Abstract
Purpose: :
The KAMRA™ intra-corneal inlay (AcuFocus, Inc.) alleviates the symptoms of presbyopia by extending the depth of focus through small aperture optics. Following monocular implantation over a patient's coaxially sighted corneal reflex, the opaque inlay, which has an overall diameter of 3.8mm and a central aperture of 1.6mm, only allows focused light rays to reach the retina and therefore increasing the eyes depth of focus. The main objective of this study was to evaluate visual acuity and any localized changes in visual field following implantation of a small aperture.
Methods: :
Nine subjects were implanted monocularly with the inlay in their non-dominant eye. Standard visual field tests were performed using the Ziess Humphrey 24-2 SITA on both the implanted and non-implanted eyes at pre-op and at 36 months post-op visits. Standard clinical examination including distance and near vision measurements were conducted at pre-op and 12 months post-op visits. Visual field indices Pattern Standard Deviation (PSD), fixation losses (FL), false positives (FP), and false negatives (FN) were evaluated and compared using t-tests between implanted and fellow eyes before and 36 months after inlay implantation. All data are presented as mean ± sd.
Results: :
UCDVA at baseline was 47.7 ± 6.1 letters and at\ post-op it was 47.0 ± 6.9 letters (p = 0.30). BCDVA at baseline 52.7 ± 3.2 letters was not significantly different from post-op BCDVA at 51.0 ± 4.5 letters (p = 0.09). UCNVA at baseline was 26.7 ± 3.6 letters and improved to 44.1 ± 7.2 letters post-op (p < 0.001). PSD at baseline in the implant eye was 1.37 ± 0.25 and in the non-implant eye it was 1.53 ± 0.61db (p = 0.36). After surgery it was 1.58 ± 0.36 in the implant eye and 1.52 ± 0.38db (p = 0.54) in the non-implant. SAP reliability indices were not significantly different between eyes at baseline and following KAMRA inlay implantation.
Conclusions: :
Implantation of a small aperture intra-corneal inlay improves UCNVA and maintains UCDVA. Additionally, implantation of the inlay does not cause any localized changes or scotomas in the visual fields as demonstrated by the lack of difference in PSD when comparing the implanted and non-implanted eye.
Keywords: accommodation • presbyopia • cornea: clinical science