Article Date: 3/1/2004

readers' forum
Reporting from the ISCLS
BY ROBERT A. KOETTING, OD, FAAO

If you don't know much about the International Society of Contact Lens Specialists (ISCLS) it's most likely because it never publicizes its events. Meetings are invitation-only, and few have taken place in North America.

Founded in 1952 by the late Frank Dickinson of London, Wilhelm Söhnges of Munich and John Neill of Philadelphia, the ISCLS membership has included renowned eyecare professionals from many nations. The 2003 meeting took place in Del Mar, CA, and focused on presbyopia, long-term lens wear, wavefront technology and post-refractive surgery problems. I'll review some of the presentations.

Surgery Update

Carlos Tellez, OD, discussed the serious challenge of lens centration when fitting surgery-altered corneas. His fluorescein pattern photos appeared in a current presentation involving high-order aberrations and the development of wavefront sensing technology.

Richard M. Davis, MD, reported that LASEK appears to effectively correct high myopia for patients who, because of inadequate stromal depth, aren't LASIK candidates.

Yaron S. Rabinowitz, MD, discussed new treatment options for keratoconus. He thinks lamellar keratoplasty may some day supplant the need for corneal transplants. He believes Intralase and Intacs are potential treatment options that might allow patients to wear contact lenses and thus avoid a transplant, and that contact lens wear has no effect on the progression of the condition. Montozumi Itoi, MD, responded that in Japan most keratoconus patients successfully wear conventional monocurve lenses fit with three-point touch, but recent trends have shown a shift towards multicurve and piggyback lenses.

Primim Non Nocere ("First, do no harm") was Barry A. Weissman, OD, PhD, FAAO's theme as he presented his personal perspective on when and how to treat any condition. He used photos of surgery problems to demonstrate that you can correct refractive errors with spectacles, contact lenses or surgery.

Investigating Dry Eye

Brigitte Lutcher, MD, said that any refractive surgery technique may cause dry eye. She cited neurotropic epitheliopathy, lesions of the limbus or conjunctiva and keratocyte lesions resulting from contact with the lacrimal film. She also referenced biochemical mechanisms that cause the eye to release stress proteins and probably trigger the flood of reactions that cause apoptosis.

Arthur B. Epstein, OD, FAAO, discussed current and future directions in managing dry eye, ocular surface disease and contact lens practice. He reviewed the current understanding of the ocular surface, explained why dry eye is an ocular surface disease and offered many management suggestions.

Vernon Reese, OD, FAAO, reviewed the M.E.I. Guidelines of Technology, diagnosis and diagnostic procedures. He stated that commonly used tear tests are only about 40 percent accurate and feels that Micro Assay is the only dependable method.

Richard M. Hill, OD, PhD, FAAO, discussed the effects of silicone hydrogel (SH) material on the corneal oxygen reservoir and tear exchange. He evaluated individual and combined contributions to hypoxic corneal relief after applying an SH lens under a PMMA cap. He compared that to measurements without the SH element, accompanied by and without blinking. Compared to an uncovered cornea, pure silicone contributed most to hypoxic relief. SH lenses were next, followed by SH lenses under blinking conditions. SH under a PMMA lens under non-blink conditions provided the least oxygen, but when regular blinking accompanied that combination, corneal oxygen demand improved by eight percent.

Damon J. Ezekiel, BOptom (UNSW), FAAO, FCLSA, stated that scleral lenses that employ new materials are easy to fit and more acceptable for many patients. You can order these in 20mm and 24mm diameters, either sealed or fenestrated.

A Look at Continuous Wear

Richard E. Weisbarth, OD, FAAO, covered high-Dk SH lenses in two separate papers. In one study, researchers fit 317 patients for bilateral wear of lotrafilcon A lenses (Focus Night & Day, CIBA Vision). Thirty-six percent reported some symptoms at dispensing, and most patients who left the study did so because of discomfort. In the second paper, researchers analyzed risk factors for 658 wearers in a one-year continuous wear trial of the same lenses. The study identified age, smoking, corneal scarring and infiltrates as significant factors. Dr. Weisbarth advised to avoid continuous wear in patients who have a history of inflammatory events and to carefully counsel wearers who smoke, especially those under age 30.

Bill Long, BS, MBA, FAAO, reported on the continued use, wearer satisfaction and clinical status of patients wearing Night & Day lenses. Six practitioners from France recalled 74 patients to whom they'd dispensed the lenses three years previously and found fewer biomicroscopic signs than in patients who wore low-Dk lenses. Almost 90 percent of the patients complied with recommended wear and replacement schedules, and 98 percent of patients who continued to wear the lenses were satisfied. Of those who discontinued, almost half complained of discomfort. He suggested that practitioners may see improved eye health among patients who wear SH lenses.

Fitting Presbyopes

David W. Hansen, OD, FAAO, shared his experience with the Menifocal (Menicon), a new GP bifocal with a unique concentric design and an intermediate zone. Clinical comparisons of visual and subjective findings among current GP bifocal wearers indicated that patients liked the acuity and the comfort of the new lens.

John DeCarle provided an update of multizone bifocals and reviewed his design principles for a bifocal with a central distance portion and alternating rings of 19 distance areas and 18 reading areas surrounded by an area of intermediate power. These lenses can provide 20/20 acuity and good reading vision in all lighting conditions, but progress has been slow because of technical difficulties, which he's mostly overcome.

Donald F. Ezekiel, AM, Dip Opt (WA), DCLP, FACLP, FAAO, FCLSA, described the evolution of the Triton soft translating bifocal lens (Gelflex). Although the initial lens design provided good results, the company has modified it to make the lenses more readily acceptable.

Touching on Ortho-k

Roger Tabb, OD, FAAO, discussed orthokeratology lens designs employed during the last 30 years, leading up to his own reverse geometry designs. He emphasized that daytime-wear lenses must move, but night-wear lenses shouldn't. His paper focused on long-term effects of night-wear ortho-k as well as corneal rehabilitation and keratoconus.

Jerome M. Garber, OD, FAAO, discussed using the Sonogage Ultrasonic Pachymeter with overnight ortho-k. As the central cornea becomes flatter and thins, the periphery becomes thicker, suggesting a shift of structure. He also compared a keratoconic eye to the non-keratoconic eye of the same individual, observing that daily wear sometimes thins the cornea, but it becomes thicker when lens wear is discontinued.

GPs and Myopia Progression

Jeffrey J. Walline, OD, PhD, discussed the Contact Lens and Myopia Progression (CLAMP) study, a three-year, single-masked randomized clinical trial to examine the effects of GP contact lenses on myopia progression in children. Complete figures are not yet available, but others have observed that myopia increased less rapidly in children wearing GP lenses. He also presented a case study of 29 eight- to 11-year-old children fit with corneal refractive therapy contact lenses. After six months, the mean uncorrected acuity improved from 20/96 to 20/26 and the mean spherical equivalent refraction improved from ­2.50 +1.37 to ­0.26 +0.81. The study provided no evidence that this modality would prevent long-term regression.

Closing with Low Vision

Contact lens meetings rarely include low vision, but Erwin H. Voss, OD, reviewed 317 case histories and noted that the average patient was older than 60 years, female and four times more likely to want help for near tasks than for distance seeing.

ISCLS members voted to meet next in the South of France in 2005.

Dr. Koetting is a retired contact lens pioneer and Contact Lens Spectrum Consulting Editor. He has lectured at numerous meetings in the United States and in other countries.

 


Contact Lens Spectrum, Issue: March 2004