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Ioannis Pallikaris, Eirini Naoumidi, Onurcan Sahin; A new method for correcting an irregular surface of a cornea.. Invest. Ophthalmol. Vis. Sci. 2019;60(9):5063.
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© ARVO (1962-2015); The Authors (2016-present)
Evaluation of a new method for smoothing an irregular surface of cornea during a femtosecond refractive surgery.
Latest Femtosecond lasers (FSL) are commonly used for correcting refractive error by creating lenticule with to separate cuts. However, these new FSL do not have advanced features like customized treatments unlike excimer lasers. Relatively, use of gels or collagen compositions for filing the depressions or other irregularities of the cornea were described for different approaches in several patents.The proposed technique aims to create custom treatments for fs refractive surgeries by the help of spherically curved contacting surface coupled with FSL and a photocurable biocompatible gel.The technique compose of application of a small quantity of the gel will be on the anterior surface of the irregular cornea. The contact material which is selected upon correction of the refractive error of the subject, will be placed on top of the gel. After the removal of excessive gel, an UV radiation is applied for solidification of the Gel. In this condition, the first cut is generated using the standard FSL setting, whereby the first correcting cut surface. Once the first correcting cut surface is created, the contact glass and the remaining gel is removed from the cornea.The contact glass once more positioned on the cornea in order to create the second correcting surface but this time no gel but vacuum is used. Another standard cut is generated is made on the top of the first correcting surface.Next, the contact glass is removed from the cornea so that both correcting cut surfaces confine the desired lenticule. The lenticule can be removed from a small incision, so that the second correcting cut surface comes to rest on the first correcting cut surface and, thus, the irregular anterior corneal surface has a different (desired) curvature. Thus, the desired correction of defective eyesight is achieved.
The proof of concept is tested with animal eyes in vitro. Both created surfaces with and without the gel are analyzed with electron microscopy and results revealed that the gel does not interfere with the FSL.
The electron microscopy results confirmed that the FSL cut with the polymerized cut is possible. As the next step, specialized contact surfaces are going to be used for creating lenticules. This, lenticules will be analyzed in order to test consistency and repeatability of the method.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
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