Poster presentations
iPad app shows promise as tool for measuring visual acuity
An iPad app for measuring visual acuity may eventually be an alternative to paper charts and pictures.
The app - called iSight - was put to the test when 35 children and 36 adults participated in a study examining the effectiveness of the technology. Findings were presented in a poster at the International Orthoptic Congress in Toronto by Nadia Northway and colleagues from Glasgow Caledonian University, Scotland.
The visual acuity of adults was measured using the Bailey Lovie eye chart, and the children were assessed using the Kay picture test. They were then retested using the iSight tool, and results were compared. No statistical difference was found between iPad measures and those for conventional eye charts in either group (p = 0.05). However, iSight results showed higher acuity in preschool children than the chart revealed and took longer to conduct, partly because the young participants were restless.
Some adults complained of blur when the iPad screen was set to 100% brightness. Researchers reported that correlation to the chart measures and compliance improved when screen brightness was reduced to 50%.
Researchers concluded that the iPad app was accurate, and suggested iSight would be a good tool for parents to use to assess their children's vision.
Corneal transplants in Quebec still rising
Corneal transplant procedures have increased dramatically over the past few years and continue to rise, according to an analysis of data from the Quebec Eye Bank and Héma-Québec.
A retrospective review of 2000-11 corneal transplant records for procedures done in Montréal and Sherbrooke showed the mean annual number of transplants between 2003 and 2009 was 149 (range of ± 38.5 in individual years), but tripled to 466 in 2010-11. During that time, 1,865 corneal transplants were performed by 20 corneal surgeons at 10 university hospitals.
The main reasons for the more recent transplants were: Fuchs endothelial dystrophy (42.3% of cases), pseudophakic corneal edema (25.3%), keratoconus (11.3%), postinfectious keratitis (5.3%) and trauma (4.6%). This was similar to records for 2007-08. Regrafts accounted for 21% of the reason for corneal transplant in 2000-11, ranging from 13.5% in 2001 to 28.9% in 2006.
There was a change over the 11-year period in the type of procedures performed. Data revealed that Descemet's stripping automated endothelial keratoplasty (DSAEK, a type of partial-thickness corneal graft) is now more common. Although just 20 DSAEK procedures were performed prior to 2008, 516 procedures were done in 2008-11.
There was a significant increase in total grafts performed after Héma-Québec took over procurement and allocation of corneal tissues, in 2009. The Quebec Eye Bank continues to be responsible for preparing and qualifying the grafts.
Amniotic membrane transplantation effective for ocular graft-versus-host disease
Two patients with allogeneic hematopoietic stem cell transplantation showed signs of active ocular inflammation secondary to graft-versus-host-disease (GVHD). Each received one layer of amniotic membrane graft as treatment.
One patient presented with GVHD in both eyes, with a visual acuity of 20/30 and 20/200 in the right and left eyes, respectively, and received amniotic membrane grafts in both eyes. At follow up more than five months later, the patient's eyes looked clear and were healthy, with visual acuity of 20/25.
The second patient presented with GVHD and visual acuity of 20/60 and 20/80 in the right and left eyes, respectively. The patient underwent bilateral amniotic membrane grafts in separate surgeries about 10 days apart. At follow up, the patient's eyes appeared healthy - with visual acuity of 20/25 in the right eye and 20/20 in the left - but had mild superficial punctate keratopathy in the right eye and a clear cornea in the left.
Researchers, led by Dr. Joel Post from the University of Saskatchewan, concluded that amniotic membrane transplantation should be considered as early treatment for ocular inflammation from GVHD. The same team had similar success with amniotic membrane transplantation to treat a patient who presented with limbal ischemia following a chemical injury.
Eye exams by ER physicians match those by ophthalmologists in most areas
Emergency physicians and ophthalmologists perform vision examinations in pretty much the same way - except when it comes to assessing pupillary responses, visual fields, anterior segment by slit lamp and fundus examination.
To address concerns about deficiencies in the ophthalmic education of non-ophthalmogists, ocular examinations performed by emergency physicians were compared with those by ophthalmologists. Researchers compared the physical exams and diagnostic accuracy of assessments of 286 eyes belonging to 143 patients referred from six hospitals.
