FDA Approves CXL For Keratoconus
By Adrienne Taron, Associate EditorCollagen crosslinking—a procedure combining ultraviolet light and a topical riboflavin photoenhancer to strengthen collagen bonds in the cornea—now comes to the US, after FDA clearance of three products from Avedro.
“This approval marks a tremendous milestone for the treatment of progressive keratoconus,” said Brian Roberts, Avedro’s chief operating and financial officer, in a statement. On April 18, the company’s KXL System and two photoenhancers, Photrexa and Photrexa Viscous, were cleared for use.
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| Avedro’s KXL System uses laser crosshairs to align its optical head with the eye in preparation for the procedure. |
The first studies of corneal crosslinking (CXL) in keratoconic humans date to 1998, and CXL treatment for progressive keratoconus has been available in Canada and Europe for more than 10 years. This recent FDA approval stems from Avedro’s NDA submission, comprised of data from three prospective, randomized, parallel-group, open-label, placebo-controlled, 12-month trials performed to assess the safety and efficacy of Avedro’s products for use in performing CXL in the eyes of patients with progressive keratoconus. The crosslinked eyes in these studies showed increasing improvements in Kmax (maximum corneal curvature) from month three to month 12. Treated patients had an average Kmax reduction of 1.4D in Study 1 and 1.7D in Study 2 at month 12, compared with average increases among untreated eyes of 0.5D in Study 1 and 0.6D in Study 2. The third study that comprised the Avedro NDA tested safety; no efficacy endpoints were included.
The most common ocular adverse reactions were corneal opacity (haze), punctate keratitis, corneal striae, corneal epithelial defect, eye pain, reduced visual acuity and blurred vision. The studies show that ulcerative keratitis can occur; Avedro advises that patients be monitored for epithelial defects.
Calling it “a landmark event that will jump-start a new era of keratoconus management in the United States,” Clark Chang, OD, of TLC Laser Eye Centers and a board member of the International Keratoconus Academy, expects CXL to make corneal transplants less common. “As CXL becomes more widely available, we could have our first generation of patients who will not routinely need keratoplasty or suffer progressive vision loss.”
Alaskan Bill Calls for Scope Expansion
Optometrists defend action to modernize practices, allow more procedures.
By Bill Kekevian, Senior Editor
Controversy over scope of practice legislation is spilling over into the op-ed pages of the Alaska Dispatch News, where dueling commentary pieces address the state’s Senate Bill 55. The brouhaha became public after a radio advertisement opposing the bill hit the airwaves in February. In mid-March, an Alaska ophthalmologist published a passionate piece warning of potential complications from noninvasive procedures (such as laser peripheral iridotomy and blepharoplasty). The turf war continued with an op-ed from an OD claiming the bill simply permits optometry to “regulate its own development.” While the debate plays out in the public eye, the bill itself provides a detailed explanation of what it will and will not allow.
Indeed, the bill does call for the ability to perform diagnostic and treatment procedures if so authorized by Alaska’s optometric board. However, it makes explicit a ban on invasive procedures. As defined by a white paper accompanying the bill, these include: LASIK; PRK; cosmetic lid surgery; any surgery where a scalpel is used to excise abnormal tissue growth on the cornea, any procedure in which a laser is used to remove scar tissue from the cornea; any procedure in which cornea tissue is transplanted from a cadaver; any surgery where a small incision is made in the cornea and two crescent or semi-circular shaped ring segments are inserted between the layers of the cornea.
The same white paper lists procedures ODs will be allowed to perform if Senate Bill 55 passes. They include treatments that do not penetrate the globe, such as procedures where a laser is fired to: create a small hole in the iris to relieve excessive pressure; create a small hole in the membrane that holds a transplanted lens in place; treat areas of tissue at the base of the cornea responsible for draining the aqueous fluid in the eye. They also include procedures that involve: cutting malignant tumors on and around the eye and lid using a scalpel or laser; cutting off excess skin of an upper eyelid or cutting and shortening the lower eyelid using a scalpel or laser; cut the eye tear drainage system using a scalpel.
The bill also says it will expand optometry’s injection authority, still prohibiting intravitreal injections but allowing ODs to inject into the front of the eye or into the tissue surrounding the eye.
