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Liu Y, He Y, Deng Y, Wang L. Lenticule addition keratoplasty for the treatment of keratoconus: A systematic review and critical considerations. Indian J Ophthalmol 2024; 72:S167-S175. [PMID: 38271413 DOI: 10.4103/ijo.ijo_695_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 09/09/2023] [Indexed: 01/27/2024] Open
Abstract
Keratoconus is a corneal disorder characterized by the progressive thinning and bulging of the cornea. Currently, the major goal of management is to halt its progression, restore normal corneal strength, prevent acute complications, and save vision. Penetrating keratoplasty and deep anterior lamellar keratoplasty as conventional surgical methods for advanced keratoconus are limited by relatively high rates of immune intolerance, slow post-operational recovery, high costs, and shortage of donor corneas. Recently, the development of lenticule addition keratoplasty enables the restoration of corneal thickness simply by implanting a lenticule into the stromal pocket created with the femtosecond laser, which can originate from cadaver corneas or more appealing, be extracted from patients via a small-incision lenticule extraction (SMILE) surgery. As the first systematic review in this field, we critically review publications on lenticule addition keratoplasty and provide our perspectives on its clinical application and the focus of future research.
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Affiliation(s)
- Yanling Liu
- Operating Room, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Yan He
- Operating Room, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Yingping Deng
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Lixiang Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
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Vanathi M. Tissue addition keratoplasty in keratoconus: Trends and concerns. Indian J Ophthalmol 2024; 72:1-2. [PMID: 38131560 PMCID: PMC10841780 DOI: 10.4103/ijo.ijo_3157_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Affiliation(s)
- M Vanathi
- Cornea & Ocular Surface, Cataract & Refractive Services, Dr. R P Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. E-mail:
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Moshirfar M, Stoakes IM, Bruce EG, Ali A, Payne CJ, Furhiman D, Ronquillo YC, Hoopes PC. Allogenic Lenticular Implantation for Correction of Refractive Error and Ectasia: Narrative Review. Ophthalmol Ther 2023; 12:2361-2379. [PMID: 37516716 PMCID: PMC10442033 DOI: 10.1007/s40123-023-00765-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 06/26/2023] [Indexed: 07/31/2023] Open
Abstract
INTRODUCTION Intrastromal lenticule implantation is a promising treatment option for corneal pathologies, from refractive error to ectasia. In this narrative review, we intend to feature up-to-date literature supporting the use of lenticular tissue, a compelling method that can be customized for a variety of applications, providing an additional source of donor tissue for treating corneal diseases. METHODS We searched databases PubMed, Mendeley, and Scopus last accessed 10 May 2023, for literature on stromal lenticules and narrowed based on relevance. Review articles, animal studies, ex vivo studies, and book chapters were excluded, while assessable and relevant articles published in English were included. RESULTS Storage methods from using fresh lenticules to dehydration have proven successful, with cryopreservation maintaining structure and cellular viability for up to 10 years. Successful use of lenticules for treatment of numerous pathologies including corneal ectasias, hyperopia, and presbyopia with additional insight into the treatment of corneal ulcers and perforations are highlighted in this narrative review. CONCLUSION Lenticular implantation is an innovative and advantageous treatment for various ocular pathologies, offering increased bioavailability, flexibility, and customization for patients. They can treat previously untreatable diseases and serve as a replacement for synthetic implants, with promising outcomes worldwide. Lenticular implantation has the potential to become a leading approach in ophthalmologic surgery. Further studies should aim to provide evidentiary support for a standardization of lenticule banking.
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Affiliation(s)
- Majid Moshirfar
- HDR Research Center, Hoopes Vision, Draper, UT, USA.
- John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA.
- Utah Lions Eye Bank, Murray, UT, USA.
