The importance of epidemiology in understanding eye disease

Most leading causes of visual impairment are age related, so the health care implications of an increasing prevalence of eye disease in the elderly are significant. Epidemiological research provides the foundation to address immediate and long-term needs associated with visual impairment and eye disease. It contributes to a community's knowledge of the presence, diagnosis, characteristics, and distribution of eye conditions affecting the elderly. Obtaining accurate epidemiological information on the extent of visual impairment and eye disease in the community is essential to determine and estimate the cost of primary and secondary eye health care needs.

Do Nutritional Supplements Have a Role in Age Macular Degeneration Prevention?

Purpose. To review the proposed pathogenic mechanisms of age macular degeneration (AMD), as well as the role of antioxidants (AOX) and omega-3 fatty acids (omega-3) supplements in AMD prevention. Materials and Methods. Current knowledge on the cellular/molecular mechanisms of AMD and the epidemiologic/experimental studies on the effects of AOX and omega-3 were addressed all together with the scientific evidence and the personal opinion of professionals involved in the Retina Group of the OFTARED (Spain). Results. High dietary intakes of omega-3 and macular pigments lutein/zeaxanthin are associated with lower risk of prevalence and incidence in AMD. The Age-Related Eye Disease study (AREDS) showed a beneficial effect of high doses of vitamins C, E, beta-carotene, and zinc/copper in reducing the rate of progression to advanced AMD in patients with intermediate AMD or with one-sided late AMD. The AREDS-2 study has shown that lutein and zeaxanthin may substitute beta-carotene because of its potential relationship with increased lung cancer incidence. Conclusion. Research has proved that elder people with poor diets, especially with low AOX and omega-3 micronutrients intake and subsequently having low plasmatic levels, are more prone to developing AMD. Micronutrient supplementation enhances antioxidant defense and healthy eyes and might prevent/retard/modify AMD.

Association between apolipoprotein E polymorphisms and age-related macular degeneration: a HuGE review and meta-analysis

A possible association between apolipoprotein E polymorphisms and age-related macular degeneration has been investigated numerous times, with conflicting results. A previous analysis pooling results from four studies (Schmidt et al., Ophthalmic Genet 2002;23:209-23) suggested an association, but those investigators did not document allele frequencies, the magnitude of the association, or the possible genetic mode of action. Thus, the authors searched MEDLINE from 1966 to December 2005 for any English-language studies reporting genetic associations. Data and study quality were assessed in duplicate. Pooling was performed while checking for heterogeneity and publication bias. Frequencies of the E2 and E4 alleles in Caucasians were approximately 8% and 15%, respectively. Allele- and genotype-based tests of association indicated a risk effect of up to 20% for E2 and a protective effect of up to 40% for E4. E2 appeared to act in a recessive mode and E4 in a dominant mode. There appears to be a differential effect of the E2 and E4 alleles on the risk of age-related macular degeneration, although the possibility of survivor bias needs to be ruled out more definitively.

The prevalence of glaucoma in the Melbourne Visual Impairment Project

PURPOSE: The purpose of the study was to determine the prevalence of glaucoma in Melbourne, Australia. METHODS: All subjects were participants in the Melbourne Visual Impairment Project (Melbourne VIP), a population-based prevalence study of eye disease that included residential and nursing home populations. Each participant underwent a standardized eye examination, which included a Humphrey Visual Field test, applanation tonometry, fundus examination including fundal photographs, and a medical history interview. Glaucoma status was determined by a masked assessment and consensus adjudication of visual fields, optic disc photographs, intraocular pressure, and glaucoma history. RESULTS: A total of 3271 persons (83% response rate) participated in the residential Melbourne VIP. The overall prevalence rate of definite primary open-angle glaucoma in the residential population was 1.7% (95% confidence limits = 1.21, 2.21). Of these, 50% had not been diagnosed previously. Only two persons (0.1%) had primary angle-closure glaucoma and six persons (0.2%) had secondary glaucoma. The prevalence of glaucoma increased steadily with age from 0.1% at ages 40 to 49 years to 9.7% in persons aged 80 to 89 years. There was no relationship with gender. The authors examined 403 (90.2% response rate) nursing home residents. The age standardized rate for this component was 2.36% (95% confidence limits = 0, 4.88). CONCLUSION: The rate of glaucoma in Melbourne rises significantly with age. With only half of patients being diagnosed, glaucoma is a major eye health problem and will become increasingly important as the population ages.

