Causes of blindness and visual impairment in the West of Scotland

Cross-sectional study investigating the prevalence and causes of vision impairment in Northwest Portugal using capture-recapture

OBJECTIVES

The aim of this study was to estimate the prevalence and causes of vision impairment (VI) in Portugal.

SETTING

Information about people with VI was obtained from primary care centres, blind association (ACAPO) and from hospitals (the PCVIP study) in the Northwest of Portugal during a period spanning years 2014-2015. Causes of VI were obtained from hospitals.

PARTICIPANTS

Administrative and medical records of people with visual acuity in the better seeing eye of 0.5 decimal (0.30logMAR) or worse and/or visual field less than 20° were investigated. Capture-recapture with log-linear models was applied to estimate the number of individuals missing from lists of cases obtained from available sources.

PRIMARY AND SECONDARY OUTCOME MEASURES

Log-linear models were used to estimate the crude prevalence and the category specific prevalence of VI.

RESULTS

Crude prevalence of VI was 1.97% (95% CI 1.56% to 2.54%), and standardised prevalence was 1% (95% CI 0.78% to 1.27%). The age-specific prevalence was 3.27% (95% CI 2.36% to 4.90%), older than 64 years, 0.64% (95% CI 0.49% to 0.88%), aged 25-64 years, and 0.07% (95% CI 0.045% to 0.13%), aged less than 25 years. The female-to-male ratio was 1.3, that is, higher prevalence among females. The five leading causes of VI were diabetic retinopathy, cataract, age-related macular degeneration, glaucoma and disorders of the globe.

CONCLUSIONS

The prevalence of VI in Portugal was within the expected range and in line with other European countries. A significant number of cases of VI might be due to preventable cases and, therefore, a reduction of the prevalence of VI in Portugal seems possible. Women and old people were more likely to have VI and, therefore, these groups require extra attention. Future studies are necessary to characterise temporal changes in prevalence of VI in Portugal.

Novel Uses and Challenges of Artificial Intelligence in Diagnosing and Managing Eyes with High Myopia and Pathologic Myopia

Myopia is a global health issue, and the prevalence of high myopia has increased significantly in the past five to six decades. The high incidence of myopia and its vision-threatening course emphasize the need for automated methods to screen for high myopia and its serious form, named pathologic myopia (PM). Artificial intelligence (AI)-based applications have been extensively applied in medicine, and these applications have focused on analyzing ophthalmic images to diagnose the disease and to determine prognosis from these images. However, unlike diseases that mainly show pathologic changes in the fundus, high myopia and PM generate even more data because both the ophthalmic information and morphological changes in the retina and choroid need to be analyzed. In this review, we present how AI techniques have been used to diagnose and manage high myopia, PM, and other ocular diseases and discuss the current capacity of AI in assisting in preventing high myopia.

Blindness and visual impairment in Central Europe

Purpose

To assess the prevalence and causes of visual impairment and blindness in a Central European country. The findings may have implications for the planning of further research and development of therapies in order to prevent blindness.

Setting

Department of Ophthalmology, Medical University of Graz, Austria.

Design

Retrospective, epidemiological study.

Methods

The database of the Main Confederation of Austrian Social Insurances was searched for patients with visual impairment, legal blindness or deaf-blindness. This database gathers data from patients of all insurance providers in the country who receive care due to visual impairment and blindness. To determine the prevalence of these conditions, the number of all entries recorded in February 2019 was evaluated. Additionally, all new entries between (January 1^st,) 2017, and (December 31^st,) 2018, were analysed for distinct characteristics, such as sex, the cause of blindness/visual impairment, and age. Since health care allowances can provide a considerable source of income (459.90€-936.90€ per month), good coverage of practically all patients who are blind and visually impaired in the country can be assumed.

Results

On February 2^nd, 2019, 17,730 patients with visual impairments, blindness or deaf-blindness were registered in Austria, resulting in a prevalence of these diagnoses of 0.2% in the country. During the observational period from 2017 to 2018, 4040 persons met the inclusion criteria. Of these, 2877 were female (65.3%), and 1527 were male (34.7%). The mean age was 75.7 ± 18.0 years (median 82). Most patients (n = 3675, 83.4%) were of retirement age, while 729 (16.6%) were working-age adults or minors. In total, an incidence of 25.0 (95% confidence limit (CL) 24.3–25.8) per 100,000 person-years was observed from 2017 to 2018. A higher incidence was observed for females (32.2, 95% CL 31.0–33.3) than for males (17.7, 95% CL 16.8–18.5). Incidences where higher for males in lower age groups (e.g. 10–14 years: rate ratio RR = 2.7, 95% CL 1.1–6.8), and higher for females in higher age groups (e.g. 70–74 years: RR = 0.6, 95% CL 0.5–0.8). In total, the most frequent diagnoses were macular degeneration (1075 persons, 24.4%), other retinal disorders (493 persons, 11.2%) and inherited retinal and choroidal diseases (IRDs) (186 persons, 4.2%). Persons with IRDs were significantly younger compared to persons with macular degeneration or retinal disorders (IRDs: median 57, range 2–96 vs 83, 5–98 and 82, 1–98 years, p<0.001). For persons of retirement age, macular degeneration, other retinal disorders and glaucoma were the three most frequent diagnoses. In contrast, among working-aged adults and children, IRDs were the leading cause of visual impairment and blindness (103 persons, 14.1%).

Conclusion

These data show that IRDs are the leading cause of blindness and visual impairment in working-aged persons and children in Austria. Thus, these findings suggest to draw attention to enhance further research in the fields of emerging therapies for IRDs.

12-month clinical outcomes of combined phacoemulsification and ab interno trabeculectomy for open-angle glaucoma in the United Kingdom

BACKGROUND/OBJECTIVES

To describe intraocular pressure (IOP) and ocular hypotensive medication outcomes of combined phacoemulsification and ab interno trabeculectomy with the Kahook Dual Blade (KDB; New World Medical, Inc, Rancho Cucamonga, CA) in adults with cataract and open-angle glaucoma (OAG).

SUBJECTS/METHODS

Retrospective chart review of existing medical records. Data collected included intraocular pressure (IOP) and IOP-lowering medication use preoperatively and through up to 24 months postoperatively. Paired t-tests were utilized to compare preoperative to postoperative mean IOP and mean medications used.

RESULTS

Data from 32 eyes of 26 subjects were analyzed. Subjects were predominantly Caucasian (25/26) had mean (standard error) age of 79.3 (1.2) years, and eyes had moderate-advanced OAG (mean visual field mean deviation -8.3 [1.3] dB). Mean IOP was 19.8 (0.8) mmHg at baseline and 15.5 (0.6) mmHg (p<0.0001) after mean follow-up of 11.5 (1.0) months; IOP reductions of ≥20% were achieved in 20/32 eyes (62.5%). Mean medication use declined from 2.4 (0.2) medications per eye at baseline to 0.5 (0.2) at last follow-up (p<0.0001); 23/32 eyes (71.9%) were medication-free at last follow-up. No vision-threatening complications were observed.

CONCLUSIONS

Combined phacoemulsification and ab interno trabeculectomy with the KDB safely provided mean IOP reductions of 21.7% and mean IOP medication reductions of 83% after mean follow-up of 12 months in eyes with moderate to advanced OAG. This procedure provides medication-independence in most eyes with statistically and clinically significant IOP reductions.

Deep Learning Approach for Automated Detection of Myopic Maculopathy and Pathologic Myopia in Fundus Images

PURPOSE

To determine whether eyes with pathologic myopia can be identified and whether each type of myopic maculopathy lesion on fundus photographs can be diagnosed by deep learning (DL) algorithms.

DESIGN

A DL algorithm was developed to recognize myopic maculopathy features and to categorize the myopic maculopathy automatically.

PARTICIPANTS

We examined 7020 fundus images from 4432 highly myopic eyes obtained from the Advanced Clinical Center for Myopia.

METHODS

Deep learning (DL) algorithms were developed to recognize the key features of myopic maculopathy with 5176 fundus images. These algorithms were also used to develop a Meta-analysis for Pathologic Myopia (META-PM) study categorizing system (CS) by adding a specific processing layer. Models and the system were evaluated by 1844 fundus image. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were used to determine the performance of each DL algorithm. The rate of correct predictions was used to determine the performance of the META-PM study CS.

MAIN OUTCOME MEASURES

Four trained DL models were able to recognize the lesions of myopic maculopathy accurately with high sensitivity and specificity. The META-PM study CS also showed a high accuracy and was qualified to be used in a semiautomated way during screening for myopic maculopathy in highly myopic eyes.

