Hospital Episode Statistics and changing trends in glaucoma surgery.

BACKGROUND: A number of authors have documented the decrease in the rate of glaucoma drainage surgery, felt to be owing to increased medical therapy options. There has also been an increase in cataract extraction. The aim of this study was, using the NHS Hospital Episode Statistics (HES), to attempt to confirm these trends and to examine the possibility that these trends are not necessarily independent. METHODS: The HES was accessed for the main glaucoma procedures between 1998 and 2004 and for cataract operations performed over the same time period. Diagnostic data were also extracted from the HES data for glaucoma. Figures for the changes in glaucoma medications were obtained from pharmaceutical data. RESULTS: Over the period that the data are available, trabeculectomy numbers have reduced by 51%, laser trabeculoplasty by 60%, and laser peripheral iridectomy (PI) by 30%. Cataract extractions have increased by 52%. Medical treatments, especially prostaglandin use, have increased. The number of admissions for acute glaucoma did not increase. CONCLUSIONS: The figures indicated a decrease in glaucoma drainage surgery and an increase in cataract extraction-consistent with other studies. More surprisingly, there was no increase in diagnosis of angle closure glaucoma or laser PIs within the figures and we suggest this may in part be related to the increase in cataract extraction. We speculate that this may also partly be responsible for the reduction in trabeculectomies. Although the HES data are a potentially rich source of information, there are potential inaccuracies in the data, which means interpretations must be made with caution.

28,000 Cases of age related macular degeneration causing visual loss in people aged 75 years and above in the United Kingdom may be attributable to smoking.

BACKGROUND: Age related macular degeneration (AMD) causing visual impairment is common in older people. Previous studies have identified smoking as a risk factor for AMD. However, there is limited information for the older population in Britain. METHODS: Population based cross sectional analytical study based in 49 practices selected to be representative of the population of Britain. Cases were people aged 75 years and above who were visually impaired (binocular acuity <6/18) as a result of AMD. Controls were people with normal vision (6/6 or better). Smoking history was ascertained using an interviewer administered questionnaire. RESULTS: After controlling for potentially confounding factors, current smokers were twice as likely to have AMD compared to non-smokers (odds ratio 2.15, 95% CI 1.42 to 3.26). Ex-smokers were at intermediate risk (odds ratio 1.13, 0.86 to 1.47). People who stopped smoking more than 20 years previously were not at increased risk of AMD causing visual loss. Approximately 28,000 cases of AMD in older people in the United Kingdom may be attributable to smoking. CONCLUSION: This is the largest study of the association of smoking and AMD in the British population. Smoking is associated with a twofold increased risk of developing AMD. An increased risk of AMD, which is the most commonly occurring cause of blindness in the United Kingdom, is yet another reason for people to stop smoking and governments to develop public health campaigns against this hazard.

National survey of antimetabolite use in glaucoma surgery in the United Kingdom.

AIMS: To assess the pattern of use of antimetabolites in trabeculectomy surgery by all consultant ophthalmologists in the United Kingdom. METHODS: A postal questionnaire of 12 questions regarding antimetabolite use in trabeculectomy surgery was sent to all 749 consultant ophthalmologists in the United Kingdom. The consultants were asked to estimate the number of trabeculectomies they performed per year, how often they used 5-fluorouracil (5-FU) in primary and redo surgery, their usual method of administration of 5-FU, how often they used mitomycin (MMC) in primary and redo surgery, and their usual dosage regimen of MMC. Factors that influenced the decision to use or not use antimetabolites were also assessed. RESULTS: The response rate of consultants returning the questionnaire was 82% (615 out of 749); 87% (533) of these consultants perform trabeculectomy surgery. Of these 533 consultants, 98 (18%) never use an antimetabolite. Most consultants (82%) use antimetabolites, but use them infrequently (only 9% using antimetabolites in more than half their cases). The preferred antimetabolite is 5-FU rather than MMC. Of the 435 consultants performing trabeculectomy surgery and using antimetabolites, 402 (93%) use 5-FU and 179 (41%) use MMC. Various factors influenced the decision to use or not use an antimetabolite, but experience of complications associated with their use was a factor for 34% of consultants. CONCLUSION: The use of antimetabolites, particularly MMC, in the United Kingdom is much less than in America or Japan, where trabeculectomy with MMC is the surgical procedure preferred by glaucoma specialists.