Visual impairment and socioeconomic factors

BACKGROUND: Information about socioeconomic factors associated with visual impairment can assist in the design of intervention programmes. Such information was collected by the Melbourne Visual Impairment Project (Melbourne VIP). METHODS: The Melbourne VIP was a population based study of non-institutionalised permanent residents in nine suburbs of the Melbourne metropolitan area aged 40 years of age and older. A standardised eye examination was provided to eligible residents which included a structured interview. Variables of interest for this analysis were age, sex, country of birth, language spoken at home, education level, use of private health insurance, employment status, and living arrangements. Visual impairment was defined as a best corrected visual acuity < 6/18 and/or visual field constriction to within 20 degrees of fixation. RESULTS: A total of 3271 (83%) residents participated. Participants ranged in age from 40 to 98 years; 54% were female. Forty four (1.34%) were classified as visually impaired due to visual acuity and/or visual field loss. To evaluate the independent association of the significant sociodemographic variables with visual impairment, a regression model was constructed that included age, retirement status, use of private health insurance, and household arrangement. The results showed that age was the significant predictor of visual impairment (OR: 3.19; CI: 2.29-4.43), with the mean age of people with visual impairment significantly older (75.0 years) compared with people without visual impairment (58.2 years) (t test = 9.71; p = 0.0001). Of the 44 visually impaired people, 39 (87%) were aged 60 years of age and older. CONCLUSION: The results indicate that age is the most significant factor associated with visual impairment. Of some importance was the finding that people with visual impairment were less likely to have private health insurance. With the aging of the population, the number of people affected by visual impairment will increase significantly. Intervention programmes need to be established before the onset of middle age to offset the escalation of visual impairment in the older population.

Changes in abdominal obesity and age-related macular degeneration: the atherosclerosis risk in communities study

OBJECTIVE: To examine the association between changes in waist-hip ratio (WHR), a measure of abdominal obesity, and age-related macular degeneration (AMD). METHODS: A total of 12 515 persons from a population-based cohort study, aged 45 to 64 years in 1987 to 1989, were followed up over 6 years. The percentage change in WHR during follow-up was ranked into sex-specific deciles; an increase in WHR was defined as the top 10% of change and a decrease in WHR as the bottom 10%. The association of increased or decreased WHR and presence of AMD at follow-up was determined using logistic regression adjusting for potential confounders. RESULTS: The average change in WHR was an increase of 2%, ranging from a decrease of 44% to an increase of 102%. A decrease in WHR of 3% or more was associated with 29% lower odds of any AMD (odds ratio = 0.71; 95% confidence interval, 0.52-0.97). This effect was most pronounced among obese participants at baseline, where a decrease in WHR was associated with 59% lower odds of AMD (odds ratio = 0.41; 95% confidence interval, 0.20-0.82). CONCLUSIONS: Middle-aged persons who had a 3% or greater reduction in WHR over time were less likely to have AMD, particularly among those who were initially obese.

Manuscript of James Cummings- August 28, 1860

Transcript (spelling and grammar retained): Chippawa [Chippewa] 28th August 1860 My Dear Sir I duly received your very kind letter of the 24th [June] asking me to communicate such facts of general interest connected with my career during the War with the United States. I have no objection to afford you such information as came under my own observation; nevertheless I do so, with the understanding, I have no desire to be my own trumpeter. With respect to your circular wherein you state you have been for several years collecting materials for a History of the late War between the United States & Great Britain, for which you are now gathering further materials to add to your collection, concerning the Second War for Independence. I am rather at a loss to know, what is meant by the second war; If you allude to the petty Rebellion, it could not be called a War, Those that caused the outbreak were very soon put down, by the Loyal people of the Province without the aid of Regular Troops being satisfied with the Independence they enjoyed. With respect to the several questions names in your circular: To the 1st I would say, this locality is made memorable by the battle of Chippawa [Chippewa] which took place about a mile above the village on the ground I pointed out to you, when I had the pleasure of seeing you a few days ago, with Mr Porter of the Niagara Falls, of which I believe you took sketches at the time. 2nd I have no historical documents of any value; so many years having gone past, the most of my old papers have either been lost or destroyed, I however came across two letters, one dated Queenston 9th July 1812 from Lt. Col. Nicholl Quarter Master General of Militia, the other from Lt. Col Myers Deputy Quarter Master General of the Regular Army date Fort George 23rd same month, directed to me in the hand writing of each of those officers as Deputy Quarter Master General of Militia, which letters I shall be obliged you would return at as early a day possible, as I wish to place them with tome others in the case, I have had made to hold the cocked hat & feather I wore during that eventful period, which I am sorry I did not exhibit when you was at my house; with reference to it I now enclose a letter from Lt. Col. Clark, residing at Port Dalhousie he was Captain & Adjutant of Militia in the War of 1812__ I send the letter in proof of the cock’d hat it is a lengthy one, but you may find time to turn over it, as I shall also place it in the hat case__ 3rd Where are [but] [for] traditionary [sic] witnesses residing in this vicinity – Col Clark above named Mr Merritt of St. Catharines, & Mr Kerby of Brantford are the only ones I now recollect, who could offord [sic] you any statistical information. 4th I have no pictorial sketches of any Military Movements or fortifications. As regards my own career, which you appear [ ? ] of knowing__ I was first a Lieutenant in a volunteer flank company stationed on the river side opposite [Navy] Island not far from the battle ground of Chippawa [Chippewa], I got promotion as Lieutenant of Cavalry before I got my Cavalry dress completed in three days more, I was called by General Brock to Fort George, was appointed Deputy Quarter Master General of Militia with the rank of Captain s the accompanying letters will show. I was at the battle of Stony Creek, several skirmishes at the Cross Roads, when the American army [ ? ] Fort George, at the taking of Col. Boerstler at the Beaver Dam, & had the honor of receiving Colonel Chapens sword at the surrender, who commanded a company of volunteer Horse Men was at the taking of 15 regulars & two officers at Fort Schlosser—was with Col. Bishop at the taking of Black Rock, near him when he fell, three men of the 8th Reg. more killed in the Boat I was in – I was at Chippawa battle, and the last, not the least in Lundy’s lane battle, which the Americans call the battle of Bridge [Waters]. I had forgot; there was another small affair at Corks Mill where I was. I could write a little history of events, but have not the time to do so. If what I have stated will be of any service for the purpose you require I shall feel happy. The history of the late War was published at Toronto in the Anglo American Magazine. Did you ever see it, I have the Books, there were however several errors which came under my notice, which I could have corrected. If my time would permit I could give you a more detailed statement of events. I trust however you may succeed with your publication , and I shall be most happy to hear from you at all times—I related many little occurances verbally to you when here, which I thought not necessary to repeat again as you would have a perfect recollection of them. Be pleased to return the letters for the purpose I require them. I am My Dear Sir Your respectful friend James Cummings

