Small-aperture intracorneal inlay implantation in emmetropic presbyopic patients: a systematic review.

Small-aperture corneal inlays, commonly known as KAMRA, are tiny optical devices inserted in the corneal stroma aiming to gain near vision in patients with presbyopia. The purpose of this study was to systematically review case series of small-aperture corneal inlays performed in presbyopic emmetropic patients and to evaluate the visual outcomes of this procedure. This systematic review included 18 articles published between 2011 and 2018, overall studying 2724 eyes from 2691 participants. The mean longest follow-up was 19 months. Results showed that 78.5% of eyes reported an uncorrected near visual acuity of 20/32 or better and 90.50% of eyes achieved an uncorrected distance visual acuity of 20/25 or better. All patients experienced an improvement in uncorrected near visual acuity with a patient satisfaction ranging between 60% and 90%. The highlighted complications were keratocyte activation leading to corneal stromal haze, epithelial growth, iron deposits and poor distance visual acuity. Explantation was carried out in 101 eyes (3.7%) due to distance vision blurriness, development of epithelial microcysts, incorrect implant placement or hyperopic shift changes. KAMRA demonstrated high efficacy. However, safety and satisfaction rates remain unclear. Despite the low explantation rates reported in the literature, some complications were permanent. The results and conclusions should be taken with caution due to the conflict of interest stated in the reviewed articles.