Beatriz Munoz

Prevalence of age-related macular degeneration in the United States

OBJECTIVE To estimate the prevalence and distribution of age-related macular degeneration (AMD) in the United States by age, race/ethnicity, and gender. METHODS Summary prevalence estimates of drusen 125 microm or larger, neovascular AMD, and geographic atrophy were prepared separately for black and white persons in 5-year age intervals starting at 40 years. The estimated rates were based on a meta-analysis of recent population-based studies in the United States, Australia, and Europe. These rates were applied to 2000 US Census data and to projected US population figures for 2020 to estimate the number of the US population with drusen and AMD. RESULTS The overall prevalence of neovascular AMD and/or geographic atrophy in the US population 40 years and older is estimated to be 1.47% (95% confidence interval, 1.38%-1.55%), with 1.75 million citizens having AMD. The prevalence of AMD increased dramatically with age, with more than 15% of the white women older than 80 years having neovascular AMD and/or geographic atrophy. More than 7 million individuals had drusen measuring 125 microm or larger and were, therefore, at substantial risk of developing AMD. Owing to the rapidly aging population, the number of persons having AMD will increase by 50% to 2.95 million in 2020. Age-related macular degeneration was far more prevalent among white than among black persons. CONCLUSION Age-related macular degeneration affects more than 1.75 million individuals in the United States. Owing to the rapid aging of the US population, this number will increase to almost 3 million by 2020.

Falls and Fear of Falling: Which Comes First? A Longitudinal Prediction Model Suggests Strategies for Primary and Secondary Prevention

OBJECTIVES: Previous cross‐sectional studies have shown a correlation between falls and fear of falling, but it is unclear which comes first. Our objectives were to determine the temporal relationship between falls and fear of falling, and to see whether these two outcomes share predictors.

Effect of ultraviolet radiation on cataract formation

To investigate the relation of ultraviolet radiation and cataract formation, we undertook an epidemiologic survey of 838 watermen (mean age, 53 years) who worked on Chesapeake Bay. The annual ocular exposure was calculated from the age of 16 for each waterman by combining a detailed occupational history with laboratory and field measurements of sun exposure. Cataracts were graded by ophthalmologic examination for both type and severity. Some degree of cortical cataract was found in 111 of the watermen (13 percent), and some degree of nuclear cataract in 229 (27 percent). Logistic regression analysis showed that high cumulative levels of ultraviolet B exposure significantly increased the risk of cortical cataract (regression coefficient, 0.70; P = 0.04). A doubling of cumulative exposure increased the risk of cortical cataract by a factor of 1.60 (95 percent confidence interval, 1.01 to 2.64). Those whose annual average exposure was in the upper quartile had a risk increased by 3.30 (confidence interval, 0.90 to 9.97) as compared with those in the lowest quartile. Analysis using a serially additive expected-dose model showed that watermen with cortical lens opacities had a 21 percent higher average annual exposure to ultraviolet B (t-test, 2.23; P = 0.03). No association was found between nuclear cataracts and ultraviolet B exposure or between cataracts and ultraviolet A exposure. We conclude that there is an association between exposure to ultraviolet B radiation and cataract formation, which supports the need for ocular protection from ultraviolet B.

Prevalence of dry eye among the elderly.

PURPOSE To study the demographics and estimate the prevalence of dry eye among elderly Americans. METHODS A population-based prevalence study was performed in 2,520 residents of Salisbury, Maryland, aged 65 years and older as of September 1993. The population was derived from the Health Care Financing Administration Medicare database. After completing a standardized questionnaire pertaining to dry eye symptoms, 2,420 subjects underwent Schirmer and rose bengal tests and anatomic assessment of the meibomian glands. RESULTS In this population, 14.6% (363/2,482) were symptomatic, defined as reporting one or more dry eye symptoms often or all the time; 2.2% (53/2,448) were symptomatic and had a low Schirmer test result (< or = 5 mm), and 2% (48/2,432) were symptomatic and had a high rose bengal test score (> or = 5). Furthermore, 3.5% (84/2,425) were symptomatic and had either a low Schirmer score or a high rose bengal score, and 0.7% (17/2,420) were symptomatic and had both a low Schirmer score and a high rose bengal score. No association of symptoms or signs was seen with age, sex, or race. Although anatomic features of meibomianitis were associated with the presence of symptoms (P = .01), 76% (67/88) of the individuals with these anatomic features were asymptomatic; 10.5% (260/2,480) reported that they currently use artificial tears or lubricants. CONCLUSIONS Symptoms and signs of dry eye are common among the elderly but were not associated with age, race, or sex in this population-based sample of elderly Americans. Extrapolating to the United States population aged 65 to 84 years, the study yields an estimate of 4.3 million who experience symptoms of ocular irritation often or all the time.

