A Look Behind Contact Lens Bacteria
Knowing the proteins responsible for cellular compromise may lead to new therapies.
By Adrienne Taron, Associate Editor
While eye infections caused by bacteria are common—especially among contact lens wearers—until now there has been limited understanding of the nature of the bacteria to blame and the specifics of the damage it causes.
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| Microbial keratitis due to contact lens wear. |
Recent research sheds light on the nature of common bacterial contaminants of contact lenses and cases. The study, presented at the American Society for Microbiology Microbe research meeting, discovered a new means by which bacteria can induce significant morphological changes in human cells. This newly discovered mechanism causes the formation of bubble-like structures (blebs) that ultimately are toxic to cells.
Among bacteria observed were Proteus mirabilis and Serratia marcescens. Using molecular genetics, the researchers discovered a regulatory protein, GumB, and a secreted protein, ShIA, to be responsible for bleb formation. Blocking these proteins will hopefully prevent infections related to inflammation and tissue damage.
Now, “greater understanding will help provide insights into better preventative mechanisms to avoid inflammation and infection of the ocular surface,” says Mile Brujic, OD, of Premier Vision Group in Ohio. “We know that the ocular surface is remarkably resistant to both inflammation and infections and a relatively small number of patients wearing contacts, even in the face of non-compliance, will truly develop an infectious insult to the eye.”
“Ultimately, this will be critical in the eye care practice that promotes wellness through healthy comfortable lens wear,” Dr. Brujic adds. “Having a better understanding of this through mechanisms previously unknown will help in developing more targeted treatments when infections have resulted in ocular surface compromise.” Researchers hope these outcomes will foster the development of new therapies to alleviate inflammation associated with these often severe infections.
Joint Program Teaches the Business of Optometry
“Some of the greatest challenges in health care today are both scientific and business-related,” said Eric Jack, PhD, dean of UAB’s Collat School of Business, in a press release. “Combining a business degree with an optometry degree can help future health care leaders learn to manage through rapid change and traverse the uncertainties of management with flexibility. An MBA education provides our optometry school graduates not only more job options, but also the ability to be active participants in shaping the future of health care.”
The program begins with business classes the summer before optometry school and integrates courses during the four years. It adds only one semester of coursework to the traditional length of optometry school, and students finish both degrees simultaneously.
“We’re proud that UAB is offering the first joint OD/MBA program in the country, and we believe program graduates will be well-equipped to pursue careers with both clinical and administrative responsibilities—adding to an existing practice or starting their own practice,” said Kelly K. Nichols, OD, MPH, PhD, dean of UAB’s School of Optometry, in a press release. “Students in this dual-degree program will learn how to use innovation and strategic thinking to solve health care problems through fluency in the languages of optometry and business, which will put them on the fast track to career advancement and the betterment of patient care.”
Shonesy K. Nation’s first joint OD/MBA degree program opens at UAB. UAB News. www.uab.edu/news/student-experience/item/7440.
Vision Care Changes with Routine Exams
Even in asymptomatic patients, comprehensive eye examinations result in a significant number of eye care management changes, a recent study out of the University of Waterloo found.
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| Photo: Gina M. Wesley, OD, MS. |
In fact, 58% of asymptomatic patients who visited the researchers’ eye clinic during a one-year period had at least one significant change on routine eye exam.
“In terms of pathology, I do believe that the routine exam produces early pathological findings that have great benefit to society,” Bill Potter, OD, says. “They reduce overall cost of care […] and help the individual to function optimally for a longer period of time.”
But there are glaring flaws in the way information is presented in this study, according to Dr. Potter. Namely, the open-endedness of the term “significant change”—which the study defined as a change in prescription, diagnosis of a new eye condition, or a change in overall patient management.
“I give a lot more weight to the health-assuring aspect of routine care,” Dr. Potter says. “We diagnose early glaucoma, cataract and macular degeneration quite often. Perhaps even more importantly, we talk about health habits such as not smoking, eating green and yellow vegetables and wearing sunglasses outdoors.”