RESULTS

The sensitivity of the DL models was 84.44% for diffuse atrophy, 87.22% for patchy atrophy, 85.10% for macular atrophy, and 37.07% for choroidal neovascularization, and the AUC values were 0.970, 0.978, 0.982, and 0.881, respectively. The rate of total correct predictions from the META-PM study CS was 87.53%, with rates of 90.18%, 95.28%, 97.50%, and 91.14%, respectively, for each type of lesion. The META-PM study CS showed an overall rate of 92.08% in detecting pathologic myopia correctly, which was defined as having myopic maculopathy equal to or more serious than diffuse atrophy.

CONCLUSIONS

The novel DL models and system can achieve high sensitivity and specificity in identifying the different types of lesions of myopic maculopathy. These results will assist in the screening for pathologic myopia and subsequent protection of patients against low vision and blindness caused by myopic maculopathy.

Markedly decreasing incidence of cause-specific blindness in Saxony (Eastern Germany)

PURPOSE

To analyze the recent time trend in Saxony.

METHODS

Data were based on administrative files in Saxony (Eastern Germany) to assess recipients of blindness allowance newly registered between January 1, 2009, and December 31, 2017. We estimated age-sex standardized incidence of all-cause and cause-specific blindness and used Poisson regression to examine age- and sex-adjusted time trends.

RESULTS

We identified 5114 new cases of blindness (63.3% female, 59.9% ≥ 80 years). We observed a markedly decrease in incidence of blindness: all-causes 2009: 15.7 per 100,000 person years [95% confidence interval: 14.6-17.0]; 2017: 8.9 [8.1-9.8]; age-related macular degeneration 2009: 6.9 [6.1-7.7], 2017: 3.8 [3.3-4.3]; glaucoma 2009: 2.6 [2.2-3.1], 2017: 1.8 [1.4-2.2]; diabetic retinopathy 2009: 1.5 [1.2-1.9], 2017: 0.7 [0.5-1.0]; myopia 2009: 0.7 [0.5-1.1], 2017: 0.4 [0.2-0.5]; optic atrophy 2009: 0.9 [0.6-1.2], 2017: 0.5 [0.3-0.7]; and cataract 2009: 0.5 [0.3-0.8], 2017: 0.1 [0.1-0.3]. The annual reduction was between 5 (glaucoma, relative risk 0.95 [0.92-0.98]) and 16% (cataract, relative risk 0.84 [0.78-0.91]).

CONCLUSION

The age- and sex-standardized incidence of blindness decreased among all common causes of blindness in Saxony in the last decade.

Interactions of cone abundancies, opsin expression, and environmental lighting with emmetropization in chickens

We had previously found that M to L cone abundancy ratios in the chicken retina are correlated with vitreous chamber depth and refractive state in chickens eyes, when they have normal visual exposure but not when they develop deprivation myopia. The finding suggests an interaction between cone abundancies and emmetropization. In the current study, we analyzed how stable this correlation was against changes in environmental variables and strain differences. We found that the correlation was preserved in two chicken strains, as long as they were raised in the laboratory facilities and not in the animal facilities of the institute. To determine the reasons for this difference, spectral and temporal lighting parameters were better adjusted in both places, whereas temperature, humidity, food, diurnal lighting cycles and illuminance were already matched. It was also verified that both strains of chickens had the same cone opsin amino acid sequences. The correlation between M to L cone abundancy and ocular biometry is highly susceptible to changes in environmental variables. Yet undetermined differences in lighting parameters were the most likely reasons. Other striking findings were that green cone opsin mRNA expression was downregulated when deprivation myopia developed. Similarly, red opsin mRNA was downregulated when chicks wore red spectacles, which made them more hyperopic. In summary, our experiments show that photoreceptor abundancies, opsin expression, and the responses to deprivation, and therefore emmetropization, are surprisingly dependent on subtle differences in lighting parameters.

Cerebral visual impairment is a major cause of profound visual impairment in children aged less than 3 years: A study from tertiary eye care center in South India

Purpose:

The purpose of this study was to evaluate causes for profound visual impairment in children ≤3 years of age at a tertiary eye care center in Andhra Pradesh, India.

Methods:

A retrospective study was conducted for all the children (≤3 years) who attended the pediatric ophthalmology service between January 2012 and February 2017.

Results:

A total of 428 severely visually impaired children aged ≤3 years were seen during the study period: 264 (62%) of them were boys and I64 (38%) were girls. The average age at presentation was 14.02 months. The causes of visual impairment were cerebral visual impairment (CVI) 142 (33%), a combination of CVI and ocular visual impairment (OVI) 48 (11%), and OVI only 236 (56%), which included congenital cataract 56 (13.1%), retinopathy of prematurity 52 (I2.6%), optic atrophy 17 (4.5%), congenital nystagmus (4.4%), congenital globe anomalies 2I (5.2%), and high refractive errors - 10 (2.8%). Delays in different areas of development were seen in 103 out of 142 children with CVI (72.5%), which included motor delay 53 (51.5%), cognitive delay 15 (14.6%), speech delay in 3 (2.9%), and delay in multiple areas of development (like combination of motor, cognitive, and speech delay) in 32 (31.1%).

Conclusion:

In children under 3 years of age, CVI is a major cause of profound visual impairment in our area and the majority of them manifest delay in several areas of development.

Understanding low functioning cerebral visual impairment: An Indian context

For several reasons, cerebral visual impairment (CVI) is emerging as a major cause of visual impairment among children in the developing world and we are seeing an increasing number of such children in our clinics. Owing to lack of early training about CVI and it being a habilitation orientated subject, we need to become equipped to optimally help the affected children. In this paper we have explained our pragmatic approach in addressing children who present with low functioning CVI. Initially we explain briefly, how vision is processed in the brain. We then present what should be specifically looked for in these children in regular clinics as a part of their comprehensive ophthalmic examination. We discuss the process of functional vision evaluation that we follow with the help of videos to explain the procedures, examples of how to convey the conclusions to the family, and how to use our findings to develop intervention guidelines for the child. We explain the difference between passive vision stimulation and vision intervention, provide some common interventions that may be applicable to many children and suggest how to infuse interventions in daily routines of children so that they become relevant and meaningful leading to effective learning experiences.

A study on correlation between oxidative stress parameters and inflammatory markers in type 2 diabetic patients with kidney dysfunction in north Indian population

BACKGROUND

Research reports support the statement that oxidative stress and inflammation are well-known risk factors for chronic kidney disease (CKD) in patients with diabetes. This study was designed to ascertain the associated role of oxidative stress parameters and inflammatory markers in diabetes and related CKD among the north Indian population.

METHODS

The study was divided into three groups as healthy subjects (group 1), patients with diabetes without complication (group 2), and with CKD (group 3). Serum levels of malondialdehyde (MDA) and nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) content were estimated in all individuals. Inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)-α were determined by enzyme-linked immuno-sorbent assay.

RESULTS

MDA, protein carbonyl, and NO were significantly elevated in patients with type 2 diabetes as compared with healthy subjects (P ≤ 0.05). Total thiols content were found to be significantly decreased in patients with diabetes with CKD. The activity of antioxidant enzymes SOD, CAT, and GR showed a significant suppression in patients with type 2 diabetes with or without CKD as compared with healthy subjects. Nevertheless, the levels of proinflammatory cytokines IL-6 and TNF-α were significantly upregulated ( P ≤ 0.05) as compared with healthy subjects.

CONCLUSION

Determination of antioxidant defense parameters and inflammatory markers contributes to understand the relationship between oxidative stress and inflammation on the development and prevention of chronic kidney disease in Indian patients with diabetes.

Cerebral visual impairment in children: Causes and associated ophthalmological problems

Purpose

The aim of this study is to identify common causes, associated ophthalmological abnormalities, and systemic comorbidities in children in Andhra Pradesh, India, with cerebral visual impairment (CVI).

Methods

A retrospective review of case records of all children aged <16 years with diagnosis of CVI seen between January 2016 and December 2016 was carried out. Data were collected for their age, gender, cause of CVI, refraction, accommodation, anterior and posterior segment examination findings, and systemic problems.

Results

A total of 124 patients were identified and studied (80 boys and 44 girls, mean age 5.23 years, 44.8% aged <2 years). The most common causes of CVI were hypoxic-ischemic encephalopathy (HIE) (34.4%), undetermined etiology (32.8%), neonatal seizures, and infantile spasms (16% each). The most common presenting complaints were poor vision (76%) and squint (11.2%). Profound visual impairment was seen in 88.8%, and 11.2% had high functioning CVI. Fifty-eight (46.4%) patients had significant refractive errors, 40 (32.25%) had strabismus, 4 (3.2%) had visually significant cataract, and 40 (32%) had optic atrophy. Motor delay was observed in 39.5%, speech delay was evident in 22.4%, and cognitive delay in 16%.

