Association of Mortality with Ocular Diseases and Visual Impairment in the Age-Related Eye Disease Study 2: Age-Related Eye Disease Study 2 Report Number 13

PURPOSE

To evaluate the association of mortality with visual acuity (VA) impairment, age-related macular degeneration (AMD), and cataract surgery.

DESIGN

Cohort study.

PARTICIPANTS

Participants with at least intermediate AMD enrolled in a randomized controlled clinical trial of lutein/zeaxanthin and/or omega-3 fatty acids, the Age-Related Eye Disease Study 2 (AREDS2), for treatment of AMD and cataract.

METHODS

Baseline and annual eye examinations included best-corrected visual acuity (BCVA) assessments, slit-lamp examinations, and stereoscopic fundus photographs that were centrally graded for development of late AMD (central geographic atrophy or neovascular AMD) or pseudophakia. Cause-specific mortality was determined on the basis of the International Classification of Diseases 9th or 10th Revision codes. Risk of all-cause and cause-specific mortality was assessed with Cox proportional hazards models adjusted for age, sex, AMD severity, VA, history of cataract surgery, and assigned AREDS2 study treatment. Analyses included baseline covariates: race, education, smoking status, diabetes, and cardiovascular disease.

RESULTS

During follow-up (median 5 years), 368 (9%) of the 4203 AREDS2 participants died. Participants with neovascular AMD in 1 eye at baseline had a statistically significant increased risk for mortality compared with participants with no or few drusen (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.21-2.01; P < 0.001). Poorer survival was associated with bilateral cataract surgery before enrollment compared with baseline bilateral phakia (HR, 1.63; 95% CI, 1.29-2.07; P < 0.001) and with BCVA of less than 20/40 compared with participants with 20/40 or better (HR, 1.56; 95% CI, 1.06-2.30; P = 0.024), adjusted for age, sex, and statistically significant covariates. Participants who received antivascular endothelial growth factor therapies for neovascular AMD had decreased mortality compared with those who did not (HR, 0.71; 95% CI, 0.57-0.88; P = 0.002). The association between all-cause mortality and AREDS2 treatment whether assessing the main or individual treatment effect was not significantly different (omega-3 fatty acids main effect HR, 1.18; 95% CI, 0.96-1.45; P = 0.12; lutein/zeaxanthin main effect HR, 1.04; 95% CI, 0.85-1.28; P = 0.71).

CONCLUSIONS

In AREDS2, the presence of late AMD, bilateral cataract surgery, and VA less than 20/40 was associated with decreased survival. However, oral supplementation with omega-3 fatty acids, lutein plus zeaxanthin, zinc, or beta-carotene had no statistically significant impact on mortality.

Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13

OBJECTIVE

To assess the association of ocular disorders and high doses of antioxidants or zinc with mortality in the Age-Related Eye Disease Study (AREDS).

METHODS

Baseline fundus and lens photographs were used to grade the macular and lens status of AREDS participants. Participants were randomly assigned to receive oral supplements of high-dose antioxidants, zinc, antioxidants plus zinc, or placebo. Risk of all-cause and cause-specific mortality was assessed using adjusted Cox proportional hazards models.

RESULTS

During median follow-up of 6.5 years, 534 (11%) of 4753 AREDS participants died. In fully adjusted models, participants with advanced age-related macular degeneration (AMD) compared with participants with few, if any, drusen had increased mortality (relative risk [RR], 1.41; 95% confidence interval [CI], 1.08-1.86). Advanced AMD was associated with cardiovascular deaths. Compared with participants having good acuity in both eyes, those with visual acuity worse than 20/40 in 1 eye had increased mortality (RR, 1.36; 95% CI, 1.12-1.65). Nuclear opacity (RR, 1.40; 95% CI, 1.12-1.75) and cataract surgery (RR, 1.55; 95% CI, 1.18-2.05) were associated with increased all-cause mortality and with cancer deaths. Participants randomly assigned to receive zinc had lower mortality than those not taking zinc (RR, 0.73; 95% CI, 0.61-0.89).

