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Liu YC, Morales-Wong F, Patil M, Han SB, Lwin NC, Teo EPW, Ang HP, Yussof NZM, Mehta JS. Femtosecond laser-assisted corneal transplantation with a low-energy, liquid-interface system. Sci Rep 2022; 12:6959. [PMID: 35484198 PMCID: PMC9050694 DOI: 10.1038/s41598-022-11461-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 04/25/2022] [Indexed: 11/26/2022] Open
Abstract
Femtosecond laser-assisted keratoplasty has been proposed as a treatment option for corneal transplantation. In this study, we investigated and compared the outcomes of Ziemer Z8 femtosecond laser (FSL)-assisted penetrating keratoplasty (PK) using a liquid interface versus flat interface. Thirty fresh porcine eyes underwent FSL-assisted PK with the Z8 using different levels of energies (30%, 90% or 150%) and different interfaces (liquid or flat). The real-time intraocular pressure (IOP) changes, incision geometry, corneal endothelial damage, as well as the accuracy of laser cutting and tissue reaction, were performed and compared. We found that the overall average IOP at all laser trephination stages was significantly higher with the flat interface, regardless of the energy used (68.9 ± 15.0 mmHg versus 46.1 ± 16.6 mmHg; P < 0.001). The overall mean laser-cut angle was 86.2º ± 6.5º and 88.2º ± 1.0º, for the liquid and flat platform respectively, indicating minimal deviation from the programmed angle of 90º. When high energy (150%) was used, the endothelial denuded area was significantly greater with the flat interface than with liquid interface (386.1 ± 53.6 mm2 versus 139.0 ± 10.4 mm2P = 0.02). The FSL cutting did not cause obvious tissue reaction alongside the laser cut on histological evaluation. The results indicated a liquid interface is the preferable choice in FSL-assisted corneal transplantation.
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Affiliation(s)
- Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore. .,Cornea and Refractive Surgery Group, Singapore Eye Research Institute, Singapore, Singapore. .,Cornea and External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore. .,Duke-NUS Graduate Medical School, Ophthalmology Academic Clinical Program, Singapore, Singapore.
| | - Fernando Morales-Wong
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore.,Cornea and External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore.,Faculty of Medicine, University Hospital "Dr Jose Eleuterio Gonzalez", Autonomous University of Nuevo Leon, San Nicolás de los Garza, Mexico
| | - Moushmi Patil
- Cornea and External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore
| | - Sang Beom Han
- Department of Ophthalmology, Kangwon National University School of Medicine, Kangwon National University Hospital, Chuncheon-si, Republic of Korea
| | - Nyein C Lwin
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore
| | - Ericia Pei Wen Teo
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore
| | - Heng Pei Ang
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore
| | - Nur Zah M Yussof
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Level 6, Singapore, 169856, Singapore.,Cornea and Refractive Surgery Group, Singapore Eye Research Institute, Singapore, Singapore.,Cornea and External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology Academic Clinical Program, Singapore, Singapore
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Application of Femtosecond Laser in Anterior Segment Surgery. J Ophthalmol 2020; 2020:8263408. [PMID: 32351726 PMCID: PMC7171667 DOI: 10.1155/2020/8263408] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/12/2020] [Indexed: 11/24/2022] Open
Abstract
Femtosecond laser (FSL) is a near-infrared laser that can create reliable and reproducible tissue cutting with minimal damage to adjacent tissue. As the laser can also create incisions with various orientations, depths, and shapes, it is expected to be a useful tool for anterior segment surgery, such as cornea, refractive, and cataract surgery. In this review, the authors will introduce the application of FSL in various anterior segment surgeries and discuss the results of studies regarding the efficacy and safety of FSL in cornea, refractive, and cataract surgery. Experimental studies regarding the potential use of FSL will also be introduced. The studies discussed in this review suggest that FSL may be a useful tool for improving the prognosis and safety of surgeries of the anterior segment.
