Prevalence and associations of presenting near-vision impairment in the Australian National Eye Health Survey.

PurposeTo describe the prevalence and associations of presenting near vision impairment (NVI) in Indigenous and non-Indigenous Australians.MethodsA sample of 3098 non-Indigenous Australians (aged 50-98 years) and 1738 Indigenous Australians (aged 40-92 years) living in 30 randomly selected Australian sites were examined as part of the population-based National Eye Health Survey (NEHS). Binocular presenting NVI was defined as near vision worse than N8 (20/50).ResultsIn total, 4817 participants (99.6% of the total sample, comprising 3084 non-Indigenous Australians and 1733 Indigenous Australians) had complete data on near visual acuity. The overall weighted prevalence of presenting NVI was 21.6% (95% CI: 19.6, 23.8) in non-Indigenous Australians and 34.7% (95% CI: 29.2, 40.8) among Indigenous Australians. In the non-Indigenous population, higher odds of presenting NVI were associated with older age (OR=1.68 per 10 years, P<0.001), fewer years of education (OR=0.95 per year, P<0.001) and residing in Remote geographical areas (OR=1.71, P=0.003) after multivariate adjustments. Among Indigenous Australians, older age (OR=1.69 per 10 years, P<0.001), fewer years of education (OR=0.91 per year, P=0.003) and residing in Inner Regional (OR=2.01, P=0.008), Outer Regional (OR=2.17, P=<0.001) and Remote geographical areas (OR=1.72, P=0.03) were associated with greater odds of presenting NVI.ConclusionsNVI represents a notable public health concern in Australia, affecting approximately 20% of non-Indigenous Australian and one-third of Indigenous Australian adults.

Prevalence and causes of vision loss in Southeast Asia and Oceania: 1990-2010.

BACKGROUND: To assess prevalence and causes of vision impairment in Southeast Asia and Oceania in 1990 and 2010. METHODS: Based on a systematic review of medical literature, prevalence of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18 but ≥3/60 in the better eye) and blindness (presenting visual acuity <3/60) was estimated for 1990 and 2010. RESULTS: In Oceania, the age-standardised prevalence of blindness and MSVI did not decrease significantly (1.3% to 0.8% and 6.6% to 5.1%) respectively, but in Southeast Asia, blindness decreased significantly from 1.4% to 0.8%, a 43% decrease. There were significantly more women blind (2.18 million) compared with men (1.28 million) in the Southeast Asian population in 2010, but no significant gender differences in MSVI in either subregion. Cataract was the most frequent cause of blindness in Southeast Asia and Oceania in 1990 and 2010. Uncorrected refractive error, followed by cataract, macular degeneration, glaucoma and diabetic retinopathy were the most common causes for MSVI in 1990 and 2010. With the increasing size of the older population, there have been relatively small increases in the number of blind (2%), and with MSVI (14%) in Southeast Asia, whereas increases have been greater in Oceania of 14% for blindness and of 31% for MSVI. CONCLUSIONS: The prevalence of blindness has reduced significantly from 1990 to 2010, with moderate but non-significant lowering of MSVI. Cataract and uncorrected refractive error are the main causes of vision impairment and blindness; cataract continues as the main cause of blindness, but at lower proportions.

Prevalence of diabetic retinopathy in Type 2 diabetes in developing and developed countries.

BACKGROUND: As the global prevalence of diabetes increases, so will the numbers of people with diabetic retinopathy. Our review aimed to provide a comprehensive picture of available studies of diabetic retinopathy and how prevalence varies around the developed and developing world. METHODS: A detailed literature search using PubMed was undertaken. The following search term was used: 'diabetic retinopathy AND prevalence'. The titles and abstracts of all publications identified by the search were reviewed and 492 studies were retrieved. Inclusion and exclusion criteria were applied. RESULTS: A total of 72 articles from 33 countries were included. There were only 26 population-based studies using fundus photography (12 in developing countries), of which only 16 (eight in developing countries) were published since 2000. Prevalence estimates varied from as low as 10% to as high as 61% in persons with known diabetes and from 1.5 to 31% in newly diagnosed diabetes. Across all the studies, the median (interquartile range) prevalence of any diabetic retinopathy in known diabetes was 27.9% (22-37%) and 10.5% (6-16%) in newly diagnosed diabetes. Prevalence of diabetic retinopathy was higher in developing countries. CONCLUSION: Significant gaps exist in that reliable population-based data from developing nations and indigenous populations in particular are lacking. Major differences in study characteristics and methodologies make comparisons very difficult. More research is required and study methodologies must be better standardized. This will provide important information for prevention and treatment strategies.

