Biomedical subjects

C A McCarty

Publications and source records attributed to C A McCarty.

At least 55 records · Page 3Linked to original sources

PubMed2000

Survey of dry eye symptoms in Australian pilots.

In 1996, a questionnaire was distributed to 4000 Australian commercial pilots for the quantification of symptoms of dry eye. The 1246 respondents ranged in age from 18-71 years (mean age 40.4 years), and 98.2% were men. Symptoms of dry eye during flight were reported by 901 (72.3%, 95% CI = 69.7 74.8) while only 67 (5.4%, 95% CI = 4.2-6.8) reported dry eye independent of flight. In univariate analyses, the following factors were associated with dry eye in flight: age, use of distance glasses, smoking, average weekly number of flight hours, type of aircraft usually flown, and normal cruising altitude. In a multiple logistic regression model, only the class of aeroplane (large jets vs. propeller-driven planes) (OR = 1.75, 95% CI = 1.34-2.28) and estimated number of flight hours per week (OR = 1.58, 95% CI = 1.34-1.86) were related to dry eye symptoms. In conclusion, self-reported symptoms of dry eye are common in Australian pilots and are associated with aeroplane class and flying time.

Adolescent↗

PubMed2000

Examination compliance and screening for diabetic retinopathy: a 2-year follow-up study.

Early detection and timely treatment of diabetic retinopathy can preserve vision, yet many people with diabetes do not have their eyes examined regularly. The purpose of this study was to examine eye care practices of people with diabetes who had not previously accessed eye care services on a regular basis. Screening with non-mydriatic retinal photography for diabetic retinopathy was initiated in 1996, and targeted people with diabetes who did not access eye care services on a regular basis. Each test area was revisited 2 years after the initial screening. Patients that did not attend the biennial screening were followed up by mail survey. Although none of the participants in this study had been previously accessing eye care services on a regular basis, 87% did so after attending the screening. These results indicate that mobile screening with non-mydriatic photography, as an adjunct to current eye care services, has the potential to increase examination compliance for diabetic retinopathy and to achieve sustained behaviour change.

Diabetic Retinopathy↗

PubMed2000

Functional implications of vision impairment.

This study investigated the functional implications of vision impairment. A total of 508 participants in the Visual Impairment Project completed the VF-14 questionnaire, vision-related functional tasks, an interview, and the ophthalmic examination. Participants with less than 6/12 presenting acuity were more likely to report a moderate to high degree of difficulty performing VF-14 items (odds ratios from 6 to 44). They were also more likely to be unable to recognize a 10 cent coin (OR; 7.0, 95% CL; 2.6, 19.3) or correctly read a telephone number (OR; 10.1, 95% CI; 5.6, 18.1). As demonstrated by the VF-14 and the functional tasks administered in this study, visual impairment affects the ability of people to conduct a variety of common daily tasks.

Aged↗

PubMed2000

Detection of vision impairment in people admitted to aged care assessment centres.

Vision is not routinely tested when the health of older people is assessed, and the aim of this study was to detect older people with vision impairment for referral to appropriate eye care services. People admitted for assessment and or rehabilitation in three aged care assessment centres had distance and near visual acuity assessed with a simplified vision test. A pinhole test was used when necessary. Referral criteria were distance visual acuity of less than 6/12; near vision of less than N8, and people with diabetes who had not attended a dilated fundus examination in the last 2 years. Visual acuity results were obtained in 93% of patients (685/735). Those unable to perform the vision test were very ill or had severe cognitive impairment. Forty-three per cent of patients (266/646) had impaired vision and, of these, 70.6% (188/266) were referred to eye care specialists. Forty-five per cent were referred to ophthalmologists, 36% to optometrists and 20% to low vision services. This significant proportion of patients with poor vision suggests that vision screening is warranted.

Aged↗

PubMed2000

Association of presbyopic correction with changes in visual fields.

The purpose of this study was to investigate the effect of presbyopic correction on changes in visual fields caused by an alteration in outflow of aqueous humour Visual fields were compared before and after introduction of presbyopic correction in participants of the Melbourne Visual Impairment Project. Height and slope of the 'Hill of Vision' were assessed by calculating median thresholds in the four sets of three eccentric points. Analysis of 101 eyes in the study group and 101 eyes in the control group shows higher decrease of the 'Hill of Vision' height in the group of participants who started wearing presbyopic correction, than in the group without presbyopic correction (P = 0.02). Intraocular pressure measured irrespectively of participant's accommodative activity was not significantly different between the two groups at both time points. These data suggest that the use of presbyopic correction is associated with changes in the visual field.