Sketches of the Battle Fields of Ontario from the War of 1812, July 15, 1876.

Accompanying caption from the Canadian Illustrated News, July 15, 1876: “We publish today a page of sketches consisting of the following battle fields in Ontario :--Lundy’s Lane where, without doubt, the hardest fought battle of 1812-15 took place, and in which more troops were engaged than in any other engagement of that war : the battle field of Stony Creek where the Canadians and Indians made a night attack on the Americans and achieved a victory over a greatly superior force and obliged the Americans to retreat back to the shelter of Old Fort George which was the scene of many engagements during the war. Beaver Dam battle field is just in the suburbs of the thriving village of Thorold, and the monument covers the remains of several soldiers whose bodies were unearthed during the building of the new Welland Canal at that place.”

Self-reported hearing loss among elderly individuals in the city of Sao Paulo, Brazil: prevalence and associated factors (SABE Study, 2006)

This article describes the prevalence of self-reported hearing loss in an elderly population in the city of Sao Paulo, Brazil, and associated factors, based on a cross-sectional descriptive and quantitative study. The sample consisted of individuals over 65 years of age selected from census tracts in two stages, with replacement and probability proportional to the population 75 years of age or older. Statistical analysis used Stata 10 with weighted data, Rao-Scott test, and backward stepwise Poisson regression. 1,115 elders were interviewed. Prevalence of self-reported hearing loss was 30.4%, and higher levels were associated with age over 75 years, male gender, self-reported musculoskeletal conditions, dizziness, visual impairment, and difficulty using the telephone. Increased knowledge of factors associated with hearing loss would support public policies on hearing. The high prevalence found in this study underlines the importance of addressing this issue among the elderly.

Effect of colostrum feeding method and presence of dam on the sleep, rest and sucking behaviour of newborn calves

"In rats, sucking milk reduces anxiety and promotes non-rapid eye movement (NREM) sleep, and in calves it induces resting but the effect on sleep is unknown. Here, we investigated how calves' sleep was affected by colostrum feeding methods. Forty-one calves were blocked by birth date and randomly allotted within blocks to the experimental treatments. Calves were housed for four days either with their dam (DAM) or individually with warm colostrum feeding (2 L four times a day) from either a teat bucket (TEAT) or an open bucket (BUCKET). DAM calves suckled their dam freely. Calves' sleeping and sucking behaviour was filmed continuously for 48 h at the ages of two and three days. Behavioural sleep (BS) was defined as calves resting at least 30 s with their head still and raised (non-rapid eye movement) or with their head against their body or the ground (rapid eye movement, REM). Latency from the end of colostrum feeding to the start of BS was recorded. We compared behaviour of TEAT calves with that of DAM and BUCKET calves using mixed models. Milk meal duration was significantly longer for TEAT calves than for BUCKET calves (mean +/- S.E.M.; 8.3 +/- 0.6 min vs. 5.2 +/- 0.6 min), but equal to that of DAM calves. We found no effect of feeding method on the duration of daily BS (12 h 59 min I h 38 min) but we found a tendency for the daily amount of NREM sleep; BUCKET calves had less NREM sleep per day than TEAT calves (6 h 18 min vs. 7 h 48 min, S.E.M. = 45 min) and also longer latencies from milk ingestion to BS (21.9 +/- 2.0 min vs. 16.2 +/- 2.0 min). DAM calves slept longer bouts than TEAT calves (10.8 +/- 1.0 min vs. 8.3 +/- 1.0 min) and less often (78 +/- 4 vs. 92 +/- 4). Sucking colostrum from a teat bucket compared with drinking from an open"