrudescence and trichiasis case searches,need to be evaluated.Strategies must address the contextual changes that arise because of transmission decline,such as loss of surgical skills.

The burden of and risk factors for active trachoma in the North and South Wollo Zones of Amhara Region,Ethiopia:a crosssectional study

Background:Trachoma is a disease of the eye,caused by the bacteria Chlamydia trachomatis,which can lead to blindness if left untreated.Ethiopia is one of the most trachoma-affected countries in the world.The objective of this study was to determine the prevalence of and associated risk factors for active trachoma among children in selected woredas of North and South Wollo Zones in Amhara Region,Ethiopia.Methods:This study was a community-based,cross-sectional study,which was conducted from October to December 2014 among children aged 1-8.A four-stage random cluster sampling technique was employed to select the study areas and participants.From each selected household,one child was clinically assessed for active trachoma.A structured questionnaire was used to collect sociodemographic,behavioral,and clinical data.Multivariate logistic regression analysis was used to analyze the association between predictor variables and active trachoma.Results:The overall prevalence of active trachoma among 1358 children was found to be 21.6%(95%CI:19.4-23.8%).When analyzed by the presence or absence of individual WHO simplified system signs of active trachoma,trachomatous inflammation-follicular cases constituted18%(95%CI:15.9-20.2%),while 4.7%(95%CI:3.6-5.8%)were trachomatous inflammation-intense cases.Ocular discharge(aOR=5.2;95%CI:3.3-8.2),nasal discharge(aOR=1.8;95%CI:1.2-2.7),time taken to fetch water(aOR=0.02;95%CI:0.01-0.05),frequency of hand and face washing(aOR=4.4;95%CI:1.1-17.8),and access to a latrine(aOR=0.006;95%CI:0.001-0.030)were found to be independently associated with the presence of active trachoma.Conclusions:There is a high burden of active trachoma among children in the study areas.Lack of personal hygiene and limited access to a safe water supply and latrines were associated with increased prevalence of active trachoma.In order to reduce the burden of active trachoma,facial cleanliness and environmental improvement components of the SAFE strategy should be upgraded in the study areas.

Changed trends of major causes of visual impairment in Sichuan,China from 1987 to 2006

AIM: To study the trends of major causes of visual impairment(VI) in adults in Sichuan,China and evaluate the effect of aging on the trends. ·METHODS: We used data from the National Sample Survey on Disabilities(NSSD) in Sichuan province conducted in 1987 and 2006. The age-adjusted prevalence of major causes of VI and the prevalence stratified by age in each cause were calculated and compared. The association between age and each cause of VI was also analyzed.·RESULTS: Retinal disease increased and became the second leading cause of VI in 2006 while blinding trachoma decreased markedly. Cataract and non-trachomatous corneal diseases were among the leading causes of VI in both years. We found associations between age and causes of VI,with age showing the strongest association with cataract and relatively lower associations with other causes. · CONCLUSION: In the last two decades,dramatic changes occurred in the major causes of VI with significantly increased retinal disease and decreased blinding trachoma. Aging of the population might be an important factor accounting for the changed trends of VI. Understanding the prevalence of VI,its major causes and trends over time can assist in prioritizing and developing effective interventional strategies and monitoring their impact.