Relation between signs and symptoms of dry eye in the elderly : A population-based perspective

PURPOSE To examine the distribution and association of dry eye symptoms, Schirmer test results, and rose bengal scores in a population-based sample of elderly Americans. DESIGN Population-based prevalence survey. PARTICIPANTS Involved were 2240 noninstitutionalized residents of Salisbury, Maryland, aged 65 years and older as of September 1993, and identified by the Health Care Financing Administration Medicare database. MAIN OUTCOME MEASURES A standardized dry eye symptom questionnaire, rose bengal scoring of ocular surface staining, and Schirmer tests. RESULTS Fourteen percent of participants reported one or more symptoms to be present often or all the time. The mean Schirmer score in the lower testing eye was 12.4 and 42% had a rose bengal score of 1 or greater. No significant differences by age, gender, or race were seen for symptoms, Schirmer, or rose bengal testing. No association was seen between lower Schirmer scores and presence of more frequent symptoms. Higher rose bengal scores were weakly associated with symptoms. The Schirmer and rose bengal test results, both individually and in combination, were insensitive in identifying individuals who had symptoms. CONCLUSIONS Although symptoms of ocular irritation are common among the elderly, these population-based data indicate that there is minimal overlap between individuals identified by questionnaire, Schirmer tests, and rose bengal scoring.

Association of nonmelanoma skin cancer and actinic keratosis with cumulative solar ultraviolet exposure in Maryland watermen

To establish the relationship between ultraviolet‐B radiation and squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and actinic keratosis (AK), a cross‐sectional prevalence survey was performed in a sample of 808 white, male watermen 30 years of age and older residing in the Eastern Shore of Maryland. A measure of personal cumulative ultraviolet‐B exposure was determined for each subject from data collected through interviews and field and laboratory measurements. A personal interview elicited skin type, medication history, and other factors. Clinical diagnoses and histologic confirmation were done for current and previously removed skin tumors. The ratio of subjects with SCC to subjects with BCC was approximately 1:1; however, the ratio of BCC to SCC was 1.25:1 because BCC cases were more prone to multiple lesions. Watermen with SCC or AK but not BCC had higher average annual ultraviolet‐B doses than age‐matched controls. This was particularly marked in watermen younger than 60 years of age. Logistic regression showed that an older age, childhood freckling, and blue eyes significantly increased the risk of the development of all three types of skin tumor. Ease of sunburning was associated with BCC and AK, but not with SCC. Watermen in the upper quartile of cumulative ultraviolet‐B exposure had a 2.5 times higher risk for the development of SCC when compared with the lower 3 quartiles. This suggests that high levels of ultraviolet‐B exposure are important in SCC occurrence. The risk of AK developing was 1.5 times higher for those whose cumulative ultraviolet‐B exposure exceeded the median. The relationship of BCC to cumulative ultraviolet‐B exposure was not clear and this suggests that different etiologic mechanisms operate for SCC and BCC.

Driving Status and Risk of Entry Into Long-Term Care in Older Adults

OBJECTIVES Given the importance of driving in American society, older non-drivers may be unable to meet basic needs while living independently. We assessed whether not driving is an independent risk factor for entering long-term care (LTC) institutions. METHODS Data were used from 1593 older adults who participated in the Salisbury Eye Evaluation cohort study and completed an additional telephone survey. Questions on driving status and LTC entry were obtained by self/proxy report. Cox time-dependent regression procedures were used to adjust for demographic and health factors. RESULTS Former and never drivers had higher hazards of LTC entry after adjustment for demographic and health variables (hazard ratio [HR]=4.85; 95% confidence interval [CI]=3.26, 7.21; and HR=3.53; 95% CI=1.89, 6.58, respectively). Also, having no other drivers in the house was an independent risk factor for LTC entry (HR=1.72; 95% CI=1.15, 2.57).Discussion. Older adults are expected to make good decisions about when to stop driving, but the hardships imposed on older adults by not driving are not widely recognized. Innovative strategies to improve transportation options for older adults should be considered.