CONCLUSIONS

The decreased survival of AREDS participants with AMD and cataract suggests that these conditions may reflect systemic rather than only local processes. The improved survival in individuals randomly assigned to receive zinc requires further study.

The association between cataract and mortality among older adults

CONTEXT

Previous research has suggested that persons with cataract have an increased risk of death.

OBJECTIVE

To compare the mortality experience of patients with cataract who elect surgery, patients with cataract who do not elect surgery, and patients without cataract independent of potentially confounding risk factors.

DESIGN

Cohort study.

SETTING

Ophthalmology and optometry clinics affiliated with the Callahan Eye Foundation Hospital in Birmingham, Alabama.

PATIENTS

384 persons with and without cataract.

MAIN OUTCOME MEASURE

Mortality.

RESULTS

Of the 384 study subjects, 286 had cataract, of whom 200 elected to have cataract surgery. Patients with cataract who did and did not elect surgery had significantly higher mortality compared to those without cataract (crude mortality rate ratio (MRR) 3.9 (95% confidence interval (CI) 1.5-9.8) and 7.3 (95% CI 2.8-19.1), respectively). After adjustment for age, gender, race, education, chronic medical conditions, smoking, drinking, depression, and cognitive status, the no-surgery cataract group had an elevated mortality rate (MRR 3.2 (95% 1.2-9.0)), compared to the no-cataract group, with a borderline elevation in MR for the surgery group (MRR 2.0 (95% 0.8-5.9). Limiting the study population to non-diabetics or those without concurrent eye conditions (glaucoma, maculopathy, retinopathy) did not materially influence the adjusted MRRs although the precision of the estimates was reduced.

CONCLUSIONS

The results suggest that older persons with cataract, in particular those who decline surgery, have an increased risk of death, supporting the hypothesis that age-related cataract reflects systemic as well as localized ocular disease.

Cataracts associated with systemic disorders and syndromes

This review article examines the ophthalmic literature published on cataracts and systemic disease during the past year. Epidemiologically, the association between alcohol consumption and lens opacification is reviewed. Cataracts continue to be strongly associated with systemic diseases such as diabetes mellitus. Clinical, basic science reports and the results of the Blue Mountains Eye Study group on the morphology of diabetes-related cataracts are presented. Patients with neurologic disorders such as Wilson disease may first present with decreased vision and cataracts. Cataracts are now associated with syndromes such as Cohen syndrome, Degos disease, and Dubowitz syndrome. A recent study suggests earlier mortality in middle-age patients undergoing cataract surgery.

The effects of introducing prospective payments to general hospitals on length of stay, quality of care, and hospitals' income: the early experience of Israel

A new reimbursement system for general hospitals in Israel was introduced in July 1990. The new system specified that for 15 selected procedures, hospitals would be paid by the insurers prospectively, rather than by the traditional per-diem arrangement. The rates were determined by the Ministry of Health. Henceforth, the number of selected procedures has increased and by now 40 procedures are included. In line with the ever-lasting interest in the effect of financial incentives on suppliers of medical care, the purpose of this paper is to examine the first-year effect of this change on the volume of activity, length of stay, quality of care, and hospitals' real income. We focused on five selected procedures (cholecystectomy, hysterectomy, hip replacement, operations on lens and heart surgeries) performed in the four largest Israeli medical centers (Sheba, Sorasky, Rambam, and Hadassah). The analysis includes more than 17,000 hospitalizations occurring during two years prior to the change (July 1988-June 1990) and the first year after its implementation (July 1990-June 1991). We, therefore, examined, the short-term effects, wherein changes in the hospitals' behavior are reflected mainly in the above-mentioned hospitalization characteristics. Further analysis will be required to examine the long-run implications of the change as well as its effect on the rest of the general inpatient sector in Israel.

