Biomedical subjects

O D Schein

Publications and source records attributed to O D Schein.

At least 19 recordsLinked to original sources

PubMed1999

Racial difference in the incidence of retinal detachment in Singapore.

OBJECTIVE: To determine the incidence of retinal detachment (RD) operations in a multiracial Southeast Asian population. DESIGN: Population-based incidence study using a universal medical savings database in Singapore. METHODS: Information on all RD operations performed for rhegmatogenous RD (International Classification of Diseases, Ninth Revision, Clinical Modification code 361.0) between 1993 and 1996 was retrieved and analyzed from a population-wide, government-administered medical savings database. Exudative, tractional, and unoperated-on rhegmatogenous RD are excluded. The 1990 Singapore population census was used to allow an estimation of age-, sex-, and race-specific annual incidence of RD. RESULTS: Between 1993 and 1996, 1126 RD operations were performed on Singapore residents. The average annual incidence of RD operations was 10.5 per 100,000 population (95% confidence interval [CI], 10.2-10.9). The annual incidence was highest for Chinese (age-adjusted incidence, 11.6 per 100,000), followed by Malays (7.0 per 100,000), and lowest for Indians (3.9 per 100,000). The age-adjusted relative risk of RD operation for Chinese compared with Indians was 3.0 (95% CI, 2.9-3.1). Males were twice as likely as females to require RD surgery (age-adjusted relative risk, 2.0; 95% CI, 1.7-2.4). Chinese men 40 years and older had a 30.9 times higher risk (95% CI, 9.9-96.1) than Indian females younger than 40 years. CONCLUSION: The incidence of RD is strongly associated with male sex and ethnic origin.

Adolescent↗

PubMed1999

Who participates in population based studies of visual impairment? The Salisbury Eye Evaluation project experience.

PURPOSE: To describe characteristics of respondents and nonrespondents to a home questionnaire and comprehensive clinical examination in a population of elderly Americans. METHODS: The SEE project is a population-based study of age-related eye diseases, visual impairment, and functional status of individuals aged 65 to 84. Potential participants were identified using the Health Care Financing Administration Medicare data base for Salisbury, MD: After sending out an introductory letter, a trained interviewer visited potential participants in their homes, obtained their consent to participate, administered a short screening interview that included questions about their general health and vision, and administered an extensive questionnaire on their diet, medical history, and difficulty performing activities related to vision. The interviewer then scheduled an appointment for the participants to visit a central site for an exam. Potential participants could fall into one of two refusal groups; refusal to take part in the study before the home questionnaire or prior to the clinic visit. RESULTS: The overall response rate for the clinic visit was 65%. Compared to individuals with complete exams, the two groups of refusals were older, less likely to have any college education, more likely to report poor health status, and more likely to need help with Independent Activities of Daily Living (IADL's). Participants with complete home questionnaires that failed to come to the clinic were more likely to have Mini-Mental scores below 25. There were not significant differences by race, gender, or self reported vision status among the three groups. CONCLUSIONS: Population-based studies requiring an in-clinic examination may selectively under-sample those with health and mental difficulties. These differential responses may introduce bias in the study results and need to be addressed when assessing the burden, type and severity of disease in the community. However, self-report of visual status was similar among refusals and participants in this study on vision.

Activities of Daily Living↗

PubMed1998

Racial differences in lens opacities: the Salisbury Eye Evaluation (SEE) project.

The purpose of this study was to determine racial differences in the prevalence of different types of lens opacities and cataract surgery. Between 1993 and 1995, the Salisbury Eye Evaluation (SEE) Project enrolled a representative sample of 2,520 community-dwelling persons aged 65-84 years in Salisbury, Maryland, 26.4% of whom were African-American. Participants received a full eye examination, and photographs were taken for documentation of lens status. Photographs were graded using a standardized grading system for the presence of cortical, nuclear, or posterior subcapsular cataract (PSC) opacification in at least one eye. The odds of having cortical opacities were 4.0 times greater among African Americans than among Caucasians (95% confidence interval (CI) 3.3-4.8). Caucasians were significantly more likely to have nuclear opacities (odds ratio = 2.1, 95% CI 1.7-2.6) and PSC opacities (odds ratio = 2.5, 95% CI 1.7-3.6). The odds of cataract surgery were 2.8 times higher among Caucasians, but these differences did not explain the differences in the prevalence of different types of lens opacities by racial group. With lower rates of nuclear and PSC opacities than Caucasians, African Americans may have a lower demand for cataract surgery. However, even with these differences, there is still significant unnecessary loss of vision due to cataract among older African Americans, for whom programs to ensure access to surgical care are indicated.