An emergent science on the brink of irrelevance: a review of the past 8 years of DNA barcoding.

DNA barcoding has become a well-funded, global enterprise since its proposition as a technique for species identification, delimitation and discovery in 2003. However, the rapid development of next generation sequencing (NGS) has the potential to render DNA barcoding irrelevant because of the speed with which it generates large volumes of genomic data. To avoid obsolescence, the DNA barcoding movement must adapt to use this new technology. This review examines the DNA barcoding enterprise, its continued resistance to improvement and the implications of this on the future of the discipline. We present the consistent failure of DNA barcoding to recognize its limitations and evolve its methodologies, reducing the usefulness of the data produced by the movement and throwing into doubt its ability to embrace NGS.

Microbiological and clinical profiles of patients with microbial keratitis residing in nursing homes.

AIM: To study the microbiological and clinical profile of patients with microbial keratitis living in nursing homes. METHODS: A retrospective analysis of hospital records from 1996 to 2006 of patients who had microbial keratitis, and were living in nursing homes, was undertaken. The main parameters evaluated were clinical and microbiological profile and final visual outcome. RESULTS: Of 66 patients included in this study, 39 were female and 27 were male, with mean age of 81(SD 11) (range 46-97) years. The major ocular and systemic factors associated with the occurrence of microbial keratitis were the presence of dry eyes (26%) and rheumatoid arthritis (81%), respectively. A positive bacterial culture was obtained in 54 (82%) cases with Staphylococcus being the most prevalent isolate (48%). Seven patients had positive culture for herpes virus. Surgical intervention had to be performed in 31(47%) of cases mainly in the form of botox injection for induction of ptosis (n = 9, 27%), keratoplasty (n = 8, 24%), tarsorrhaphy (n = 5, 15%) or glue (n = 3, 9%). The mean pre-treatment and post-treatment visual acuity was counting fingers and 6/60 respectively. CONCLUSIONS: Microbial keratitis in patients living in nursing homes is usually caused by Staphylococcus and is associated with dry eyes and ocular surface disease. Surgical intervention is required in majority of cases with poor visual outcome.

Comparison of clinical and photographic assessment of trachoma.

AIMS: The aim of the study was to determine the rates of trachoma in Aboriginal communities and to compare clinical assessment with photographic assessment for the presence of signs of trachoma. METHODS: Five Aboriginal communities in the Katherine region of the Northern Territory, Australia, were assessed for the presence of trachoma. Trachoma was diagnosed by clinical eye examination using a fine grading based on the World Health Organization (WHO) simplified grading system. Photographs were taken of the left eye of every person and graded using the fine grading system. The clinical assessment was compared with the photographic assessment for each person using the fine grading system. RESULTS: A total of 1316 people out of 1545 (85.2%) were screened for trachoma from five communities, with 1254 photographs being compared with clinical assessment scores. The overall prevalence of active trachoma was greater than 10% across the five communities, and greater than 20% in two communities. CONCLUSION: Active trachoma in young people and scarring in older people remain as problems in Aboriginal communities. Photographic assessment is a useful technique, but in comparison with clinical assessment it can result in overestimation of scoring for trachoma for inflammation.

Doyne Lecture: trachoma, is it history?

Trachoma has been known since pre-Pharaonic times and this infectious cause of blindness is targeted by the World Health Organization (WHO) for elimination by 2020. During the 19th century, trachoma was a major political problem in European countries as an important cause of disability in both soldiers and among the urban poor in the slums created by the Industrial Revolution. Even 100 years ago, trachoma was a major problem worldwide. Trachoma has now been eliminated from most developed regions, but the disease still affects some 150 million people in 56 developing countries. This paper reviews our current understanding of trachoma and the key strategies for the elimination of trachoma as a major blinding disease.

Trachoma in the Pacific Islands: evidence from Trachoma Rapid Assessment.

AIMS: To establish the presence or absence of trachoma in the Pacific Island region. METHODS: Trachoma Rapid Assessment methodology was used in Kiribati, Nauru, Vanuatu, Solomon Islands and Fiji. Advised by key informants, high-risk communities were chosen from each country. All available children aged 1-9 years and adults > or = 40 years were examined. RESULTS: A total of 903 adults > or = 40 years and 3102 children aged 1-9 years were screened at 67 sites. Rates of active trachoma in children were >15% in all sites in Kiribati and >20% in all sites in Nauru. However, there was a high variability of rates of active trachoma in survey sites in Vanuatu, Solomon Islands and Fiji with rates ranging from 0% to 43% (average 23.3%), 6.0% to 51.9% (average 30.5%) and 0% to 48.8% (average 22.1%) respectively. Average rates of scarring trachoma in adults were 61.9% in Kiribati, 12.5% in Nauru, 38.2% in Vanuatu, 67.0% in the Solomon Islands and 18.8% in Fiji. Rates of trichiasis and trichiasis surgeries suggest the possibility of blinding trachoma in the region. CONCLUSION: The findings indicate that trachoma is present in all the Pacific Island countries screened. Further prevalence studies are required, and trachoma control measures should be considered.

