Prevalence and Pattern of Geographic Atrophy in Asia: The Asian Eye Epidemiology Consortium.

PURPOSE: Although there have been many population-based studies of age-related macular degeneration (AMD), only limited information is available in Asia on the epidemiology of geographic atrophy (GA). We aimed to determine the prevalence and patterns of GA through an analysis of multiple studies conducted within the Asian Eye Epidemiology Consortium (AEEC). DESIGN: Cross-sectional meta-analyses. PARTICIPANTS: A total of 97 213 individuals aged 40 years and older. METHODS: Data from 22 population-based studies from countries belonging to the AEEC were included. In all studies, AMD was defined on the basis of standardized grading systems. Geographic atrophy was defined as an area of pallor in the fundus with visibility of the underlying choroidal blood vessels and sharply defined borders. Random-effects meta-analysis was performed to estimate overall and age-, gender-, and region-specific pooled prevalence of GA. MAIN OUTCOME MEASURES: Prevalence of GA per 1000 persons. RESULTS: The mean age was 60.8 ± 10.0 years, and 42 673 (43.9%) were male. Overall, a total of 223 individuals (0.2%) had GA. The pooled overall prevalence of GA was 1.57 per 1000 persons (95% confidence interval [CI], 1.04-2.10), which was 3 times less than that of neovascular AMD of 5.20 per 1000 persons (95% CI, 3.97-6.43). Compared with those aged 50 to 59 years, the prevalence of GA increased from 0.34 per 1000 persons (95% CI, 0.07-0.62) to 2.90 per 1000 persons (95% CI, 1.55-4.25) in those aged ≥70 years. The GA prevalence per 1000 persons was similar between urban (2.22; 95% CI, 1.22-3.23) and rural residents (1.33; 95% CI, 0.70-1.96). Geographic atrophy was more prevalent in South Asia (based on studies from India and Nepal, 3.82 per 1000 persons; 95% CI, 1.72-5.93) compared with East Asia (based on studies from China, Korea, Hong Kong, Taiwan, and Japan, and the Singapore Chinese Eye Study, 0.76 per 1000 persons; 95% CI, 0.31-1.22, P = 0.005). CONCLUSIONS: Geographic atrophy is uncommon in Asian populations compared with those of European ancestry. Even within Asia, geographic differences in GA prevalence were seen. The findings of this meta-analysis suggest that better dissection of risk factors in the Asian population for GA may provide insights into the biological pathways that drive these late-stage manifestations, thus suggesting better targets for prevention.

Assessing the accuracy and feasibility of a refractive error screening program conducted by school teachers in pre-primary and primary schools in Thailand.

INTRODUCTION: As part of the development of a system for the screening of refractive error in Thai children, this study describes the accuracy and feasibility of establishing a program conducted by teachers. OBJECTIVE: To assess the accuracy and feasibility of screening by teachers. METHODS: A cross-sectional descriptive and analytical study was conducted in 17 schools in four provinces representing four geographic regions in Thailand. A two-staged cluster sampling was employed to compare the detection rate of refractive error among eligible students between trained teachers and health professionals. Serial focus group discussions were held for teachers and parents in order to understand their attitude towards refractive error screening at schools and the potential success factors and barriers. RESULTS: The detection rate of refractive error screening by teachers among pre-primary school children is relatively low (21%) for mild visual impairment but higher for moderate visual impairment (44%). The detection rate for primary school children is high for both levels of visual impairment (52% for mild and 74% for moderate). The focus group discussions reveal that both teachers and parents would benefit from further education regarding refractive errors and that the vast majority of teachers are willing to conduct a school-based screening program. CONCLUSION: Refractive error screening by health professionals in pre-primary and primary school children is not currently implemented in Thailand due to resource limitations. However, evidence suggests that a refractive error screening program conducted in schools by teachers in the country is reasonable and feasible because the detection and treatment of refractive error in very young generations is important and the screening program can be implemented and conducted with relatively low costs.

Prevalence of age-related macular degeneration in Thailand.