Accommodation, Ocular↗

PubMed2000

Ocular trauma in an urban population in southern India: the Andhra Pradesh Eye Disease Study.

PURPOSE: To assess the cumulative prevalence of ocular trauma and presence of vision loss due to ocular trauma in an urban population in southern India. METHODS: As part of the population-based Andhra Pradesh Eye Disease Study, 2522 people of all ages from 24 clusters representative of the population of Hyderabad city in southern India, underwent a detailed interview and standardized dilated ocular evaluation. An eye was considered to be blind due to trauma if best corrected distance visual acuity was worse than 6/60 due to trauma. RESULTS: One hundred and thirteen subjects gave a history of ocular trauma and another two had evidence of ocular trauma by examination, a combined age sex-adjusted rate of 3.97% (95% CI 2.52-5.42%). Blindness in one eye due to trauma was present in 17 subjects, and in both eyes in one subject, a combined age-sex-adjusted prevalence of 0.60% (95% CI 0.23-1.04%). Visual acuity in all the blind eyes except one was worse than 3/60. With multiple logistic regression, the odds of blindness in at least one eye due to trauma were highest for current age range of 30-39 years (odds ratio 6.33, 95% CI 1.69-23.77 compared with a current age of less than 30 years), were significantly higher for lower socioeconomic status (3.74, 95% CI 1.18 -11.84), and were higher for males (2.48, 95% CI 0.91-6.82) though this did not reach statistical significance. Trauma resulting in blindness had occurred by the age of 15 years in 55% of subjects, and before the age of 40 years in 92.1% of subjects; this had occurred most commonly while playing (53.6% of the cases). With multiple logistic regression, the odds ratios for any ocular trauma were significantly higher for males (2.10, 95% CI 1.40-3.15), and for labourers than for other occupations (2.50, 95% CI 1.62-3.86). CONCLUSIONS: Ocular trauma affects one in 25 people in this urban population in India, and one in 167 people in this population are estimated to be blind in at least one eye due to trauma. The majority of the trauma resulting in blindness occurs during childhood and young adulthood, and slightly more than half occurs while playing. Targeting mothers and children of lower socioeconomic strata in eye health awareness strategies to reduce blindness due to trauma needs to be considered in urban India.

Adolescent↗

PubMed2000

Methods for detecting age-related maculopathy: a comparison between photographic and clinical assessment.

PURPOSE: To examine the sensitivity, specificity and overall agreement between photographic and clinical assessment in detecting age-related maculopathy (ARM) features in the context of an epidemiological study, the Vitamin E, Cataract and Age-related Maculopathy Study (VECAT). METHODS: A total of 1204 volunteers aged between 55 and 80 years of age, who were enrolled in the VECAT Study, had both slit-lamp biomicroscopy examination and fundus photos taken as part of the baseline ophthalmic examination. The Nidek 3-DX fundus camera (Nidek, Gamagori, Japan) was used to produce paired, one-framed, coloured, 15 degrees stereoslides of the macular area at a fixed angle. An International Classification and Grading System for Age-related Maculopathy and Age-related Macular Degeneration was used to grade the stereoslides. Agreement in the detection of drusen, pigment abnormalities, and late stage ARM features was assessed using unweignted kappa statistic. Cases of disagreement were verified using clinical data records, grading documentation and the review of stereoslides. RESULTS: Macula status was available for 2386 eyes. For drusen of size < 63 microm, sensitivity was 47%, specificity was 68% with a kappa value of 0.20. For drusden > or = 125 microm, sensitivity and specificity were > or =81%. Kappa values ranged from 0.56 to 0.71. Levels of agreement for pigment abnormalities and late ARM were in the substantial range (i.e. kappa values from 0.70 to 1.00). CONCLUSIONS: Slit-lamp biomicroscopy was found to be comparable to photograding (using the Nidek 3-DX fundus camera) for detecting features pertaining to ARM. However, given the objectivity and permanency of stereoslides, photograding is still the more reliable and the preferred system of assessing ARM in the context of an epidemiological study.