Aged↗

PubMed1998

Sunlight exposure and risk of lens opacities in a population-based study: the Salisbury Eye Evaluation project.

CONTEXT: Exposure to UV-B radiation in sunlight has been shown to increase the risk of cataract formation in high-risk occupational groups, but risk to the population has not been quantified. OBJECTIVES: To determine the ocular exposure to UV-B radiation in sunlight for a population of older persons and to determine the association between UV-B and lens opacities. DESIGN: The Salisbury Eye Evaluation project, a population-based cohort of older adults. SETTING: Salisbury, Md. PARTICIPANTS: A total of 2520 community-dwelling 65-year-old to 84-year-old adults in Salisbury, Md, from 1993 to 1995, of whom 26.4% were African Americans. MAIN OUTCOME MEASURE: Association of photographically documented cortical opacity 3/16 or greater in at least 1 eye with ocular UV-B exposure, reported in Maryland sun-years of exposure. RESULTS: The odds of cortical opacity increased with increasing ocular exposure to UV-B (odds ratio [OR], 1.10; 95% confidence interval [CI], 1.02-1.20). The relationship was similar for women (OR, 1.14; 95% CI, 1.00-1.30) and for African Americans (OR, 1.18; 95% CI, 1.04-1.33). Analyses of the ocular dose by each age group after the age of 30 years showed no vulnerable age group, suggesting damage is based on cumulative exposure. CONCLUSIONS: Although this population of older Americans has relatively low ocular exposure to UV-B in sunlight, there is still an association between ocular exposure and increasing odds of cortical opacity. Our study found an association among African Americans, which, to our knowledge, has not been reported previously. All sex and racial groups would benefit from simple methods to avoid ocular sun exposure.

Aged↗

PubMed1998

The use of processed pericardial tissue in anterior ocular segment reconstruction.

PURPOSE: To report the use of processed pericardial tissue in reconstructing the anterior ocular segment. METHOD: Three case reports. RESULT: Processed pericardial tissue was found to be a helpful adjunct in providing tectonic support and promoting epithelialization in the cases described. CONCLUSION: Processed pericardial tissue has potential application to a variety of anterior ocular segment conditions.

Adult↗

PubMed1998

Photorefractive keratectomy versus laser in situ keratomileusis for moderate to high myopia. A randomized prospective study.

OBJECTIVE: This report presents the results of a randomized clinical trial of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK). DESIGN: A randomized, prospective multicenter clinical trial. PARTICIPANTS: A total of 220 eyes of 220 patients entered the study cohort: 105 randomized to PRK and 115 to LASIK. The mean preoperative manifest refraction spherical equivalent was -9.23 diopters (D) in the PRK group and -9.30 D in the LASIK group. INTERVENTION: All patients received a one-pass, multizone excimer laser ablation as part of either a PRK or LASIK procedure using the Summit Apex excimer laser. Attempted corrections ranged from 6.00 to 15.00 D. MAIN OUTCOME MEASURES: Data on uncorrected and spectacle-corrected visual acuity, predictability,and stability of refraction, corneal haze, and flap complications were analyzed. Patients were observed for up to 6 months. RESULTS: One day after surgery, 0 (0.0%) and 3 (4.5%) eyes in the PRK group saw 20/20 and 20/40 or better uncorrected, respectively, while 7 (10%) and 48 (68.6%) eyes in the LASIK group saw 20/20 and 20/40 or better, respectively. At 6 months after PRK, 13 (19.1%) and 45 (66.2%) eyes saw 20/20 and 20/40 or better, respectively, while after LASIK, 16 (26.2%) and 34 (55.7%) eyes saw 20/20 and 20/40 or better, respectively (odds ratio = 0.56 for likelihood of uncorrected visual acuity < 20/40 for PRK vs. LASIK, 95% confidence interval [CI] = 0.31-1.19). After PRK, 39 eyes (57.4%) were within 1.0 D of attempted correction compared with 24 eyes (40.7%) in the LASIK group (odds ratio = 0.50 for likelihood fo undercorrection 1.0 D for PRK vs. LASIK, 95% CI = 0.24-1.04); however, the standard deviation of the predictability was similar between groups: 1.01 D for PRK and 1.22 D for LASIK. From months 1 to 6, there was an average regression of 0.89 D in the PRK group and 0.55 D in the LASIK group. After PRK, eight eyes (11.8%) had a decrease in spectacle-corrected visual acuity of two Snellen lines or more; after LASIK, two eyes (3.2%) had a decrease of two lines or more (odds ratio = 3.89 for risk of loss of spectacle-corrected visual acuity for PRK vs. LASIK, 95% CI = 0.71-21.30). Only two eyes had postoperative spectacle-corrected visual acuity less than 20/32, however. CONCLUSIONS: Although improvement in uncorrected visual acuity is more rapid in LASIK than in PRK, efficacy outcomes in the longer term generally are similar between the two procedures. There is a greater tendency toward undercorrection in LASIK eyes using the specific laser and nomogram in this study, but the scatter in achieved versus attempted correction is similar, suggesting little difference in the accuracy of the two procedures. A suggestion of decreased propensity for loss of spectacle-corrected visual acuity in LASIK eyes requires further investigation.