Resuturing following penetrating keratoplasty: a retrospective analysis.

AIM: To examine the clinical profile of cases requiring resuturing following penetrating keratoplasty (PKP) at a tertiary care eye hospital. METHODS: The medical records of 947 consecutive patients who had undergone PKP between 1998 and 2006 were reviewed retrospectively and cases that were resutured during this period were analysed. The main parameters studied were indications for PKP, suturing techniques, causes of resuturing, visual acuity outcome and post-resuturing complications. RESULTS: The incidence of resuturing was 5.4% (51 eyes). The number of cases requiring resuturing was higher in corneal grafts performed for microbial keratitis (12%) than those for keratoconus (10%) and corneal endothelial decompensation (2.5%; p = 0.08). Wound dehiscence was the leading cause for resuturing (43%), followed by loose or broken sutures (37.3%). The most common complications after resuturing were occurrence of microbial keratitis (7.8%) and graft failure (5.9%). DISCUSSION: Resuturing may have to be performed more commonly for corneal transplantation surgery done for microbial keratitis and keratoconus. The major indications for resuturing are wound dehiscence and loose/broken sutures.

Comparative study of the polaroid and digital non-mydriatic cameras in the detection of referrable diabetic retinopathy in Australia.

AIM: To show that the non-mydriatic retinal camera (NMRC) using polaroid film is as effective as the NMRC using digital imaging in detecting referrable retinopathy. METHODS: A series of patients with diabetes attending the eye out-patients department at the Royal Victorian Eye and Ear Hospital had single-field non-mydriatic fundus photographs taken using first a digital and then a polaroid camera. Dilated 30 degrees seven-field stereo fundus photographs were then taken of each eye as the gold standard. The photographs were graded in a masked fashion. Retinopathy levels were defined using the simplified Wisconsin Grading system. We used the kappa statistics for inter-reader and intrareader agreement and the generalized linear model to derive the odds ratio. RESULTS: There were 196 participants giving 325 undilated retinal photographs. Of these participants 111 (57%) were males. The mean age of the patients was 68.8 years. There were 298 eyes with all three sets of photographs from 154 patients. The digital NMRC had a sensitivity of 86.2%[95% confidence interval (CI) 65.8, 95.3], whilst the polaroid NMRC had a sensitivity of 84.1% (95% CI 65.5, 93.7). The specificities of the two cameras were identical at 71.2% (95% CI 58.8, 81.1). There was no difference in the ability of the polaroid and digital camera to detect referrable retinopathy (odds ratio 1.06, 95% CI 0.80, 1.40, P = 0.68). CONCLUSION: This study suggests that non-mydriatic retinal photography using polaroid film is as effective as digital imaging in the detection of referrable retinopathy in countries such as the USA and Australia or others that use the same criterion for referral.

Moraxella keratitis: predisposing factors and clinical review of 95 cases.

AIM: To analyse the clinical presentation, identify predisposing risk factors and evaluate the outcome of treatment of Moraxella keratitis. METHODS: A retrospective analysis was carried out of culture-proved cases of Moraxella keratitis from hospital records during a 10-year period (from December 1995 to November 2005) at the Corneal Unit of the Royal Victorian Eye and Ear Hospital, Melbourne, Australia. RESULTS: 95 episodes of Moraxella keratitis were identified in 92 patients. 3 (3.2%) patients had recurrent keratitis. The mean age of the patients was 70 (range 17-93) years. Multiple predisposing factors were identified in 23 (24%) eyes, including corneal graft (n = 15), previous herpes keratitis (n = 15) and eye lid diseases (n = 15). Adjunctive procedures were carried out in 42 eyes. These included botulinum toxin injection (n = 17), tarsorraphy (n = 12), penetrating keratoplasty (n = 8), enucleation (n = 3), tissue adhesive and bandage contact lens (n = 4), and conjunctival flap (n = 5). Polymicrobial infection was present in 17 eyes. Final visual acuity was counting finger or less in 25 (26%) eyes. CONCLUSIONS: Local ocular predisposing factors play a major role in Moraxella keratitis. This infection has a poor visual outcome attributable to both the nature of the infection and the predisposing factors.