PURPOSE: To determine the prevalence of age-related macular degeneration (AMD) in Thailand. METHODS: In this population-based study, data of participants in the Thailand National Survey of Visual Impairment in 2006-2007 were analyzed. Participants selected for this study were more than 50 years old, and were recruited from 42 districts of 21 provinces. They were interviewed, tested for visual acuity, examined for eye screening, and measured for intraocular pressure. They had digital fundus photographs taken using a nonmydriatic fundus camera through dilated pupils. The diagnosis of AMD, according to the standard international grading system, was made from the interpretation of the digital images by at least 2 retinal specialists. The observed data were used for predicting estimates of the prevalence of AMD in Thailand. RESULTS: Data from 10,788 participants were analyzed. There were 321/10,788 (3%, 95% CI: 2.7-3.3%) participants diagnosed as having AMD. The mean age was 62.1 (range 50-98, SD 8.8) years old. There were 294 (2.7%) and 27 (0.3%) participants with early AMD (38.4% male) and late AMD (74.1% male) respectively. Of the late AMD, 20 (74.1%) were wet AMD and 7 (25.9%) were geographic atrophy. Based on the population census of Thailand, this could be translated into 351,000 and 39,000 patients with early and late AMD respectively. CONCLUSIONS: Based on these data, it is projected that Thailand will have a large number of late AMD sufferers. This makes it imperative to develop new strategies for the national public health system, aiming to incorporate already available late AMD treatment.

The sustained and holistic health care program for the priests Commemoration of His Majesty the King's 60 Years Accession to the Throne (first phase: February to June 2006).

OBJECTIVES: To determine the health status and risk factors of the priests in 28 temples in central Bangkok. MATERIAL AND METHOD: Recruiting priests to answer health related questionnaire, then screening by laboratory testing and physical examination. Finally, setting an appointment to the specialists for consultation and special investigation in the suspected and abnormal cases. RESULTS: In all the priests and novices, 64.8% were healthy, 17.74% were asymptomatic cases with risk factors, and 17.47% had clinical diseases that require treatment. CONCLUSION: Since almost 35 % of the priests and novices in central Bangkok have some health problems and health risks, providing periodic physical check up and basic laboratory test for the priests is a compulsory measure to fulfill the requirement of the health promotion policy and be a productive and effective Buddhist successor.

Eye health in the priests and novices in central Bangkok.

BACKGROUND: Early detection and proper management of eye diseases in priests and novices is cost effective, and minimize serious ocular damage and permanent loss of vision. Therefore, the Department of Ophthalmology, Priest Hospital set-up an eye examination project for the priests and novices who came for physical examination. The laboratory test was part of the Sustained and Holistic Healthcare Program for Priests and Novices as Commemoration of His Majesty the King's 60 Years of Accession to the Throne. OBJECTIVE: To evaluate eye health status and screening for refractive error in priests and novices and to provide free spectacles and eye health education to fulfill the criteria of voluntary Buddhist eye health workers. MATERIAL AND METHOD: Between February and June 2006, the Department of Ophthalmology, Priest Hospital conducted eye examination for the priests and novices in 28 temples in central Bangkok. The priest and novices with refractive error and abnormal eye examination received appointment for repeated refraction and complete eye examination in Priest Hospital. RESULTS: Six hundred forty nine priests and novices had complete eye examination. Normal visual acuity (Snellen VA 20/20) was found in 355 (54.69%) cases. The most common eye diseases were refractive error with 294 cases (45.30%), cataract with 41 cases (6.32%), glaucoma with 10 cases (1.54%) and vitreoretinal diseases, which included diabetic retinopathy, age related macular degeneration and branch retinal venous occlusion with eight cases (1.23%). Three novices had amblyopia (0.46%). CONCLUSION: Most of the priests and novices in central Bangkok had good eye health. Half of the eye problems were refractive errors. Since most of other eye diseases reported in priests were associated with aging and systemic diseases as hypertension, diabetes, and ischemic heart disease, regular ophthalmic examination should be provided in this risk group. Eye health education should be provided for sustainable eye health development as voluntary eye health workers in Buddhism.