Conclusion

HIE is the most common cause (one-third) of CVI in our population, and the majority of them presented at age <2 years (44.8%) with profound visual impairment (88.8%). A significant number of them have treatable ophthalmic conditions such as refractive errors (46.4%), accommodative insufficiency (12.1%), and cataract (3.2%), and more than one-third of them also have delay in other areas of development.

Trends in Blind and Low Vision Registrations in Taipei City

Purpose

To determine the overall reported incidence and causes of registrable blindness and low vision in Taipei, Taiwan, that have occurred in the previous 10 years.

Methods

Study data were obtained from disability identification registration forms completed between January 1995 and December 2004. Definitions of low vision and blindness were defined by WHO criteria: low vision included visual acuity worse than 6/18 (20/60) to a lower limit of 3/60 (20/400). Blindness was defined as visual acuity worse than 3/60 (20/400) in the better eye with best possible correction.

Results

There were 3151 registrations for visual impairment during the study period. A total of 239 registrations were excluded due to insufficient data. Of the remaining 2912 (1518 males and 1394 females), 640 males and 647 females were legally blind (44.20%). A total of 878 males and 747 females were partially sighted. The six leading causes of low vision and blindness, in decreasing frequency, were glaucoma, optic neuropathy, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and myopic macular degeneration.

Conclusions

The proportions of new registrations owing to glaucoma, diabetic retinopathy, age-related macular degeneration, and myopic macular degeneration have changed significantly since 2000; the proportion due to diabetic retinopathy has increased.

Two- and three-dimensional topographic analysis of pathologically myopic eyes with dome-shaped macula and inferior staphyloma by spectral domain optical coherence tomography

PURPOSE

To investigate the posterior anatomical structure of pathologically myopic eyes with dome-shaped macula and inferior staphyloma using spectral domain optical coherence tomography (SD-OCT).

METHODS

Our database of 260 pathologically myopic eyes was analyzed retrospectively to identify patients with dome-shaped macula and inferior staphyloma. All patients underwent vertical and horizontal SD-OCT scans across the central fovea, with three-dimensional macular map reconstruction. Best-corrected visual acuity, axial length, and choroidal thickness measurements were recorded. The macular bulge height was also analyzed in eyes with dome-shaped macula. In the three-dimensional images, the symmetry and orientation of the main plane of the inward incurvation of the macula were examined.

RESULTS

Twenty-eight (10.7%) of the 260 pathologically myopic eyes had dome-shaped macula of one of three different types: a round radially symmetrical dome (eight eyes, 28.5%), a horizontal axially symmetrical oval-shaped dome (15 eyes, 53.5%), or a vertical axially symmetrical oval-shaped dome (five eyes, 17.8%). The macular bulge height was significantly greater in horizontal oval-shaped dome eyes (p = 0.01, for each comparison). Inferior posterior staphylomas were observed in ten (3.8%) of the 260 pathologically myopic eyes with asymmetrical macular bends.

CONCLUSIONS

Vertical and horizontal OCT sectional scanning in combination with three-dimensional macular map reconstruction provides important information for understanding the posterior anatomical structure of dome-shaped macula and inferior staphyloma in pathologically myopic eyes.

[Incidence and causes of visual impairment in the district of Mahdia, in east Tunisia: Retrospective study of 1487 cases]

OBJECTIVE

To study socio-demographic characteristics and main causes related to visual impairment (VI) as a function of age bracket and to analyze their trends over time in the district of Mahdia.

METHOD

A retrospective review was performed on 1487 cases of visual impairment registered with the social authorities in Mahdia, between 1980 and 2013. The social, demographic, vision exam findings and causes were ascertained and analyzed in an SPSS database. Incidence rates of VI and blindness due to various causes were calculated based on the demographic data from the NSI to estimate the time trends using the general linear regression model and Spearman correlation.

RESULTS

Analyses included 1487 participants with a median age of 47 years, 40.6% of cases were aged under 45 years. Children accounted for 11.1% (165 patients), while age was between 16 and 45 years in 29.5% (439 patients), between 46 and 65 years in 31.5% (469 patients) and greater than 65 years in 27.8% (414 patients). The sex-ratio (M/F) was 1.78. Socially, 51% came from rural areas, 62% were illiterate, and 84% were unemployed. We observed blindness in 70% of participants and low vision in 30%. In children, the causes were dominated by congenital cataract and congenital glaucoma, each present in 31 children (18.8%). Between 16 and 45 years, glaucoma and hereditary dystrophies of the retina were found in 62 and 61 patients respectively (14% each). For age between 46 and 65 years, trachoma was responsible for 19.8% of cases of VI, glaucoma in 15.8% and cataract in 15.1%. Beyond 65 years, glaucoma accounted for 30.7% of the causes of VI and cataract 27.8% of cases. Trend analysis shows a significant increase in the incidence rate of visual impairment with an average of 12% per year (P=0.001). The mean age increased by 46% (P=0.003). Trachoma increased by 118% (P<0.0001) between 1980 and 1990, then declined by 42% (P=0.0013) between 1991 and 2013. Incidence of VI significantly increased by 4% for cataract (P=0.001), 23% (P=0.001) for glaucoma and 20% (P=0.02) for diabetic retinopathy, while VI related to refractive errors and AMD showed no significant change.

CONCLUSION

Advanced age, lower educational and socio-economic status were associated with bilateral VI. Age related eye problems are the main causes of VI, and their incidence is tending to increase. Public health policies and procedures should be targeted to risk related populations and age-related diseases in order to control the incidence of visual impairment and avoid its consequences.

The Prevalence of Visual Impairment in People with Dementia (the PrOVIDe study): a cross-sectional study of people aged 60–89 years with dementia and qualitative exploration of individual, carer and professional perspectives

Background

The prevalence of visual impairment (VI) and dementia increases with age and these conditions may coexist, but few UK data exist on VI among people with dementia.

Objectives

To measure the prevalence of eye conditions causing VI in people with dementia and to identify/describe reasons for underdetection or inappropriate management.

Design

Stage 1 – cross-sectional prevalence study. Stage 2 – qualitative research exploring participant, carer and professional perspectives of eye care.

Setting

Stage 1 – 20 NHS sites in six English regions. Stage 2 – six English regions.

Participants

Stage 1 – 708 participants with dementia (aged 60–89 years): 389 lived in the community (group 1) and 319 lived in care homes (group 2). Stage 2 – 119 participants.

Interventions

Stage 1 gathered eye examination data following domiciliary sight tests complying with General Ophthalmic Services requirements and professional guidelines. Cognitive impairment was assessed using the Standardised Mini-Mental State Examination (sMMSE) test, and functional ability and behaviour were assessed using the Bristol Activities of Daily Living Scale and Cambridge Behavioural Inventory – Revised. Stage 2 involved individual interviews (36 people with dementia and 11 care workers); and separate focus groups (34 optometrists; 38 family and professional carers).

Main outcome measures.

VI defined by visual acuity (VA) worse than 6/12 or worse than 6/18 measured before and after refraction.

Results

Stage 1 – when participants wore their current spectacles, VI prevalence was 32.5% [95% confidence interval (CI) 28.7% to 36.5%] and 16.3% (95% CI 13.5% to 19.6%) for commonly used criteria for VI of VA worse than 6/12 and 6/18, respectively. Of those with VI, 44% (VA < 6/12) and 47% (VA < 6/18) were correctable with new spectacles. Almost 50% of remaining uncorrectable VI (VA < 6/12) was associated with cataract, and was, therefore, potentially remediable, and one-third was associated with macular degeneration. Uncorrected/undercorrected VI prevalence (VA < 6/12) was significantly higher in participants in care homes (odds ratio 2.19, 95% CI 1.30 to 3.73;p < 0.01) when adjusted for age, sex and sMMSE score. VA could not be measured in 2.6% of group 1 and 34.2% of group 2 participants (p < 0.01). The main eye examination elements (excluding visual fields) could be performed in > 80% of participants. There was no evidence that the management of VI in people with dementia differed from that in older people in general. Exploratory analysis suggested significant deficits in some vision-related aspects of function and behaviour in participants with VI. Stage 2 key messages – carers and care workers underestimated how much can be achieved in an eye examination. People with dementia and carers were unaware of domiciliary sight test availability. Improved communication is needed between optometrists and carers; optometrists should be informed of the person’s dementia. Tailoring eye examinations to individual needs includes allowing extra time. Optometrists wanted training and guidance about dementia. Correcting VI may improve the quality of life of people with dementia but should be weighed against the risks and burdens of undergoing examinations and cataract surgery on an individual basis.

Limitations

Sampling bias is possible owing to quota-sampling and response bias.

