Correction of presbyopia with a small aperture corneal inlay

Abstract

Purpose: To assess the efficacy of a small aperture corneal inlay (KAMRA, AcuFocus Inc) to improve near vision in emmetropic presbyopes.

Methods: Prospective, nonrandomized, multicenter clinical trial in presbyopic emmetropes aged 45 to 60 years. A small corneal pocket or flap was created in the nondominant eye by femtosecond laser or mechanical microkeratome, and the inlay (N=507) placed on the stromal bed. Uncorrected visual acuity was measured for the implanted eye at near (40 cm), intermediate (80 cm), and distance (20 ft) using ETDRS charts with the Optec 6500 Vision Tester (Stereo Optical Inc) at the preoperative, and 1-, 3-, 6-, 9-, 12-, and 18-month postoperative examinations. Contrast sensitivity (CS) was measured with best distance correction in the implanted eye using the Optec system and FACT chart under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) conditions preoperatively and at 1-year follow-up.

Results: Mean patient age was 52.87±3.64 years. Monocular mean uncorrected near visual acuity was J8 (0.482±0.925 logMAR) preoperatively, J3 (0.185±0.848 logMAR) at 1 month (n=506, P<.0001), and J2 (0.139±0.851 logMAR) at 18 months (n=99, P<.0001). Mean uncorrected intermediate visual acuity was 20/35 (0.239±0.837 logMAR) preoperatively and 20/26 (0.139±0853 logMAR) at 18 months (P<.0001). Mean uncorrected distance visual acuity (UDVA) was 20/20 (0.011±0.890 logMAR) at 18 months. Photopic (P<.001) and mesopic (P<.0001) monocular contrast sensitivities were within the range of the normal population at 1 year.

Conclusions: The KAMRA corneal inlay improved near visual acuity with minimal impact on UDVA or mesopic contrast sensitivity in the implanted eye.