Contact lens trials poised for promising advances

Take-Home Message

A number of clinical trials are focusing on various medical uses for contact lenses. The latest updates on these and other studies are always accessible via clinicaltrials.gov.

By Rose Schneider, Content Specialist, Ophthalmology Times

Gone are the days when contact lenses are used just for vision correction. Today, contact lenses have applications in many different medical uses, such as protecting the cornea from injury and stabilizing myopia.

Furthermore, researchers are exploring several more advances, such as in the areas of dry eye disease and persistent epithelial defects.

Dry eye disease

Dry eye disease-a huge issue for many contact lens wearers-and its effects have become more widely recognized in recent years.

One current study recruiting participants is testing whether a novel daily disposable contact lens material with alginic acid improves comfort to patients with dry eye, said Paul Velting, OD, co-director of contact lens services, North Suburban Vision Consultants, Deerfield, IL.

“Alginic acid is a zwitterionic (neutral polarity) material found in the cell walls of brown algae, and forms a viscous gum when it binds with water¹,” Dr. Velting explained. “It is similar to hyaluronic acid in animals, which is already being used in contact lens solutions and materials, and also has wound-healing applications in medicine².”

The use of autologous serum eye drops in conjunction with silicon hydrogel soft contact lenses to treat persistent epithelial defects is also currently being studied, said Dan Mlnarik, OD.

“Autologous eye drops, if used without protection from the mechanical involvement of the eyelid, can provide relief and reparation of persistent epithelial defects, as serum eye drops provide growth factors, fibronectin, and vitamins that other eye drops may lack,” said Dr. Mlnarik, of PersonalEYES Vision Care, Grand Rapids, MI.

The hope is that the trial-slated to close in August-will show there is a significantly better outcome for patients suffering from persistent epithelial defects, Dr. Mlnarik said.

NEXT: Myopia stabilization

Myopia stabilization through the use of contact lenses is another heavily researched area that has become increasingly relevant, Dr. Velting explained.

“Soft multifocal contact lenses have been shown to reduce myopia progression in children by as much as 50%³, (and) there are several clinical trials currently under way that aim to further this research,” he said.

One clinical trial is evaluating the myopic response to different add powers to soft multifocal lenses, whereas another study is assessing the effect of lenses on accommodation and binocular vision when worn by pediatric patients, he said.

“The prevalence of myopia in the United States has doubled since the 1970s, rising to [more than] 42% of the adult population⁴,” Dr. Velting said. “Controlling this rising epidemic will no doubt continue to gain significant attention in clinical research.”

A distance-center design multifocal lens to help slow axial elongation and myopic progress is being looked at as well, Dr. Mlnarik said.

“Biofinity multifocal lenses are a standby for most eye clinics that work with multifocal soft contact lenses,” he said. “In other multifocal contact lens trials that have focused on myopia control, some modest success in controlling myopia progression has been reported. (This trial is examining how) Biofinity +1.50 [CooperVision] distance-center and +2.50 distance-center multifocal lenses perform in myopic control when compared with a single-version Biofinity lens.”

It is hoped by investigators that the trial will become an applicable guide to determining when to begin myopia control, he said.

“If this testing provides promising results, a follow-up study in younger age groups to further prevent myopia progression in likely affected individuals (will be conducted),” Dr. Mlnarik said.

NEXT: Bandage contact lenses

While bandage contact lenses have been used to protect the cornea and reduce pain after injury, they do not address the corneal edema commonly associated with the injuries, and in some cases, can increase it⁵, Dr. Velting said.

A current study is attempting to evaluate the use of hyperosmotic soft contact lenses as an added therapy for corneal edema, along with its benefits as a bandage lens, he explained.

“The Hyper-CL lens [EyeYon Medical] would have therapeutic indications for conditions such as persistent epithelial defects, bullous keratopathy, entropion, and corneal dystrophies, as well as indications for post-surgical therapy after cataract extraction and various corneal surgeries,” Dr. Velting said. “This trial is not yet recruiting participants, but will hopefully aid in the treatment of corneal edema as an adjunct to current hyperosmotic medications.”

Full- versus half-time wearers

When patients who have never worn contact lenses are fit for the first time, they initially are told to start wearing them for 4 to 6 to 8 hours, and then build up wear time by steps until a full day’s worth of wear has been achieved, Dr. Mlnarik said.

But do new contact lens wearers benefit from this “wet-your-feet” approach, or would they react better from a “dive-in” method? he posed.

Researchers at The Ohio State University are currently investigating the answer to that question by observing both effects on patients.

“It is hoped that if no significant difference is noted between the two approaches a change in clinical practice can be implemented, which would simplify clinical contact lens practice for new wearers,” Dr. Mlnarik explained.

References

1. Raymond C. Rowe, Paul J. Sheskey, Marian E. Quinn, ed. (2009), "Adipic Acid," Handbook of Pharmaceutical Excipients (Rowe, Handbook of Pharmaceutical Excipients) (Sixth ed.), Pharmaceutical Pr, pp. 11–12.

2. Fraser, J.R.E et al. (1997). "Hyaluronan: its nature, distribution, functions and turnover" (PDF). Journal of Internal Medicine 242(1):27–33.

3. Walline, Jeffrey J., Katie L. Greiner, M. Elizabeth Mcvey, and Lisa A. Jones-Jordan. "Multifocal Contact Lens Myopia Control." Optometry and Vision Science 90.11 (2013):1207-1214.

4. Pascolini, D, and S.P. Mariotti. "Global Estimates of Visual Impairment: 2010." British Journal of Ophthalmology 96.5 (2012):614-618.

5. Moezzi, Amir M., Desmond Fonn, and Trefford L. Simpson. "Overnight Corneal Swelling With Silicone Hydrogel Contact Lenses With High Oxygen Transmissibility." Eye & Contact Lens: Science & Clinical Practice 32.6 (2006):277-280.