The authors wish to thank FORTE Project, funded by Tuscany Region (POR CReO FESR 2007-2013, Bando Unico R&#38;S 2012), the EU FP7 ECHORD++ Experiment LA-ROSES that partially supported the research activities, and the FP7 BiophotonicPlus Project &#8220;LITE&#8221; granted by Tuscany Region.

The study was conducted with the prospectively approval of the hospital&#8217;s Ethics Committee; informed consent was obtained. The study was in adherence to the tenets of the Declaration of Helsinki.
1. Donor Endothelium Preparation
<ol>
	<li>Use a donor cornea as prepared by the local eye bank at room temperature.</li>
	<li>In the surgery room, pull out the donor cornea from its delivery container and set apart the solution for tissue preservation and nutrition that is used for corneal tr...

<ol>
	<li>Tan, D. T., Dart, J. K., Holland, E. J., Kinoshita, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Corneal+transplantation.">Corneal transplantation.</a> Lancet. 379 (9827), 1749-1761 (2012).</li><li>El Husseiny, M. A., Manero, F., Gris, O., Elies, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Historical+Review+and+Update+of+Surgical+Treatment+for+Corneal+Endothelial+Diseases.">Historical Review and Update of Surgical Treatment for Corneal Endothelial Diseases.</a> Ophthalmol Ther. , (2014).</li><li>Rossi, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+tissue+welding+in+ophthalmic+surgery.">Laser tissue welding in ophthalmic surgery.</a> J Biophotonics. 1 (4), 331-342 (2008).</li><li>Pini, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combining+femtosecond+laser+ablation+and+diode+laser+welding+in+lamellar+and+endothelial+corneal+transplants.">Combining femtosecond laser ablation and diode laser welding in lamellar and endothelial corneal transplants.</a> Proc. SPIE Ophthalmic Technologies XVIII. 6 (844), 684411-1-684411-7 (2008).</li><li>Rossi, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=All-laser'+endothelial+corneal+transplant+in+human+patients.">All-laser' endothelial corneal transplant in human patients.</a> Proc. SPIE Ophthalmic Technologies XXII. 8209, 82091O-1-82091O-3 (2012).</li><li>Rossi, F., Pini, R., Menabuoni, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+and+model+analysis+on+the+temperature+dynamics+during+diode+laser+welding+of+the+cornea.">Experimental and model analysis on the temperature dynamics during diode laser welding of the cornea.</a> J Biomed Opt. 12 (1), 014031-1-014031-7 (2007).</li><li>Menabuoni, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-assisted+corneal+welding+in+cataract+surgery:+retrospective+study.">Laser-assisted corneal welding in cataract surgery: retrospective study.</a> J Cataract Refract Surg. 33 (9), 1608-1612 (2007).</li><li>Buzzonetti, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+Welding+in+Penetrating+Keratoplasty+and+Cataract+Surgery+in+Pediatric+Patients.+Early+Results.">Laser Welding in Penetrating Keratoplasty and Cataract Surgery in Pediatric Patients. Early Results.</a> J Cataract Refract Surg. 39 (12), 1829-1834 (2013).</li><li>Menabuoni, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+'anvil'+profile+in+femtosecond+laser-assistedpenetrating+keratoplasty.">The 'anvil' profile in femtosecond laser-assistedpenetrating keratoplasty.</a> Acta Ophthalmol. 91 (6), e494-e495 (2013).</li><li>Canovetti, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-assisted+penetrating+keratoplasty:+one+year&#8217;s+results+in+patients,+using+a+laser-welded+&#8220;anvil&#8221;-profiled+graft.">Laser-assisted penetrating keratoplasty: one year&#8217;s results in patients, using a laser-welded &#8220;anvil&#8221;-profiled graft.</a> Am J Ophthalmol. 158 (4), 664-670 (2014).</li></ol>

The authors declare that they have no competing financial interests.

