Bill Harvey selects a few highlights from the annual ARVO meeting in Florida
Diet and AMD were ripe areas for discussion during the Association for Research in Vision and Ophthalmology (ARVO) meeting. A study from Melbourne has shown that intake of red meat and processed meat is associated with an increased prevalence of early AMD, whereas intake of chicken is inversely associated with late AMD.
Meanwhile, the Wills Eye Institute in Philadelphia has published results of a three- year longitudinal study of over 200 non-dementia patients with AMD. It has found that there is a clear link between the decline in activities that occurs with central vision loss (such as reading, physical or social activities) and a decline in mental welfare. Indeed, the study has found that the number of dropped activities is an accurate predictor of cognitive decline after all other risk factors are controlled for.
Looking at glaucoma, a new intraocular pressure measurement device has been developed at the University of Louisville. The device is designed to be implanted within the eye and uses radio frequency transmission to allow continuous remote monitoring of IOP. Animal trials have proved successful and a key indicator of compliance or treatment effectiveness may become easier to monitor in years to come.
Most readers will be aware of the suggested link between thin corneas and glaucoma established by the 2002 Ocular Hypertension Study. A study by Ohio State University has recently found that a stiff cornea plays an important role in regulating IOP elevation. Stiffened corneas were associated with much higher IOP elevation, indicating that corneal stiffness could be an important risk factor for glaucoma.
A comparative study of IOP measurement instrumentation undertaken at the University of Freiburg has shown that the Ocular Response Analyser (the non-contact tonometer that takes into account corneal hysteresis) yields somewhat higher results in glaucoma patients than Goldmann applanation tonometry or dynamic contour tonometry. The difference increased as IOP increased.
In paediatric optometry, a fascinating study, again from Ohio, has shown that in a survey of 221 children with symptomatic convergence insufficiency, a higher proportion were found to have attention deficit hyperactivity disorder than would be expected in the normal population. No reasons for why this might be are offered.
A study from Indiana University looked at accommodative performance in a group of optically corrected refractive esotropes. The study found that, while uncorrected hyperopes showed large lags of accommodation, the corrected esotropes seemed not to differ from normal levels, suggesting that the strabismic visual system is capable of 'near normal' accommodative performance.
Two papers from McGill University in Canada looked at amblyopia intervention. A new amblyopia treatment known as repetitive transcranial magnetic stimulation (rTMS) has been used, involving a non-invasive method of stimulating the visual cortex. Early results look promising, with the technique apparently reducing amblyopia, but the researchers acknowledge much is yet to be done before the test can be fully validated.
The second paper proposes that current amblyopia therapy tends to be monocular and shows how better results may be achieved by binocular stimuli.
Meanwhile, a multicentre study involving such dry eye luminaries as Korb and Lemp has suggested that a novel treatment of meibomian gland dysfunction is showing promise. The technique involves the application of 'thermodynamic energy' to induce lipid gland regenesis, to open and reactivate dysfunctional meibomian glands. In all cases with treatment, lipid layer thickness improved as did symptoms of dry eye.
? A snapshot review of a conference as comprehensive as ARVO can only scratch the surface. A more detailed search by topic is available at www.arvo.org.