Assessing health-related quality of life in cataract patients: the relationship between utility and health-related quality of life measurement

The relationship between health-related quality of life (HQL) measures and patient preference for their health status was studied. Study subjects consisted of 132 patients at four hospitals who were scheduled for cataract surgery. Generic and disease-specific health status measures were determined in study subjects. The Medical Outcomes Study Short-form 36 (SF-36) item health status instrument was used to measure generic health status and the Visual Function 14 (VF-14) item visual health status instrument was used as the disease-specific health measure. Preference for general health and visual health was measured by assessing utilities assigned by patients to certain health states. Utilities assigned for general health were correlated with all categories of the SF-36 and VF-14 scores. Utilities assigned for visual health were correlated with four categories of the SF-36 (role limitation due to emotional health, general health, physical functioning, and vitality) and VF-14 scores. Utilities assigned for visual health were more strongly correlated with VF-14 scores than generic measures of health. Verbal ratings for visual health were correlated with Snellen visual acuity (SVA) (r = 0.20), utilities assigned for visual health (r = 0.58), VF-14 scores (r = 0.74), all categories of the SF-36 (r values ranging from 0.21 to 0.28), utilities assigned for general health (r = 0.19), and verbal ratings for general health (r = 0.29). Utility measures and verbal ratings for general and visual health were shown to be appropriate HQL measures. These measures were strongly correlated with other established generic and disease-specific health measures and should be included in the array of health status measures.

Mortality rates after cataract extraction

Senile cataract may be a marker of generalized tissue aging. We examined this hypothesis using population-based linked health data. We hypothesized that any such association would diminish with increased use of cataract surgery. Mortality rates of those 50-95 years of age undergoing cataract surgery in British Columbia during either 1985 or 1989 were compared with the provincial population of comparable age who did not undergo cataract surgery during the study period. The 1985 cohort included 8,262 patients undergoing surgery and a comparison population of 804,303, and the 1989 cohort included 11,952 patients and a comparison population of 839,393. Using Cox regression, for the 1985 cohort, the hazard ratios for dying during follow-up were 3.2 for males 50-54.9 years of age [95% confidence limits (CL) = 2.0, 5.0] and 3.3 for females (95% CL = 1.9, 5.7). Hazard ratios for older age groups decreased with age. We also fit an additive risk model that produced excess mortalities that were less age dependent. In the 1985 analysis, these ranged from +7.1 per 1,000 (95% CL = +0.44, +13.76) to +20.3 (95% CL = +13.24, +27.36) for males and -17.5 (95% CL = -28.28, -6.72) to +2.0 (95% CL = -2.12, +6.12) for females. Findings for the 1989 analyses were similar, indicating that the association between cataracts and generalized aging remained constant despite a large increase in the use of cataract surgery.

Mortality and causes of mortality among cataract-extracted patients. A 10-year follow-up

PURPOSE

The purpose of this study was to compare the mortality among patients undergoing intracapsular cataract extraction to the mortality in a gender-and age-identical Danish reference population, and to compare the patients' primary causes of death to those in the general population.

MATERIALS AND METHODS

We reviewed medical records of patients undergoing ICCE from January 1st 1984 to December 31st 1986 at the Department of Ophthalmology, Aalborg Hospital, Denmark. Information on the deaths of these patients was obtained from the Danish National Population Register. Information on mortality in Denmark was obtained from published statistics.

RESULTS

We found an increased mortality among the patients with cataract with an SMR (standard mortality rate) of 1.12 (95% confidence interval 1.02-1.23). The slightly increased mortality was observed for both men and women and for all examined causes of death.

CONCLUSION

The slightly increased mortality among patients with cataract may indicate a general deterioration of health for these patients.

Cataract patients in a defined Swedish population 1986-90: VII Inpatient and outpatient standardised mortality ratios

AIMS

Cataract surgery has at times been said to correlate with an increased death risk. We have therefore analysed the standardised death ratio in a population based cohort of patients that had undergone cataract surgery.

