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Background: Trichiasis surgery is believed to reduce the risk of losing vision from trachoma. There are limited data on the long term outcome of surgery and its effect on vision and corneal opacification. Similarly, the determinants of failure are not well understood. Methods: A cohort of people in the Gambia who had undergone surgery for trachomatous trichiasis 3–4 years earlier was re-assessed. They were examined clinically and the conjunctiva was sampled for Chlamydia trachomatis polymerase chain reaction (PCR) and general bacterial culture. Results: In total, 141/162 people were re-examined. Recurrent trichiasis was found in 89/214 (41.6%) operated eyes and 52 (24.3%) eyes had five or more lashes touching the globe. Corneal opacification improved in 36 of 78 previously affected eyes. There was a general deterioration in visual acuity between surgery and follow up, which was greater if new corneal opacification developed or trichiasis returned. Recurrent trichiasis was associated with severe conjunctival inflammation and bacterial infection. C trachomatis was detected in only one individual. Conclusions: Recurrent trichiasis following surgery is a common potentially sight threatening problem. Some improvement in the cornea can occur following surgery and the rate of visual loss tended to be less in those without recurrent trichiasis. The role of conjunctival inflammation and bacterial infection needs to be investigated further. Follow up of patients is advised to identify individuals needing additional surgical treatment.

Aim: To describe the distribution of cataract subtypes present before surgery among a defined population of older, bilaterally pseudophakic individuals. Methods: This was a cohort study of bilaterally pseudophakic individuals participating in the Salisbury Eye Evaluation (SEE), and their locally resident siblings. Subjects underwent slit lamp and retroillumination photography and grading using the Wilmer Cataract Grading System. For all individuals determined to be bilaterally pseudophakic, an attempt was made to determine for each eye the type(s) of cataract present before surgery, based on previous SEE photographs (for SEE participants) and/or medical records obtained from the operating ophthalmologist (for both SEE participants and their siblings). Results: The mean age of 223 participants providing data in this study was 78.7 (SD 5.2) years, 19.3% of subjects were black and 60.1% female. The most common surgically removed cataract subtype in this population was pure nuclear (43.5%), followed by nuclear combined with posterior subcapsular cataract (PSC) (20.6%), and nuclear combined with cortical (13.9%); less common types were pure cortical (4.9%), pure PSC (4.5%), and PSC combined with cortical (2.7%). Factors such as sex and source of lens data (study photograph versus clinical record) did not significantly affect the distribution of lens opacity types, while PSC was significantly (p = 0.01) more common among younger people and nuclear cataract was significantly (p = 0.001) more common among white compared to black people. Conclusion: Epidemiological studies have suggested that the different subtypes of cataract are associated with different risk factors. As studies begin to identify new prevention strategies for cataract, it would appear likely that different strategies will be efficacious against different types of cataract. In this setting, it will be helpful to know which cataract types are most frequently associated with surgery. Among this older, majority white population, nuclear cataract showed a clear predominance among individuals having undergone surgery in both eyes. This may be contrasted with both clinic and population based studies of younger people, which have generally found PSC cataract to predominate.

To describe the prevalence of different types of cataract and their association with visual acuity in a Tanzanian population aged 40 years and older.A prevalence survey for lens opacity, glaucoma, and visual impairment was carried out on all residents age 40 and older of six villages in Kongwa, Tanzania. One examiner graded the lens for presence of nuclear (NSC), posterior subcapsular (PSC), and cortical cataract (CC), using the new WHO Simplified Cataract Grading System. Visual acuity was measured in each eye, both presenting and best corrected, using an illiterate E chart.The proportion of eligible subjects participating was 90% (3268/3641). The prevalence of cataract was as follows: NSC, 15.6%; CC, 8.8%; and PSC, 1.9%. All types of cataract increased with age, from NSC, 1.7%; CC, 2.4%; and PSC, 0.4% for those aged 40 to 49 years to NSC, 59.2%; CC, 23.5%; and PSC, 5.9% for those aged 70 years and older (P0.0001 for all cataract types, chi(2) test for trend). Cataract prevalence was higher among women than men for NSC (P = 0.0001), but not for CC (P = 0.15) or PSC (P = 0.25), after adjusting for age. Prevalence rates of visual impairment (BCVA6/12), US blindness (or = 6/60) and WHO blindness (6/120) for this population were 13.3%, 2.1%, and 1.3%, respectively. Older age and each of the major types of pure and mixed cataract were independently associated with worse vision in regression modeling.Unlike African-derived populations in Salisbury and Barbados, NSC rather than CC was most prevalent in this African population. The seeming lower prevalence of CC may to some extent be explained by different grading schemes, differential availability of cataract surgery, the younger mean age of the Tanzanian subjects, and a higher prevalence of NSC in this population.