Conclusions

The prevalence of VI is disproportionately higher in people with dementia living in care homes. Almost 50% of presenting VI is correctable with spectacles, and more with cataract surgery. Areas for future research are the development of an eye-care pathway for people with dementia; assessment of the benefits of early cataract surgery; and research into the feasibility of specialist optometrists for older people.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Lutein Leads to a Decrease of Factor D Secretion by Cultured Mature Human Adipocytes

Purpose. Complement plays an important role in the pathogenesis of age related macular degeneration (AMD) and trials are currently being conducted to investigate the effect of complement inhibition on AMD progression. We previously found that the plasma level of factor D (FD), which is the rate limiting enzyme of the complement alternative pathway, was significantly decreased following lutein supplementation. FD is synthesized by adipose tissue, which is also the main storage site of lutein. In view of these findings we tested the hypothesis whether lutein could affect FD synthesis by adipocytes. Methods. A cell line of mature human adipocytes was incubated with 50 μg/mL lutein for 24 and 48 h, whereafter FD mRNA and protein expression were measured. Results. Lutein significantly inhibited adipocyte FD mRNA expression and FD protein release into adipocyte culture supernatants. Conclusions. Our earlier observations showing that a daily lutein supplement in individuals with early signs of AMD lowered the level of circulating FD might be caused by blocking adipocyte FD production.

Lutein and Factor D: two intriguing players in the field of age-related macular degeneration

Age-related macular degeneration (AMD) is a progressive eye disease that impairs central vision among elderly populations in Western, industrialized countries. In this review we will focus on the role of factor D (FD) and lutein in AMD. FD is a rate-limiting enzyme of the alternative complement activation pathway that may play an important role in the development of AMD. Several independent studies have shown a significant increase in the level of a number of complement factors of the alternative pathway, including factor D in the blood of AMD patients as compared to healthy individuals, which suggests a systemic involvement in the pathogenesis of AMD. FD, also called adipsin, is mainly produced by adipose tissue. Besides playing a role in the activation of the alternative pathway, FD is also known to regulate the immune system. Of interest is our preliminary finding that lutein supplementation of early AMD cases was shown to lower the level of systemic FD. If confirmed, these findings provide further support for the application of anti-factor D intervention as a new approach to control the development of this disease.

Environmental and behavioural interventions for reducing physical activity limitation in community-dwelling visually impaired older people

BACKGROUND

Impairment of vision is associated with a loss of function in activities of daily living. Avoidance of physical activity and consequent reduced functional capacity is common in older people with visual impairment and an important risk factor for falls. Indeed, the rate of falls and fractures is higher in older people with visual impairment than age-matched visually normal older people. Depression and anxiety is common in older people with vision impairment and leads to further restriction of activity, reduced social contact and reduced quality of life. Possible mechanisms to reduce activity restriction and therefore improve mobility and activity include environmental and behavioural interventions delivered by a number of health professionals, including occupational therapists.

OBJECTIVES

The objective of this review was to assess the effectiveness of environmental and behavioural interventions in reducing activity limitation and improving quality of life amongst visually impaired older people.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to November 2012), EMBASE (January 1980 to November 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to November 2012), Allied and Complementary Medicine Database (AMED) (January 1985 to November 2012), OT Seeker (inception to November 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 9 November 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-randomised controlled trials (Q-RCTs) that compared environmental interventions, behavioural interventions or both, versus control (placebo control or no intervention or usual care), and trials comparing different types of environmental or behavioural interventions, in older people (aged 60 and over) with irreversible visual impairment living independently or in residential settings. To be eligible for inclusion the primary aim of studies must be reducing physical activity limitation and must include a measure of physical activity. Secondary outcome measures included falls, fear of falling, quality of life.

DATA COLLECTION AND ANALYSIS

Two authors independently read abstracts retrieved by the search to identify eligibility and study quality. We contacted study authors for additional information.

MAIN RESULTS

Our searches found no RCTs or Q-RCTs that met the eligibility criteria for this review.

AUTHORS' CONCLUSIONS

We are unable to reach any conclusion about the effectiveness of environmental or behavioural interventions for reducing physical activity limitation in community-dwelling visually impaired older people, as no eligible studies were found. However a number of studies reviewed included only the secondary outcome measures of this review. Although behavioural interventions delivered by occupational therapists have been shown to reduce the rate of falls, we are unable to conclude if this is due to reduced activity restriction (increased mobility) or reduced activity (lessening exposure to risk). There are inconclusive and conflicting results from trials evaluating the effectiveness of behavioural and environmental interventions aimed at improving quality of life. Further research is necessary (such as ongoing Dutch and UK trials considering the effectiveness of orientation and mobility training on activity restriction, physical activity, falls, fear of falling and quality of life in older adults with low vision, and the effect of an occupational therapist delivering home safety modification, coping strategies and exercise with older people with low vision) before any conclusions can be reached.

Comparison of resource utilization in the treatment of open-angle glaucoma between two cities in Finland: is more better?

INTRODUCTION

Glaucoma is a progressive optic neuropathy associated with neural rim loss of the optic disc and the retinal nerve fibre layer typically causing visual field (VF) deterioration. Generally, glaucomatous lesions in the eye and in the visual field progress slowly over the years. In population-based cross-sectional studies, the percentage of unilateral or bilateral visual impairment varied between 3-12%. In screening studies, 0.03-2.4% of patients have been found to suffer visual impairment. Glaucoma has previously been associated with substantial healthcare costs and resource consumption attributable to the treatment of the disease. The disease also causes reduction in health-related quality of life (HRQoL) in patients with glaucoma.

OBJECTIVE AND METHODS

This study compares patients with diagnosed open-angle glaucoma from two geographically different regions in Finland. A total of 168 patients were examined, 85 subjects from an area with higher per patient treatment costs (Oulu) and 83 patients from a region with lower per patient treatment costs (Turku). All patients had a history of continuous glaucoma medication use for a period of 11 years. For each patient, the total direct costs from glaucoma treatment were calculated and the total amount of resource consumption was determined from registries and patient records. Each patient underwent a clinical examination with visual field assessment and fundus photography. These data were used to determine the current stage of disease for each patient. Health-related quality of life questionnaire (15D) was used in determining each patient's subjective HRQoL score.

RESULTS

When applying the current diagnostic criteria for open-angle glaucoma, a total of 40% of patients did not to display any structural or functional damage suggesting glaucoma after 11 years of continuous medical treatment and follow-up. Patients with higher glaucoma stage (worse disease) were found to have statistically higher treatment costs compared with those at lower disease stages. Resource consumption was also greater in the patients in higher glaucoma stage. Patients in the Oulu district consumed more resources, and glaucoma treatment was more expensive than in the Turku area. The total treatment cost in Oulu and Turku was 6010 € and 4452 €, respectively, for the whole 11-year period. There was no statistically significant difference in quality-of-life scores between the two areas. No difference was noted between the higher-spending and lower-spending areas in this respect. However, when the population was analysed as a whole, patients with higher glaucoma stage were found to have lower vision-based 15D scores compared with those at lower disease stages. This observation was made also at both districts independently.

CONCLUSIONS

Major cost source in open-angle glaucoma treatment is medication, up to 74% of annual costs. In addition, it seems that higher resource consumption and higher treatment costs do not increase the patients' HRQoL as assessed by the 15D instrument.

Long-term remission of type 2 diabetes in morbidly obese patients after sleeve gastrectomy

BACKGROUND

The aim of this study was to evaluate the long-term effects of laparoscopic sleeve gastrectomy (LSG) on type 2 diabetes mellitus (T2DM) and other related co-morbidities in severely obese patients.

METHODS

From May 2003 to July 2008, 33 morbidly obese diabetic patients (20 with body mass index [BMI]>50 kg/m(2)) underwent LSG. A total of 23 females and 10 males participated, with a mean age of 49.3±8 years, mean preoperative BMI of 52.1±8.5 kg/m(2), mean fasting plasma glucose (FPG) of 143.2±47.9 mg/dL, mean glycosylated hemoglobin (HbA1c) of 7.3%±1.4%, and a mean T2DM duration of 7 years. All patients had a 36-month follow-up, and 13 had a 60-month follow-up.

RESULTS

Twenty-nine patients (87.8%) discontinued antidiabetic medications 3 months after LSG, (mean BMI of 42.8±7.8 kg/m(2); FPG of 104.5±22.1 mg/dL; HbA1c of 5.3%±.4%). At 36 months, 22 of 26 LSG patients (84.6%) had normal FPG and HbA1c values without antidiabetic therapy. At the 60-month follow-up, 10 of 13 patients (76.9%) had normal FPG and HbA1c values without antidiabetic therapy. The Framingham risk score decreased significantly from 9.7% preoperatively to 4.7% postoperatively. No new diabetic retinopathy occurred during the whole period of observation.