Adult↗

PubMed1998

Vision-specific function and quality of life after cataract extraction in south India.

PURPOSE: To assess visual and overall patient function after intracapsular (ICCE) and extracapsular (ECCE) cataract extraction in rural South India. SETTING: Aravind Eye Hospital, Tirunelveli, Tamil Nadu, South India, and the Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Baltimore, Maryland, USA. METHODS: This study evaluated preoperative visual acuity and demographic information and postoperative visual acuity and functional status measures in 71 patients having ECCE with posterior chamber intraocular lens (IOL) placement and 73 patients having ICCE with aphakic spectacle correction at Aravind-Tirunelveli Eye Hospital, Tamil Nadu, India. The principal outcomes assessed were visual acuity; quality-of-life score (possible range 0 to 100%); visual function measurement (possible range 0 to 100%). RESULTS: Patients in the ECCE group scored 10.17 (P = .0001) points higher than those in the ICCE group on the visual function scale after adjustment for differences in age, sex, level of education, marital status, residence, and type of employment. The ECCE group scored 7.69 points higher on visual function when adjusting for the differences in best corrected visual acuity, which was also better in the ECCE group. In the quality-of-life assessment, 77.1% in the ECCE group and 46.6% in the ICCE group scored 90% or better (OR 3.85; P = .006). CONCLUSIONS: Patients in rural south India having ECCE with posterior chamber IOL implantation obtained better postoperative visual function, quality of life, and visual acuity than those receiving ICCE with aphakic spectacle correction. These differences, which were not significantly affected by adjustment for age, sex, education, marital status, type of residence, and occupation, indicate that ECCE is clearly superior to ICCE.

Adult↗

PubMed1998

Assessing disability in the patient with cataract.

Significant progress has been made over the past decade in assessing the functional impact of cataract on patients. Several questionnaires have been shown to predict well the outcomes of cataract surgery. The following article highlights the most recent research in this area and reviews the progress that has been made in the past several years.

Cataract↗

PubMed1998

Prevalence of symptoms of dry mouth and their relationship to saliva production in community dwelling elderly: the SEE project. Salisbury Eye Evaluation.

OBJECTIVE: To estimate the prevalence of dry mouth symptoms and their correlation with saliva production in a population based sample of elderly people in the United States. METHODS: Two dry mouth questions were administered to and a modified Saxon test was performed in participants in a population based prevalence survey conducted among 2520 noninstitutionalized community dwelling residents of Salisbury, Maryland, aged 65-84 years. RESULTS: Seventeen percent reported having either dryness of mouth or waking at night feeling dryness in the mouth and needing to drink fluids often or all the time; 10.7% noted the former and 11.5% the latter. The prevalence of dry mouth symptoms increased with increasing age, was greater in women than men, and was greater in whites than blacks. The mean (SD) amount of saliva production was 2.38 (1.00) g/min; mean saliva production decreased with increasing age and was lower in women than men; no difference was noted by race. Persons with dry mouth symptom either often or all the time had significantly lower salivary production, even after adjustment for age and sex. CONCLUSION: Symptoms of dry mouth are common in the community dwelling elderly population, especially in white women, and correlate with decreased salivary production.

