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Review
. 2022 Jan 7;12(3):282-294.
doi: 10.4103/tjo.tjo_45_21. eCollection 2022 Jul-Sep.

Review of surgical devices using small aperture optics

Robert Edward T Ang  1 , Michelle Marie Q Araneta  1 , Emerson M Cruz  1
Affiliations
Review

Review of surgical devices using small aperture optics

Robert Edward T Ang et al. Taiwan J Ophthalmol. .

Abstract

Small aperture optics work by blocking unfocused peripheral light rays while allowing central light rays to focus on the retina. This pinhole effect creates an extended depth of focus and has been used in presbyopia correction, improving intermediate and near vision without markedly affecting distance vision. Another beneficial effect of small aperture optics is reducing aberrations caused by irregular corneas or irregular pupils. The first small aperture surgical device was the Kamra corneal inlay used on the nondominant eyes of presbyopic emmetropes. The pinhole concept was also adapted into the IC-8 intraocular lens (IOL) for presbyopia correction during cataract surgery and by the XtraFocus piggyback device to lessen unwanted aberrations in eyes with irregular corneas or pupils. The IC-8 IOL can be placed monocularly or binocularly with mini-monovision for further near vision improvement. The XtraFocus piggyback device can be placed either in the sulcus or capsular bag. The aim of this literature review is to synthesize evidence on the efficacy, safety, and patient-reported outcomes on surgical devices utilizing small aperture optics. A comprehensive search on PubMed was conducted with the keywords "small aperture optics," "small aperture corneal inlay," "small aperture IOL," "Kamra corneal inlay," "IC-8 IOL," and "XtraFocus." In this review, we describe the progression of small aperture surgical devices, patient criteria, visual outcomes, complications, satisfaction, and recommendations for surgical success.

Keywords: Complex corneas; IC-8; Kamra; Xtrafocus; extended depth of focus; irregular pupils; presbyopia; small aperture.

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Conflict of interest statement

Dr. Ang was a principal investigator for clinical studies conducted on the Kamra corneal inlay and IC-8 intraocular lens. Dr. Ang and the co-authors have no financial interest related to this submitted work.

Figures

Figure 1
Figure 1
Flow chart showing the study selection process
Figure 2
Figure 2
(a) Kamra corneal inlay showing grade 1 haze. (b) The corneal haze imprint after explantation of a Kamra corneal inlay. (c) The IC-8 intraocular lens features a small aperture mask embedded at the center of the optic. (d) The small aperture mask of the IC-8 IOL has microperforations similar to the Kamra corneal inlay. (e) The XtraFocus piggyback device is opaque but is transparent under infrared imaging. (f) The XtraFocus device is intended for pseudophakes and may be implanted in the sulcus or capsular bag (images e and f courtesy of Claudio C. Trindade, MD, PhD, Cançado-Trindade – Brazil)
See this image and copyright information in PMC

References

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