CONCLUSIONS

This study confirms the efficacy of LSG in the treatment of T2DM and indicates that, at both 36- and 60-month follow-ups, LSG can provide a significant percentage of treated patients with a prolonged remission of T2DM, with diminished cardiac risk factors and no development of diabetic retinopathy. These results compare favorably with those reported after standard medical therapy.

Protection of exenatide for retinal ganglion cells with different glucose concentrations

Exendin-4 is a peptide resembling glucagon-like peptide-1 (GLP-1), which has protective effects on nerve cells. However, the effects of Exendin-4 on retinal ganglion cells (RGC) are still under clear. The purpose of the present study is to demonstrate that exenatide prevents high- or low-glucose-induced retinal ganglion cell impairment. We observed the expression of GLP-1R in RGC-5 cells by immunofluorescence and Western blot. To investigate the effect of exenatide on RGC-5 cells incubated different glucose concentrations, CCK-8 measured the survival rates and electron microscopy detected cellular injury. The expression levels of Bcl-2 and Bax were analyzed by immunocytochemistry and Western blot. Exenatide protects RGC-5 from high- or low-glucose-induced cellular injury and the optimum concentration was 0.5μg/ml. Exenatide can inhibit high- or low-glucose-induced mitochondrial changes. Exenatide protects RGC-5 from high- or low-glucose-induced Bax increased and Bcl-2 decreased. Furthermore, the protective effect of exenatide could be inhibited by Exendin (9-39). These findings indicate that exenatide shows a neuroprotective effect for different glucose concentrations-induced RGC-5 cells injury. Exenatide could protect RGC-5 cells from degeneration or death, which may protect retinal function and have a potential value for patients with diabetic retinopathy.

Retinopathy and visual impairment in diabetes, impaired glucose tolerance and normal glucose tolerance: the Nord-Trøndelag Health Study (the HUNT study)

PURPOSE

The aim of the study was to describe the prevalence of visual impairment and retinopathy and to investigate risk factors for retinopathy in persons with diabetes, screen-detected diabetes, impaired glucose tolerance and normal glucose tolerance in a subpopulation of the HUNT study.

METHODS

We used a sample (n = 163) from a population-based screening survey of hyperglycaemia, undertaken in 2004-2005 in Verdal, Norway. Baseline information was accessible through the second Nord-Trøndelag Health Study (HUNT2), 1995-97. Data collection was made in 2005 and included patient history, refraction, visual acuity, cataract assessment and single-field, nonmydriatic retinal photography. Retinal photographs were graded independently by two graders blinded to patient information. Data were analysed with standard statistical methods, and p < 0.05 was considered significant.

RESULTS

In all, 126 (77%) persons participated, 55% were women. The mean (SD) age was 59 (± 14) years. Four (3%) had correctable visual impairment, and none were visually impaired. Retinal photographs were gradable for both eyes in 109 (87%) participants. The prevalence of retinopathy was 11% in persons with known diabetes, 4% in persons with screen-detected diabetes, 3% in persons with impaired glucose tolerance and 10% in persons with normal glucose tolerance. Retinopathy was not associated with known history of diabetes or current glycaemic status. Nonfasting plasma glucose (in 1995-97) was an independent risk factor for retinopathy (in 2005), OR (95% CI) 1.5 (1.01, 2.13), p = 0.046.

CONCLUSION

The prevalence of diabetic retinopathy in persons with diabetes in this study was low. Appropriate optical correction and regular eye examination can prevent unnecessary visual impairment in both persons with and without diabetes.

Detection of new vessels on the optic disc using retinal photographs

Proliferative diabetic retinopathy is a rare condition likely to lead to severe visual impairment. It is characterized by the development of abnormal new retinal vessels. We describe a method for automatically detecting new vessels on the optic disc using retinal photography. Vessel-like candidate segments are first detected using a method based on watershed lines and ridge strength measurement. Fifteen feature parameters, associated with shape, position, orientation, brightness, contrast and line density are calculated for each candidate segment. Based on these features, each segment is categorized as normal or abnormal using a support vector machine (SVM) classifier. The system was trained and tested by cross-validation using 38 images with new vessels and 71 normal images from two diabetic retinal screening centers and one hospital eye clinic. The discrimination performance of the fifteen features was tested against a clinical reference standard. Fourteen features were found to be effective and used in the final test. The area under the receiver operator characteristic curve was 0.911 for detecting images with new vessels on the disc. This accuracy may be sufficient for it to play a useful clinical role in an automated retinopathy analysis system.

[Characterization of the biometric eye profile of a high myopic population: does high myopia correspond to a homogenous phenotype?]

PURPOSE

High myopia is a public health problem because of its high prevalence and is a major cause of blindness. The physiopathology of myopia remains unknown and mechanisms causing the disease are most probably complex, combining acquired environmental and genetic factors. The most recent data suggest that genetic determinisms of high myopia could be highly dependent on subject phenotype. The aim of this study was to analyse the ocular components of a high myopic population to verify whether high myopia corresponds to a homogeneous phenotype.

PATIENTS AND METHODS

We analysed the biometric characteristics of 718 myopic eyes with a spherical equivalent of less than -5 diopters. The biometric parameters (corneal radius, axial length, and intraocular pressure) were compared controlling for sex and the degree of myopia.

RESULTS

We found a difference between the phenotype of males and females. For men, axial length was the only determinant of the myopic phenotype, whereas for women, the myopic phenotype was determined by axial length and corneal radius. This difference between the phenotypes was more evident for myopia with a spherical equivalent greater than -10 diopters (moderate myopia). This difference between males and females disappeared in myopia less than -15 diopters.

CONCLUSION

There are intersex differences considering the high myopia phenotype at a spherical equivalent less than -5 diopters. However, this difference disappears for extremely high myopia with a spherical equivalence of less than -15 diopters.

Assessing the diagnostic validity of a blind register

BACKGROUND

To validate the accuracy of clinical ophthalmic information held on the West Australian blind register.

DESIGN

Community-based cross-sectional study.

PARTICIPANTS

Legally blind or severely vision-impaired people were selected randomly from the Association for the Blind of Western Australia register.

METHODS

Individuals were reviewed by one of two consultant ophthalmologists.

MAIN OUTCOME MEASURES

The positive predictive value (ppv), sensitivity and specificity for legal blindness status and diagnostic causes of vision loss were calculated using data extracted from the Association for the Blind of Western Australia blind register.

RESULTS

273 blind or near blind people were reviewed from the register total of 4271 individuals. There were more women (57%) than men, median age 81 years. For legal blindness status the ppv was 0.88 (95% confidence interval [CI] 0.82-0.92), sensitivity 0.75 (95% CI 0.74-0.84) and specificity 0.6 (95% CI 0.46-0.73). The ppv for the diagnostic causes of blindness were: age-related macular degeneration = 0.95 (95% CI 0.91-0.97), retinitis pigmentosa ppv = 1 (95% CI 0.81-1.0), diabetic retinopathy ppv = 0.9 (95% CI 0.57-0.99), optic neuropathies ppv = 0.77 (95% CI 0.51-0.92) and glaucoma ppv = 0.87 (95% CI 0.7-0.96). Forty individuals (15%) had treatable conditions contributing to their vision loss.

CONCLUSIONS

The blind register diagnoses and legal blindness status are of high accuracy. This information allows useful linkages to other databases for studies of blindness interactions. A regular updating mechanism would improve the future accuracy of this valuable regional asset. The presence of untreated cataract suggests that regular follow up and appropriate treatment may help optimize vision in blind patients.

Oxidative stress in diabetic nephropathy

Diabetic nephropathy is a leading cause of end-stage renal failure worldwide. Its morphologic characteristics include glomerular hypertrophy, basement membrane thickening, mesangial expansion, tubular atrophy, interstitial fibrosis and arteriolar thickening. All of these are part and parcel of microvascular complications of diabetes. A large body of evidence indicates that oxidative stress is the common denominator link for the major pathways involved in the development and progression of diabetic micro- as well as macro-vascular complications of diabetes. There are a number of macromolecules that have been implicated for increased generation of reactive oxygen species (ROS), such as, NAD(P)H oxidase, advanced glycation end products (AGE), defects in polyol pathway, uncoupled nitric oxide synthase (NOS) and mitochondrial respiratory chain via oxidative phosphorylation. Excess amounts of ROS modulate activation of protein kinase C, mitogen-activated protein kinases, and various cytokines and transcription factors which eventually cause increased expression of extracellular matrix (ECM) genes with progression to fibrosis and end stage renal disease. Activation of renin-angiotensin system (RAS) further worsens the renal injury induced by ROS in diabetic nephropathy. Buffering the generation of ROS may sound a promising therapeutic to ameliorate renal damage from diabetic nephropathy, however, various studies have demonstrated minimal reno-protection by these agents. Interruption in the RAS has yielded much better results in terms of reno-protection and progression of diabetic nephropathy. In this review various aspects of oxidative stress coupled with the damage induced by RAS are discussed with the anticipation to yield an impetus for designing new generation of specific antioxidants that are potentially more effective to reduce reno-vascular complications of diabetes.