Causes of visual impairment in people aged 75 years and older in Britain: an add-on study to the MRC Trial of Assessment and Management of Older People in the Community.

BACKGROUND: Visual impairment and blindness are common in older people in Britain. It is important to know the causes of visual impairment to develop health service and research priorities. The authors aimed to identify the causes of visual impairment in people aged 75 years and older in Britain. METHODS: In the MRC Trial of the Assessment and Management of Older People in the Community, trial nurses tested visual acuity in everyone aged 75 years and older in 53 general practices. For all visually impaired patients in 49 of the 53 medical practices, data regarding the cause of vision loss were extracted from the general practice medical notes. Additional follow up questionnaires were also sent to the hospital ophthalmologist to confirm the cause of vision loss. Visual impairment was defined as a binocular acuity of less than 6/18. RESULTS: There were 1742 (12.5%) people visually impaired in the 49 participating practices. Of these, 450 (26%) achieved a pinhole visual acuity in either eye of 6/18 or better. In these people, the principal reason for visual loss was considered to be refractive error. The cause of visual loss was available for 976 (76%) of the remaining 1292 visually impaired people identified. The main cause of visual loss was age related macular degeneration (AMD); 52.9% (95% confidence interval 49.2 to 56.5) of people had AMD as a main or contributory cause. This was followed by cataract (35.9%), glaucoma (11.6%), myopic degeneration (4.2%), and diabetic eye disease (3.4%). CONCLUSIONS: A substantial proportion of visual impairment in our sample of older people in Britain can be attributed to remediable causes-refractive error and cataract. There is considerable potential for visual rehabilitation in this age group. For the large proportion with macular degeneration, low vision services will be important.

Iris configuration in accommodation in pigment dispersion syndrome.

PURPOSE: This study was conducted in order to investigate the effect of accommodation on the iris morphology and iridolenticular contact, in eyes with Pigment Dispersion Syndrome and Pigmentary Glaucoma, using high-resolution ultrasound. METHODS: We performed a prospective observational study, examining a group of 30 Pigment Dispersion Syndrome and Pigmentary Glaucoma patients (49 eyes) and a smaller group of eight 'normals' non-Pigment Dispersion Syndrome patients (8 eyes). All patients underwent ultrasound biomicroscopy, before and during accommodation. RESULTS: The iris profile before accommodation was found convex in 48.5%, flat in 19.7% and concave in 31.8%. Following accommodation the iris configuration remained unchanged in 66.2%, increased in concavity in 20.3% and decreased in concavity in 13.5%. CONCLUSIONS: The effect of accommodation on iris configuration and accommodation is highly variable. From our experience the measurement of iris configuration using ultrasound biomicroscopy may not be a useful method of evaluating the effect of different treatments on iris configuration.

Intraobserver and interobserver reliability of the R/D score for evaluation of iris configuration by ultrasound biomicroscopy, in patients with pigment dispersion syndrome.

UNLABELLED: The work has been presented at The Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting, Fort Lauterdale, Florida, May 1999. PURPOSE: To evaluate inter- and intraobserver variability of the R/D score in assessing the iris configuration in Pigment Dispersion Syndrome patients. METHODS: Fifty-seven high-resolution ultrasound biomicroscopy images were obtained by a single ophthalmologist. All images were examined twice by each of three ophthalmologists, the second assessment being at least 2 weeks after the first. Each observer was masked to their colleagues' and their previous measurements. R/D scores were calculated at each examination. Agreement between and amongst observers was assessed using Bland-Altman plots. In addition, the R/D scores were categorised and reassessed using the Kappa statistic. RESULTS: Intraobserver variability was small, the average differences between first and second scores of each observer being less than 0.01 units. Agreement within observers was 89% or higher, with Kappa values of 0.8 or higher, indicating almost perfect agreement. Interobserver variability was, however, greater. Although there was substantial agreement between two of the observers (87% agreement, first assessment; 80%, second assessment with respective kappa statistics of 0.78 and 0.66), they only moderately agreed with the other observer (kappa statistics between 0.55 and 0.68). CONCLUSIONS: This study suggests that when using R/D scores to demonstrate changes in iris configuration, assessments should preferably be made by the same observer.

Prevalence of visual impairment in people aged 75 years and older in Britain: results from the MRC trial of assessment and management of older people in the community.

AIMS: To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community. METHODS: 53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed. RESULTS: Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%). CONCLUSION: The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%.