There were no significant differences between examinations done by emergency physicians and ophthalmologists looking at visual field, ocular movements and noting elevated intraocular pressure, but the researchers said improvements are needed in assessing visual acuity in patients whose vision was worse than 20/400, and in slit-lamp assessments, fundus history and relative afferent papillary defects.
Findings were presented in a poster by Dr. Steven Schendel, from the department of ophthalmology and visual sciences, University of British Columbia, Vancouver.
Barriers among teens to seeking eye care?
Adolescents are more likely to go for eye exams if there is provincial coverage of the fee, but even when cost isn't a factor they don't seek eye care on the same scale that they visit the dentist.
This finding comes from data on annual utilization of eye care providers and dental care providers from the Canadian Community Health Survey 2007-08. Data included reports on 5,457 patients ages 12-14.
Five Canadian provinces - Alberta, British Columbia, Ontario, Quebec and Saskatchewan - provide insurance for routine annual eye examinations but no coverage for dental checkups. Nevertheless, teens went to dental care providers 1.8 times more frequently than they did eye care providers (p < 0.05).
Prince Edward Island provides 100% coverage for preventive dental services but nothing for routine eye exams. Here, utilization was 2.6 times greater for dental care providers than for eye care providers (86.2% versus 32.9%, p < 0.05). In Newfoundland and Labrador, New Brunswick and Nova Scotia, where neither routine eye examinations nor dental care services are covered by government, utilization was 2.3 times higher for dental care providers than for eye care providers (78.5% versus 34.6%, p < 0.05).
Researchers from McMaster University in Hamilton, Ont., and the University of Toronto note that barriers to vision care services other than cost need to be identified and addressed.
Canadian Eye Injury Registry off to a promising start
An online database storing information on all serious eye injuries is showing promise in its evolution to become the only registry of its kind in Canada.
Dr. David Dudok, an ophthalmology resident at University of Western Ontario (UWO) in London, Ont., said the model for the database is the United States Eye Injury Registry (USEIR). An earlier version of the Canadian database has been in use at the Ivey Eye Institute, affiliated with UWO, since March 2011. There are an estimated 100,000 significant eye injuries occurring in this country annually, and tracking may help with prevention strategies.
Inclusion criteria for reports include all injuries that could significantly affect the structure or long-term function of the eye. All reporting physicians to date have been staff or resident ophthalmologists.
In a pilot study, 88 injuries matching the inclusion criteria have been assessed. The most common places of injury were: home (34.1%), recreational facility or sports field (30.6%), street or highway (13.6%).
According to researchers, the data obtained from the registry to date have shown a trend toward less-severe injuries, in comparison with other data reported in the medical literature. They add that expanding the project to other centres will increase the strength of interventions recommended.
Teleglaucoma: improving access in northern Alberta
A remote telemedicine program designed to improve care for glaucoma patients in northern Alberta is proving useful. Patients have expedited access to specialist expertise, and participating optometrists are becoming more comfortable making referrals this way.
The teleglaucoma program was launched in 2008 to help people living in remote and underserved areas. Developed at the University of Alberta, the program offers the services of 15 community optometrists in Alberta and one comprehensive ophthalmologist in Yellowknife. Patient details such as history and exam, details of visual field and images - such as fundus photos and OCT (optical coherence tomography) - are stored on a secure server so that specialists in other cities can review the information and advise on patient diagnosis and treatment.
Researchers reported that 195 consults have been graded through the remote model since 2008. There were 53 in 2008-09, 46 in 2009-10 and 96 in 2011 (January through November).
Printed text beats most digital in AMD
Traditional printed text trumps digital versions in most cases for quick, easy reading, patients with low vision report. But when text is enlarged, the iPad sneaks into first place.
A prospective study of 26 patients who have low vision (average age 76 years) was undertaken to assess reading speed and ease using the Apple iPad, Sony Reader and standard printed text. All participants had stable, wet age-related macular degeneration (AMD), with visual acuity of 20/25.
The study reported average reading speeds of 123.75 words per minute (WPM) with printed text, 126.53 using the iPad and 120.23 with the Sony e-reader. Reading speeds were also measured for different text sizes (16, 24, ≥ 32). With larger text sizes (24 or 32+), patients read 5.52 WPM faster on the iPad compared with 3.54 WPM faster when reading text printed on paper.
The study was conducted by researchers at the University of Western Ontario, London, Ont.
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