Prevalence and progression of visual impairment in patients newly diagnosed with clinical type 2 diabetes: a 6-year follow up study

BACKGROUND

Many diabetic patients fear visual loss as the worst consequence of diabetes. In most studies the main eye pathology is assigned as the cause of visual impairment. This study analysed a broad range of possible ocular and non-ocular predictors of visual impairment prospectively in patients newly diagnosed with clinical type 2 diabetes.

METHODS

Data were from a population-based cohort of 1,241 persons newly diagnosed with clinical, often symptomatic type 2 diabetes aged ≥ 40 years. After 6 years, 807 patients were followed up. Standard eye examinations were done by practising ophthalmologists.

RESULTS

At diabetes diagnosis median age was 65.5 years. Over 6 years, the prevalence of blindness (visual acuity of best seeing eye ≤ 0.1) rose from 0.9% (11/1,241) to 2.4% (19/807) and the prevalence of moderate visual impairment (> 0.1; < 0.5) rose from 5.4% (67/1,241) to 6.7% (54/807). The incidence (95% confidence interval) of blindness was 40.2 (25.3-63.8) per 10,000 patient-years. Baseline predictors of level of visual acuity (age, age-related macular degeneration (AMD), cataract, living alone, low self-rated health, and sedentary life-style) and speed of continued visual loss (age, AMD, diabetic retinopathy (DR), cataract, living alone, and high fasting triglycerides) were identified.

CONCLUSIONS

In a comprehensive assessment of predictors of visual impairment, even in a health care system allowing self-referral to free eye examinations, treatable eye pathologies such as DR and cataract emerge together with age as the most notable predictors of continued visual loss after diabetes diagnosis. Our results underline the importance of eliminating barriers to efficient eye care by increasing patients' and primary care practitioners' awareness of the necessity of regular eye examinations and timely surgical treatment.

A genome-wide association study for myopia and refractive error identifies a susceptibility locus at 15q25

Myopia and hyperopia are at opposite ends of the continuum of refraction, the measure of the eye's ability to focus light, which is an important cause of visual impairment (when aberrant) and is a highly heritable trait. We conducted a genome-wide association study for refractive error in 4,270 individuals from the TwinsUK cohort. We identified SNPs on 15q25 associated with refractive error (rs8027411, P = 7.91 × 10⁻⁸). We replicated this association in six adult cohorts of European ancestry with a combined 13,414 individuals (combined P = 2.07 × 10⁻⁹). This locus overlaps the transcription initiation site of RASGRF1, which is highly expressed in neurons and retina and has previously been implicated in retinal function and memory consolidation. Rasgrf1(-/-) mice show a heavier average crystalline lens (P = 0.001). The identification of a susceptibility locus for refractive error on 15q25 will be important in characterizing the molecular mechanism responsible for the most common cause of visual impairment.

Screening for eye disease in the elderly: is it worth it?

Should we be screening for eye disorders in the elderly population? Visual impairment in the elderly can be associated with reduced functional status and quality of life, low social contact, depression, and falls and hip fractures (Dargent-Molina et al, 1996). It therefore would seem sensible to identify those elderly patients who have or are at risk of developing sight-threatening eye disorders, and offer them treatment. However, screening for disease of any kind raises a number of issues.

Rhegmatogenous retinal detachment in Scotland: research design and methodology

Background

Rhegmatogenous retinal detachment (RRD) is a potentially blinding condition and a common cause of ocular morbidity. Establishing an accurate estimate of disease incidence and distribution is an important first step in assessing the healthcare burden related to this condition and in subsequent planning and provision of treatment strategies. The aim of this study is to obtain a first estimate incidence of RRD in Scotland, to estimate the incidence of familial RRD and to describe the known associations of RRD within the study population.

Methods/Design

We have established a national prospective observational study seeking to identify and recruit all incident cases of RRD in the Scottish population over a 2 year period. After fully informed consent, all participants will have a blood sample taken and a full medical history and clinical examination performed including visual acuity, refraction, slit-lamp examination, intra-ocular pressure measurement and detailed fundal examination. We describe the study design and protocol.

Conclusion

This study will provide the first estimate of the annual incidence of RRD in Scotland. The findings of this study will be important in estimating the burden of disease and in the planning of future health care policy related to this condition. This study will also establish a genetic resource for a genome wide association study to investigate if certain genetic variants predispose to RRD.

[Humanistic burden and health resource utilization among neovascular age-related macular degeneration patients in France]

OBJECTIVE

To assess the impact of bilateral neovascular age-related macula degeneration (NV-AMD) on function and health resource utilization (HRU) in France.

PATIENTS AND METHODS

Cross-sectional study including 401 NV-AMD patients and 471 controls conducted in five countries in 2006. In both groups, demographic and clinical data were collected and the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25), the EuroQoL (EQ-5D), the Hospital Anxiety and Depression Scale (HADS), and questionnaires on HRU were administered.

RESULTS

Eighty-seven NV-AMD patients and 92 controls were recruited in France. The mean age of the NV-AMD patients was 79 (range, 65-95), and 64% were female. After adjusting for age, gender, and co-morbidities, compared to controls, NV-AMD patients reported substantially worse vision-related quality of life on the NEI-VFQ (adjusted mean, 44.4 [36.2-52.7] versus 91.8 [86.2-97.5], p<0.0001). HADS anxiety and depression scores were significantly worse in NV-AMD patients (anxiety score, 8.5 [6.3-10.8] versus 5.1 [3.5-6.7] p=0.0005; depression score: 7.1 [5.1-9.1] versus 2.9 [1.5-4.4] p<0.0001). Per patient yearly cost analysis showed significantly higher direct medical costs: 3396 euro versus 85 euro (p<0.0001), and indirect nonmedical-related costs (mainly for assistance with activities of daily living): 2985 euro versus 494 euro (p=0.014).

CONCLUSIONS

NV-AMD patients in France reported substantially worse QoL and more anxiety and depression symptoms. The functional impact of blindness led to significantly higher health resource utilization in the AMD patients, resulting in higher total health costs compared to a similarly aged control group.

Care of vision and ocular health in diabetic members of a national diabetes organization: a cross-sectional study

Background

Regular examination and early treatment of diabetic retinopathy can prevent visual loss. The aim of the study was to describe the care of vision and ocular health in people with diabetes in Norway.

Methods

A cross-sectional questionnaire survey of a random sample (n = 1,887) of the Norwegian Diabetic Associations' (NDA) members was carried out in 2005. Questions were asked about care of vision and ocular health, history of ocular disease and visual symptoms, general medical history and diabetes management. The study was approved by the Regional Committee for Medical Research Ethics.

Results

The response rate was 74%. Forty-four questionnaires with incomplete data regarding gender, age or type of diabetes were excluded, leaving 1352 cases (52% females) for analysis. 451 (33%) had type 1 and 901 (67%) had type 2 diabetes, the mean duration of diabetes was respectively, 22 (sd ± 14) and 10 (sd ± 9) years. In all 1,052 (78%) had their eyes examined according to guidelines and 1,169 (87%) confirmed to have received information about regular eye examinations. One in two recalled to have received such information from their general practitioner. To have received information about the importance of eye examinations (PR 3.1, 95% CI 2.4 to 4.0), and diabetes duration > 10 years (PR 1.2, 95% CI 1.2 to 1.3), were independently associated with reporting regular eye examinations. A history of diabetic retinopathy was reported by 178 (13%) responders, of which 101 (57%) reported a history of laser treatment. Responders who had regular eye examinations reported more frequently a history of diabetic retinopathy (19% vs. 5%, p < 0.001). The frequency of retinopathy was significantly higher in responders with reported HbA1c values above treatment target (23% vs. 13%, p = 0.001). However, in responders who were not regularly examined, there was no difference in reported frequency of retinopathy with regard to HbA1c level.

Conclusion

Eight out of ten diabetic members of the NDA had their eyes examined according to current guidelines and the majority was well informed about the risk of vision loss due to diabetes. The results indicate that the reported history of diabetic retinopathy likely underestimates the prevalence of retinopathy.