Survey of refractive errors among Buddhist scripture, Dhamma-Bali and regular school of Buddhist novices in the Bangkok metropolitan area.

BACKGROUND: Refractive errors that affect learning are common eye problems in children. Eye-screening for refractive errors in the children population is accepted as a cost-effective method in the prevention of such problems. The Department of Ophthalmology, Priest Hospital, conducted a visual screening program for the novices of the Buddhist Scripture Schools. OBJECTIVE: To conduct the visual screening, evaluate eye health status and ocular abnormalities; to correct refractive errors among school novices of the Buddhist Scripture Schools. MATERIAL AND METHOD: A survey of refractive errors was conducted in 76 Buddhist Scripture schools in the Bangkok Metropolitan area between October 2005 and September 2007. The novices whose ages were between 9 and 20 years were included in the present study. Refraction and eye examinations were performed by ophthalmic nurses, optometrists, and the health personnel team, resulting in novices with refractive errors receiving custom-made eyeglasses, without charge along with eye health education. The present survey was conducted during public holidays. RESULTS: Two thousand six hundred fifty eight novices of the Buddhist Scripture were initially screened, leading to refractive errors being identified and corrected in 498 (18.74 %) of the cases. Of the corrected cases, 465 (93.37 %) needed eyeglasses, with the most common cause of refractive error being myopia. Three hundred and thirteen (62.85 %) eye diseases were found in 158 (5.94 %) of the novices, with pterygium and pinguecula being the most common diseases found in 51 (32.27 %), and amblyopia (lazy eye) in seven (4.43 %), while 75.32% of the novices had good visual acuity with no eye disease. The authors suggested that the percentage of novices with amblyopia could be reduced to less than 4.43% if it were to be detected earlier CONCLUSION: From the present study, 498 (18.74 %) of the novices had refractive errors, and the 465 (93.37 %) of them needed and received eyeglasses. Furthermore, after having received the glasses, they reported that they were satisfied with a much better vision and ability to study in classes. Due to being in a low-age group, they had no serious eye diseases.

Eye health of priests and novices in rural area.

BACKGROUND: Early detection and treatment of eye diseases is important to minimize visual morbidity and permanent visual loss in general and priests' population. OBJECTIVE: To evaluate eye health status, visual acuity and eye diseases of the priests and novices, to estimate the prevalence and causes of visual impairment, and to provide eye health education. MATERIAL AND METHOD: Between May 2006 and March 2007, the priests and novices in selected village (stratified population cluster random sampling) of 22 provinces in The First National Survey of Blindness and Visual Impairment Program in Thailand (TVIP) had their visual acuity (VA) and intraocular pressure (IOP) measured and eye examined by ophthalmic nurses. An ophthalmologist examined the anterior and posterior segment and took fundus pictures. RESULTS: Two hundred sixty eight priests and novices were examined. Their age ranged between 12 and 88 years with a mean of 48.5 years. Most priests and novices had normal vision (20/20-20/40 - 67.54%). No priest and novices had bilateral blindness. Almost half (48.13%) had eyeglasses and 2.24% had bilateral low vision. Unilateral low vision and unilateral blindness were 3.73% and 3.36%. One eye blindness and one eye low vision was only 0.37%. Refractive error was the leading cause of visual impairment (22.39%), followed by cataract (17.54%), glaucoma (5.97%), vitreo-retinal diseases (1.49%), and glaucoma suspected (occludable angle and ocular hypertension) (3.35%). Fifty five priests (20.52%) were referred for further investigation and treatment. CONCLUSION: Because the mean age of the priests and novices in this survey was only 48.5 years, the prevalence of visual impairment was low. Most of the cases were avoidable or preventable. The implementation of an effective screening program and access to eye treatment with standard of care remains a priority for the priests in rural areas. For sustainable development, eye health education must be promoted.

Visual acuity in patients having cataract surgery by different techniques.