Age Factors↗

PubMed1997

International variation in ophthalmologic management of patients with cataracts. Results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in the management of patients with cataacts in 4 health care systems and to discuss the potential implications for cost and utilization of services. DESIGN: To characterize current clinical practice on patients with no coexisting medical or ocular conditions, a standardized questionnaire was sent to random samples of ophthalmologists in the United States (response rate, 82.5%), Canada (66.9%), and Barcelona, Spain (70.4%), and to all ophthalmologists in Denmark (80.1%). From the United States, 526 ophthalmologists who performed cataract surgery participated in the study; there were 276 from Canada, 89 from Barcelona, and 82 from Denmark. RESULTS: Although in all 4 sites most surgeons reported that they performed A-scanning, fundus examination, and refraction routinely before surgery, significant crossnational variation was observed in preoperative ophthalmic and medical testing. While preoperative medical tests were virtually unused in Denmark, they were widely used in the other sites. A significantly higher proportion of the surgeons in the United States and Barcelona reported that they performed less than 100 extractions per year compared with surgeons in Canada and Denmark (P < .001). A significantly higher proportion of the surgeons in the United States and Canada were performing predominantly phacoextraction compared with surgeons in Denmark and Barcelona (P < .001). Both within and across sites, considerable variation in number of follow-up visits and postoperative tests was observed. CONCLUSIONS: Significant international variation in the management of healthy patients with cataracts has been observed. If less intensive care is not associated with poorer outcomes, there is the potential for less costly care of patients with cataracts. Further research identifying the most cost-effective practices is needed.

Adult↗

PubMed1997

International variation in anesthesia care during cataract surgery: results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in anesthesia care and monitoring during cataract surgery and to discuss its implications for cost and safety. METHODS: A standardized questionnaire was sent to random samples of ophthalmologists in the United States, Canada, and Barcelona, Spain, and to all ophthalmologists in Denmark. The survey was conducted in 1993 and 1994. Certified ophthalmologists who had performed 1 or more cataract extractions in the previous year were eligible for enrollment. RESULTS: The response rates were 62% in the United States (n=148), 67% in Canada (n=276), 70% in Barcelona (n=89), and 80% in Denmark (n=82). The anesthetic technique for cataract surgery varied significantly between sites (P<.001). Surgeons reported that retrobulbar blocks were used for 46% of the cataract extractions in the United States, 70% in Canada, 66% in Denmark, and 31% in Barcelona. In Barcelona, general anesthesia was used for 23% of the cataract extractions; it was used for less than 3% of the extractions at the other 3 sites. Peribulbar blocks or topical anesthesia was used for the remaining extractions. In the United States, Canada, and Barcelona, surgeons reported that vital functions were monitored during more than 97% of the extractions and anesthesia surveillance was used during more than 78% of the extractions. In Denmark, ophthalmologists reported that vital functions were monitored and anesthesia surveillance was used for 1% of the cataract extractions (P<.001). CONCLUSIONS: Substantial international variation in anesthesia care and monitoring during cataract surgery was observed. The findings suggest a need for further research to determine whether less intensive monitoring is cost-effective.

Anesthesia↗

PubMed1997

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.

Aged↗

PubMed1997

Results of phase III excimer laser photorefractive keratectomy for myopia. The Summit PRK Study Group.

OBJECTIVE: The purpose of the study is to determine safety and efficacy outcomes of excimer laser photorefractive keratectomy (PRK) for the treatment of mild-to-moderate myopia. DESIGN: A prospective, multicenter, phase III clinical trial. PARTICIPANTS: A total of 701 eyes of 701 patients were entered in the study; 612 eyes were examined at 2 years after surgery. INTERVENTION: Intervention was photorefractive keratectomy using the Summit ExciMed UV200LA excimer laser (Summit Technology, Inc., Waltham, MA). The treatment zone diameter used was 4.5 mm in 251 eyes (35.8%) and 5 mm in 450 eyes (64.2%). Attempted corrections ranged from 1.50 to 6.00 diopters (D). MAIN OUTCOME MEASURES: Predictability and stability of refraction, uncorrected and spectacle-corrected visual acuity, refractive and keratometric astigmatism, corneal haze, contrast sensitivity, subjective reported problems of glare and halo, and patient satisfaction were the parameters measured. RESULTS: At 2 years, 407 (66.5%) eyes achieved 20/20 or better uncorrected visual acuity and 564 (92.5%) eyes achieved 20/40 or better visual acuity. Three hundred thirty-six (54.9%) eyes were within 0.5 D and 476 (77.8%) eyes were within 1.0 D of attempted correction. Stability of refraction improved with time; 86.8% of eyes were stable within 1.0 D from 6 to 12 months, 94% were stable from 12 to 18 months, and 96.3% were stable from 18 to 24 months. There was no evidence of progressive or late myopic or hyperopic refractive shifts. One hundred fourteen (18.6%) eyes gained 2 or more lines of spectacle-corrected visual acuity, whereas 42 (6.9%) eyes lost 2 or more lines; however, of the latter, 32 (76.2%) had spectacle-corrected visual acuity of 20/25 or better and 39 (92.9%) eyes had 20/40 or better. Four hundred forty-two (72.2%) corneas were clear, 138 (22.5%) showed trace haze, 20 (3.3%) mild haze, 9 (1.5%) moderate haze, and 3 (0.5%) marked haze. On patient questionnaires, 87 (29.7%) patients reported worsening of glare from preoperative baseline; 133 (50.1%) reported worsening of halo symptoms from baseline. CONCLUSIONS: Photorefractive keratectomy appears effective for myopic corrections of -1.50 to -6.00 D. Uncorrected visual acuity is maximized in most eyes by 3 months, although some patients require between 6 months and 1 year to attain their best postoperative uncorrected visual acuity and some may require from 1 to 2 years for stabilization of refraction. Refraction stabilizes progressively without evidence of late myopic or hyperopic refractive shifts. Optical sequelae of glare and halo occur in some patients treated with a 4.5- or 5-mm treatment zone.