| | - Isabella M Stoakes
- HDR Research Center, Hoopes Vision, Draper, UT, USA
- Pacific Northwest University of Health Sciences, Yakima, WA, USA
| | | | - Amir Ali
- University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Carter J Payne
- HDR Research Center, Hoopes Vision, Draper, UT, USA
- Case Western Reserve School of Medicine, Cleveland, OH, USA
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Deshmukh R, Shrivastava AK, Vaddavalli PK. Prevailing practice patterns in keratoconus among Indian ophthalmologists. Indian J Ophthalmol 2023; 71:3229-3234. [PMID: 37602613 PMCID: PMC10565949 DOI: 10.4103/ijo.ijo_595_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/19/2023] [Accepted: 06/30/2023] [Indexed: 08/22/2023] Open
Abstract
Objective The past few years have seen a rapid advancement in the management of keratoconus (KC). However, there is no prescribed standard of care for the management of KC. This study evaluated the prevailing practice patterns among Indian ophthalmologists in the diagnosis and treatment of KC via an online survey. Methods This was a survey-based cross-sectional study in which a questionnaire (Supplement 1) was created. Questions pertaining to the practicing experience, setting of practice, and training background were asked in addition to the investigations done and decision making in KC management. Responses were collected via Survey Monkey (Survey Monkey, Palo Alto, California, USA) and statistical analysis performed using R software (4.1.3). Results The survey was answered by 273 ophthalmologists. Pentacam was the most used topographer (195 users), followed by Orbscan (41 users), Sirius (34 users), and Galilei (3 users). The lowest limit of pachymetry for performing collagen crosslinking (CXL) was 400μ for most practitioners. More than half the respondents (50.55%) did not perform photorefractive keratectomy (PRK) or intracorneal ring segment (ICRS) implantation in a suitable patient. Accelerated 10-minute protocol (9 mW/cm2 for 10 minutes) was the most commonly (54.21%) used for CXL, followed by Dresden protocol (3 mW/cm2 for 30 minutes) (36.63%). When a patient was unsuitable for CXL, 55.31% surgeons advise contact lens (CL) trial, 35.16% surgeons advise keratoplasty, 26.74% surgeons perform stromal augmentation, and 7.69% surgeons advise spectacle correction. Corneal scar was the most common indication (49.45%) for performing keratoplasty. Conclusion Topography remains the most used diagnostic modality for initial diagnosis. Optical coherence tomography and epithelial mapping are increasingly being used for early diagnosis of KC. Not all ophthalmologists were comfortable performing ICRS or PRK. When patients are unsuitable for CXL, CL trial remains the most frequently advised option followed by keratoplasty.
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Affiliation(s)
- Rashmi Deshmukh
- Cataract and Refractive Services, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Alok Kumar Shrivastava
- Cataract and Refractive Services, LV Prasad Eye Institute, Hyderabad, Telangana, India
- Sri Innovation and Research Foundation, Ghaziabad, Uttar Pradesh, India
| | - Pravin Krishna Vaddavalli
- Cataract and Refractive Services, LV Prasad Eye Institute, Hyderabad, Telangana, India
- Shantilal Sanghvi Eye Institute, Hyderabad, Telangana, India
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Deshmukh R, Ong ZZ, Rampat R, Alió del Barrio JL, Barua A, Ang M, Mehta JS, Said DG, Dua HS, Ambrósio R, Ting DSJ. Management of keratoconus: an updated review. Front Med (Lausanne) 2023; 10:1212314. [PMID: 37409272 PMCID: PMC10318194 DOI: 10.3389/fmed.2023.1212314] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023] Open
Abstract
Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman's layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.
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Affiliation(s)
- Rashmi Deshmukh
- Department of Cornea and Refractive Surgery, LV Prasad Eye Institute, Hyderabad, India
| | - Zun Zheng Ong
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Radhika Rampat
- Department of Ophthalmology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Jorge L. Alió del Barrio
- Cornea, Cataract and Refractive Surgery Unit, Vissum (Miranza Group), Alicante, Spain
- Division of Ophthalmology, School of Medicine, Universidad Miguel Hernández, Alicante, Spain
| | - Ankur Barua
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Jodhbir S. Mehta
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Dalia G. Said
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Harminder S. Dua
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Renato Ambrósio
- Department of Cornea and Refractive Surgery, Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Darren Shu Jeng Ting
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Femtosecond laser-assisted stromal keratophakia for keratoconus: A systemic review and meta-analysis. Int Ophthalmol 2021; 41:1965-1979. [PMID: 33609200 DOI: 10.1007/s10792-021-01745-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/06/2021] [Indexed: 10/22/2022]
Abstract
PURPOSE Femtosecond lasers have revived the possibility of stromal keratophakia or tissue additive keratoplasty, a technique originally introduced by Prof. Jose Ignacio Barraquer in the 1960s. The surgical technique offers a unique solution to treat keratoconus. In the current study, we reviewed and performed a meta-analysis of the clinical outcomes of the femtosecond laser-assisted stromal keratophakia in the treatment of keratoconus. METHODS This is a systematic review and meta-analysis of the estimated outcome difference between pre- and post-lenticule implantations. RESULTS A total of related 10 studies were found in the literature. No studies reported adverse events, such as persistent haze or graft rejection, at last patients' visits. We further narrowed down the article selection in accordance to our inclusion criteria to report the composite outcomes (9 studies) and meta-analysis (4 studies). In the composite analysis, we demonstrated that lenticule implantation in keratoconus and post-LASIK ectasia patients appeared to expand the stromal volume of the thin corneas, flattened the cones, and significantly improved uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA) and spherical equivalent (SE). The meta-analysis showed that the random estimated UCVA, BCVA, SE and mean keratometry (Km) differences following the lenticule implantation was -0.214 (95% CI: -0.367 to 0.060; p = 0.006), -0.169 (-0.246 to 0.091; p < 0.001), -2.294 D (-3.750 to -0.839 D; p = 0.002), and 2.909 D (0.805 to 5.012 D; p = 0.007), respectively. CONCLUSIONS Femtosecond laser-assisted stromal keratophakia is a feasible technique to correct the refractive aberrations, expand corneal volume and regularize corneal curvature in patients with keratoconus. However, there is a need to standardize the technique (e.g., whether to crosslink or not or to use convex or concave lenticules) and to formulate a mathematical model that accounts for the long-term epithelial thickness changes and stromal remodeling to determine the shape or profile of the lenticules, in order to improve the efficacy of the keratophakia further.