The bill itself is sponsored by State Senator Cathy Giessel and was written by Jeff Gonnason, OD, a past president of the Alaska Optometric Association, according to the Alaska Dispatch News.
| Limstrom S, SB 55 Surgery Provision. Alaska State Legislature. www.legis.state.ak.us/basis/get_documents.asp?session=29&docid=3968. March 20, 2015. |
Optometry Mourns Loss of Larry Alexander
Optometric educator Larry Alexander, 68, died April 16, 2016 at his home in Venice, Fla. Born in Plainfield, Indiana, he graduated from the school of optometry at Indiana University and later served as an optometrist in the United States Navy. Dr. Alexander also practiced in Elizabeth City, NC; Louisville, KY; and Jeffersonville, IN; and taught at the University of Alabama (UAB) School of Optometry. He most recently was a consultant for Optovue as well as a successful author and lecturer.
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“Dr. Larry Alexander was a quintessential educator, with the rare ability to condense complex topics and concepts into easily understandable language that inevitably resonated with clinicians. He had a passion for writing and teaching and was himself a consummate doctor, with a broad patient following. More importantly, his sincerity and unassuming style served as a magnet for friendships throughout the country,” said Jimmy D. Bartlett, OD, a long-time faculty colleague at UAB. “Larry gave of himself with no expectation for return. On the dedication page for the latest edition of his classic Primary Care of the Posterior Segment, he quotes Drummond: ‘I shall pass this way but once. Any good, therefore, that I can do, any kindness I can show any human being, let me do it now, for I shall not pass this way again.’”
Dr. Alexander is survived by his wife, Lynn Alexander; children Kari Alexander and Dan Alexander and grandchildren Kathryn and Nate.
Canaloplasty Lowers IOP, Avoids Bleb Complications
Canaloplasty may be a suitable alternative to trabeculectomy in patients with open-angle glaucoma, reports a study in the May 2016 Journal of Glaucoma. Though trabeculectomy is considered by many to be the gold standard in glaucoma surgery, potential early and late-term complications can occur, including athalamia, hypotonus, choroidal detachment and bleb infection.1 Other attempts at creating surgical alternatives have yielded techniques that do not provide sufficient intraocular pressure control and may result in other complications.
Researchers considered 218 eyes of 197 glaucoma patients who underwent canaloplasty, a non-perforating blebless technique similar to viscocanalostomy, over 42 months. Success criteria were defined as achieving postoperative IOP≤21mm, ≤18mm or ≤16mm Hg with or without medical treatment. Mean intraocular pressure was 28.4±7.5mm Hg pre-op and 15.9±4.7mm Hg at two-year follow-up. Additionally, after two years, a qualified success rate based on the post-op IOP≤21mm, ≤18mm or ≤16mm Hg success criteria was achieved in 82 (92.1%), 60 (67.4%) and 53 (59.5%) eyes, respectively. Complications included hyphema in 47 eyes (23.7%), detachment of Descemet’s membrane in 11 eyes (5.5%) and 12 cases of IOP spikes > 10mm Hg (6.1%).
“One of the most advantageous characteristics of canaloplasty” is the increased safety from avoidance of a filtering bleb, the researchers noted, which reduces post-op treatments, follow-up visits and associated social health costs, they said.
| Brusini P, Caramello G, Benedetti S and Tosoni C. Canaloplasty in open-angle glaucoma: mid-term results from a multicenter study. J Glaucoma. 2016 May;25(5):403-7. |
Insects’ Bacterial Defense May Protect Corneal Transplants
Research presented at the National Meeting & Exposition of the American Chemical Society shows coating synthetic polymers, which are being developed for use in corneal implants, in antibacterial nanopillars may help stave off infection. These pillars are small enough to impale any bacteria that lands on them, eliminating the need for biocidal coating or antibacterial drugs in the construction of poly(methyl methacrylate) based materials. The technology is inspired by similar pointed pillars that cover insect wings, according to the scientists.
