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Epidemiological information is expected to be used to develop key aspects of eye care such as to control and minimise the impact of diseases, to allocate resources, to monitor public health actions, to determine the best treatment options and to forecast the consequence of diseases in populations. Epidemiological studies are expected to provide information about the prevalence and/or incidence of eye diseases or conditions. To determine prevalence is necessary to perform a cross-sectional screening of the population at risk to ascertain the number of cases. The aim of this review is to describe and evaluate capture-recapture methods (or models) to ascertaining the number of individuals with a disease (e.g. diabetic retinopathy) or condition (e.g. vision impairment) in the population. The review covers the fundamental aspects of capture-recapture methods that would enable non-experts in epidemiology to use it in ophthalmic studies. The review provides information about theoretical aspects of the method with examples of studies in ophthalmology in which it has been used. We also provide a problem/solution approach for limitations arising from the lists obtained from registers or other reliable sources. We concluded that capture-recapture models can be considered reliable to estimate the total number of cases with eye conditions using incomplete information from registers. Accordingly, the method may be used to maintain updated epidemiological information about eye conditions helping to tackle the lack of surveillance information in many regions of the globe. [ABSTRACT FROM AUTHOR]

Purpose: To determine the prevalence of childhood blindness and ocular morbidity in a rural pediatric population in South India. Methods: A population-based, cross-sectional survey of children was conducted in three phases in Pavagada and Madhugiri taluks (subdivisions) of Tumkur district in the state of Karnataka, India. In the first phase, trained fieldworkers screened 23,100 children. In the second phase, children with eye diseases were referred to the peripheral hospital to be examined by a general ophthalmologist. In the third phase, children with major eye diseases were examined by a pediatric ophthalmologist. Results: The prevalence of ocular morbidity was 2.66% (95% confidence interval, CI, 2.46–2.87%). The most commonly observed ocular morbidity was Bitot spots (1%) followed by refractive error (0.6%). In total, 18 children were blind and the prevalence of childhood blindness (best-corrected visual acuity <3/60) was 0.08% (95% CI 0.04–0.11%); 8 (44.44%) had retinal blindness, 5 (27.76%) had lens-related blindness, 2 (11.11%) had bilateral microphthalmos, 1 (5.56%) was blind due to anterior staphyloma in the right eye and anophthalmos in the left eye, 1 (5.56%) had bilateral uveal coloboma and 1 (5.56%) had cortical visual impairment. Conclusions: Nearly half of the blindness in the population was due to unavoidable causes (retinal). In addition to providing eye care services, an appropriate service delivery model would include the provision of rehabilitative and low vision services and implementation of genetic studies to understand the causes and increase awareness of inherited eye diseases. [ABSTRACT FROM PUBLISHER]

Purpose: To describe the trend of Acanthamoeba keratitis case reports following an outbreak and the recall of a multipurpose contact lens disinfection solution. Acanthamoeba keratitis is a serious eye infection caused by the free-living amoeba Acanthamoeba that primarily affects contact lens users. Methods: A convenience sample of 13 ophthalmology centers and laboratories in the USA, provided annual numbers of Acanthamoeba keratitis cases diagnosed between 1999-2009 and monthly numbers of cases diagnosed between 2007-2009. Data on ophthalmic preparations of anti- Acanthamoeba therapies were collected from a national compounding pharmacy. Results: Data from sentinel site ophthalmology centers and laboratories revealed that the yearly number of cases gradually increased from 22 in 1999 to 43 in 2003, with a marked increase beginning in 2004 (93 cases) that continued through 2007 (170 cases; p < 0.0001). The outbreak identified from these sentinel sites resulted in the recall of a contact lens disinfecting solution. There was a statistically significant (p ≤ 0.0001) decrease in monthly cases reported from 28 cases in June 2007 (following the recall) to seven cases in June 2008, followed by an increase (p = 0.0004) in reported cases thereafter; cases have remained higher than pre-outbreak levels. A similar trend was seen in prescriptions for Acanthamoeba keratitis chemotherapy. Cases were significantly more likely to be reported during summer than during other seasons. Conclusion: The persistently elevated number of reported cases supports the need to understand the risk factors and environmental exposures associated with Acanthamoeba keratitis. Further prevention efforts are needed to reduce the number of cases occurring among contact lens wearers. [ABSTRACT FROM AUTHOR]

Purpose: Current knowledge of ethnic variability in the epidemiology of major eye diseases in Asia is limited. This report summarizes the rationale and study design of the Singapore Indian Chinese Cohort (SICC) Eye Study, a population-based study of ethnic South Asian (Indians) and East Asian (Chinese) older adults in Singapore. Methods: The SICC examined a population-based cross-sectional sample of 3,300 ethnic Indians and 3,300 ethnic Chinese aged 40–80+ years residing in the South-Western part of Singapore. Results: From two lists of 12,000 names of each ethnic group provided by the Ministry of Home Affairs, age-stratified random sampling was used to select 6,350 names in each group, with a target sample size of 3,300. Invitations were sent to attend a central clinic using letters, telephone calls and home visits. Examination procedures included interviews, measurement of blood pressure, anthropometry, presenting and best-corrected visual acuity, subjective refraction, ocular biometry, Goldmann applanation tonometry, slit-lamp biomicroscopy, optic disc imaging and digital photography of the lens and retina, using a standardized protocol. Selected participants underwent gonioscopic examination, visual field testing, and anterior and posterior segment optical coherence tomography. Blood, tear, and urine samples were collected for biochemical analyses, and stored for genetic and proteomic studies. Conclusions: In conjunction with the Singapore Malay Eye Study, the SICC study will permit an in-depth evaluation of the prevalence, risk factors, and impact of major eye diseases in Chinese, Indians and Malays, three distinct Asian ethnic groups, whose combined numbers represent half the world’s population. [ABSTRACT FROM AUTHOR]

Purpose: Evisceration is an alternative treatment modality to enucleation for many end-stage eye diseases. No study has addressed the indications for evisceration of eyes in Saudi Arabia. The aim of this study was to determine the current clinical indications for evisceration in patients at a tertiary eye care center and attempt clinicopathological correlation. Methods: Clinical records of patients who had undergone evisceration at a tertiary eye care center over a 4-year period were reviewed retrospectively. The patients' demographic data and clinical indications for evisceration were studied, and the results from histopathological findings were correlated with the clinical diagnosis. Results: Evisceration of the eyes was performed in 187 patients. Males outnumbered females in a ratio of 1.3:1 (105 males and 82 females). Blind painful eye was the primary presenting symptom in 117 (62.6%) patients and unsightly eye in 38 (20.3%) patients. Clinical indications for evisceration included endophthalmitis in 85 (45.5%), phthisis bulbi in 38 (20.3%), traumatic injury in 36 (19.2%), and glaucoma in 14 (7.5%) patients. Sixty-three patients (33.7%) had prior history of cataract surgery, penetrating keratoplasty, glaucoma surgery, or retina surgery. Clinicopathological correlation was 100% in cases with definite clinical diagnosis of endophthalmitis. Conclusion: Blind painful eye, endophthalmitis, phthisis bulbi, severe traumatic injury, and glaucoma were the major indications for eviscerations in a tertiary eye care center. [ABSTRACT FROM AUTHOR]