The prevalence rate of diabetes is probably higher in Hispanics than in Caucasians, although there is controversy about differences in the risk of diabetic retinopathy. The purpose of the study is to determine the prevalence rates of diabetes and diabetic retinopathy in a population-based study of Hispanics agedor = 40 years.Proyecto VER is a random sample of Hispanic populations agedor = 40 years in Arizona. A total of 4,774 individuals (71.6% of the eligible sample) completed the examinations. Diabetes was defined as self-report of a physician diagnosis or HbA(1c) value ofor = 7.0%. Diabetic retinopathy was assessed on stereo fundus photographs of fields 1, 2, and 4.The prevalence rate of diabetes in the Hispanic community (individualsor = 40 years of age) was 22%. The prevalence rate of diabetic retinopathy (DR) was 48%; 32% had moderate to severe nonproliferative and proliferative retinopathy. DR increased with increasing duration of diabetes and increasing level of HbA(1c). The prevalence rate of DR-like changes in the sample of individuals without diabetic retinopathy was 15% and was not associated with hypertension, systolic blood pressure, or diastolic blood pressure.The prevalence rate of diabetes in this population of Hispanics is high, almost twice that of Caucasians. The prevalence rate of DR is high but similar to reports in a Caucasian population. The prevalence rate of 9% moderate to severe retinopathy in the newly diagnosed group suggests that efforts to improve detection and treatment of diabetes in Hispanics may be warranted.

To assess the psychometric properties of the NEI-VFQ-25 in a population-based study of older Hispanic persons living in the United States, explore other demographic factors that affect participant response, and observe the comparability of the Spanish and English versions of the instrument.A sample of randomly selected block groups in Tucson and Nogales, Arizona, were selected for study. Participants were interviewed at home; a majority of the interviews were conducted in Spanish. The home interview included questions from the NEI-VFQ-25 and HHANES: Presenting acuity was done using ETDRS methodology, followed by a standardized eye examination by an ophthalmologist. The authors analyzed the internal consistency of the NEI-VFQ-25 responses using Cronbach's alpha coefficient and the construct validity by assessing the relationship between presenting acuity and scale scores, adjusting for age and gender. A second model was also explored to determine whether other demographic variables affected scale scores; differences in reporting between the Spanish and English versions was observed in this model, used in a subset of the population that minimized interviewer effect.Of the 4774 participants in the study, 99.7% had completed questionnaires, not completed by proxy. The highest nonresponse rate occurred in the Driving scale, with 25% of participants not driving for reasons other than problems with vision. Internal consistency was high, with Cronbach alpha ranging between 0.65 and 0.86 for scales with multiple items. Adjusting for age and gender, those with presenting acuity worse than 20/40 scored significantly lower than those with presenting acuity 20/40 or better, for all scales. The demographic variables with the most consistent association across the NEI-VFQ-25 scales were presenting acuity, income, and gender. No significant differences in reporting were found between the Spanish and English versions of the questionnaire in the subset of the population.In this study of Hispanic people age 40 years or older, the NEI-VFQ-25 was sensitive to presenting acuity and other demographic variables, such as age, gender, and income. The findings from this psychometric analysis provide evidence of the reliability and validity of some of the scales in the 25-item NEI-VFQ when used among people with a range of visual acuity level, providing other explanatory variables are also considered.

A classical twin study was performed to establish the relative importance of genes and environment in cortical cataract.Five hundred six pairs of unselected female twin volunteers (226 monozygotic and 280 dizygotic) with a mean age of 62 years (range, 49-79 years) were examined. Cortical cataract was assessed using the slit-lamp-based Oxford Clinical Cataract Classification and Grading System (clinical grading) and the Wilmer Automated Grading System, which analyzed digital retroillumination images of subjects' lenses (digital grading). The worse eye categorized score for each individual was used in maximum likelihood path modeling of the correlations within twin pairs. These correlations were used to determine the underlying liability to cortical cataract.Prevalence of significant cortical cataract (/=5% of lens area) was similar in monozygotic and dizygotic twins, occurring in 19.4% and 20.6% with the clinical grading system and 24% and 23% using the digital grading system, respectively. Modeling suggested liability to cortical cataract is explained by additive and dominant genes, individual environment, and age. Estimates of the broad sense heritability of cortical cataract were 58% (95% confidence interval [CI], 51%-64%) for the clinical grading system and 53% (95% CI, 45%-60%) for the digital system. Dominant genes were estimated to contribute to 38% (95% CI, 1%-64%) of the genetic effect with the clinical grading and 53% (95% CI, 28%-60%) with the digital grading. Individual environment explained 26% and 37% and age 16% and 11% of cortical cataract variance in clinical and digital gradings, respectively.Genetic effects are important in the development of cortical cataract and involve the action of dominant genes.

To compare the incidence of retinal detachment in patients treated with the ganciclovir implant compared with those treated using systemic therapy only, among 511 patients with the acquired immunodeficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis and to describe the influence of highly active antiretroviral therapy (HAART) on retinal detachment incidence.All patients with AIDS and CMV retinitis at 1 center were followed up prospectively from CMV retinitis diagnosis for incidence of retinal detachment. Patient- and eye-specific data regarding demographic and clinical characteristics were collected at the time of CMV retinitis diagnosis. Use of anti-CMV and antiretroviral treatments and the development of an immunologic response to HAART during follow-up were recorded.No significant difference in the rate of retinal detachment was found between eyes treated with systemic therapy only and those treated with ganciclovir implants, whether used as primary therapy or subsequent to using systemic anti-CMV therapy. The use of HAART was associated with a 60% reduction in retinal detachment rate (P.001), with the greatest benefit observed among patients who developed an immunologic response to HAART.Our results suggest that there is no substantial excess risk of retinal detachment when patients with AIDS and CMV retinitis are treated with ganciclovir implants as opposed to systemic anti-CMV therapy only. However, the use of HAART in these patients appears to reduce the risk of retinal detachment substantially.

