Stereoacuity after small aperture corneal inlay implantation

Abstract

PurposeThe aim of this study was to compare stereoacuity before and after KAMRA corneal inlay implantation for the correction of presbyopia.Patients and methodsThis is a prospective study of 60 patients who underwent KAMRA inlay implantation. Patients were examined before and 6 months after surgery for stereoacuity, uncorrected distance visual acuity (UDVA), and uncorrected near visual acuity (UNVA).ResultsThe mean stereoacuity before surgery was 29.5±28.1 arcsec (range: 20–200) and at 6 months was 29.8±26.4 arcsec (range: 20–200). The decline in stereoacuity was not statistically significant. At 6 months follow-up, UDVA was 20/25 or better in all 60 patients and UNVA was J2 (20/25) or better in 51 (85%) patients.ConclusionThere is no significant change in stereoacuity following KAMRA inlay implantation. The KAMRA inlay is a good treatment option for improving near vision in presbyopic patients while preserving stereoacuity and distance vision.

Presbyopia: Effectiveness of correction strategies

“…based on the USA regulatory submission of the corneal inlay clinical trials to date (Moshirfar et al, 2017) suggests both inlay types are safe, but secondary surgical intervention was required in 12% of thin lens inlays within 3 years of implantation; a drop in corrected visual acuity of ≥2 acuity lines was more common in pinhole inlays (3.4% vs 1.0%). However, clinical studies suggest that when implanted monocularly in the non-dominant eye meniscus shaped inlays cause only minimal distance visual acuity compromise in the implanted eye and provide good near acuity, stereopsis and contrast sensitivity (Igras et al, 2016a, b;Jalali et al, 2016;Lin et al, 2016;Linn et al, 2017). They can be implanted safely with similar outcomes before or after traditional or femtosecond laser-assisted cataract surgery (Ibarz et al, 2017;Stojanovic et al, 2016) and with simultaneous photorefractive keratectomy (PRK) (Moshirfar et al, 2016b).…”

Pinholes and presbyopia: solution or sideshow?

“…Comparison of pre-and post-implantation of distance stereo performance for patients with Kamra inlays, using a conventional stereo screener, suggests that this is not the case. 62 Stereo acuity was found to be unchanged, unlike the situation with surgically-created monovision, where stereo acuity was found to be adversely affected. 63 It is not clear, however, whether the Kamra result would still apply at lower luminance levels than those used in the screener, or at other, shorter, distances when the differences between the two retinal images might be greater.…”

“…One obvious possibility is that stereo acuity might be affected. Comparison of pre‐ and post‐implantation of distance stereo performance for patients with Kamra inlays, using a conventional stereo screener, suggests that this is not the case . Stereo acuity was found to be unchanged, unlike the situation with surgically‐created monovision, where stereo acuity was found to be adversely affected .…”

Applications of the pinhole effect in clinical vision science

“…The KAMRA inlay in the nondominant eye does not worsen stereoacuity, in contrast with monovision induced by a contact lens or LASIK. 36,37,[81][82][83] Overall satisfaction was reported high at 89%. 82 Improvement in intermediate and near vision was much better in bright light than in dim light.…”