Diagnostic thresholds for diabetes: the association of retinopathy and albuminuria with glycaemia.

AIM: We examined the association of fasting plasma glucose (FPG), 2-h plasma glucose (2hPG) and HbA1c with retinopathy and microalbuminuria using both deciles of glycaemia and change point models, to validate current diagnostic criteria for diabetes and to identify therapeutic thresholds for glycaemic control. METHODS: The Australian Diabetes Obesity and Lifestyle study (AusDiab), conducted in 1999-2000, included adults aged > or =25 years from 42 randomly selected areas of Australia. Retinopathy and albuminuria were assessed in participants identified as having diabetes (based on self report and oral glucose tolerance test), impaired fasting glucose, impaired glucose tolerance and in a random sample with normal glucose tolerance. Data were available for 2,182 participants with retinal photographs and 2,389 with urinary albumin/creatinine results. RESULTS: The prevalence of retinopathy in the first 8 deciles of FPG and HbA1c and the first 9 deciles of 2hPG were 7.2, 6.6, and 6.3%, respectively and showed no variation with increasing glucose or HbA1c. Above these levels, the prevalence rose markedly to 18.6% in the top 2 deciles of FPG, 21.3% in the top 2 deciles of HbA1c and 10.9% in the top decile of 2hPG. The thresholds for increasing prevalence of retinopathy were 7.1 mmol/l for FPG, 6.1% for HbA1c and 13.1 mmol/l for 2hPG. The prevalence of microalbuminuria rose gradually across deciles of each glycaemic measure. Thresholds were less clear than for retinopathy, but were seen at a FPG of 7.2 mmol/l and HbA1c of 6.1%, with no evidence of a threshold effect for 2hPG. CONCLUSIONS: The prevalence of retinopathy rose dramatically in the highest deciles of each glycaemic measure, while for microalbuminuria the increase of prevalence was more gradual. The FPG values corresponded well with the WHO diagnostic cut-point for diabetes, however the 2hPG value did not. HbA1c thresholds were similar for both retinopathy and microalbuminuria and compared well to values shown in other studies. These results support current targets for FPG and HbA1c in preventing microvascular complications.

Randomised controlled trial of topical ciclosporin A in steroid dependent allergic conjunctivitis.

AIM: To evaluate the efficacy, safety, and therapeutic effect of topical ciclosporin A 0.05% as a steroid sparing agent in steroid dependent allergic conjunctivitis. METHODS: Prospective, randomised, double masked, placebo controlled trial comparing signs, symptoms, and the ability to reduce or stop concurrent steroid in steroid dependent atopic keratoconjunctivitis and vernal keratoconjunctivitis using 0.05% topical ciclosporin A compared to placebo. Steroid drop usage per week (drug score), symptoms, and clinical signs scores were the main outcome measures. RESULTS: The study included an enrolment of 40 patients, 18 with atopic keratoconjunctivitis and 22 with vernal keratoconjunctivitis. There was no statistical significant difference in drug score, symptoms, or clinical signs scores between the placebo and ciclosporin group at the end of the treatment period. No adverse reactions to any of the study formulations were encountered. CONCLUSIONS: Topical ciclosporin A 0.05% was not shown to be of any benefit over placebo as a steroid sparing agent in steroid dependent allergic eye disease.

The economic impact and cost of visual impairment in Australia.

AIMS: To quantify the total economic costs of vision loss in Australia. METHODS: Prevalence data of visual impairment, unpublished data on indirect costs, and national healthcare cost databases were used. RESULTS: Vision disorders cost Australia an estimated A$9.85 billion in 2004. A$4.8 billion is the loss of wellbeing (years of life lost as a result of disability and premature mortality). Vision disorders rank seventh and account for 2.7% of the national loss of wellbeing. Direct health system costs total A$1.8 billion. They have increased by A$1 billion over the last 10 years and will increase a further A$1-2 billion in the next 10 years. Cataract, the largest direct cost, takes 18% of expenditure. The health system costs place vision disorders seventh, ahead of coronary heart disease, diabetes, depression, and stroke. Indirect costs, A$3.2 billion, include carers' costs, low vision aids, lost earnings, and other welfare payments and taxes. CONCLUSIONS: Even a developed economy such as Australia's cannot afford avoidable vision loss. Priority needs to be given to prevent preventable vision loss; to treat treatable eye diseases; and to increase research into vision loss that can be neither prevented nor treated.