This report examines the relationship between psychophysical measures of visual impairment and self-reported difficulty with everyday visual tasks in a population-based sample of individuals 65 years of age and older.Community-dwelling residents (n = 2520) of Salisbury, MD, between the ages of 65 and 84 were recruited for the study. Visual acuity under normal and low luminance, contrast and glare sensitivity, stereoacuity, and visual fields were measured. Subjective physical disability was assessed with the Activities of Daily Vision Scale (ADVS).In multiple regression analyses adjusted for demographic factors, cognitive status, depression, and number of comorbid medical conditions, each of the vision tests except low luminance acuity was independently associated with lower ADVS scores. The analyses indicate that a factor of 2 reduction in visual acuity or contrast sensitivity, comparable with that observed in mild to moderate lens opacity, was associated with a three- to fivefold odds of reporting difficulty with daily tasks. Although age alone was a significant risk factor for disability, it was not associated with overall ADVS score, once visual impairment and other chronic medical conditions were taken into account.Visual acuity, contrast and glare sensitivity, stereoacuity, and visual fields are significant independent risk factors for self-reported visual disability in an older population. Visual impairment defined by acuity alone is not the only dimension of the association with subjective disability. Additional vision measures are required to understand the impact of vision loss on everyday life.

To examine the relationship between monocular and binocular visual acuities as predictors of visual disability in a population-based sample of individuals 65 years of age and older.Two thousand five hundred twenty community-dwelling residents of Salisbury, Maryland, between the ages of 65 and 84 years of age were recruited for the study. Corrected visual acuity was measured monocularly and binocularly using ETDRS charts. Reading speed, face discrimination, and self-reported difficulty with visual tasks were also determined.Binocular acuity is predicted with reasonable accuracy by acuity in the better eye alone, but not by the widely used American Medical Association (AMA) weighted-average algorithm. The AMA algorithm significantly underestimates binocular acuity when the interocular acuity difference exceeds one line. Monocular acuity and binocular acuity were significantly better predictors of reading speed than the AMA weighted score or a recently proposed Functional Vision Score (FVS). Monocular acuity in the better eye, binocular acuity, and the AMA and FVS algorithms were equally good predictors of self-reported vision disability. None of the acuity measures were good predictors of face recognition ability.The binocular acuities of older individuals can be inferred from measures of monocular acuity. There is little evidence for binocular inhibition when the monocular acuities in the two eyes are unequal, as opposed to the widely used AMA algorithm for computing binocular visual impairment. For tasks that are strongly associated with visual acuity, such as reading, this association can be captured from measures of monocular acuity and does not require separate assessment of binocular acuity.

To determine the causes of blindness and visual impairment in a population-based sample of older Americans.A random sample of 3821 residents of Salisbury, Md, between the ages of 65 and 84 years was identified from Medicare records. Sixty-six percent (2520 persons) agreed to undergo an eye examination; 26% of the participants were African American. The clinical examination included acuity testing with an Early Treatment Diabetic Retinopathy Study chart and standardized refraction testing for those with a visual acuity worse than 20/30, slitlamp and dilated retinal examination by an ophthalmologist, tonometry, lens and fundus photography, and a suprathreshold visual field test. Visual impairment was defined as a best-corrected acuity in the better-seeing eye worse than 20/40 and better than 20/200, while blindness was acuity in the better-seeing eye of 20/200 or worse. For those with a visual acuity worse than 20/40 in either eye, one or more causes were assigned by an ophthalmologist and a final cause for each eye was confirmed by a panel of 3 subspecialty ophthalmologists (O.D.S., H.A.Q., and S.B.B.) based on all available evidence.Bilateral presenting acuity worse than 20/40 increased from 4% in the 65- to 74-year age group to 16% in the 80- to 84-year age group. One third of those with presenting acuity worse than 20/40 improved to 20/40 or better with refraction. Overall, 4.5% had a best-corrected acuity worse than 20/40. African Americans were more likely to remain visually impaired than were whites despite refraction (odds ratio [95% confidence interval], 1.7 [1.1-2.6]). Whites were most often impaired or blind from age-related macular degeneration (1.2% vs 0.5%; P=.09). African Americans had higher rates of impairment and blindness from cataract or posterior capsular opacification (2.7% vs 1.1%; P=.006), glaucoma (0.9% vs 0.1%; P=.006), and diabetic retinopathy (1.2% vs 0.2%; P=. 004).More than half of those with visual impairment or blindness had conditions that were either surgically treatable or potentially preventable. African Americans had a disproportionate number of blinding diseases, particularly those amenable to eye care intervention. Targeted interventions for specific populations to increase appropriate eye care use would greatly improve vision and function in older Americans. Arch Ophthalmol. 2000;118:819-825