Aged↗

PubMed2000

Digital cataract photography.

This study compares the cost effectiveness of two methods of grading cataract changes in the Australian population. The conventional film-based method has comparatively low set-up costs, but is more subjective in its assessment and more reliant on manpower, while the digital method has high set-up costs, but the results are more objective and available more quickly using fewer people. By a careful assessment of all the costs involved it is possible to estimate how many participants need to be recruited to a study in order to make the digital method cost effective.

Australia↗

PubMed2000

Diabetes in Victoria, Australia: the Visual Impairment Project.

OBJECTIVES: To establish the prevalence and characteristics of self-reported diabetes in a representative sample of Victorian residents aged 40 years and older, and to compare the vision between people with and without self-reported diabetes. DESIGN: Cross-sectional survey. SETTING: Nine randomly selected suburban Melbourne clusters and four randomly selected rural Victorian clusters. PARTICIPANTS: 4,744 subjects (86% participation rate) aged > or = 40 years. MAIN OUTCOME MEASURES: Subjects answered a detailed questionnaire which provided demographic details, body mass index, and the duration and treatment of any diagnosis of diabetes. Refraction was performed and best-corrected visual acuity was measured. RESULTS: The prevalence of self-reported diabetes was 5.1%. In a multivariate analysis, self-reported diabetes was positively associated with age (p < 0.01), male sex (p = 0.01), higher body mass index (p = 0.01), Mediterranean ethnicity (p = 0.01), unemployment (p = 0.05) and lack of private health insurance (p < 0.05). People with self-reported diabetes were more likely to have mild or moderate levels of visual impairment than people who reported no previous diagnosis of diabetes (p < 0.01). CONCLUSIONS: Diabetes in Victoria is more prevalent among men and among people of Mediterranean origin. When planning educational programs and health service delivery, it is also important to consider that, compared with the general population, people with diabetes are less likely to be employed or to have private health insurance, and are more likely to have impaired vision.

Adult↗

PubMed2000

Utilisation of eyecare services in an urban population in southern India: the Andhra Pradesh eye disease study.

AIM: To assess utilisation of eyecare services by people with visual impairment <6/18 or equivalent visual field loss in the better eye in the urban population of Hyderabad in southern India. METHODS: 2522 subjects of all ages, representative of the population of Hyderabad city, underwent a detailed interview and dilated examination as part of the population based Andhra Pradesh eye disease study. Subjects more than 15 years of age were interviewed regarding the use of eyecare services. RESULTS: Of 250 subjects with presenting distance visual acuity <6/18 or equivalent visual field loss in the better eye, information on utilisation of eyecare services was available for 229 (91.6%). Of these 229 subjects, 44 (19%) had visual acuity <6/60 or equivalent visual field loss in the better eye, and 202 (88.2%) had noticed decrease in vision over the past 5 years. Multivariate analysis showed that this decrease in vision was noticed significantly less by subjects with refractive error as the cause of visual impairment (odds ratio 0.34, 95% confidence interval 0.12-0.93). Of the 229 subjects who were visually impaired, 108 (59%) did not seek treatment. Multivariate analysis revealed that the odds for seeking treatment were significantly lower for Hindus than Muslims (odds ratio 0.53, 95% confidence interval 0.28-0.98). The reasons for not seeking treatment could be classified as personal (49.5%), economic (30.8%), and social (19.6%). CONCLUSION: A large proportion of subjects with visual impairment in this urban population in India did not seek treatment even after noticing decrease in vision. Projecting these data to the 155 million urban population >15 years of age in India, there may be 4.9 million (95% confidence interval 4.3-5.5 million) people in urban India who are not seeking treatment for their visual impairment even after noticing decrease in vision. These data suggest that efforts have to be made to better understand the reasons for this phenomenon so that optimal utilisation of the available eyecare services in urban India can be planned.

Adolescent↗

PubMed2000

Epidemiology of pterygium in Victoria, Australia.