Corneal biomechanical properties in primary open angle glaucoma and normal tension glaucoma

PURPOSE

To determine and compare the corneal biomechanical properties between eyes with primary open angle glaucoma (POAG) and eyes with normal tension glaucoma (NTG).

PATIENTS AND METHODS

Prospective cross-sectional study. Consecutive eligible POAG and NTG patients attending the Glaucoma Clinic had assessment of their corneal biomechanical properties-corneal hysteresis (CH) and corneal resistance factor (CRF)-using the Ocular Response Analyzer by an observer masked to the diagnosis. Exclusion criteria included previous intraocular surgery, corneal pathology, inflammatory connective tissue disease, and refraction of 5-dimensional or over. If both eyes were eligible, then the right eye was used for analysis. The main outcome measures were corneal hysteresis and CRF measurements. Data analysis was performed using the t test and general linear model.

RESULTS

Eighty-one patients (80 whites) were analyzed. Forty had NTG, whereas 41 had POAG. Thirty-five were females. There was a statistically significant difference in mean CH (NTG 9.6+/-1.3 mm Hg; POAG 9.0+/-1.4 mm Hg; P=0.01), but not in mean CRF (NTG 9.9+/-1.4; POAG 10.8+/-1.7; P=0.06). The highest recorded Goldmann applanation intraocular pressure (IOP) was statistically significantly associated with lower CH (P=0.01) and higher CRF (P=0.02).

CONCLUSIONS

There was a small but statistically significant difference in the mean CH between POAG and NTG (CH was higher in NTG). The highest recorded Goldmann applanation IOP was also statistically significantly correlated with lower CH and higher CRF, suggesting that alterations to the corneal biomechanical properties may occur as a result of chronic raised IOP in POAG.

A qualitative study in the United Kingdom of factors influencing attendance by patients with diabetes at ophthalmic outpatient clinics

INTRODUCTION

Many diabetics do not have regular eye examinations, although it is known that early diagnosis and treatment of sight-threatening retinopathy reduces the risk of blindness. The barriers that prevent diabetics from attending eye clinics are poorly understood.

PURPOSE

To determine what factors may influence diabetic patients' attendance at eye clinics.

METHODS

A qualitative survey of both patients and eye care providers was undertaken in a rural district general hospital and in an urban tertiary teaching hospital. Methods employed included semi-structured interviews, focus groups and non-participatory observations. All interviews and discussions were recorded and transcribed. The transcripts were then analyzed to detect emerging themes. Data collection continued until no new themes emerged.

RESULTS

Lack of awareness was seen as the greatest barrier by both patients and providers. Patients were aware that diabetes could affect the eye, but not that it could lead to blindness, nor that severe retinopathy could be asymptomatic. Patients reported that fundus images used for screening were a valuable educational resource. Fear, particularly of laser treatment, and guilt, about poor control causing retinopathy, deterred patients from attending. Both patients and providers recognized that regular attendance was inconvenient; however, providers underestimated the difficulties patients faced in obtaining time off work to attend clinics.

CONCLUSION

Providing more complete information about diabetic retinopathy, and making eye clinic attendance more convenient for patients, may increase the number of diabetics who have regular eye examinations.

Macular oedema is not predicted by perifoveal single blot haemorrhages

AIMS

To ascertain which perifoveal changes on digital retinal screening in diabetes predict the need for subsequent macular grid or focal laser therapy.

METHODS

Between 1 January 2004 and 31 December 2005, all consecutive retinal images where any lesion was within one disc diameter of the fovea were reviewed. Patients were categorized by lesion at screening as having microaneurysm, single blot haemorrhage, multiple blot haemorrhages and exudates or circinate exudates within one disc diameter of the fovea. We compared these retinal images with the findings on slit lamp examination and the related decision for laser photocoagulation.

RESULTS

Four hundred and twenty-four retinal images were identified. Of these, 52 were excluded, principally because of an interval between photography and clinic attendance of greater than 120 days, leaving 372 retinal images in the study group (313 patients). No patients with a single blot haemorrhage required immediate laser therapy at ophthalmology review compared with 13 (23%) of those with multiple blot haemorrhages and 36 (16%) of those with exudates or circinate lesions (P < 0.001). Thirty-nine patients with a single blot haemorrhage who did not require laser therapy underwent ongoing follow-up. None of these underwent laser therapy for maculopathy within the study time frame (9 months from initial screening event).

CONCLUSIONS

In this study, no patients with a single blot haemorrhage within one disc diameter of the fovea on digital retinal screening required laser treatment.

Glycaemic control and control of risk factors in diabetes patients in an ophthalmology clinic: what lessons have we learned from the UKPDS and DCCT studies?

PURPOSE

The Diabetes Control and Complications Trial (DCCT) and UK Prospective Diabetes Study (UKPDS) have studied glycaemic control as well as other risk factors in preventing the progression of diabetic end-organ disease, including diabetic retinopathy. We wished to determine to what extent a cross-section of diabetes patients attending our eye clinic met the targets laid down by recent landmark studies.

METHODS

We prospectively assessed 44 consecutive diabetes patients attending outpatient clinics for assessment of diabetic retinopathy. Each patient had HbA1c levels, serum cholesterol and blood pressure checked. A proforma was completed for each patient.

RESULTS

Of the 44 patients studied, 11 had type 1 diabetes mellitus (DM) and 33 had type 2 DM (11 insulin-dependent DM [IDDM], 22 non-insulin-dependent DM [NIDDM]). The mean age of type 1 DM patients was 43 years; that of type 2 DM patients was 62 years. Five of 11 (46%) type 1 DM patients had poorly controlled diabetes (HbA1c > 9%) compared with four of 33 (12%) type 2 DM patients. Overall, 27 of 44 (62%) patients were on antihypertensive medication. The prevalence of poorly controlled blood pressure (> 150/85 mmHg treated; > 160/90 mmHg untreated) was 16 of 44 (36%) patients overall, and was higher for type 2 DM patients (13/33, 39%) than for type 1 DM patients (3/11, 27%). Random serum cholesterol levels > 5.2 were found in 10 of 44 (23%) patients overall (4/11 [36%] type 1 and 6/33 [18%] type 2 DM patients).

CONCLUSIONS

Control of HbA1c, hypertension and hypercholesterolaemia can slow progression of retinopathy and other DM end-points. Many of our patients were poorly controlled in terms of these risk factors. More attention should be addressed to these primary preventative factors in the management of diabetes patients.

Patient profile and management in advanced glaucoma

Purpose: to study patient characteristics and management profile in advanced glaucoma. Method: A retrospective study of 87 case notes of patients registered blind due to glaucoma, and cross-sectional interview of 29 patients. Results: advanced glaucoma at presentation was documented in 43 cases (49%). Insufficient optometry assessment was significantly associated with advanced disease (p = 0.0339). Normal tension glaucoma patients were significantly more likely to present with advanced disease compared to other types of glaucoma (p = 0.0034). Poor compliance with medication was significantly higher in those with hearing loss (p = 0.0168). Patients with advanced field defect at presentation and those with poor compliance had significantly higher social deprivation scores compared to others on the blind register (p < 0.0001). Nine (10%) patients had partial registration before full registration and 29 (33%) patients had late registration. Of the 29 patients interviewed, 20 (69%) did not demonstrate basic knowledge regarding their disease or its management; nor had they received written information on glaucoma or instructions on drop technique. Conclusion: Special care pathways are required in advanced glaucoma taking into account co-existent morbidity, disease education and compliance.

The efficacy of automated "disease/no disease" grading for diabetic retinopathy in a systematic screening programme

AIM

To assess the efficacy of automated "disease/no disease" grading for diabetic retinopathy within a systematic screening programme.

METHODS

Anonymised images were obtained from consecutive patients attending a regional primary care based diabetic retinopathy screening programme. A training set of 1067 images was used to develop automated grading algorithms. The final software was tested using a separate set of 14 406 images from 6722 patients. The sensitivity and specificity of manual and automated systems operating as "disease/no disease" graders (detecting poor quality images and any diabetic retinopathy) were determined relative to a clinical reference standard.

RESULTS

The reference standard classified 8.2% of the patients as having ungradeable images (technical failures) and 62.5% as having no retinopathy. Detection of technical failures or any retinopathy was achieved by manual grading with 86.5% sensitivity (95% confidence interval 85.1 to 87.8) and 95.3% specificity (94.6 to 95.9) and by automated grading with 90.5% sensitivity (89.3 to 91.6) and 67.4% specificity (66.0 to 68.8). Manual and automated grading detected 99.1% and 97.9%, respectively, of patients with referable or observable retinopathy/maculopathy. Manual and automated grading detected 95.7% and 99.8%, respectively, of technical failures.

CONCLUSION

Automated "disease/no disease" grading of diabetic retinopathy could safely reduce the burden of grading in diabetic retinopathy screening programmes.