To determine the prevalence of glaucoma in an adult population in rural central Tanzania.Six villages were randomly selected from eligible villages in the Kongwa district, and all residents more than 40 years of age were enumerated and invited to a comprehensive eye examination including presenting visual acuity, refraction, automated 40-point Dicon (San Diego, CA) suprathreshold screening field test, Tono-Pen (Bio-Rad, Inc., Boston, MA) intraocular pressure (IOP) measurement, and standardized examination by an ophthalmologist of anterior segment, optic nerve head, and retina after pupil dilation. Gonioscopy and Glaucoma-Scope (Ophthalmic Imaging Systems, Sacramento, CA) optic disc imaging were performed on those with IOP higher than 23 mm Hg and cup-to-disc ratio (c/d) more than 0.6 and on a 20% random sample of participants.Of 3641 eligible persons, 3268 (90%) underwent ophthalmic examination. The prevalence of glaucoma of all types was 4.16% (95% confidence interval [CI] = 3.5, 4.9%). Primary open-angle glaucoma (OAG) was diagnosed in 3.1% (95% CI = 2.5, 3.8%), primary angle-closure glaucoma (ACG) in 0.59% (95% CI = 0.35, 0.91%), and other forms of glaucoma in 0.49%. The prevalence of glaucoma was found to be sensitive to changes in the diagnostic criteria.The high prevalence of OAG in this group was similar to that of African-derived persons in the United States but less than in African-Caribbean populations. ACG was more prevalent in east Africans than suggested by anecdotal reports.

For more than two decades, researchers have sought to identify "risk factors" for age-related macular degeneration (AMD), a major cause of irreversible vision loss in the Western world, particularly in the elderly. Two issues have complicated this search: failure to differentiate between different stages of AMD and misinterpretation of measures of association (odds ratios) and risk (risk ratios) derivable from different research designs. Fortunately, in more recent epidemiologic studies, more attention has been given to these issues. Three groups of potential "risk factors" that have been studied were reviewed: those known to be risk factors for cardiovascular disease, environmental factors, and racial and ethnic factors. Of these, only tobacco smoking, a known risk factor for cardiovascular disease, has been demonstrated to be associated with AMD consistently across many studies of different design, carried out within different populations. The available evidence supports at least a doubling of risk of late AMD associated with long-term smoking, a factor that is under the control of the individual. The preponderance of evidence has not supported other factors to the same degree. Presently, racial and ethnic factors are high priorities for further research.

To develop and validate a digital imaging and analysis technique for assessing the extent of posterior capsular opacification after cataract surgery.Retroillumination images of the posterior capsule were obtained by using a digital camera mounted on a slit lamp. The images were analyzed using an available image analysis software program. The image acquisition and analysis techniques were tested for face validity, reproducibility, and the ability to detect progression of capsular opacity over time.Digital retroillumination images were obtained without patient discomfort. Automated analysis of images correlated well with clinical grading both at slit lamp examination and when looking at the images themselves (Spearman's correlation coefficient0.7). Analysis of images taken at different times showed high reproducibility (intraclass correlation0.9), and the system was able to identify progression of capsular opacity over a 2-year period with a mean increase of 15.8% in progressors versus an increase of 0.6% in nonprogressors (P0.05).Digital retroillumination images of the posterior capsule can be obtained reliably, and automated analyses correlate well with clinical assessment. The system presented here uses commercially available instruments and software, and it is practical for use in longitudinal studies of posterior capsule opacification. It is reliable, easy to use, and can detect small changes in the percentage area covered by posterior capsule opacification over time.

To describe the reported usual dietary intakes of the participants in the Salisbury Eye Evaluation (SEE) project and to estimate the prevalence of inadequate nutrient intakes using the probability approach.A representative sample of elderly residents (aged 65 to 85 years) of Salisbury, Md.Cross-sectional survey, using a food frequency questionnaire to obtain nutrient intakes. We estimated energy and protein; percent of energy intake from carbohydrates, fat, and protein; as well as usual intakes of cholesterol, vitamin A, carotenoids, vitamin C, thiamin, riboflavin, vitamin B-6, vitamin E, niacin, iron, calcium, zinc, and folate. Estimates of prevalence of inadequate nutrient intakes were calculated using the probability approach among the 2,655 participants with complete nutrient intake information.The chi 2 test for independence and analysis of variance. A P.05 was considered significant in a 2-sided test.On average, white participants of both genders reported higher mean energy and nutrient intakes than did black participants. Zinc had the highest estimated prevalences of inadequacy across all gender and race categories, followed by calcium, vitamin E, and vitamin B-6. Vitamin C, with estimated prevalences of inadequacy lower than 13%, and folate, with prevalences lower than 17%, had the lowest estimated prevalences of inadequacy across all gender, race, and age categories.In this population, there are race differences in estimated prevalences of inadequate nutrient intake. According to the current nutrient requirements for adults aged 51 years and older, many elderly persons have inadequate dietary intakes of key nutrients.

