I spent a good part of last week taking part in the annual migration to Ft. Lauderdale for ARVO. ARVO stands for the Association for Research in Vision and Ophthalmology, an organization whose mission is to further global eye and vision research for the prevention of blindness and the reduction of eye diseases.

The meeting brings together some of the greatest minds in optometry and ophthalmology. Noted for its ultra-casual, laid back attitude, flip-flops and shorts are not uncommon—even among presenters. For those with a scientific bent, the lectures and poster sessions are incredibly stimulating and serve as a showcase for the latest research in eye care.

As most of you know, my interests lie primarily in the anterior segment. And within that sphere, few things fascinate me as much as the ocular surface. This year, ARVO was stunning. The incredible number of papers and posters on dry eye and ocular surface disease was nearly overwhelming.

ARVO is often a harbinger of things to come. Based on what I saw this year, we stand at the precipice of a period of transformation. Greater understanding, better-targeted therapies and an in-need and aging population assure opportunity for those open to the possibilities and willing to get involved. I predict that this will be the decade of the ocular surface.

Arthur B. Epstein, OD, FAAO Chief Medical Editor artepstein@optometricphysician.com

 

 

Contact lenses, collected from subjects wearing Acuvue Oasys or PureVision lenses, were extracted in chloroform:methanol (1:1, v/v) and amount of cholesterol was estimated by thin-layer chromatography to examine the effect of cholesterol on the adhesion of bacteria to silicone hydrogel contact lenses. Unworn lenses were soaked in cholesterol, and the numbers of Pseudomonas aeruginosa strains or Staphylococcus aureus strains that adhered to the lenses were measured. Cholesterol was tested for effects on bacterial growth by incubating bacteria in medium containing cholesterol.

From ex vivo PureVision lenses, 3.4 ± 0.3 μg/lens cholesterol was recovered, and from Acuvue Oasys lenses, 2.4 ± 0.2 to 1.0 ± 0.1 µg/lens cholesterol was extracted. Cholesterol did not alter the total or viable adhesion of any strain of P. aeruginosa or S. aureus. However, worn PureVision lenses reduced the numbers of viable cells of P. aeruginosa (5.8 ± 0.4 log units) compared with unworn lenses (6.4 ± 0.2 log units). Similarly, there were fewer numbers of S. aureus 031 adherent to worn PureVision (3.05 ± 0.8 log units) compared with unworn PureVision (4.6 ± 0.3 log units). Worn Acuvue Oasys lenses did not affect bacterial adhesion. Cholesterol showed no effect on the growth of any test strain.

Although cholesterol has been shown to adsorb to contact lenses during wear, this lipid does not appear to modulate bacterial adhesion to a lens surface.

Forty young adult subjects (20 myopes and 20 emmetropes, mean age 22 ± 2 years) had their IOP and axial length measured before, during and after a 3 minute period of swimming goggle wear to investigate the influence of a short period of elevated IOP (induced through the wearing of standard swimming goggles) upon axial length. IOP was measured using a non-contact tonometer, and axial length with an optical biometer based upon the principle of partial coherence interferometry.

A 3-min period of swimming goggle wear was found to be associated with a significant increase in IOP (mean change 3.7 ± 2.6 mmHg) and a significant axial elongation of the eye (mean change in axial length of 18 ± 12 µm). Both IOP and axial length were found to return to baseline levels upon removal of the swimming goggles. A significant positive association was found between the changes in IOP and axial length. There were no significant differences between the emmetropic and myopic subjects in terms of their magnitude of change in axial length and IOP during swimming goggle wear.

A small magnitude of elevation in IOP, induced through mechanical means and imposed for a short period of time was associated with a small but statistically significant axial elongation of the eye.

Ten patients with skin prick and ocular conjunctival provocation confirmed allergic sensitivity to grass pollen were recruited (average age 27.4 ± 7.7 years) to examine the potential barrier and lubricating effects of modern daily disposable contact lenses (DD) against airborne antigens. Each had their ocular symptoms (on a 0 none to 5 extreme scale) and appearance of bulbar and limbal conjunctival redness, palpebral conjunctival redness and roughness, and corneal and conjunctival fluorescein staining (CCLRU scale) graded before and five minutes after exposure to 400 grains grass pollen/m³ for 2 min in a purpose-designed exposure chamber to simulate the conditions of a ‘very high’ pollen-count day. This was repeated on three occasions separated by >72h wearing etafilcon A (sDD), nelfilcon A with enhanced lubricating agents (ELDD) and no contact lenses in random order out of the pollen season. Each sign and symptom was compared to baseline for each condition. The duration of the symptoms was also recorded.

Only symptoms of burning and stinging were significantly reduced in severity by ELDD, but overall symptoms were significantly reduced in duration. Bulbar hyperemia, corneal and conjunctival staining, and palpebral conjunctival roughness were significantly reduced by DD wear, with limbal and palpebral conjunctival redness further reduced in ELDD.

Daily disposable contact lenses offer a barrier to airborne antigen, which is enhanced by modern lenses with enhanced lubricating agents.