AIM: To describe the prevalence of and risk factors for pterygium in a population based sample of residents of the Australian state of Victoria who were aged 40 years and older. METHODS: The strata comprised nine randomly selected clusters from the Melbourne statistical division, 14 nursing homes randomly selected from the nursing homes within a 5 kilometre radius of the nine Melbourne clusters, and four randomly selected clusters from rural Victoria. Pterygium was measured in millimetres from the tip to the middle of the base. During an interview, people were queried about previous ocular surgery, including surgical removal of pterygium, and their lifetime exposure to sunlight. RESULTS: 5147 people participated. They ranged in age from 40 to 101 years and 2850 (55.4%) were female. Only one person in the Melbourne cohort reported previous pterygium surgery, and seven rural residents reported previous surgery; this information was unavailable for the nursing home residents. Pterygium was present upon clinical examination in 39 (1.2%) of the 3229 Melbourne residents who had the clinical examination, six (1. 7%) of the nursing home residents, and 96 (6.7%) of the rural residents. The overall weighted population rate in the population was 2.83% (95% CL 2.35, 3.31). The independent risk factors for pterygium were found to be age (OR=1.23, 95% CL=1.06, 1.44), male sex (OR=2.02, 95% CL=1.35, 3.03), rural residence (OR=5.28, 95% CL=3. 56, 7.84), and lifetime ocular sun exposure (OR=1.63, 95% CL=1.18, 2. 25). The attributable risk of sunlight and pterygium was 43.6% (95% CL=42.7, 44.6). The result was the same when ocular UV-B exposure was substituted in the model for broad band sun exposure. CONCLUSION: Pterygium is a significant public health problem in rural areas, primarily as a result of ocular sun exposure.

Adult↗

PubMed2000

Population based assessment of uveitis in an urban population in southern India.

AIM: To assess the prevalence of active and inactive uveitis unrelated to previous surgery or trauma in an urban population in southern India. METHODS: As part of the Andhra Pradesh Eye Disease Study, 2522 subjects (85.4% of those eligible), a sample representative of the population of Hyderabad city in southern India, underwent interview and detailed dilated eye examination. Presence of sequelae of uveitis without current active inflammation was defined as inactive uveitis. RESULTS: Unequivocal evidence of active or inactive uveitis unrelated to previous surgery or trauma was present in 21 subjects, an age-sex adjusted prevalence of 0.73% (95% confidence interval (CI) 0.44-1.14%). Active uveitis was present in eight subjects, an age-sex adjusted prevalence of 0.37% (95% CI 0. 19-0.70), of which 0.06% was anterior, 0.25% intermediate, and 0.06% posterior. The 0.36% (95% CI 0.17-0.68%) prevalence of inactive uveitis included macular chorioretinitis scars (0.26%), anterior (0. 07%) and previous vasculitis involving the whole eye (0.03%). The prevalence of visual impairment due to uveitis of less than 6/18 in at least one eye was 0.27%, less than 6/60 in at least one eye was 0. 16%, and less than 6/60 in both eyes was 0.03%. CONCLUSION: These population based cross sectional data give an estimate of the prevalence of various types of uveitis in this urban population in India. Active or past uveitis that might need treatment at some stage was present in one of every 140 people in this population.

Acute Disease↗

PubMed2000

Diabetic retinopathy in Victoria, Australia: the Visual Impairment Project.

AIM: To establish the prevalence, severity, and risk factors for diabetic retinopathy in a representative sample of Victorian residents aged 40 years and older. METHODS: A population based, cluster sampling method was used to recruit 4744 participants (86% participation rate). Nine randomly selected, suburban Melbourne clusters and four randomly selected, rural Victorian clusters were used. Participants provided a detailed medical and personal history and underwent an ocular examination including funduscopy and fundus photography. Rural participants provided a blood sample, from which the glycosylated haemoglobin percentage was measured. The diagnosis of diabetic retinopathy was based on fundus photographs from participants with self reported diabetes. RESULTS: The prevalence of diabetic retinopathy among people with self reported diabetes was 29. 1%. The prevalence of untreated, vision threatening retinopathy was 2.8%. Retinopathy was positively associated with a longer reported duration of diabetes diagnosis (p<0.01) and with higher fractions of glycosylated haemoglobin (p<0.01). Retinopathy was not significantly associated with age, ethnicity, body mass index, glaucoma, myopia or intake of alcohol, tobacco, or aspirin (all p > 0.05). CONCLUSIONS: Most people in Victoria with proliferative diabetic retinopathy or clinically significant macular oedema have received laser treatment. There remains however, a small but important group who have not received treatment and whose vision is threatened. People with diabetes should be encouraged to maintain strict glycaemic control and to undergo regular screening to delay or prevent the development of retinopathy.

