Editorial

Full text: Welcome to issue 1 of 2012 and a belated Happy New Year to all CLAE readers and BCLA members. The hardest job I had for this issue was to decide which papers to include and which papers to hang on to and save for issue 2 of 2012. At the end of December when I was choosing the content for this issue there were additional 5 papers that could have been included. The final choice came down to various factors; such as first come first served – i.e. which papers had been ready and waiting the longest; secondly which papers had been submitted the earliest; are there similar papers so that it may be beneficial to publish them alongside this paper; and also was the content something which needed to be out there quicker than other papers as it was a current hot topic? But it should be noted that once papers are proofed and deemed ready by authors they are published in the epub version and put online for others to see in their final version. An epub version is given a DOI number (digital object identifier) so that it can be cited by other authors. Apart from being on line the only other difference is that an epub version is essentially waiting to be assigned to a particular issue. So those papers that are being held off for issue 2 of this year are actually already available for you to read (and cite) on line. In this issue there is a paper related to the cost of different contact lens replacement schedules – this may be a topic that is debated more in the future since as a society we are thinking more ‘green’ and all trying to help by reducing our carbon footprint, whether that be by recycling or using less in the first place. A timely review paper on the management of allergic eye disease may help us to better manage those patients we see in the spring with pollen allergies. We have two papers looking at different aspects in keratoconus patients, another looking at a modified fluoret strip and its application in measuring tear break up time and a review paper on corneal erosions. Another interesting paper comes from Professor Harminder Dua and his team. Professor Dua is the UK Royal College of Ophthalmologists’ president and has been interested in corneal anatomy and physiology for much of his research career. Finally, an unusual case of an ocular injury related to a snake bite. Overall I would say there is enough to sink your ‘fangs’ into! Finally, it gives me great pleasure in announcing the newest person to join our Editorial Board, Dr Florence Malet. Dr Malet is an Ophthalmologist and since September 2000 she has been at the Bordeaux Hospital in France developing the Contact Lens Unit of in the Ophthalmology University Department. She is ex-president of the French Contact Lens Society and president of the European Contact Lens Society of Ophthalmologists.

Editorial

Full text: There are phrases in daily use today which were not so common a decade or so back, such as ‘ageing population’ or ‘climate changes’ or ‘emerging markets’ or even ‘social networking’. How do these things affect our lives is certainly interesting but for us as eye care practitioners how these changes affect our clinical work may be also relevant and sometimes more interesting. A recent advertisement for recruitment to the Royal Marine Corps of the British Army ended with a comment ‘find us on Facebook!’ The BCLA, IACLE and other organisations as well as many manufacturers have their own Facebook groups. In 2011 Chandni Thakkar was awarded the BCLA summer studentship and her project was based around increasing the contact lens business of a small independent optometric practice where contact lens sales were minimal. The practice typically recruited one new wearer per month. Chandni was able to increase the number of new patient fits with various strategies (her work was presented as poster at the 2012 BCLA conference in Birmingham). One of her strategies was to start a Facebook group and 655 joined the special group she started in just over a month. Interestingly she found that the largest single factor in convincing patients to trial contact lenses was recommendation by the eye care practitioner at the end of the examination, but nonetheless it is interesting that so many people used the social networking site to find out more information regarding contact lenses in her study. Moreover, we already see the use, by some practitioners, of smart phone ‘apps’ or electronic diaries or text messages when coordinating patient check-ups. Climate change has affected the way we think and act; we now leave out special recycle bins and we hope that the items that are recyclable are actually recycled and do not just join our other refuse somewhere down the track! How environmentally friendly are contact lenses? This was discussed by various speakers at this year's BCLA conference in Birmingham. Daily disposable lenses surely produce more contact lens waste but do not involve solutions in plastic bottles like monthly lenses. It is certainly something that manufacturers are taking seriously and of course there are environmental benefits but the cynic in each of us sees the marketing potential too. The way the ageing population is certainly something that will impact all healthcare providers. In the case of eye care with people living longer they will need refractive corrections for longer. Furthermore, since presbyopes are not resigning themselves to only gentle hobbies like knitting and gardening, but instead want to continue playing tennis or skiing or whatever, their visual demands are becoming more complex. This is certainly an area that contact lens manufacturers are focussing on (pun not intended!). Again the BCLA conference in Birmingham saw the launch of various new products by different companies to help us deal with our presbyopic contact lens wearers. It is great to have such choice and now with fitting methods becoming easier too we have no excuse not to try them out with our clients. Finally to emerging markets – well there was not a specific session at the BCLA conference in May discussing this but this most certainly would have been discussed by professional services managers and marketing directors of most of the contact lens companies. ‘How will we conquer China?’ ‘How can we increase our market share in Russia?’ Or ‘How should we spend our marketing budget in India?’ These topics as well as others would certainly have cropped up in backroom discussions. Certainly groups like IACLE (International Association of CL Educators) have increasing numbers of members and activities in developing markets to ensure that educators educate, to that practitioners can practice successfully and in turn patients can become successful contact lenses wearers. Companies also wish to increase their market share in these developing markets and from the point of view of CLAE we are certainly seeing more papers being submitted from these parts of the world. The traditional centres of knowledge are being challenged, I suppose as they have been throughout history, and this can only be a good thing for the pursuit of science. The BCLA conference in Birmingham welcomed more international visitors than ever, and from more countries, and long may that continue. Similarly, CLAE looks forward to a wider audience in years to come and a wider network of authors too.