To determine eye care utilization patterns among older Americans, particularly characterizing those who sought different types of providers, and the predictive factors for seeking eye care services in general and among those with diabetes and those with visual loss.The SEE Project, a population-based survey of 2520 persons aged 65 to 84 in Salisbury, Maryland, provided cross-sectional data on eye care use. Questions on eye care use, demographics, medical history, and other factors were asked on the home interview.Use of an eye care provider in the previous year, with additional outcomes of use of different types of eye care providers.Blacks were significantly less likely to see any type of eye care provider over 1 year: 50% versus 69% among whites. Those who reported having a vision problem, those with more education, and those in the older age groups were significantly more likely to see either an ophthalmologist or an optometrist. Diabetes and driving a car were predictive factors for seeing an ophthalmologist but not for seeing an optometrist. Self-report of diabetes and eye care problems, and being a current driver, were predictive of seeing an eye care professional among those with visual impairment.Although blacks are known to be at greater risk for several age-related eye diseases, they are much less likely to see an eye care provider. Interventions that remove barriers to eye care services should be considered.

Visual impairment is a risk factor for morbidity in the elderly and is often screened for by self-report. This study evaluates whether there are subsets for whom there is a discrepancy between self-reported and measured function.The prevalence of a discrepancy between self-reported difficulty reading a newspaper and measured reading speed was determined in 2520 community-based men and women, aged 65 to 84 years, and the discrepant group characterized by polychotomous regression.Of subjects who reported minimal difficulty reading a newspaper, 10.8% (227/2107) read newsprint-sized text (0.21 degrees) more slowly than 80 words/min, a level previously shown to be necessary for sustained reading. Poor visual acuity, presence of psychiatric symptoms, and less satisfaction with vision were associated with being in the group that read slowly and reported difficulty with reading. Better cognition, better visual acuity, more years of education, white race, and fewer psychiatric symptoms were associated with being in the group that read more quickly and reported minimal difficulty. When reading the text size at which subjects read their fastest, only 2.6% of those with minimal difficulty remained discrepant. These individuals were more likely to have less education, be male, be African American, and have poorer cognitive status than those who did not remain discrepant.A subset of the elderly population have a substantial discrepancy between self-reported reading difficulty and measured reading speed. In some, this discrepancy may be based on underlying expectations and experiences, and in others it may represent a transition from no visual impairment to visual impairment.

To report on the usefulness of the Activities of Daily Vision Scale (ADVS) questionnaire for assessing visual functioning, a population-based sample of elderly Americans.The ADVS questionnaire was administered to a population-based sample of 2520 community-dwelling individuals 65 to 84 years of age in Salisbury, MD. Items and subscales were evaluated for internal consistency, item discrimination, and content validity. Published subscale groupings and item associations in our population were compared for coherence using correlation, factor, and cluster analyses. Whole-sample and race- and gender-specific analyses were conducted. External validity was explored by regressing ADVS scores on standard psychophysical vision measures.ADVS scores were skewed to high visual functioning levels; approximately 60% of the population had function scores of 95 or better (of a possible 100). The overall, night driving, and near vision scales were internally consistent and had strong item-subscale associations; the day driving and glare subscales were not acceptable regarding these properties. The far vision subscale was acceptably scalable but only weakly differentiated from the other subscales. Overall, night driving, near vision, and far vision scores were all statistically and independently associated with multiple psychophysical vision measures. Findings were consistent across race and gender subgroups.As assessed by the ADVS, reported visual functioning is high in our representative older population. The overall scale and selected subscales effectively distinguish persons along a spectrum of ability. They correlate with measures of visual impairment in a reasonable way and thus hold promise for risk factor investigations. The published day driving and glare subscales should be examined for relevance and consistency before being applied in population-based settings. Methods specific to population-based settings should be investigated for their ability to better elicit additional visual function dimensions and early visual disability.

We have developed an empirical model with which to estimate the ocular exposure in the UVB wavelength band. This model incorporates aspects of personal behavior, geographic location, season and wavelength that have been developed from population-based data. This model, in conjunction with job history interviews, allows the estimate of cumulative exposures from age 30 in our population-based study. We present data on average annual exposure by age, gender, race, education and reported photophobia. The exposures in the general population are considerably lower than exposures reported in previous works based on occupational groups. There is a statistically significant difference between males and females, with females having lower exposures. African-Americans have median exposures similar to whites. Exposures decrease with education and with reported photophobia. These data provide the basis for characterizing lifetime exposure for the general population. The variability of exposure is much greater than found in occupational groups and includes numbers in the lowest exposure. The model should permit determination of a dose-response relationship with eye disease, even to the lower dose ranges.

Many studies of functional status in elderly people use performance-based measures. There is an underlying assumption that these measures reflect, at least for some tasks, functional abilities in everyday tasks carried out at home. The purpose of this study was to determine the correlation between tasks carried out in the clinic and at home, and the role of visual impairment in performance at either setting.We compared the performance of 97 participants in the Salisbury Eye Evaluation (SEE) project at the clinic and at home on eight different tasks: semitandem stand, functional reach, stair climb and descend, inserting a plug, looking up and dialing a telephone number, and reading.The correlations were good for all tasks, with coefficients ranging from .52 to .86. Those with visual impairment were slightly more likely to perform better at home compared to the clinic, although the differences were statistically significant only for the reading task. The most important predictor of performance on any task in the home was performance on the task at the clinic, even after adjusting for age, race, sex, education, and visual impairment. Educational level and visual impairment were consistent predictors of performance in the home for most tests.We conclude that performances on standardized tasks in the clinic setting do correlate with similar tasks performed in the home, although the relationship is complicated in the presence of visual impairment.