In particular, investigators modeled their research on cicada and dragonfly wings. Currently, the researchers have been able to replicate nanopillars like those found on cicada wings, which protect against gram-negative bacteria, such as E. Coli. They hope to soon replicate the different kinds of nanopillars found on dragonfly wings, which can also kill gram-positive bacteria, such as MRSA and Streptococcus.
Proactive Medicine: A Focus of Vision Expo East’s CE
Lecturers encouraged optometrists to be more attuned to prevention of ocular disease and awareness of systemic health.
By Cheryl G. Murphy, OD, Contributing Editor
Proactively examining patients for preliminary warning signs of ocular conditions was one key focus of continuing education classes at this year’s Vision Expo East. By finding and diagnosing subtle warning signs of looming health conditions, we can sometimes get to the root of the problem and correct it. This may allow us to begin treatment of a patient’s disease before irritating symptoms and threatening repercussions manifest.
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| Drs. Schaeffer, Bloomenstein and Karpecki educated attendees about early signs of dry eye as well as factors that can lead to it. |
At the Ocular Surface Disease and Wellness Symposium, Drs. Paul Karpecki, Jack Schaeffer and Marc Bloomenstein discussed how doctors should be looking for signs of dry eye during their annual checkups. This starts with the doctor asking the right questions to probe for symptoms of dryness that the patient may be experiencing, yet overlooking. A dry eye questionnaire in the waiting room can help identify dry eye symptoms and measure severity. “Four things we watch for and treat to ensure ocular surface wellness are obstruction, inflammation, tear stability and biofilm,” said Dr. Karpecki at the lecture. Being able to identify which component or combination of those four resulted in dry eye helps to guide practitioners in how to treat it. A careful examination of the lids, lashes, tears and ocular surface each year is recommended and the importance of tear osmolarity testing was also emphasized.
In Dr. Lisa Renzi-Hammond’s course, “Macular Carotenoids and Cognitive and Visual Function Across the Lifespan,” the importance of proper nutrition was highlighted. A healthy helping of lutein and zeaxanthin not only improves retinal health, she said; it also allows for optimal retinal functioning.
Dr. Renzi-Hammond explained the link between a well-nourished retina and improved visual processing speed and reaction time. Carotenoids, such as lutein and zeaxanthin, are essential to the function of the retina, she noted, and proper supplementation of them can enhance our visual memories, executive functioning and reasoning.
Another speaker who explained how proactive testing can reveal early signs of systemic conditions was Craig Thomas, OD, who lectured on color vision in health and disease. Dr. Thomas said that acquired loss of chromatic discrimination—or dyschromatopsia—can precede more classic signs of glaucoma and can reveal visual functioning changes early in the course of diabetes. “Acquired color vision defects may precede field loss in patients with glaucoma and I have seen this in my own patients,” Dr. Thomas noted, “and chromatic disturbances can also precede diabetic retinopathy in some patients.”
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| Dr. Thomas stressed the importance of color vision testing. |
He went on to explain that the “absence of dot-blot hemorrhages does not mean the retina isn’t affected by diabetes. The retina may still have hypoxia and its function can be affected.” Dr. Thomas recommends skipping Ishihara color plates when testing an adult’s color vision because they do not measure for blue-yellow defects, which are the most common type of acquired color vision defects. Instead, doctors should employ computer-assisted color vision tests such as ColorDx (Konan), which make testing accurate and scoring faster than Farnsworth D-100 testing, he stated.
Dr. Joe Rappon’s course, “Smart Contact Lenses and Other Future Eye Care Technology” showed attendees how breakthrough technologies are helping us to better detect eye conditions and manage illnesses more efficiently. Dr. Rappon said, “Today, one out of every 11 people globally has diabetes” and noted that “people have better control over their diabetes when glucose can be continually monitored.” Advances in technology have led to the development of Google’s glucose monitoring contact lens containing “a circuit the size of a piece of glitter which allows us to measure and store data and also transmit that data to a smartphone.”
Dr. Rappon explained that the future of health monitoring contact lenses is on the way as companies other than Google are developing similar biometric sensing contact lenses, such as Sensimed’s Triggerfish for glaucoma patients. These advances will allow clinicians to monitor for daily fluctuations in our patient’s disease course. The earlier ODs detect changes in health, the earlier they can intervene to improve overall outcomes.