METHODS

Data for all patients undergoing cataract surgery from 1986 up to and including 1990 in the Lund Health Care District were prospectively recorded, and 5120 were retrieved for analysis. Death dates and primary death diagnoses for each patient were obtained from the Swedish Bureau of Census up to and including 1991. Standardised mortality ratios were calculated for all patients, subdivided into a number of categories: inpatients, outpatients, sex, age < 75 years, age > or = 75 years, patients with heart and circulatory diseases, with malignant tumours, and with diabetes. The cut off age was set at 74 because this divided the patients into two approximately equal groups. Using time dependent survival regression, the relative risk for dying were estimated for sex, age, and for postoperative YAG laser capsulotomy, and also for diabetic patients and patients with rheumatoid arthritis.

RESULTS

Inpatients almost always show an increased standardised mortality ratio compared with outpatients. Young patients and diabetic patients also showed an increased standardised mortality ratio, compared with the normal population, but not older patients, who constitute the majority. Cardiovascular death diagnoses were overrepresented among the young.

CONCLUSIONS

Cataract surgery is correlated with an increased standardised mortality ratio only in young patients and in patients with certain complicating diseases like diabetes and cardiovascular diseases.

National five-year mortality after inpatient cataract extraction

We assessed the five-year mortality in all United States Medicare beneficiaries aged 65 to 79 years who underwent inpatient cataract extraction in 1984. The risk of dying within five years after cataract extraction was compared to the five-year mortality risk of the same aged persons in the United States population. Patients with cataracts who were younger than 75 years had significantly higher age-specific rates of mortality than would be predicted from United States life tables (P less than .001). For example, at the age of 65 years, patients with cataracts had 1.34 times the risk of the United States population (95% confidence interval = 1.29 to 1.41). This risk progressively declined until the age of 75 years, at which age there is little difference between the patients with cataracts and the United States population, except for the oldest women with cataracts (at the age of 79 years, relative risk = .90; 95% confidence interval = .82 to .99). Although selection factors may account for the excess mortality observed among these individuals, these data do support previous analyses that suggest an association between senile cataract and increased risk of mortality.

Increased mortality rates after cataract surgery. A statistical analysis

One hundred ninety-three patients 50 to 89 years of age had cataract surgery between January 1, 1979, and December 31, 1980, at West Virginia University Medical Center, Morgantown. In comparison with 182 patients who elected one of three other surgical procedures, cataract surgery patients had a significantly higher mortality rate (P = 0.0005) than control group patients, according to life-table analysis estimates adjusted for age and sex. Patients with adult onset diabetes mellitus had slight increased survival and did not alter relative mortality. The authors' results support the hypothesis that senile cataracts may reflect systemic factors in addition to localized ocular disease.

Epidemiology of aphakic retinal detachment following intracapsular cataract extraction: a follow-up study with an analysis of risk factors

We reviewed 604 eyes in 521 patients who had intracapsular cataract extraction. The follow-up period averaged 39 months. The incidence of rhegmatogenous aphakic retinal detachment (ARD) was 1.3% in the whole group. The ARD incidence was 1.0% in eyes without surgical complications and 5.4% in myopic eyes (myopia defined as an aphakic refraction less than or equal to +9.0 diopters). The log-rank test was used to estimate the statistical significance of various ARD predictors. Significant predictors were age at surgery below 70 years (P = .0004) and myopia (P = .001). Our results indicate that the high risk of ARD is concentrated in a small group of myopic patients operated on at a relatively early age. During the follow-up period, 128 patients died. Compared with the mortality rate of the entire Danish population, this was not an above average mortality rate. Thus, our results do not support the hypothesis that senile cataracts reflect general systemic deterioration rather than local eye disease.

Increased mortality among elderly patients undergoing cataract extraction

One hundred sixty-seven patients aged 50 years or more had cataracts extracted between Jan 1, 1979, and Dec 31, 1979, at the New England Medical Center, Boston. In comparison with 824 patients who elected one of six other surgical procedures, when data were stratified according to age and sex, patients undergoing cataract extraction had nearly twice the mortality of the reference patients. Analysis indicated diabetic patients did not significantly alter the relative mortality. Our results support the concept that senile cataracts reflect systemic phenomena rather than only local ocular disease.