Adult↗

PubMed2000

Recruitment methods for community-based screening for diabetic retinopathy.

Regular screening of all people with diabetes is the most efficient and cost-effective way to detect early stages of diabetic retinopathy so that laser treatment can be performed at the optimal time. A major aim of the Program for the Early Detection of Diabetic Retinopathy was to increase compliance with guidelines for screening for diabetic retinopathy. This community-based screening program used non-mydriatic retinal photography and was initiated in four areas of Victoria, Australia from 1996-1998. Recruitment strategies included targeted mail-outs, provision of the program brochure in English and the main languages spoken in the areas and media promotion in ethnic newspapers and on ethnic radio stations. In Victoria, only 55% of the population with diabetes currently access eye care services at the recommended intervals. This program was able to increase compliance with guidelines to 70% among people with diabetes that had not had a recent eye examination. A total of 1,197 people with diabetes were screened for diabetic retinopathy. Of the 1,197 people who were screened, 620 (15% of the estimated number of people with diabetes) had not had their eyes examined in the past two years. This pilot study identified strategies to encourage people with diabetes to have their eyes examined at the recommended intervals.

Age Distribution↗

PubMed2000

Attributable risk estimates for cataract to prioritize medical and public health action.

PURPOSE: Cataract is the most common cause of blindness in the world. The purpose of this study was to estimate the population attributable risk associated with identified risk factors for cortical, nuclear, and posterior subcapsular (PSC) cataract in a representative sample of the Victorian population aged 40 years and older. METHODS: Cluster, stratified sampling was used and participants were recruited through a household census. At locally established test sites, standardized clinical examinations were performed to assess cataract and personal interviews were conducted to quantify potential risk factors. Multivariate logistic regression was used to determine the independent risk factors associated with the three types of cataract, and the population attributable risk was calculated. RESULTS: A total of 3271 (83% of eligible) of the urban residents and 1473 (92%) rural residents participated. The urban residents ranged in age from 40 to 98 years (mean, 59 years), and 1511 (46%) were men. The rural residents ranged in age from 40 to 103 years (mean, 60 years), and 701 (48%) were men. The overall prevalence of cortical cataract was 12.1% (95% CL 10.5, 13.8), nuclear cataract 12.6% (95% CL 9.61, 15.7), and PSC cataract 4.93% (95% CL 3.68, 6.17). Significant risk factors for cortical cataract included age, female gender, diabetes for greater than 5 years, gout for greater than 20 years, arthritis, myopia, average annual ocular UV-B exposure, and family history of cataract (parents or siblings). Significant risk factors for nuclear cataract included age, female gender, rural residence, age-related maculopathy, diabetes for greater than 5 years, smoker for greater than 30 years, and myopia. The significant risk factors for PSC cataract were age, rural residence, thiazide diuretic use, and myopia. Of the modifiable risk factors, ocular UV-B exposure explains 10% of the cortical cataract in the community, and cigarette smoking accounts for 17% of the nuclear cataract. CONCLUSIONS: Because of the near universal exposure to UV-B in the environment, ocular protection has one of the highest modifiable attributable risks for cortical cataract and would therefore be an ideal target for public health intervention. Quit smoking campaigns can be expanded to incorporate information about the excess cataract in the community associated with long-term smoking. Nonmodifiable risk factors such as age, gender, and long-term medication use have implications for the timely referral and treatment for those at higher risk of cataract.

Adult↗

PubMed2000

Vision impairment predicts five-year mortality.