Irving EL, Harris JD, Machan CM, et al. Value of routine eye examinations in asymptomatic patients. Optom Vis Sci. 2016;93(7):660.
Crosslinking Approved for Corneal Ectasia Treatment
Avedro’s corneal collagen crosslinking has an expanded scope with the recent FDA approval for Photrexa Viscous, Photrexa and the KXL system to treat corneal ectasia following refractive surgery. This marks the system’s second indication. In April, it received approval for the treatment of keratoconus (see coverage in our May News Review) and still remains the first and only approved corneal collagen crosslinking in the United States.
FDA approval was based on Avedro’s NDA submission, which incorporates data from three prospective, randomized, parallel-group, open-label, placebo-controlled, 12-month trials. Study 1 included 58 patients with progressive keratoconus and 49 patients with corneal ectasia following refractive surgery; Study 2 enrolled 147 patients with progressive keratoconus; and Study 3 included 120 patients with corneal ectasia following refractive surgery.
“At month 12, the CXL-treated eyes in corneal ectasia patients had an average Kmax reduction of 1.0 diopter in Study 1 and 0.5 diopter in Study 3, while the sham eyes had an average increase of 1.0 diopter in Study 1 and 0.5 diopter in Study 3; the treatment difference between the CXL and sham groups was: -2.0 (-3.0, -1.1) diopters in Study 1 and -1.1 (-1.9, -0.3) diopters in Study 3,” a company press release said.
Walt Whitley, OD, MBA, director of optometric services at Virginia Eye Consultants, whose practice was involved with these studies, says this approval provides an exciting new treatment option optometrists can offer patients. “We understand the progressive nature of keratoconus and ectasia and the negative impact on our patients’ vision,” Dr. Whitley says. “Passive management of keratoconus with contact lenses only is no longer an option, and we cannot allow our patients to continuously progress and worsen without doing something about it.”
The new treatment option will impact clinical practice and comanagement strategies for ODs, Dr. Whitley says. “One additional step prior to referring patients for keratoconus (or any other corneal surgery or procedure) will be aggressive treatment of ocular surface disease. There are numerous treatment options that are available from artificial tears, nutraceuticals, anti-inflammatories, punctal occlusion, etc., and the most recent addition to our dry eye armamentarium, lifitegrast. By doing so, we can optimize the corneal topography which will provide more accurate measurements pre/post procedure.”
“Education will be key to let our patients know about their condition, what the procedure entails, expectations after the procedure and the importance of follow-up care to monitor changes within the cornea, which can progressively flatten for up to six years,” Dr. Whitley says.
Avedro receives additional indication for Photrexa Viscous, Photrexa and the KXL system for the treatment of corneal ectasia following refractive surgery. Avedro press release. http://avedro.com/en-us/press-releases.
In the news
Humira (adalimumab, AbbVie) recently received FDA approval for the treatment of non-infectious intermediate, posterior and panuveitis. The FDA approval is based on results from two Phase III studies, which demonstrate that adult patients with active and controlled non-infectious intermediate, posterior and panuveitis treated with Humira had a significantly lower risk for treatment failure compared with placebo.
A new study, reported in PLOS Computational Biology, might lead to better treatment options for diabetic retinopathy. Researchers combined data on optometry patients’ eyes with advanced computational methods to create a virtual tissue model of diabetes in the eye—illustrating how a small protein in the eye causes vision loss and blindness in people with diabetes.
A recent proof-of-concept study published in Cornea found that Descemet stripping allowed rejuvenation of surrounding tissue, without the need for a corneal transplant. Six months after the operation, 77% of the treated eyes had clear corneas and eight had 20/20 vision or better. Three eyes did not respond and required a standard cornea transplant.
A study recently published in the American Journal of Transplantation found that female corneal transplant patients did better if they got their new corneas from female donors—but there was no gender difference in failure rates for men receiving women’s tissue. With Fuchs’ endothelial dystrophy, researchers found that women’s transplants were 40% less likely to fail if they received a woman’s cornea instead of a man’s.