The &#8220;all laser&#8221; endothelial transplant is an original approach to minimally invasive corneal transplantation.
All the procedures described within the protocol were performed in the surgery room, observing the hygienic and sterilization procedure that are common practices during surgeries, such as the use of sterilized gloves, gown, mask and cap. The ICG solution was prepared in the surgery room, soon before its application in staining the donor endothelium. The ICG powder, the wate...

In this work we present an original approach to endothelial keratoplasty, based on the use of a femtosecond laser to prepare donor tissue and a near infrared diode laser to weld it onto the recipient bed. Intraoperative measurement of the donor cornea is necessary to correctly design the donor tissue dimensions. Endothelial keratoplasty has been proposed in the recent years to replace penetrating keratoplasty in treating endothelial disease1,2. The main advantage of this technique is a faster visual recovery, with respect to penetrating keratoplasty, reduced anesthesia during surgery, a decreased risk of graft rejection and the preservation of eye integrity. The main risk factor is postoperative donor lenticule dislocation. The standard technique is performed by inserting the donor endothelium in its final position where it is maintained by the injection of an air bubble: no sutures are used because of the mechanical, biophysical and dimensional characteristics of the endothelium. Moreover, visual acuity recovery can be limited mainly because of a mismatch between donor and recipient tissues due to a thick tissue transplanted.
Here we present a procedure in performing endothelial keratoplasty that can overcome those main problems. The donor endothelium can be assured in its final position by the use of the laser welding technique. This is a controlled and localized photothermal process: it can be induced at the donor/recipient interface. It has been studied in the last ten years and proposed in penetrating keratoplasty and in the transplant of endothelium3-5. The near infrared light (wavelength: 810 nm) emitted by a low power diode laser is delivered towards the biological tissue at the wound site. The cornea is naturally transparent to this wavelength: in order to make this tissue to absorb the laser light, it is necessary to stain it with a chromophore. The proposed dye is a sterile saturated water solution of Indocyanine Green (ICG). We demonstrated that when corneal tissue is properly stained with this ICG preparation, it shows an absorption peak at 810 nm6. Moreover, ICG is widely used in clinical diagnostics and its safety has been already demonstrated in human subjects. The stained cornea absorbs the diode laser light energy and the main resulting effect is a controlled temperature rise at the welding site. No thermal effects are induced in the unstained tissues. The temperature enhancement induces reversible thermal denaturation in the stromal collagen, with an immediate closuring of the wound walls upon cooling. This laser welding effect was firstly demonstrated in cataract surgery7,8 and penetrating keratoplasty9,10. An optimized approach that we are presenting in this paper has been studied for application in endothelial keratoplasty.
In the proposed surgery, single laser spots (lasting tens of msec) are delivered to the tissue, resulting in a photothermal effect localized within the spot dimension (a few hundreds of &#181;m in diameter): the induced effect is a hard laser welding, consisting of a photocoagulation of the collagen confined at the donor/host interface. The result of the collagen denaturation at the welded site is a strong adhesion between the donor and host tissues, thus providing a suturing effect that is impossible to obtain with standard technique (stitches). The tissue regains his natural appearance in a short follow up (1 month) and the adhesion between donor/host tissues is improved by the welding provided in the very early stage of the healing phase.
To avoid the other main risk of the endothelial keratoplasty, i.e. the transplant of a thick donor tissue, intrasurgical optical coherence tomography (OCT) is used: a commercial device measures the thickness of donor cornea, so that a correct cut profile can be designed with the femtosec laser. The proposed &#8220;all laser&#8221; endothelial transplant thus seems to improve the clinical results of this minimally invasive surgery.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Indocyanine Green</td>
			<td>Pulsion Medical Systems, Germany</td>
			<td>ICG-PULSION (http://www.pulsion.com/international-english/perfusion/icg-pulsion/)</td>
			<td>Alternative product: IC-GREEN, Akorn&#160; Inc., Lake Forest, Illinois- US (http://www.icginjection.com/)</td>
		</tr>
		<tr>
			<td>Femtosecond Laser&#160;</td>
			<td>Abbott Medical Optics,&#160; Abbott Laboratories Inc. Abbott Park, Illinois, USA</td>
			<td>iFS150 (http://www.abbottmedicaloptics.com/products/refractive/ilasik/ifs-advanced-femtosecond-laser)</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical Coherence Tomography (OCT)</td>
			<td>Carl-Zeiss Meditec, Dublin, California- US (http://www.zeiss.com/meditec/en_de/home.html)</td>
			<td>Visante</td>
			<td></td>
		</tr>
		<tr>
			<td>Diode Laser</td>
			<td>E.l.En. Group s.pa., Calenzano-FI, Italy (http://www.elengroup.com/en/divisions/medical)</td>
			<td>Mod. WELD 800</td>
			<td></td>
		</tr>
		<tr>
			<td>Artificial Anterior Chamber</td>
			<td>CORONET, corneal graft products. Network Medical Products Ltd. Coronet House, Kearsley Road, Ripon, North Yorkshire, HG4 2SG, UK</td>
			<td>&#160;Artificial Anterior Chamber (A.A.C.) with large and small tissue-retaining heads. Code 51-935 (http://www.networkmedical.co.uk/ophthalmic_artificial_anterior_chamber.html)</td>
			<td></td>
		</tr>
		<tr>
			<td>Solution for tissue preservation and nutrition&#160;&#160;</td>
			<td>&#160;AL.CHI.MI.A. Srl, Viale Austria 14, 35020 - Ponte S. Nicol&#242; - PD 
			&#160;ITALY</td>
			<td>Carry-C media for corneal deturgescence and transport at room temperature - 12 x 50 ml (http://www.alchimiasrl.com/en/organ-culture-at-31&#176;-c-eb/carry-c-eb)</td>
			<td></td>
		</tr>
	</tbody>
</table>

