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Riaz KM, Gill MS, Murphy DA, Ding K, Khaimi MA. Surgical Management of Intraocular Pressure With Ab Interno Canaloplasty in Postkeratoplasty Patients: 12-Month Results. Cornea 2023; 42:52-59. [PMID: 35249980 DOI: 10.1097/ico.0000000000003009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/12/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this study was to report clinical outcomes of ab interno canaloplasty (ABiC) with the iTrack microcatheter (Nova Eye Medical, Fremont, CA) for surgical management of intraocular pressure (IOP) in postkeratoplasty patients. METHODS This study was a single-center retrospective case series of postkeratoplasty eyes undergoing ABiC. Efficacy was evaluated based on graft survivability and mean reduction in IOP at 12 months postoperatively. Secondary end points consisted of visual acuity outcomes, number of topical hypotensive medications, and rate of complications. RESULTS ABiC was successfully performed in 17 eyes after keratoplasty (8 penetrating keratoplasty, 6 DSAEK, 2 penetrating keratoplasty + DSAEK, and 1 DMEK) with elevated IOP refractory to topical hypotensive medications. The baseline mean IOP was 26.2 ± 8.4 mm Hg and reduced significantly to 15.0 ± 4.21 mm Hg at 6 months and 13.0 ± 2.99 mm Hg at 12 months ( P < 0.005). The best-corrected visual acuity improved from 0.61 ± 0.55 logMAR at baseline to 0.47 ± 0.59 and 0.49 ± 0.64 at 6 and 12 months, respectively, following ABiC (not statistically significant: P = 0.6769). The baseline mean number of topical hypotensive medications was 3.7 ± 1.8 and reduced to 2.7 ± 1.4 and 2.9 ± 1.3 at 6 and 12 months, respectively ( P = 0.096). One patient developed a hyphema which required anterior chamber washout. One patient required additional glaucoma surgery 19 months after ABiC. No patients experienced graft failure. CONCLUSIONS ABiC is a clinically safe and effective treatment that can be performed in postkeratoplasty patients to reduce IOP for at least 1 year without any significant complications.
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Affiliation(s)
- Kamran M Riaz
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK; and
| | - Mohsain S Gill
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK; and
| | - David A Murphy
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK; and
| | - Kai Ding
- Hudson College of Public Health, University of Oklahoma, Oklahoma City, OK
| | - Mahmoud A Khaimi
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK; and
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Gupta PK, Berdahl JP, Chan CC, Rocha KM, Yeu E, Ayres B, Farid M, Lee WB, Beckman KA, Kim T, Holland EJ, Mah FS. The corneal endothelium: clinical review of endothelial cell health and function. J Cataract Refract Surg 2021; 47:1218-1226. [PMID: 34468459 DOI: 10.1097/j.jcrs.0000000000000650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/19/2021] [Indexed: 12/17/2022]
Abstract
The endothelial cell is a critical structure within the cornea and is responsible for maintaining corneal clarity through its pump function. Endothelial cells are lost over time naturally but can be injured medically, surgically, or as a part of various dystrophies. Monitoring of endothelial cells can be performed clinically or more formally with specular microscopy. In cases of significant compromise, endothelial cells can be transplanted by various endothelial keratoplasty techniques. The future pipeline is bright for possible endothelial cell regeneration and rehabilitation. This article reviews these topics in depth to provide a comprehensive look at the structure and function of the endothelial cell, etiologies of endothelial cell damage, detailed review of iatrogenic causes of endothelial cell loss, and management strategies.