To estimate the numerical value of the ocular-ambient exposure ratio (OAER) (ratio of the facial exposure to that on a horizontal plane) as a function of wavelength band, season, and job category and to establish the effect of various modifiers, such as geography and the use of hats, for use in general population studies.Two hundred sixty-four persons within several job categories representing the jobs in our Salisbury, Maryland, population were instrumented with ultraviolet-B (UVB) and visible band sensors for 1 complete day. Studies were done over all four seasons, both with and without hats.OAERs in the UVB wavelength band generally are higher than in the visible (13% versus 6%), display no significant variation with job category, show a seasonal effect (highest in the winter-spring [18%], lowest in the summer [10%], and intermediate in the fall [14%]), and are reduced 34% by the use of hats. In the visible wavelength band, OAERs are affected weakly by job function, although this variation is not significant, display a seasonal effect with three seasons as in the UVB, and are not affected significantly by the use of hats. In neither the UVB nor the visible portions of the spectrum did the authors find an effect on the OAER due to photophobia or eye color.With the authors' exposure model, the authors have at their disposal a valuable tool for exploring the relation between UVB, UVA, and visible radiation and a number of age-related eye diseases.

The Salisbury Eye Evaluation Project is a longitudinal study of risk factors for age-related eye diseases and the impact of eye disease and visual impairment on physical disability. In this article, the authors report the prevalence of visual impairment in their population and explore the relations among the various measures of visual function.A population-based sample of 2520 residents of Salisbury, Maryland, between the ages of 65 and 84 years were enrolled in the study. Twenty-six percent of participants were black. Vision tests included best-corrected Early Treatment Diabetic Retinopathy Study acuity, Pelli-Robson contrast sensitivity with and without glare, Randot stereoacuity, and 60 degrees Humphrey visual fields.Visual function decreased linearly with age for the acuity, contrast sensitivity, glare, and visual field tests. Stereoacuity remained constant into the mid-70s and declined at an accelerating rate thereafter. Black participants had lower contrast sensitivity, reduced stereoacuity, and worse visual fields, at all ages compared to white participants; however, white participants were more sensitive to glare. The overall prevalence of visual acuity impairment in blacks was 5.6% versus 3.0% for whites, using the traditional United States definition (worse than 20/40 to better than 20/200) and 3.3% for blacks versus 1.6% for whites, using the World Health Organization definition (worse than 20/60 to 20/400). Acuity was correlated moderately with contrast sensitivity, stereoacuity, and visual fields (Spearman rho = 0.50, 0.35, and 0.34, respectively). The correlation between acuity and glare sensitivity was low (rho = 0.12).Many aspects of visual function, not just acuity, decline with age. Black participants have more visual impairement than do white participants for all tests except glare sensitivity. The prevalence of visual acuity impairement in the Salisbury Eye Evaluation population is lower than that reported by other studies using similar test procedures. Low-to-moderate correlations among vision test scores suggest that several different dimensions of visual function are being assessed.

The Salisbury Eye Evaluation (SEE) project investigates the impact of vision on functional status in a population-based sample of elderly persons. The prevalence of self-reports of functional status and the association with visual acuity loss are described.A random sample of men and women 65 to 84 years of age from Salisbury, Maryland were recruited for home interviews and clinic examinations. Of the eligible sample, 78% responded to the home questionnaire and 65% responded to the questionnaire and the clinic examination. Binocular visual acuity of each person was measured using ETDRS charts and protocols. Questions were asked concerning activities of daily living, instrumental activities of daily living, physical function, social interaction, and activities of daily vision. Analyses of the association of presenting visual acuity worse than 20/40 with the measures of function were carried out and adjusted for age, race, and sex.All measures of functional status showed a decline with age; women and blacks were more likely to report difficulties. The age-adjusted proportions of those with visual impairment were not significantly different between men and women (7.2% versus 6.7%; P = 0.60). Black persons had almost twice the rate (10.4%) of white persons (5.6%; P0.001). Age, race, gender, and visual impairment were all significantly related to declines in functional status in multivariate models.Data on functional status in the project population were similar to national data and confirmed higher rates of disability in women and blacks. Binocular visual acuity worse than 20/40 appeared to have an impact on all the self-report measures of functional status. Further analyses on the interaction of vision with other comorbid conditions on function status clearly are indicated.

Eyelid repair surgery can prevent the effects of trichiasis leading to visual loss. Cost, transportation difficulties, and familial responsibilities have been identified as major barriers to surgical compliance. We evaluated whether offering trichiasis surgery in the village was effective in increasing the rate of surgical acceptance and in decreasing perceived barriers to surgery.In 1989, 205 women with trichiasis were identified in Central Tanzania and were offered free surgery along with free transport. As of 1991, only 18% of these women had undergone the surgery. We followed-up these women 7 years later after village level surgery was introduced.Since 1991, an additional 12% of the women had undergone eyelid surgery. 44% were conducted in the village. Surgical cases since 1991 reported shorter travel times to the place of surgery, similar post-surgical problems, and fewer days in the hospital. While providing benefits to the patient, increased village eye services did not increase the rate of surgical acceptance. The women who declined surgery did not know surgery in the village was available and the perceived cost and transportation difficulties continued to be barriers. 50% of the non-acceptors stated that there was nothing that would enable them to accept surgical intervention despite the fact that 3/4 of them reported eye symptoms that interfered with their daily activities.The cost efficacy of village level eye services needs to be evaluated and the awareness of these services increased.

