Assessment of Small-Aperture Inlay Clinical Outcomes Using Videokeratography and Corneal OCT: 2-Year Results
Narrative Responses:
Purpose
To evaluate the long-term visual outcomes and corneal stability of eyes implanted with a small-aperture intracorneal inlay.
Methods
Forty ametropic presbyopes (age 43 to 57 years) were monocularly implanted with a small-aperture corneal inlay (KAMRA, AcuFocus, inc) in their non-dominant eye. All patients underwent inlay implantation subsequent to a LASIK procedure. Spherical equivalent refraction varied between -4.50D to +3.75D. Inlay-implanted eyes were targeted for -0.75D and fellow eyes were targeted for plano. UCDVA, UCNVA, BDVA and accommodative amplitude were measured. Corneal topography (Optikon 2000, Oculus or Sirius Scheimpflug) and OCT (OTI) were used to assess the corneal stability and thickness of the flap. All tests were performed at 1 week, 1, 3, 6, 12, 18 and 24 months.
Results
At 3 months, UCDVA, UCNVA and BCDVA were 20/25 or better in 85%, 90% and 100% of patients respectively. On average amplitude of accommodation was 2.75 ± 0.45 D. OCT measured flap thickness ranged from 171 to 211 microns. Corneal topography showed a mild circular steeping over the inlay. The steeping was negatively correlated to a) the flap thickness (r= -0.723), b) negatively correlated to time after surgery (after month 3), and c) the type of attempted correction (steeper in eyes which had hyperopic ablation).
Conclusion
The small aperture KAMRA inlay provides satisfactory uncorrected distance and near outcomes in ametropic presbyopes treated concurrently with a LASIK procedure. Corneal topography is a great tool for evaluating the corneal healing response. OCT is very helpful to assess the actual flap thickness and stromal health over the inlay.