Global trends in myopia management attitudes and strategies in clinical practice

PURPOSE: Myopia is a global public health issue; however, no information exists as to how potential myopia retardation strategies are being adopted globally. METHODS: A self-administrated, internet-based questionnaire was distributed in six languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. RESULTS: Of the 971 respondents, concern was higher (median 9/10) in Asia than in any other continent (7/10, p<0.001) and they considered themselves more active in implementing myopia control strategies (8/10) than Australasia and Europe (7/10), with North (4/10) and South America (5/10) being least proactive (p<0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by increased time outdoors and pharmaceutical approaches, with under-correction and single vision spectacles felt to be the least effective (p<0.05). Although significant intra-regional differences existed, overall most practitioners 67.5 (±37.8)% prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients. The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (35.6%), inadequate information (33.3%) and the unpredictability of outcomes (28.2%). CONCLUSIONS: Regardless of practitioners' awareness of the efficacy of myopia control techniques, the vast majority still prescribe single vision interventions to young myopes. In view of the increasing prevalence of myopia and existing evidence for interventions to slow myopia progression, clear guidelines for myopia management need to be established.

We are being myopic about myopia control

Editorial

Wound healing studies and interfacial phenomena:use and relevance of the corneal model

The interaction of the wound dressing as a biomaterial with the wound bed is the central issue of this chapter. The interfacial phenomenon that encompasses the biological and biochemical consequences that arise when a biomaterial is introduced to a host biological environment is discussed. A great deal can be learned from observations arising from the behaviour of biomaterials at other body sites; one particularly relevant body site in the context of wound healing is the anterior eye. The cornea, tear film and posterior surface of the contact lens provide an informative model of the parallel interface that exists between the chronic wound bed, wound fluid and the dressing biomaterial. © 2011 Woodhead Publishing Limited All rights reserved.

Short- and long-term changes in corneal aberrations and axial length induced by orthokeratology in children are not correlated

PURPOSE: To assess the correlation between changes in corneal aberrations and the 2-year change in axial length in children fitted with orthokeratology (OK) contact lenses. METHODS: Thirty-one subjects 6 to 12 years of age and with myopia −0.75 to −4.00DS and astigmatism ≤1.00DC were fitted with OK. Measurements of axial length and corneal topography were taken at regular intervals over a 2-year period. Corneal topography at baseline and after 3 and 24 months of OK lens wear was used to derive higher-order corneal aberrations (HOA) that were correlated with OK-induced axial length changes at 2 years. RESULTS: Significant changes in C3, C4, C4, root mean square (RMS) secondary astigmatism and fourth and total HOA were found with both 3 and 24 months of OK lens wear in comparison with baseline (all P0.05). Coma angle of orientation changed significantly pre-OK in comparison with 3 and 24 months post-OK as well as secondary astigmatism angle of orientation pre-OK in comparison with 24 months post-OK (all P0.05). DISCUSSION: Short-term and long-term OK lens wear induces significant changes in corneal aberrations that are not significantly correlated with changes in axial elongation after 2-years.

