Toward emmetropia: More advances, more improvements
Refractive, corneal surgery in 2016 saw gains in therapies for keratoconus, presbyopia
Take-home message: Advances in treatments for keratoconus and presbyopia in 2016 continued to move patients toward emmetropia.
Reviewed by Dimitri Azar, MD, MBA; Arun Gulani, MD, and Peter Hersh, MD
Areas attracting the most attention in 2016 were crosslinking for keratoconus and presbyopia therapies. Other areas of interest, as expressed by surgeons, include LASIK and corneal inlays among others. Specialists in those fields discuss the advances and benefits of the new therapies.
“Crosslinking is probably the most meaningful advance of the year in the field of cornea, as well as the most clinically significant change in keratoconus management that we have had in many years,” said Peter Hersh, MD, clinical professor, and director, cornea and refractive surgery, Institute of Ophthalmology and Visual Science, both at Rutgers-New Jersey Medical School, Newark, NJ, and in private practice at the Cornea and Laser Eye Institute in Teaneck, NJ.
The procedure from Avedro was approved in April 2016 for treating progressive keratoconus and then in August 2016 for corneal ectasia, he pointed out. These approvals are the endpoints of 8 years of work beginning in 2008 in multicenter clinical trials carried out at 10 study sites.
FDA approval was based on the study results for progressive keratoconus (defined by changes in topography, refraction, etc.), in patients 14 years and older, or for patients with corneal ectasia, he explained.
“This is the first procedure that we have to decrease keratoconus progression, so it represents an important breakthrough,” Dr. Hersh said.
The clinical trials for keratoconus showed clinically meaningful results in more than 200 eyes in the U.S. clinical trial for keratoconus.
“We found that the average improvement in the keratoconus cone was about 1.6 D,” Dr. Hersh said. “In fact, about one-third of patients saw improvements of 2 D or more.”
Although actual topography improvement is not the goal of crosslinking in keratoconus, but rather stabilization of the disease progression, the results seen in the study clearly indicated that the procedure can effectively treat keratoconus with an excellent safety profile, he explained.
“Most patients stabilize, a good number improve, and a small percentage continues to have progression,” Dr. Hersh said.
Crosslinking also is effective in stabilizing progression of ectasia over time.
However, the actual topography improvement in these patients might not be as robust as that observed in patients with keratoconus, likely because of the steeper cones initially and more central cones in patients with keratoconus.
In other analyses performed by Dr. Hersh, he found that crosslinking patients with steeper cones tend to achieve more improvement; patients with a K reading of 54 or more were five or six times more likely to flatten by 2 D or more, and typically ectasia patients have less steep and more peripheral changes.
However, the actual stabilization of the cornea is effective with either keratoconus or ectasia, independent from the preoperative severity.
Crosslinking may ultimately eliminate the need for corneal transplantation in many patients. Dr. Hersh noted that in his practice patients have been stable for 8 years and in European studies, patients have been stable for 5 to 10 years after treatment.