Adult↗

PubMed1997

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.

Aged↗

PubMed1997

New objective classification system for nuclear opacification.

We have developed an autonomous objective classification scheme for degree of nuclear opacification. The algorithm was developed by using a series of color 35-mm slides acquired with a Topcon photo slit-lamp microscope and use of standard camera settings. The photographs were digitized, and first, and second-order gray-level statistics were extracted from within circular regions of the nucleus. Classifications of severity were performed by using these features as input to a neural network. Training versus classification performance was tested by using photographs of different eyes, and test/retest classification reproducibility was evaluated by using paired photographs of the same eyes. We demonstrate good performance of the classifier against subjective assessments rendered by the Wilmer grading system [Invest. Ophthalmol. Visual Sci. 29, 73 (1988)] and markedly better test/retest reproducibility.

Algorithms↗

PubMed1997

Effects of randomizing second eyes in a trial to evaluate preoperative medical testing for cataract surgery.

The statistical and practical implications of including second eye surgeries were examined in a clinical trial designed to evaluate the impact of routine preoperative testing prior to cataract surgery on major medical events occurring within seven days following surgery. In order to detect a 0.8% difference in the rates of rare major medical events between the tested and untested groups, 20,000 surgeries must be randomized. About 30% of cataract operations were estimated to be done on second eyes of patients already included in the cohort. Different options for dealing with second eye surgeries were: (1) exclusion of all second eye surgeries, (2) inclusion of second eye surgeries only if the first eye is not enrolled, (3) inclusion of first and second eyes but randomization of patients rather than eyes, and (4) inclusion of first and second eyes but randomization of surgeries rather than patients. The final decision was to exclude second eye surgeries done within 28 days of first eye surgeries, but to rerandomize all other second eye surgeries. Differences in event rates between treatment groups can be estimated using Generalized Estimating Equations, and the association between outcomes of first and second eye operations estimated with pairwise odds ratios. An anticipated small positive correlation is likely to have minimal impact on statistical power and effective sample size.

Cataract↗

PubMed1997

Function and visual impairment in a population-based study of older adults. The SEE project. Salisbury Eye Evaluation.

PURPOSE: 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. METHODS: 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. RESULTS: 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%; P < 0.001). Age, race, gender, and visual impairment were all significantly related to declines in functional status in multivariate models. CONCLUSIONS: 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.

Activities of Daily Living↗

PubMed1997

Self-reported assessment of dry eye in a population-based setting.

PURPOSE: To report on a subjective dry eye assessment method for use in large-scale research, to evaluate its application in a population-based study of dry eye among elderly persons in the United States, and to apply novel techniques to improve simple questionnaire item summaries. METHODS: A dry eye questionnaire was administered to a population-based sample of 2520 volunteers ages 65 to 84 years in Salisbury, Maryland. Individual symptoms and signs, counts of symptoms and signs, and latent class model summary of item responses were evaluated for validity and internal consistency. RESULTS: Approximately 15% of participants reported experiencing one or more of six dry eye symptoms often or all the time; 20% reported experiencing three or more symptoms sometimes, often or all the time. Four groups were derived on the basis of symptomatology, using latent class analysis. The groups exhibited face validity, revealed symptom patterns that added specificity to simple symptom counts, and were qualitatively similar when derived separately within population subgroups. Internal consistency was moderate (Cronbach's alpha = 0.61), indicating some variability in reporting. CONCLUSIONS: Dry eye symptoms are commonly reported in a representative elderly population. Symptom data were moderately consistent, suggesting their usefulness for dry eye assessment if properly summarized. A latent class summary revealed biologically meaningful summary patterns of symptoms reported in this population and holds promise for use in risk factor investigations and in clinical trials.

Aged↗