We studied the rates and distribution of cataract surgery throughout Ontario using population-based administrative data.
We identified patients who had had cataract surgery performed between April 1, 1994, and March 31, 2005. We calculated crude cataract surgery rates, overall and regional adjusted rates per 100,000 residents aged 65 and over, and age- and sex-specific rates.
The number of cataract surgeries performed on patients over 65 more than doubled, from 43,818 to 90,183, over the 10-year period and accounted for approximately 81% of all cataract surgeries in Ontario. Age- and sex-adjusted rates varied considerably among health administrative geographic regions. For 2004-2005, rates including all cataract surgeries ranged from 4272 to 6563 cataract surgeries per 100,000 residents aged 65 or older.
There has been a significant increase in the number of cataract surgeries performed over the past decade in Ontario with considerable regional variation. Observed rates were higher than those reported for other countries.
Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photokeratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process.
Diabetes has been shown to be a risk factor for age-related (AR) cataract. As statins (HMG-CoA reductase inhibitors) are now commonly prescribed for patients with type 2 diabetes, their impact on AR cataract prevalence should be considered. This study determines associations between AR cataract, type 2 diabetes, and reported statin use in a large optometric clinic population.
In all, 6397 patient files (ages 38 years) was 56% for those with type 2 diabetes and 16% for those without diabetes. Type 2 diabetes was significantly associated with nuclear sclerosis (OR = 1.62, 1.14-2.29) and cortical cataract (OR = 1.37, 1.02-1.83). Statin use was associated with nuclear sclerosis (OR = 1.48, 1.09-2.00) and posterior subcapsular cataract (OR = 1.48, 1.07-2.04). The 50% probability of cataract in statin users occurred at age 51.7 and 54.9 years in patients with type 2 diabetes and without diabetes, respectively. In non-statin users, it was significantly later at age 55.1 and 57.3 years for patients with type 2 diabetes and without diabetes, respectively (p
Cataracts in farmed Atlantic salmon have been known for many years, but the aetiology and importance of the disease have not been clarified. A cross-sectional field study of 51 cages of Atlantic salmon at 49 randomly selected sea sites was performed during the summer of 1998. The target population was spring and autumn entry groups of the 1997 generation salmon. Approximately 15 fish from each cage, altogether 777 fish, were autopsied by the same person. Each eye of the fish was scored for cataracts on a scale from 0 to 4 using an otoscope lamp with magnification. The weight and length of each fish were measured. The prevalence of cataracts was 83 % and 79% in spring entry groups and autumn entry groups, respectively. The overall mean cataract index (mean score of both eyes) was 1.23, being significantly higher in the spring entry groups (1.36) than the autumn entry groups (0.85). The final results in the spring entry groups showed that the fish groups with higher weight at sea transfer also had a higher cataract index at inspection. The risk of development of cataracts varied significantly among the offspring from the 5 strains represented in the study. Fish from sites located in 2 counties in the southern part of Norway had a significantly higher cataract index than fish farmed in the northernmost county in the study. For the autumn entry groups none of the explanatory variables was significant. In the spring entry groups a significant negative relationship was observed between the cataract score and the weight of the fish at the time of inspection (Pearson's r = -0.17), while the corresponding correlation for the autumn released groups was r = -0.10. Among the spring entry groups the average weight of the fish with the highest cataract score was estimated to about a third of the weight of the fish with no visible cataracts.
The relationship between cataract surgery wait times and rates of surgery was investigated to determine whether wait times correlate with rates of surgery.
We collected 2 Ontario registries for cataract surgeries: (i) Cancer Care Ontario wait time registry; and (ii) The Ontario Health Insurance Plan billing records.
Both registries were used to determine whether wait times correlated with rates of surgery, and the data were then stratified by region of the province, priority (severity) of cases, age, and sex.
The total number of surgeries performed between April 2, 2007, and March 31, 2008, was 65,520. The overall mean number of wait days was 69.8 days; the mean patient age was 72.5 years; and the surgery rate was 540.3 per 100,000 members of the population. For high-priority cases (priorities 1 and 2), there was a very weak inverse correlation (p = -0.27 and -0.21) between wait time and surgery rate, whereas the overall correlation between wait time and surgical rate was close to zero in both databases, regardless of the region, the patients' ages, and the patients' genders.
This study demonstrates a very weak correlation between wait times for and rates of cataract surgery, and this should be a concern for policy makers. Further study is needed to see whether this null relationship persists over time and whether it exists for other monitored wait time procedures. Reasons for this null relationship will have to be determined and remedied as the use of wait times becomes a more widespread outcome in Canadian Healthcare.
Autosomal recessive inheritance of juvenile cataract is described amongst several related sibships of Lehrerleut Hutterites. The main features of the cataract include onset between three and seven years of age; rapid progression to maturity within one to three months; normal intelligence; no systemic associations, and no urinary reducing substances and normal erythrocyte galactokinase activity. Genetic analysis demonstrates the close relationship between parents of affected sibships with a coefficient of inbreeding of affected sibships of 0.0512. Estimates of heterozygote frequency within Lehrerleut Hutterites at 0.128 indicate that if current inbreeding practice continues additional cases can be expected.