Automatic detection of retinal anatomy to assist diabetic retinopathy screening

Screening programmes for diabetic retinopathy are being introduced in the United Kingdom and elsewhere. These require large numbers of retinal images to be manually graded for the presence of disease. Automation of image grading would have a number of benefits. However, an important prerequisite for automation is the accurate location of the main anatomical features in the image, notably the optic disc and the fovea. The locations of these features are necessary so that lesion significance, image field of view and image clarity can be assessed. This paper describes methods for the robust location of the optic disc and fovea. The elliptical form of the major retinal blood vessels is used to obtain approximate locations, which are refined based on the circular edge of the optic disc and the local darkening at the fovea. The methods have been tested on 1056 sequential images from a retinal screening programme. Positional accuracy was better than 0.5 of a disc diameter in 98.4% of cases for optic disc location, and in 96.5% of cases for fovea location. The methods are sufficiently accurate to form an important and effective component of an automated image grading system for diabetic retinopathy screening.

The incidence of visual impairment due to diabetic retinopathy in Leeds

AIM

A key aim of the photographic screening model for diabetic retinopathy advocated by the National Screening Committee is a reduction in new blindness due to diabetic retinopathy within 5 years. This study determines the incidence of visual impairment due to diabetic retinopathy in Leeds in 2002 and provides a benchmark against which the success of the retinopathy screening programme in Leeds will be judged.

METHODS

A retrospective review of all blind and partially sighted registrations for 2002 was conducted. The 2001 Census data and the diabetes prevalence model developed by the Yorkshire and Humber Public Health Observatory were used to determine the total and diabetic populations of Leeds.

RESULTS

Diabetic retinopathy was the primary cause of registration in 24 of the 398 completed records obtained; seven patients were registered blind and 17 partially sighted. For the total population in 2002, the incidence of blind and partially sighted registration due to diabetic retinopathy was 10 per million and 24 per million per year, respectively. For the diabetic population of Leeds in 2002, the incidence of blind and partial sighted registration due to diabetic retinopathy was 337 and 817 per million per year, respectively.

CONCLUSIONS

The incidence of blind registration due to diabetic retinopathy in Leeds in 2002 is similar to the estimate provided by the National Screening Committee but higher than the figure from other UK centres.

Trends in blind registration in the adult population of the Republic of Ireland 1996-2003

BACKGROUND/AIM

The Republic of Ireland has a centralised database of all registered, blind people in the country. The last study of the national blind register was undertaken in 1996. The current study sought, firstly, to investigate and identify any recent changes in the register composition. Secondly, there is concern that many eligible people are not appropriately registered. To examine this further, registration levels among patients attending an Irish outpatient ophthalmology clinic were determined.

METHODS

Criteria for blind registration in Ireland are (1) a best corrected visual acuity of 6/60 or less in the better eye, or (2) a visual field subtending an angle of 20 degrees or less. The National Council for the Blind in Ireland (NCBI) is the sole custodian of a national registration database recording all eligible, registered people. This computerised database was analysed to provide information on the demographics and blind registration condition of those on the register in 2003. This information was compared with the results of the 1996 study. To assess the accuracy of the current register, the registration status of eligible patients attending the outpatient clinic of a busy, tertiary referral ophthalmology department, over a 9 week period, was studied.

RESULTS

6862 adults were registered as blind on the NCBI register in Ireland in 2003, representing an increase of 37% since 1996. The leading causes of registration were age related macular degeneration (ARMD) (25%), glaucoma (12%), and retinitis pigmentosa (7%). Comparing the 1996 and 2003 data, dramatic increases in the numbers registered caused by ARMD (from 812 to 1729 people, a 113% increase) and diabetic retinopathy (DR) (from 147 people to 323 people, a 120% increase) were found. The numbers registered as a result of glaucoma were relatively stable (795 in 1996 and 811 in 2003). A substantial drop, of 53%, was noted in the number of people registered as a result of cataracts, from 561 people to 261. Of the 672 new cases registered in 2003, ARMD accounted for 44%, glaucoma 13%, and DR 7%. Over the 9 week study period 75 patients, out of a total 2320 patients who attended the outpatient department, fulfilled the blind registration criteria. It was found that 21% (16 of 75) of the eligible clinic outpatients had not been appropriately registered.

CONCLUSION

An overall increase in adult blind registration of 37% in the Republic of Ireland was found between 1996 and 2003. There were large increases in registered blindness as a result of ARMD (113%) and DR (120%). A notable decrease in registration as a result of cataracts was discovered. Vigilance by clinicians is necessary to ensure that eligible patients are registered.

Lifetime visual prognosis for patients with primary open-angle glaucoma

AIM

To investigate final visual outcome in primary open angle glaucoma (POAG) including low-tension glaucoma (LTG).

METHODS

Retrospective review of case notes for patients who died between 1999 and 2002. All were booked for a follow-up appointment in glaucoma clinic at time of death.

RESULTS

A total of 121 case notes were reviewed. In all, 113 patients had POAG and eight had LTG. All were White Caucasians. Mean ages at presentation and death were 74.6 (SD 9.6, range 49-94) and 81.9 (SD 8.3, range 51-98) years, respectively. Mean follow-up duration was 7.4 (SD 6.8, range up to 29) years. Average number of clinic visits was 18 (SD 17, range 1-95). At final visit, 50.4% had cataract operations, and 45.5% had glaucoma operations. At final visit, vision was inadequate for driving in the UK in 47.1%. In 18.2%, this was due to glaucoma alone, while in 28.9%, other ocular pathologies contributed to poor vision. In all, 14% were eligible for partial sight certification, with 6.6% due to glaucoma alone. A total of 3.3% were eligible for blind certification, none due to glaucoma alone.

CONCLUSION

This study shows that POAG does affect the quality of life, with regards to glaucoma clinic visits, eye drops, and surgical procedures. Most patients with treated POAG in Norfolk will retain useful vision for their whole life. A significant proportion of patients with POAG do lose vision resulting in driving ineligibility and certification as visually impaired, although actual blindness is uncommon.

The impact of the Health Technology Board for Scotland's grading model on referrals to ophthalmology services

AIM

To ascertain the impact of the Health Technology Board for Scotland's grading model on referrals to ophthalmology services.

METHODS

An analysis was performed of the screening outcomes of 5575 consecutive patients, who were screened by the Grampian Diabetic Retinopathy Screening Programme between March and September 2003 according to the recommendations of the Health Technology Board and the Scottish Diabetic Retinopathy Grading Scheme 2003.

RESULTS

3066 (55%) were male. The median age was 65 years. 5.4% were passed on to the level 3 grader and 3.4% were finally referred to ophthalmology services. 2.3% required re-screening in 6 months; 85% were screened without mydriasis; 11.9% had ungradeable images despite a staged mydriasis protocol. Time to complete grading was 32 days (22-45).

CONCLUSION

The impact of the Health Technology Board for Scotland's recommendations on referrals to ophthalmology services is modest and should be containable within existing resources.

The Validity of a New Noncontact Tonometer and Its Comparison with the Goldmann Tonometer

PURPOSE

This study compared a new noncontact tonometer (NCT), the Nidek NT-4000 (Nidek Co., Ltd., Aichi, Japan), with a pulse detection feature; an earlier model, the Nidek NT-2000, without this pulse detection facility; and Goldmann tonometry.

METHODS

Thirty-one young subjects had their intraocular pressure (IOP) in one eye randomly measured by two NCT's, followed by a Goldmann tonometer. The pulse detection mode used by the NT-4000 included synchronizing the IOP with the peak of the pulse (P-P), the middle of the pulse (P-M), or the bottom of the pulse (P-B). The order of measurements from these three modes was also random. Three consecutive readings were obtained from each mode/tonometer, and the mean was used for analysis.

RESULTS

Goldmann tonometry demonstrated the smallest variation from consecutive measurements (coefficient of variation, <4%), followed by the NT-4000 (coefficient of variation, <5% in various modes) and the NT-2000 (coefficient of variation, >5%). For the NT-4000, the mean IOP decreased from the highest in the P-P mode (16.1 mm Hg) to the lowest in the P-B mode (14.7 mm Hg), with the P-M mode in the middle. A significant difference was found among the IOP readings using the NT-4000 (in various modes), NT-2000, and Goldmann tonometry (repeated-measures analysis of variance, p < 0.01). More than 80% of the results from the NT-4000 were within 3 mm Hg of those from the Goldmann tonometry.

CONCLUSIONS

The pulse detection feature from this new NCT could capture and monitor pulse waves, thus reducing the variations in the consecutive measurements. The NT-4000 also performed better than the NT-2000 when compared with the Goldmann tonometry.