This year's meeting of the Association for Research in Vision and Ophthalmology (ARVO) attracted record numbers. In all, some 10,250 delegates attended the five-day conference held in Fort Lauderdale to attend a wide range of seminars, lectures, workshops and symposia all presenting the latest findings in vision research.
As ever, the scope of the meeting is such that no single article can do it justice and for a more complete look through the abstracts, readers are recommended to visit the website (www.arvo.org).
The renowned Harold Quigley, of the epidemiology of glaucoma fame, presented his concerns about the effectiveness of topical therapy for glaucoma. Although such treatment reduces the progression of glaucoma by up to 60 per cent if used in ideal conditions, real-world conditions tend to make it less than satisfactory. Quigley concluded that doctors need to be more aware of poor compliance from patients and that a new approach to topical treatment or the development of alternative modes of delivery was essential.
Talking of new methods, Victor Lee of the Food and Drug Administration Department, talked about the potential for nanotechnology in drug delivery. The miniscule size of such systems would allow them access to hitherto unreachable areas of the eye.
Namtram Pham (Maryland) presented results of a study suggesting acupuncture might be of help to dry eye patients. It has already been established that acupuncture helps some patients with dry mouth, possibly by stimulating parasympathetic nervous system activity. Pham used a randomised double blind study of 12 moderate to severe dry eye patients who received either acupuncture or 'sham acupuncture'. The test group all showed improvements in break-up time and rose bengal staining scores.
The Airforce Warfighter Refractive Surgery Study looked at 1,310 eyes after refractive surgery and compared the refractive outcome of Lasek against Lasik. While the best spectacle corrected acuity was better at one year for the Lasik group, this difference was minor and the researchers concluded that the two techniques have 'similar efficacy in correcting moderate myopia'. From a safety point of view, the US military would continue to select Lasek as 'some of the trauma to the soldiers overseas are flaps being dislocated…'
enhanced images
A number of presentations looked at the developments in using polarised light for retinal imaging and analysis. Polarimetric techniques have long been used to look at the retinal nerve fibre layer (such as in the GDx for example) but researchers such as Elsner (Indiana) are using near infra-red light in scanning laser polarimetry to analyse data over a wide range of polarisation condition so giving enhanced images of the retina. As these techniques become honed further, it is likely that we will see improvements in assessment of retinal lesions such as diabetes and central serous retinopathy.
For some time now we have been told about the potential for adaptive optics in improving the quality of imaging systems in ophthalmology. Studies by Roorda (Berkeley) have concentrated on incorporating adaptive optics into a confocal scanning laser ophthalmoscope. This has already shown benefits in imaging precise detail, such as the microstructure and micro-dynamics of pre-capillary vessels in diabetics, for example. However, an added advantage has been discovered. By correcting for the small distortions in each frame caused by eye movements, the system allows researchers to record eye movements with extreme precision and speed. By modulating the laser beam, it is possible to deliver adaptive optics-corrected stimuli to the retina allowing simultaneous recording from individual photoreceptors. Such techniques could give much new information on retinal function and perhaps solve some of the debate about eccentric viewing and retinal function changes with altered fixation.
One of the effects of ultraviolet light upon corneal tissue has been identified as epithelial cell apoptosis. A study by Ling Wang and colleagues (Los Angeles) has found that the initial result of such exposure is an induced super activity of potassium channels in the cell membrane, resulting in a signal transduction followed by epithelial cell death. Understanding the precise mechanism of UV damage to external and anterior ocular structures will go some way to help prevent eye damage.
My vote for the most obscure results goes to NASA who presented the results of their Study of Cataract in Astronauts. The study looked at all the 215 astronauts involved in missions to the moon as well as those involved in flights just within the Earth's atmosphere. Their eye health was compared with that of pilots and ground staff along with results from a Harvard Food Frequency Questionnaire. First-year data suggest that exposure to radiation in space is related to cortical cataract formation but not to nuclear or subcapsular cataract formation. The questionnaire suggested that vitamin A intake helped reduce cataract formation, while omega-3 intake led to increases in cortical cataract. This conflicted somewhat with the latest offerings from the AREDS study, also presented here, which suggested omega-3 to have a protective effect against cataracts. Budding space cadets be warned.