We have designed, developed, and field evaluated a two-part personal dosimeter for estimating ocular exposure to visible and ultraviolet radiation. The detector head id compact enough to be mounted on the bow of eyeglass frames, and the recorder is small enough to be carried in a shirt pocket. The detector head consists of a silicon photodiode with filter (Schott glass GG400) and diffuser for visible light measurements and a polysulphone film badge for ultraviolet-B (UVB, 290-320 nm) measurements. The measurements correspond well to those obtained using ambient monitors and should be useful for studies of ocular UVB exposure.

Analysis of the results of ophthalmic examinations of 29 alpacas (Lama pacos) revealed a direct relationship among coat color, iris color, and ocular fundus pigmentation. Alpacas with light-pigmented coats had iris color that included combinations of gray, blue, and brown, and had reduced pigmentation of the ocular fundi. Alpacas with dark coats had brown irides and pigmented ocular fundi. Eleven alpacas had evidence of ophthalmic conditions, including bilateral conjunctivitis (1); formation of a superficial corneal scar (1); formation of posterior synechiae and anterior cataracts (4); development of a deep corneal scar with anterior synechiae, buphthalmia, a subluxated lens, and cataracts (1); development of focal incipient primary cataracts (2); formation of vitreous opacities (1); and development of a unilateral optic nerve coloboma (1).

Chisholm and colleagues’ paper is important to policy makers,1 so serious errors in the trachoma analysis require correction.2 Firstly, “mass treatment with azithromycin” for trachoma was defined as azithromycin treatment for all children aged 1-10 years,3 whereas the World Health Organization recommends treatment of all residents. Secondly, data from a 1998-9 western Nepal trial were extrapolated to estimate effectiveness of mass treatment throughout sub-Saharan Africa and South East Asia. Thirdly, the …

A total of 469 males over the age of 50 years were tested by the prostate specific antigen (PSA) with follow-up evaluations on those that exceeded 4.0 ng/ml. Thirty six (7.7 percent) of the participants had abnormal results, 23 (63.9 percent) had abnormal digital rectal examinations (DRE) and had biopsies done. Ten of the 23 biopsied participants had positive findings of prostate malignancy and 16 participants had benign prostatic hyperplasia. Three participants with abnormal PSA had negative DRE and no evidence of malignancy by ultrasound. Based on age-specific reference ranges, only one positive biopsy would have been missed while five of the 16 males who had negative biopsies would not have had to undergo this procedure. This would have resulted in a significant savings of medical costs as well as undue worry by the patient.

A model of organizational performance measurement that compels attention to the proper balance among quality, cost, and access; takes into account patient perceptions; produces clear targets for continual quality improvement (CQI); yields easily understood graphical displays; and captures health care organizations in simultaneous operation across the functions of cost, quality, and access was designed for the 22 medical treatment facilities of the Strategic Air Command. Such a tool provides practitioners, payers, and patients a range of information--from systemwide, facility, clinical service, and practitioner-specific insights on current performance to resource forecasts and easily understood targets for CQI. This case study shows that integrated performance modeling may be useful in examining many health management and reform issues.

Purpose Explore driving errors in older drivers and the subsequent decision to restrict or stop driving. Methods 1425 drivers aged 67–87, enrolled in a longitudinal study completed 5-day naturalistic driving assessment. Rate of failure to stop at red traffic lights, stop signs or safely execute left turns were modelled as predictors of stopping or restricting driving. Results 1237 (87%) completed 12-months, excluding those already restricting driving(n=35), 1.5% (18/1202) had stopped and 3.4% (41/1202) restricted their driving. Errors were observed in 32/1171 (2.7%) participants at red lights, 75/1155 (6.5%) at stop-signs, 88/1170 (7.5%) at left turns. The average failure rate per traffic light, stop sign and left turn was 0.2%, 2.2% and 0.4%, respectively. Police stopped 182 drivers during the year (15%), 81 were issued infringement notices (7%) and 34 were advised to stop or restrict driving (3%) however these factors were not predictive of incident driving change. Those with traffic light failures were more likely to stop or restrict their driving (adjusted OR 1.295; 95% CI 1.078 to 1.555 per per cent increase in failure rate). Failed stop sign (p=0.6) and left turns (p=0.4) were not predictive. Conclusions Driving errors were measured objectively in a large cohort of older drivers. While a rare event, red traffic light errors increased likelihood of subsequently restricting or ceasing driving. These findings lend support for self-regulation of driving exposure.

The relationship between intraocular and systemic blood pressures was investigated in a prospective study of 572 middle-aged men. There was no consistent relationship between intraocular pressure at first visit and age. Subjects with an intraocular pressure greater than 20 mm Hg had a significantly higher systolic blood pressure than controls matched for age. An autoregressive model was used to examine the relationship between change in intraocular pressure and initial intraocular pressure, age, and blood pressure. When the authors compared data obtained 1 or 2 years apart, a change in intraocular pressure was positively correlated with a change in systolic blood pressure. Thus, the results of this study indicate that changes in intraocular pressure over time are associated with changes in systolic blood pressure and that intraocular pressure does not necessarily increase with age.