an &#8220;all-laser&#8221; endothelial transplant

The &#8220;all laser&#8221; assisted endothelial keratoplasty is a procedure that is performed with a femtosecond laser used to cut the donor tissue at an intended depth, and a near infrared diode laser to weld the corneal tissue. The proposed technique enables to reach the three main goals in endothelial keratoplasty: a precise control in the thickness of the donor tissue; its easy insertion in the recipient bed and a reduced risk of donor lenticule dislocation. The donor cornea thickness is measured in the surgery room with optical coherence tomography (OCT), in order to correctly design the donor tissue dimensions. A femtosecond laser is used to cut the donor cornea. The recipient eye is prepared by manual stripping of the descemetic membrane. The donor endothelium is inserted into a Busin-injector, the peripheral inner side is stained with a proper chromophore (a water solution of Indocyanine Green) and then it is pulled in the anterior chamber. The transplanted tissue is placed in the final and correct location and then diode laser welding is induced from outside the eyeball. The procedure has been performed on more than 15 patients evidencing an improvement in surgery performances, with a good recovery of visual acuity and a reduced donor lenticule dislocation event.

The &#8220;all laser&#8221; surgical procedure is proposed to perform minimally invasive corneal transplantation. The procedure is easy to perform (see Figure 1): with respect to a standard endothelial transplant only the steps of measuring the corneal thickness, staining the donor tissue and delivering the laser light are added. The achieved advantages largely compensate an increased surgical time of a few min. The use of intraoperative OCT to measure the donor cornea thickness and the femtosecond laser...

Watch this Scientific Journal Video about An â€œAll-laserâ€ Endothelial Transplant at JoVE.com

An &amp;#8220;All-laser&amp;#8221; Endothelial Transplant

An all laser procedure is proposed in the endothelial transplant. The surgical technique is based on the use of a femtosecond laser to prepare the donor tissue. Laser welding technique is then used to secure the donor endothelium in the correct position.

An &#8220;All-laser&#8221; Endothelial Transplant

The &#8220;all laser&#8221; assisted endothelial keratoplasty is a procedure that is performed with a femtosecond laser used to cut the donor tissue at an ...

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Medicine

9.3K ビュー.  Italian National Research Council. An all laser procedure is proposed in the endothelial transplant. The surgical technique is based on the use of a femtosecond laser to prepare the donor tissue. Laser welding technique is then used to secure the donor endothelium in the correct position.