PURPOSE: To describe predictors of mortality in the 5-year follow-up of the Melbourne Visual Impairment Project (VIP) cohort. METHODS: The Melbourne VIP was a population-based study of the distribution and determinants of age-related eye disease in a cluster random sample of Melbourne residents aged 40 years and older. Baseline examinations were conducted between 1992 and 1994. In 1997, 5-year follow-up examinations of the original cohort commenced. Causes of death were obtained from the National Death Index for all reported deaths. RESULTS: Of the original 3,271 participants, 231 (7.1%) were reported to have died in the intervening 5 years. Of the remaining 3,040 participants eligible to return for follow-up examinations, 2,594 (85% of eligible) did participate, 51 (2%) had moved interstate or overseas, 83 (3%) could not be traced, and 312 (10%) refused to participate. Best corrected visual acuity < 6/12 and cortical cataract were associated with a significantly increased risk of mortality, as were increasing age, male sex, increased duration of cigarette smoking, increased duration of hypertension, and arthritis. CONCLUSIONS: Even mild visual impairment increases the risk of death more than twofold.

Aging↗

PubMed2000

Prevalence of amblyopia and associated refractive errors in an adult population in Victoria, Australia.

The study aimed to describe the prevalence of amblyopia and associated refractive errors among an adult Australian population. The Visual Impairment Project (VIP) is a population-based study of age-related eye disease in the state of Victoria, Australia. Data were collected through standardised interviews and orthoptic and ophthalmic dilated examinations. Amblyopia was defined as best-corrected visual acuity of 6/9 or worse in the absence of any pathological cause. The participants were 3,265 urban residents and 1,456 rural residents of the VIP ranging in age from 40-92 years (mean = 59 years; 53% female). The prevalence of unilateral amblyopia was 3.06% (95% C.I. 2.59, 3.53). Amblyopia was not found to be statistically different by age group (p=0.096), gender (p=0.675), or place of birth (p=0.14). Anisometropia was statistically more common (p<0.001) in amblyopic cases (51.1%) compared to the normal population (9.7%), and 54% of amblyopic eyes had visual acuity of worse than 6/12. Amblyopia is a significant cause of unilateral reduced visual acuity in a population aged 40 years and older. Anisometropia was more prevalent and the degree of anisometropia was greater in the amblyopic group compared with the normal population. Oblique astigmatism was more prevalent in the amblyopic group compared with the normal population.

Adult↗

PubMed2000

Unilateral visual impairment in an urban population in southern India.

This study assessed the prevalence and causes of unilateral visual impairment in the urban population of Hyderabad city as part of the Andhra Pradesh Eye Disease Study. Stratified, random, cluster, systematic sampling was used to select 2,954 subjects from 24 clusters representative of the population of Hyderabad. Eligible subjects underwent detailed eye examination including logMAR visual acuity, refraction, slitlamp biomicroscopy, applanation tonometry, gonioscopy, dilatation, cataract grading, and stereoscopic evaluation of fundus. Automated threshold visual fields and slitlamp and fundus photography were done when indicated by standardised criteria. Unilateral visual impairment was defined as presenting distance visual acuity < 6/18 in the worse eye and > or = 6/12 in the better eye, which was further divided into unilateral blindness (visual acuity < 6/60 in the worse eye) and unilateral moderate visual impairment (visual acuity < 6/18-6/60 in the worse eye). A total of 2,522 subjects (85.4% of eligible), including 1,399 > or = 30 years old, participated in the study. In addition to the 1% blindness and 7.2% moderate visual impairment (based on bilateral visual impairment criteria) reported earlier in this sample, 139 subjects had unilateral visual impairment, an age-gender-adjusted prevalence of 3.8% (95% confidence interval 2.7-4.9%). The major causes of this visual impairment 39.9% were refractive error (42.9%), cataract (14.4%), corneal disease (11.5%), and retinal disease (11.2%). Of this unilateral visual impairment was blindness. The major causes of unilateral blindness were corneal disease (23.2%), cataract (22.5%), retinal disease (18%), and optic atrophy (12.9%). On the other hand, the predominant cause of unilateral moderate visual impairment was refractive error (67%) followed by cataract (9%). Of the total unilateral visual impairment, 34.3% was present in those < 30 years old and 36.2% in those 30-49 years old. Unilateral visual impairment afflicts approximately 1 in 25 persons in this urban population. A large proportion of this unilateral visual impairment is present in younger age groups. The causes of unilateral visual impairment, like those of bilateral visual impairment in this population, are varied, suggesting therefore, that in addition to the current focus of eye care in India predominantly on cataract, other causes of visual impairment need to be addressed as well.

Adolescent↗