reader and industry forum
Highlights From the Sixth ACCLC
BY ETTY BITTON, OD, MSC, FAAO, WILLIAM L. MILLER, OD, PHD, FAAO, & GEORGE C. WOO, OD, PHD, FAAO
The sixth Asia Cornea and Contact Lens Conference (ACCLC), the annual conference of the Hong Kong Association of Professional Optometrists, took place in Hong Kong last April 23 to 24 with more than 300 delegates in attendance. The conference featured formal lectures, scientific paper sessions, and poster presentations highlighting research from local and international institutions. Keynote speakers included Professor Victor Woo (Hong Kong), Richard Lindsay (Australia), Dr. William Miller (United States), Dr. Etty Bitton (Canada), and Dr. Godfrey Lam (Hong Kong).
Refractive Surgery Review
Professor Woo discussed the historical and present situation of refractive surgery, from early attempts in refractive correction to the more recent inventions including the femtosecond laser and microkeratome versus intralase corneal flaps. He suggested that refractive errors outside of the range of LASIK can be managed with phakic IOLs or a refractive lens exchange. However, the latter remains reserved for patients who exhibit cataractous changes.
Prof. Woo mentioned that both dynamic and static approaches in refractive surgery techniques need to be developed for emerging presbyopes to help them remain functional in not only their distance vision, but also in their near visual performance.
Richard Lindsay presented contact lens fitting options for post-refractive surgery patients. He discussed all types of refractive surgery procedures including radial keratotomy (RK), photorefractive keratectomy (PRK), and LASIK. Contact lens options included soft lenses (using the more breathable silicone hydrogel materials), bandage lenses, piggyback lens systems, GPs, and hybrid contact lenses.
Dr. William Miller (Houston, Tx) and Dr. Etty Bitton (Montreal, Canada) were amongst the keynote speakers for the conference.
Mr. Lindsay discussed the collagen cross-linking procedure as a more recent technique to decrease the progression of early keratoconus. In this technique, the epithelium is removed, riboflavin is added and ultraviolet light is applied to irradiate the cornea and increase the corneal collagen cross-linking. This procedure requires a minimal corneal thickness of 380μm to 400μm, so this is not available for more advanced cases of keratoconus.
Dr. Miller discussed the adjunctive uses of the in vivo confocal microscope in clinical practice. He presented a short overview of the capabilities of the instrument and discussed standardized sizes and densities for relevant entities that might be encountered in the scanned corneal images such as macrophages, corneal nerves, keratocytes, and neutrophils. Dr. Miller showed actual cases with biomicroscopic and confocal images representing disease conditions such as Schnyder's Crystalline Dystrophy, Fuch's Dystrophy, and Posterior Polymorphous Dystrophy.
The importance of confocal microscopy in diagnosis was also demonstrated using several clinical cases of acanthamoebic and fungal keratitis. Dr. Miller provided insight into the instrument's further value in monitoring therapy in these particular infectious keratitis cases.
Dyes and Dry Eye
Dr. Bitton presented a lecture on dry eye reviewing the importance of using ophthalmic dyes such as fluorescein and lissamine green. Apart from the traditional uses of these dyes, such as evaluating tear film stability and ocular surface dryness, they may also assist in evaluating upper lid margin staining and solution-induced corneal staining (SICS), which can contribute to contact lens intolerance and dry eye symptoms.
Dr. Bitton reinforced the message that clinicians often underestimate the effect of the meibomian glands, and that simply pulling down the lid to observe their openings at the slit lamp is insufficient. The meibomian glands need to be expressed on every patient and their content evaluated for liquidity and clarity. Treating the lids together with the meibomian glands are key factors in preserving lid hygiene and the proper functioning of the lipid layer of the tear film.
Dr. Lam's topic explored lid anomalies that may affect lens wear. They include meibomian gland dysfunction (MGD), blepharitis, dermatitis, lid apposition (such as ectropion/entropion), and epiblepharon. Epiblepharon of the lower lid is common amongst the Chinese because the lid margin is pushed out but not turned in. The lower lashes consequently grow upwards and may cause trichiasis and irritation of the corneal surface. Dr. Lam suggests not to “pluck” these lower lashes as they will regrow shorter and tougher and hence poke the corneal surface. Most are left alone. Surgical options are available if trichiasis is a chronic problem; however they often result in visible scars of the lower lid.
Attendees were also exposed to research highlights during paper and poster sessions on topics including tear film analysis, contact lens fitting and designs, contact lens materials, biocidal activity of contact lens solutions, SICS updates, and more. Several representatives from industry also presented lectures throughout the conference.
The 7th annual ACCLC is scheduled to take place from March 3 to 5, 2010 in the Philippines. CLS
Dr. Bitton is an associate professor of optometry at the École d'optométrie, Université de Montréal and is the Externship Director. She is also Chair of the AOCLE. Dr. Miller is an associate professor and chair of the Clinical Sciences Department at the University of Houston College of Optometry. He is a member of the American Optometric Association and serves on its Journal Review Board. Professor Woo is the Dean of the Faculty of Health and Social Sciences and Chair Professor of Optometry, The Hong Kong Polytechnic University. He is also president of the World Council of Optometry, president of the Asia Pacific Council of Optometry, and president of the Hong Kong Contact Lens Research Association.