BACKGROUND: Question of different techniques of cataract surgery would offer different post-operative visual acuity (VA) has been asked. OBJECTIVES: To compare the pre-and post-operative VA of cataract patients operated by different techniques as Extracapsular Cataract Extraction (ECCE), Phacoemulsification (PE), and Manual Phaco Fragmentation (MPF) and compare in different age groups. METHOD: The post-operative visual acuity of cataract patients was collected from 72 hospitals in Bangkok and rural part of Thailand. Techniques of cataract surgery were recorded. The cases with pre-operative and intraoperative complication and cases operated without intraocular lens (IOLs) implantation were ruled out. RESULTS: VA of cataract patients post-operation was statistically significant better than pre-operation at p-value (less than 0.05) and the result persisted for every age group. Cataract patients operated by PE had better post-operative VA than patients operated by ECCE and MPF even if MPF had the best post-operative VA. This is because the total cases were less than the other procedure. CONCLUSION: Due to the nature of retrospective study, the cause of poor post-operative VA was due to astigmatism. The pre-operative astigmatism was not recorded thus preventing a complete analysis.

Visual acuity in patients having foldable and non-foldable intra-ocular lens for cataract surgery.

BACKGROUND: Intra-ocular lens (IOLs) is the most commonly use organ substitute worldwide. Question of different type of IOLs which would offer different post operative visual acuity (VA) has been asked. OBJECTIVES: To compare the pre-operative and post operative visual acuity (VA) of cataract patients operated-patient and the use of non foldable and foldable IOLs in different age groups. METHOD: Retrospective study of post operative VA of cataract patients-operated from Priest, Lerdsin Hospital in Bangkok and Lampang Hospital in northern part of Thailand. Methods to operate and type of IOLs implantation were recorded. The cases with pre-operative and intra-operative complications were excluded. RESULTS: Post operative VA of cataract patients was better than pre-operation VA with statistically significant at p-value less than 0.05 and the results persisted for every age group. With phacoemulsification (PE) techniques, non-foldable IOLs offered better post operative VA than foldable IOLs in every age group except in age group of less than 40 and age group over 59 that showed statistically significant different at p-value less than 0.05. CONCLUSION: Due to the nature of retrospective study, the cause of poor post operative VA was due to astigmatism which the pre-operative astigmatism were not recorded to fulfill complete analysis.

Glaucoma care and clinical profile in Priest Hospital, Thailand.

OBJECTIVE: To assess the prevalence, mechanism and status of glaucoma, and to investigate the magnitude of visual impairment from glaucoma and its relating factors in Buddhist priest and novices. MATERIAL AND METHOD: Cross-sectional study of 190 patients treated in Glaucoma service, Priest hospital was performed. One hundred thirty seven patients with glaucoma and suspected glaucoma had comprehensive ophthalmic examination included interview on medical and ocular history, visual acuity, applanation tonometry, gonioscopy, optic disc, visual field evaluation, and retinal nerve fiber layer thickness measurement (Stratus Optical Coherence Tomography; Stratus OCT). RESULTS: Glaucoma was diagnosed in 106 (77%) patients (181 eyes); 31 patients (23%) were glaucoma suspects. Open angle glaucoma (OAG) was found in 53 (50%) cases and classified into 36 (33%) primary open angle glaucoma and 17 (16%) normal tension glaucoma (NTG). Five (4.6%) patients had pseudoexfoliative glaucoma, 24 (23%) had primary angle-closure glaucoma (PACG), 10 (9.4%) had angle-closure glaucoma secondary to other causes (SACG), seven (6.6%) had secondary open angle glaucoma and seven (6.6%) were diagnosed of juvenile glaucoma. Among 31 glaucoma suspects, 18 cases were diagnosed based on disc appearance, eight based on intraocular pressure (IOP), two based on visual field and three cases had primary angle closure (PAC). The prevalence of glaucoma increased with age, with the highest prevalence (33%) in the age range 71 to 80 years. The Glaucoma service of Priest hospital diagnosed glaucoma in 53% of the priest. Rate of glaucoma was higher in priest from rural area than those from Bangkok and urban area. The mean baseline IOP was 26.5 +/- 14.7 mmHg. The mean treated IOP was 14.5 +/- 7.9 mmHg. The average mean deviation (MD) was -14.45 +/- 11.11. OCT showed average RNFL thickness of 70.8 +/- 35.6 microm. Glaucoma medications was received by 72% of the priest, 18% had laser treatment, and 22 % had glaucoma surgery. At diagnosis, two patients were blind according to WHO criteria, 29 (28%) patients were unilaterally blind, and seven (6.5%) had low vision. After treatment, 31 (29%) patients had unilateral blindness and none had bilateral blindness. The main associated diseases were hypertension, dyslipidemia, and diabetes. Transportation and financial condition were the major barriers in receiving eye care. CONCLUSIONS: OAG comprised 50% of all glaucoma, 23% of PACG, and 16% of all subtypes of secondary glaucoma. The prevalence of glaucoma in priest rose significantly with age. In the treated glaucoma patients, 47% retained good visual outcome. Delayed diagnosis was a major factor for unsatisfactory outcome as 28% of patients had monocular blindness at diagnosis and 53% were previously unaware of their disease.