Développement d’une lentille cornéenne médicamentée

L’utilisation de lentilles cornéennes peut servir à améliorer le profil d’administration d’un principe actif dans les yeux. Avec une efficacité d’administration de 5% par l’utilisation de gouttes, on comprend rapidement que l’administration oculaire doit être améliorée. Cette faible administration a donné naissance à plusieurs tentatives visant à fabriquer des lentilles cornéennes médicamentées. Cependant, à cause de multiples raisons, aucune de ces tentatives n’a actuellement été mise sur le marché. Nous proposons dans cette étude, une possible amélioration des systèmes établis par le développement d’une lentille cornéenne à base de 2-(hydroxyéthyle)méthacrylate (HEMA), dans laquelle des microgels, à base de poly N-isopropylacrylamide (pNIPAM) thermosensible encapsulant un principe actif, seront incorporé. Nous avons donc débuté par développer une méthode analytique sensible par HPCL-MS/MS capable de quantifier plusieurs molécules à la fois. La méthode résultante a été validée selon les différents critères de la FDA et l’ICH en démontrant des limites de quantifications et de détections suffisamment basses, autant dans des fluides simulés que dans les tissus d’yeux de lapins. La méthode a été validée pour sept médicaments ophtalmiques : Pilocarpine, lidocaïne, proparacaïne, atropine, acétonide de triamcinolone, timolol et prednisolone. Nous avons ensuite fait la synthèse des microgels chargés négativement à base de NIPAM et d’acide méthacrylique (MAA). Nous avons encapsulé une molécule modèle dans des particules ayant une taille entre 200 et 600 nm dépendant de la composition ainsi qu’un potentiel zêta variant en fonction de la température. L’encapsulation de la rhodamine 6G (R6G) dans les microgels a été possible jusqu’à un chargement (DL%) de 38%. L’utilisation des isothermes de Langmuir a permis de montrer que l’encapsulation était principalement le résultat d’interactions électrostatiques entre les MAA et la R6G. Des cinétiques de libérations ont été effectuées à partir d’hydrogels d’acrylamide chargés en microgels encapsulant la R6G. Il a été trouvé que la libération des hydrogels chargés en microgels s’effectuait majoritairement selon l’affinité au microgel et sur une période d’environ 4-24 heures. La libération à partir de ces systèmes a été comparée à des formules d’hydrogels contenant des liposomes ou des nanogels de chitosan. Ces trois derniers (liposomes, microgels et nanogels) ont présenté des résultats prometteurs pour différentes applications avec différents profils de libérations. Enfin, nous avons transposé le modèle développé avec les gels d’acrylamide pour fabriquer des lentilles de contact de 260 à 340 µm d’épaisseur à base de pHEMA contenant les microgels avec une molécule encapsulée devant être administrée dans les yeux. Nous avons modifié la composition de l’hydrogel en incorporant un polymère linéaire, la polyvinylpyrrolidone (PVP). L’obtention d’hydrogels partiellement interpénétrés améliore la rétention d’eau dans les lentilles cornéennes. L’encapsulation dans les microgels chargés négativement a donné de meilleurs rendements avec la lidocaïne et cette dernière a été libérée de la lentille de pHEMA en totalité en approximativement 2 heures qu’elle soit ou non encapsulée dans des microgels. Ainsi dans cette étude pilote, l’impact des microgels n’a pas pu être déterminé et, de ce fait, nécessitera des études approfondies sur la structure et les propriétés de la lentille qui a été développée. En utilisant des modèles de libération plus représentatifs de la physiologie de l’œil, nous pourrions conclure avec plus de certitude concernant l’efficacité d’un tel système d’administration et s’il est possible de l’optimiser.