Attempts to slow myopia progression in children only minimally effective

Surgeons seeking to appease concerned parents must weigh pros and cons of treatment options.

Roberto Warman

Despite ample efforts by medical practitioners over the past several decades, attempts to slow the progression of myopia in children have been minimally effective.

“For many years, we have tried different approaches to slow myopia. The bottom line is nothing really works, at least not consistently and at least not practically,” Roberto Warman, MD, OSN Pediatrics/Strabismus Board Member, said in an interview with Ocular Surgery News.

The concerns of parents who are eager for their children to avoid advanced myopia have prompted surgeons to pursue numerous methods of slowing progression, many of which require substantial effort from ophthalmologists and patients and only lead to 0.5 D or 1 D of visual improvement.

“It is true that once you get a certain axial length and a higher myopia, you have a little higher incidence of getting retinal detachment and other medical conditions like myopic degeneration of the retina,” Rudolph S. Wagner, MD, OSN Pediatrics/Strabismus Board Member, said. “So, it would be better if you didn’t have higher myopia, but I don’t know that there’s any easy way to prevent it.”

Atropine drops

Rudolph S. Wagner

Of the various treatments pursued, atropine eye drops are one of the more popular. However, Dr. Wagner said that myopia progression is reduced by only 1 D at most, and patients often experience light sensitivity from constant dilation, as well as blurred near vision.

“With the complaints you get and with the data supporting that the benefit is slight, I do not believe in using [atropine],” he said.

According to Dr. Warman, patients must begin treatment early, around age 3 years or 4 years, and maintain the use of atropine drops and plus/minus bifocal glasses up until 16 years of age. Such a long-term regimen is not practical, he said, because many patients do not adhere to it longer than a year or two.

“Maybe in about 20% to 30% of patients, you can hold off the myopia from progressing drastically … but the price in practice or in practical terms is to me too big,” he said.

Orthokeratology or RGP lenses

A few studies with small sample sizes have suggested that rigid gas-permeable (RGP) lenses worn at night may slow myopia, but Drs. Warman and Wagner said that these lenses are not popular among practitioners, may be associated with corneal ulcers and do not have permanent effects.

The nonpermanent effect is a benefit for use in children, according to Jeffrey J. Walline, OD, PhD, one of the authors of the CRAYON (Corneal reshaping and yearly observation of nearsightedness) study.

“If they had a permanent effect, then they could not be used in children, just like refractive surgery is not done on children,” he said.

“Whenever you are using a contact lens at night over a prolonged period of time, you certainly would be more prone to infection, because the eye is closed and it is a moist environment,” Dr. Wagner said. “That in itself is enough to make me stay away from [RGP lenses].”

A retrospective study of 1,316 patients presented at the 2009 American Academy of Optometry meeting suggested that the risk of microbial keratitis for overnight reshaping lenses is similar to that of other overnight modalities. Additionally, in a 2004 issue of Ophthalmology, the authors of an observational case series of six children with orthokeratology-related corneal ulcers recommended that parents be warned of the potential for permanent vision loss.

According to Dr. Warman, orthokeratology initially became popular in the 1960s but declined when ophthalmologists realized that in addition to the safety issues, it could not maintain effects beyond a few weeks of discontinued treatment because the cornea bounces back to its original curvature and myopia returns. The newer overnight lenses are better designed but still pose the same problem, he said.

“What I have seen is that if [patients] stop using this kind of lens … maybe not immediately but over a short period of time in many cases the refractive error starts to creep back,” Dr. Wagner said.

LORIC, CRAYON studies

The LORIC (Longitudinal orthokeratology research in children) study is a nonrandomized clinical trial that compared 35 children who underwent overnight orthokeratology and 35 matched control subjects. Results suggest that patients undergoing treatment may experience myopia reduction of up to 4 D as well as approximately 50% slower eye elongation.

“The changes to corneal curvature are transient and reversible, should patient or parent find any aspect of the treatment unacceptable,” the study authors wrote.

The CRAYON study included 28 patients who wore corneal reshaping lenses for 2 years. Data for these patients was compared with that of age-matched controls, and the treatment group demonstrated a statistically significant lower rate of annual change in axial length; mean difference between the rates of change for treatment patients vs. control patients was 0.16 mm. Vitreous chamber depth also grew at a significantly slower rate for those treated with corneal reshaping lenses.

“It is believed, but far from proven, that the myopia control effect of corneal reshaping contact lenses may be permanent because it slows the axial growth of the eye by about 50%, and the axial length is less likely to rebound than the corneal curvature,” Dr. Walline said in an email interview with OSN.

Consulting parents

Treatment options for myopia progression have thus far proven minimally effective, but physicians continue to weigh the risks and benefits and share this information with parents, who are then equipped to make an informed decision.

Some physicians, however, encourage parents to accept myopia progression as inevitable.

“I tell them: I am myopic, and my own kids got myopia. Basically, we wear glasses or contact lenses, and once you are an adult, refractive surgery on most is an appropriate procedure,” Dr. Warman said.

According to several studies, an option that does not involve treatment is increased outdoor activity.

“Again, we are only talking about less than 0.5 D in the progression, so it was not significant,” Dr. Wagner said. “But at least it is something you can tell parents that they can hold on to.” – by Michelle Pagnani

References:

• Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005;30(1):71-80.
• Jones LA, Sinnott LT, Mutti DO, Mitchell GL, Moeschberger ML, Zadnik K. Parental history of myopia, sports and outdoor activities, and future myopia. Invest Ophthalmol Vis Sci. 2007;48(8):3524-3532.
• Rose KA, Morgan IG, Ip J, et al. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology. 2008;115(8):1279-1285.
• Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009;93(9):1181-1185.
• Young AL, Leung AT, Cheng LL, Law RW, Wong AK, Lam DS. Orthokeratology lens-related corneal ulcers in children. Ophthalmology. 2004;111(3):590-595.

• Rudolph S. Wagner, MD, can be reached at Children’s Eye Care Center, 1 Clara Maass Drive, Belleville, NJ 07109; 973-751-1702; fax: 908-665-8482; email: wagdoc@comcast.net.
• Jeffrey J. Walline, OD, PhD, can be reached at Ohio State University College of Optometry, 338 W. Tenth Avenue, Columbus, OH 43210; 614-247-6840; email: walline.1@osu.edu.
• Roberto Warman, MD, can be reached at Miami Children’s Hospital, 3200 SW 60th Court, Suite 103, Miami, FL 33155-4072; 305-662-8390; fax: 305-661-7862; email: rwarman@eyes4kids.com.
• Disclosures: Drs. Wagner and Warman have no relevant financial disclosures. Dr. Walline is a consultant for Bausch + Lomb.