In a rural village in the Philippines, sera were collected from 744 residents and tested for evidence of hepatitis B virus infection. In the subsequent year, every household was visited every other week for a period of three months in an attempt to identify clinically apparent cases. At the end of the year, sera were obtained from 78% of persons initially negative for hepatitis B virus and 97% of those initially positive for hepatitis B surface antigen (HBsAg). Overall, HBsAg was found in 8.8% of the population tested, of whom 86% were still HBsAg-positive at the end of the year. Susceptibility to hepatitis B virus infection declined significantly with age, to only 16% in the age group 50 years and older. No difference in the prevalence of markers by sex was observed. The risk of infection in children appeared to increase if one or both parents were infected, compared with both parents susceptible (odds ratio = 3.3 and 7.6, respectively); the risk increased if older siblings were infected, compared with all older siblings susceptible. The overall incidence rate of hepatitis B virus infection was 3.3% per year. For those aged five years or younger, the incidence rate was 9.2%. None of the seroconverters manifested acute symptoms of infection. Despite the evident clustering in families of persons with hepatitis B virus markers, which is suggested by the prevalence survey, only two of nine incident infections observed were in children with HBsAg-positive close relatives. The findings support the impression that in countries endemic for hepatitis B virus, most new cases occur in the young and are clinically inapparent. Furthermore, screening families of young children for chronic carriers in an effort to identify children at high risk for hepatitis B virus infection would have a low sensitivity in the Philippine setting.

A simple grading system for trachoma, based on the presence or absence of five selected ”key” signs, has been developed. The method was tested in the field and showed good observer agreement, the most critical point being the identification of severe cases of the disease. It is expected that the system will facilitate the assessment of trachoma and its complications by non-specialist health personnel working at the community level.

A simple system has been developed for the clinical grading of the presence and severity of lens opacities. The densities of nuclear opacities as seen on clinical slit-lamp examination are graded in comparison with a set of standard photographs. The extent of cortical opacities seen on retroillumination is estimated in terms of segments involved. The dimensions of posterior subcapsular opacities are measured using the slit beam. Inter- and intraobserver trials were conducted with three observers. Twenty subjects were selected to provide a range of lens opacities. Weighted Kappa statistics for intraobserver agreement for these three types of opacities range between 0.58 and 1.00 and for interobserver agreement between 0.41 and 0.71. This clinical grading system shows good reproducibility and compares well with the grading of lens opacities in photographs. It should prove to be of considerable use in clinical and epidemiological studies of cataract.

Microbial findings were analyzed from a group of 167 patients with psoriasis in an attempt to discover specific associations. Positive findings include associations between Malassezia ovalis and scalp/ear/face psoriasis and between bacteria and bodyfold, nailfold, and gluteal/rectal psoriasis.

A new simplified grading system for trachoma, which is based on the presence or absence of five selected key signs, has been assessed. The level of inter-observer variation and of variation for individual observers (intra-observer variation) showed that the system had good reproducibility following a training period that included interactive clinical teaching. The grading scheme was quickly learned by experienced ophthalmologists and auxiliary health personnel (ophthalmic nurses). The scheme should therefore be suitable for widespread application in field surveys of trachoma.

1. Partial purification of liver microsomal cytochrome p-450 results in the separation of two forms of cytochrome p-450 from phenobarbital-treated rats and two forms of cytochrome p-44, from 3-methylcholanthrene-treated rats. 2. Each of the four cytochrome fractions had different spectral properties (absolute spectra, CO differences spectra, and ethylisocyanide difference spectra). 3. The hemeprotein in fractions which elute from a DEAE-cellulose column at 100 mKM KCl fraction IV B) are more highly purified than the hemeproteins (fraction IV A) that elute in the column volume. 4. The more highly purified cytochrome fractions (IV B) contain 9-11 moles of cytochrome P-450 or P-448 per mg protein (an approximately 5-7 fold purification over microsomes) and are enzymatically active in the metabolism of a variety of substrates when combined with lipid and NADPH-cytochrome c reductase. These hemeprotein fractions are free of cytochrome b5 and NADPH-cytochrome c reductase, and the hemeproteins are purified approximately 100-fold with respect to phospholipid. The cytochrome P-450 and P-448 are virtually free of epoxide hydrase.

Methods for objectively documenting and grading different varieties of lens opacities are needed in order to conduct research on risk factors for cataracts. This study tested the feasibility and reliability of using two different photographic methods to grade nuclear opacities. Photographs were taken of 41 eyes using a regular Topcon SL-5D photo slit lamp, and using a Topcon SL-45 (Scheimpflug) camera. The photographs were graded against a set of four standard photographs of increasing nuclear opacification. Densitometric analyses were also performed on both sets of photographs. The clinical grade, on examination, of the nucleus was compared to the examiner's grade of each photograph. Agreement was fair between the examination results and the grading of the photographs. Inter-observer reliability was high (kappa = 0.71) with photographs taken using the photo slit lamp. Moreover, the severity grading of the photographs showed a good correlation with the severity of opacity as determined by densitometric analyses. On the basis of these data, and on the field experience, the use of photographs of the nucleus obtained by photo slit lamp may be used in epidemiological surveys.