Diabetic retinopathy in Priest Hospital.

BACKGROUND: Diabetic retinopathy (DR) is common complication of DM and is one of the leading causes of visual loss in working age population in developed and developing countries. The known risk of retinopathy is directly related to the degree and duration of hyperglycemia. Priests are one of the disadvantageous groups because they cannot select their food and have poor access to health care. These two reasons are suspected to be causes of high prevalence of DM and DR in the priests. OBJECTIVES: To perform complete eye examinations and take fundus pictures at DR screening to estimate the prevalence of DR in the priests and to perform appropriate treatment. MATERIAL AND METHODS: Retrospective review of the medical records of the priests and novices who had diabetes in Priest Hospital between October 2005 and September 2007 was done. Appointment for crosssectional DR screening for those who never had an eye exam and to complete DR treatment. RESULTS: Four hundred and fourteen diabetic priests and novices were enrolled in the study with the mean age was 61.65 years. Only 297 (71.74 %) of the diabetic priests had a visual acuity measurement previously. DR screening program was done in 176 priests. The result revealed that 123 priests had no DR (69.89 %), 33 (18.75%) had non-proliferative DR (NPDR), 20 (11.36%) had proliferative DR (PDR), and 11 (6.25% or 33.33% of NPDR) had clinically significant macula edema (CSME). From the previously diagnosed patients, 15 (28.3%) had Laser treatment performed and 2 (3.77%) had pars plana vitrectomy (PPV). CONCLUSION: Although Priest Hospital sent DR screening postcards to diabetic priests twice, only 176 (42.51%) priests came, and of those, 53 (30.11%) had DR. There is poor co-operation from the priests because of their lack of medical knowledge about DM complication and DR. The priest who came for the appointment were concerned with their health therefore, they had low prevalence of DR with moderate glycemic control. DR in the priests led to low vision (11.83%) and blindness (5.92%). For the priests, adherence to clinical guidelines for glycemic and BP control was low, even in a well-developed health care system with free ophthalmic care access because they cannot select their food and have poor transportation services to health care facilities.

Prevalence of diabetic retinopathy in relation to duration of diabetes mellitus in community hospitals of Lampang.

Three thousand and forty nine patients diagnosed with diabetes mellitus were examined in 13 community (district) hospitals in Lampang from January to December 2002. Complete eye examination with standard protocol was used to determine the prevalence and severity of diabetic retinopathy. The prevalence of the background or non-proliferative diabetic retinopathy (BDR or NPDR) was 18.9% and proliferative diabetic retinopathy (PDR) was 3% in all age groups. For the relationship of the duration of diabetes, it showed that the longer the duration of diabetes the higher the prevalence of diabetic retinopathy. In BDR or NPDR, the retinopathy varied from 13.11 to 22.91% in persons having diabetes for less than 10 years and up to 42.86% in those with diabetes for up to 20 years. In the PDR group, the prevalence was 2.15 to 2.42% in persons with diabetes for less than 10 years and up to 10.20% for those with diabetes for up to 20 years. The severity of retinopathy was found to be not only related to a longer duration of diabetes but also related to higher glycosylated hemoglobin levels, higher systolic blood pressure and the presence of proteinuria.