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Liu YC, Ji AJS, Tan TE, Fuest M, Mehta JS. Femtosecond Laser-assisted Preparation of Conjunctival Autograft for Pterygium Surgery. Sci Rep 2020; 10:2674. [PMID: 32060326 PMCID: PMC7021803 DOI: 10.1038/s41598-020-59586-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/16/2019] [Indexed: 11/09/2022] Open
Abstract
Femtosecond laser-assisted conjunctival autografts (CAG) preparation was recently proposed. This study reports the outcomes of the first clinical trial on the use of laser to prepare CAG in pterygium surgery, and to compare the outcomes with those of manual technique. Forty eyes undergoing primary pterygium excision with laser-assisted CAG transplantation were prospectively included (L group). Two historical matched cohorts whose CAGs were prepared manually were compared (n = 78 eyes by the same experienced surgeon, M group; n = 78 eyes by trainees; TM group). We found the laser-created CAGs had only 11 μm deviation from the targeted thickness. The best-corrected visual acuity improved, and the astigmatism significantly decreased after surgery, with comparable efficacy across 3 groups. The 1-year recurrence rate was 2.5%, 3.8% and 7.7% in the L, M and TM groups, respectively (P = 0.12). There was no significant difference between the L and M groups in the complication rate (5.0% and 1.3%, respectively), surgical time (19.4 ± 5.1 and 19.1 ± 6.2 minutes, respectively), and postoperative discomfort scores (0.1 ± 0.3 and 0.2 ± 0.3, respectively), but these outcomes were significantly less favorable in the TM group. The results of this first comparative clinical trial suggest that femtosecond laser-assisted CAG preparation can be considered as an alternative technique for CAGs preparation.
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Affiliation(s)
- Yu-Chi Liu
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore.,Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Angel Jung Se Ji
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Tien-En Tan
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore, Singapore
| | - Matthias Fuest
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Jodhbir S Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore. .,Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore, Singapore. .,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore. .,School of Material Science and Engineering, Nanyang Technological University, Singapore, Singapore.
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Liu YC, Devarajan K, Tan TE, Ang M, Mehta JS. Optical Coherence Tomography Angiography for Evaluation of Reperfusion After Pterygium Surgery. Am J Ophthalmol 2019; 207:151-158. [PMID: 30959005 DOI: 10.1016/j.ajo.2019.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To describe the use of optical coherence tomography angiography (OCTA) to quantitatively monitor the conjunctival graft revascularization after pterygium excision and conjunctival autograft (CAG) transplantation. DESIGN Prospective, interventional case series. METHODS Ten patients undergoing pterygium excision and femtosecond laser-assisted CAG transplantation were included. OCTA was performed at 1 week, 1 and 3 months postoperatively at the CAG transplantation site and harvested area. The vessel density at three different depths: conjunctival epithelium or CAG epithelium, conjunctival stroma or CAG stroma, and episclera, was evaluated and quantified. The revascularization rate was assessed and correlated with the postoperative CAG thickness. RESULTS No intraoperative and postoperative complications occurred. Reperfusion of the CAGs was observed at 1 week, and early reperfusion within the first month accounted for more than half of graft revascularization. The vessel regrowth density was 9.6±2.6 % and 11.1±2.8 % between 1 week and 1 month, and was 9.8±1.8 % and 11.9±1.9 % between 1 and 3 months, at the CAG and underlying episcleral levels, respectively. All the CAGs were well-perfused at 3 months. The vessel regrowth density was significantly and strongly correlated with the changes of CAG thickness in a negative relationship (γ = -0.94, P = 0.019). At the harvested site, the vascular network of episclera was not affected, and the conjunctival vascularization was restored at 1 month. CONCLUSIONS OCTA is a promising tool to evaluate the vascularization or revascularization of conjunctiva, conjunctival graft and episclera, in a quantitative and serial manner, helping in diseases diagnosis and treatment monitoring. The graft revascularization rate was predictive of postoperative graft deswelling.
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