Impact of face-washing on trachoma in Kongwa, Tanzania

Observational studies have suggested that the prevalence of trachoma is lower in children with clean faces than in those with ocular or nasal discharge or flies on the face. We carried out a community-based randomised trial in three pairs of villages to assess the impact on trachoma of a face-washing intervention programme following a mass topical antibiotic treatment campaign. Six villages in Kongwa, Tanzania, were randomly assigned mass treatment plus the face-washing programme or treatment only. 1417 children aged 1-7 years in these villages were randomly selected and followed up for trachoma status and observations of facial cleanliness at baseline and 2, 6, and 12 months. At 12 months, children in the intervention villages were 60% more likely to have had clean faces at two or more follow-up visits than children in the control villages. The odds of having severe trachoma in the intervention villages were 0.62 (95% Cl 0.40-0.97) compared with control villages. A clean face at two or more follow-up visits was protective for any trachoma (odds ratio 0.58 [0.47-0.72]) and severe trachoma (0.35 [0.21-0.59]). This community-based participatory approach to face-washing intervention had variable penetration rates in the villages and was labour intensive. However, we found that, combined with topical treatment, community-based strategies for improving hygiene in children in trachoma-endemic villages can reduce the prevalence of trachoma.

Strategies for control of trachoma: observational study with quantitative PCR

BACKGROUND Antibiotics are an important part of WHOs strategy to eliminate trachoma as a blinding disease by 2020. At present, who needs to be treated is unclear. We aimed to establish the burden of ocular Chlamydia trachomatis in three trachoma-endemic communities in Tanzania and The Gambia with real-time quantitative PCR. METHODS Conjunctival swabs were obtained at examination from 3146 individuals. Swabs were first tested by the qualitative Amplicor PCR, which is known to be highly sensitive. In positive samples, the number of copies of omp1 (a single-copy C trachomatis gene) was measured by quantitative PCR. FINDINGS Children had the highest ocular loads of C trachomatis, although the amount of pooling in young age groups was less striking at the site with the lowest trachoma frequency. Individuals with intense inflammatory trachoma had higher loads than did those with other conjunctival signs. At the site with the highest prevalence of trachoma, 48 of 93 (52%) individuals with conjunctival scarring but no sign of active disease were positive for ocular chlamydiae. INTERPRETATION Children younger than 10 years old, and those with intense inflammatory trachoma, probably represent the major source of ocular C trachomatis infection in endemic communities. Success of antibiotic distribution programmes could depend on these groups receiving effective treatment.

Association of visual field loss and mobility performance in older adults: Salisbury Eye Evaluation Study.

Purpose. To determine the association between visual field loss and orientation and mobility (O&M) performance in a population-based sample of older adults and to identify the specific regions of the visual field that are most strongly associated with O&M performance. Methods. A population-based sample of 1504 persons between the ages of 72 to 92 was enrolled in the third round of Salisbury Eye Evaluation. Monocular visual fields (60° radius) were tested with the 81-point, single intensity (24 dB) screening test strategy on the Humphrey Field Analyzer. Binocular visual fields were estimated from a combination of the monocular fields. The number of points missed was calculated for the overall visual field and for 3 non-overlapping regions: central (≤ 20° radius), upper- and lower-peripheral visual fields. Orientation and mobility performance was evaluated by walking speed, number of bumps, and number of orientation errors on a circuitous, 32.8-m course seeded with obstacles. Log-linear regressions and linear regressions, adjusting for age, gender, body mass, height, cognitive and general health status, were performed. Results. Loss in the overall visual field was associated with an increase in the number of bumps and decrease in walking speed. Visual field loss was not associated with the number of orientation errors. Out of the three visual field sub-regions that we tested, in terms of percentage of loss, the central and lower peripheral regions showed comparable decrements in walking speed and the central region was most strongly associated with number of bumps. Conclusions. The loss in visual field, which occurs with aging, is associated with a decline in mobility performance. Walking speed decreases, and the number of bumps into obstacles increases, with decreases in the visual field. The number of orientation errors is not associated with the loss in visual field that occurs with aging.