This article is more than 5 years old. Information may no longer be current.
Lessons learned over 5 years of follow-up with Kamra inlay for presbyopia
Click Here to Manage Email Alerts
MILAN — Long-term outcomes with the Kamra small aperture inlay have shown how to ensure safety and optimize efficacy of the implant. At the OSN Italy meeting, Jay Pepose, MD, PhD, said that lessons were learned from the FDA investigational device exemption study, which enrolled 507 patients from 24 sites in the U.S., Europe and Asia-Pacific region.
The Kamra inlay (AcuFocus) is implanted monocularly in a corneal pocket in the nondominant eye. The inlay blocks the peripheral unfocused light and allows only focused light to reach the retina.
Jay Pepose
“It does not work by changing the dioptric power of the eye but by extending depth of focus, with no reduction of stereopsis,” Pepose said.
Over the 5 years of the study, with the inlay implanted at different depths, with the corneal pocket performed by microkeratome and then femtosecond laser with different spot/line settings, it was possible to establish what the best strategy is to optimize outcomes.
“We learned from the study that the inlay must be implanted under a femtosecond laser-created pocket, at least 200 µm deep, at greater than 40% of the total corneal thickness,” Pepose said.
This is because keratocyte density drops at approximately 40% depth, beyond the boundaries between the anterior and posterior stroma. Keratocyte activation causes haze, Pepose explained.
“The deeper implantation group achieved better visual results and refractive stability and was correlated with reduced incidence of haze,” he said.
Another lesson learned was that a tighter spot/line separation of less than 6 × 6 µm results in a smoother pocket and reduces removal rate.
“No inlays were removed from patients treated in the 6 × 6 pocket group with deeper implantation,” Pepose said.
Steroids and dry eye therapy were also shown to be critical for modulating the healing response. – by Michela Cimberle
Reference:
Pepose J. Update on small aperture corneal inlay for presbyopia. Presented at: OSN Italy; May 20-21, 2016; Milan.
Disclosure: Pepose reports he is a consultant to Abbott Medical Optics, AcuFocus, Bausch + Lomb, TearLab and Visiometrics.