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Intrastromal implantation of chicken corneal grafts into the cornea of rabbits for corneal thickening: an experimental study. Int Ophthalmol 2020; 41:243-255. [PMID: 32845463 DOI: 10.1007/s10792-020-01573-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the feasibility and effects of the intrastromal implantation of chemically modified corneal stroma obtained from chicken into the corneas of rabbits for corneal thickening. METHODS Chicken corneas were cut, debrided, treated with cross-linking and implanted in an intrastromal pouch created in the cornea of 10 white New Zealand rabbits with femtosecond laser. Slit-lamp biomicroscopy and optical coherence tomography were performed immediately, 7, 30 and 90 days postoperatively. Corneas were removed at 90 days and cut in two halves. One half was sent to histological analysis for the presence of necrosis, polymorphonuclear inflammatory cells, blood vessels and fibrosis, while the other half was evaluated with transmission electron microscopy to verify tissue organization and the presence of keratocytes and inflammatory cells. Corneal thicknesses were comparatively analyzed over time with Wilcoxon test (p ≤ 0.05). RESULTS The chicken grafts were incorporated into the cornea of all animals over time. Mean rabbit cornea thickness increased from 338 µm preoperatively to 538 µm (p < 0.0077) at 90 days, while mean chicken graft thickness decreased from 350 to 215 µm (p < 0.0077). No clear signs of rejection attributable to the xenograft were observed in any of the implanted eyes. However, some macroscopic and histological events were observed in some of the eyes, probably due to procedural issues during implantation. CONCLUSION The intrastromal implantation of chicken grafts was shown to be feasible and predictable to thicken the recipient rabbit cornea without apparent rejection. However, before being considered in humans, further meticulous clinical trials are required to establish the clinical utility, safety and efficacy of xenografts for the treatment of patients with advanced keratoconus.
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Recent developments in regenerative ophthalmology. SCIENCE CHINA-LIFE SCIENCES 2020; 63:1450-1490. [PMID: 32621058 DOI: 10.1007/s11427-019-1684-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/21/2020] [Indexed: 12/13/2022]
Abstract
Regenerative medicine (RM) is one of the most promising disciplines for advancements in modern medicine, and regenerative ophthalmology (RO) is one of the most active fields of regenerative medicine. This review aims to provide an overview of regenerative ophthalmology, including the range of tools and materials being used, and to describe its application in ophthalmologic subspecialties, with the exception of surgical implantation of artificial tissues or organs (e.g., contact lens, artificial cornea, intraocular lens, artificial retina, and bionic eyes) due to space limitations. In addition, current challenges and limitations of regenerative ophthalmology are discussed and future directions are highlighted.
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Riau AK, Liu YC, Yam GH, Mehta JS. Stromal keratophakia: Corneal inlay implantation. Prog Retin Eye Res 2020; 75:100780. [DOI: 10.1016/j.preteyeres.2019.100780] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/28/2019] [Accepted: 09/02/2019] [Indexed: 12/31/2022]
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Human allograft refractive lenticular implantation for high hyperopiccorrection. J Cataract Refract Surg 2020; 46:305-311. [DOI: 10.1097/j.jcrs.0000000000000011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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