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Affiliation(s)
- Preeya K Gupta
- From the Department of Ophthalmology, Duke Eye Center, Durham, North Carolina (Gupta, Kim); Vance Thompson Vision, Sioux Falls, South Dakota (Berdahl); Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada (Chan); Medical University of South Carolina, Storm Eye Institute, Charleston, South Carolina (Rocha); Virginia Eye Consultants, Norfolk, Virginia (Yeu); Cornea Service, Wills Eye Hospital, Philadelphia, Pennsylvania (Ayres); Gavin Herbert Eye Institute, University of California-Irvine, Irvine, California (Farid); Eye Consultants of Atlanta and Georgia Eye Bank, Atlanta, Georgia (Lee); Comprehensive EyeCare of Central Ohio, Westerville, Ohio (Beckman); Department of Ophthalmology, The Ohio State University, Columbus, Ohio (Beckman); Cincinnati Eye Institute and the University of Cincinnati, Cincinnati, Ohio (Holland); Scripps Clinic Medical Group, La Jolla, California (Mah)
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Shetty R, Kumar NR, Subramani M, Krishna L, Murugeswari P, Matalia H, Khamar P, Dadachanji ZV, Mohan RR, Ghosh A, Das D. Safety and efficacy of combination of suberoylamilide hydroxyamic acid and mitomycin C in reducing pro-fibrotic changes in human corneal epithelial cells. Sci Rep 2021; 11:4392. [PMID: 33623133 PMCID: PMC7902619 DOI: 10.1038/s41598-021-83881-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 02/01/2021] [Indexed: 12/14/2022] Open
Abstract
Corneal haze post refractive surgery is prevented by mitomycin c (MMC) treatment though it can lead to corneal endothelial damage, persistent epithelial defects and necrosis of cells. Suberanilohydroxamic acid (SAHA) however has been proposed to prevent corneal haze without any adverse effects. For clinical application we have investigated the short and long term outcome of cells exposed to SAHA. Human donor cornea, cultured limbal epithelial cells, corneal rims and lenticules were incubated with SAHA and MMC. The cells/tissue was then analyzed by RT-qPCR, immunofluorescence and western blot for markers of apoptosis and fibrosis. The results reveal that short term exposure of SAHA and SAHA + MMC reduced apoptosis levels and increased αSMA expression compared to those treated with MMC. Epithelial cells derived from cultured corneal rim that were incubated with the MMC, SAHA or MMC + SAHA revealed enhanced apoptosis, reduced levels of CK3/CK12, ∆NP63 and COL4A compared to other treatments. In SAHA treated lenticules TGFβ induced fibrosis was reduced. The results imply that MMC treatment for corneal haze has both short term and long term adverse effects on cells and the cellular properties. However, a combinatorial treatment of SAHA + MMC prevents expression of corneal fibrotic markers without causing any adverse effect on cellular properties.
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Affiliation(s)
- Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Nimisha Rajiv Kumar
- GROW Laboratory, Narayana Nethralaya Post Graduate Institute of Ophthalmology, Narayana Nethralaya Foundation, Narayana Nethralaya, Narayana Health City, Bommasandra, , Bangalore, Karnataka, 560 099, India
| | - Murali Subramani
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Lekshmi Krishna
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Ponnalagu Murugeswari
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Himanshu Matalia
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Pooja Khamar
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Zelda V Dadachanji
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Rajiv R Mohan
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, 65211, USA. .,Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA. .,Harry S Truman Veterans' Memorial Hospital, Columbia, MO, 65201, USA.
| | - Arkasubhra Ghosh
- GROW Laboratory, Narayana Nethralaya Post Graduate Institute of Ophthalmology, Narayana Nethralaya Foundation, Narayana Nethralaya, Narayana Health City, Bommasandra, , Bangalore, Karnataka, 560 099, India.
| | - Debashish Das
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India.
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Ang BCH, Yap SC, Toh ZH, Lim EWL, Tan MMH, Nah GKM, Zhao PSB, Tan MCL. Refractive outcomes, corneal haze and endothelial cell loss after myopic photorefractive keratectomy in an Asian population: The Singapore Armed Forces' experience. Clin Exp Ophthalmol 2020; 48:558-568. [DOI: 10.1111/ceo.13759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/17/2020] [Accepted: 04/04/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Bryan Chin Hou Ang
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- National Healthcare Group Eye Institute Tan Tock Seng Hospital Singapore Singapore
| | - Sae Cheong Yap
- Department of Family Medicine National University Health System Singapore Singapore
| | - Zhi Hong Toh
- National Healthcare Group Eye Institute Tan Tock Seng Hospital Singapore Singapore
| | - Edmund Wei Long Lim
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
| | - Mellisa Mei Hui Tan
- DSO National Laboratories Defence Medical and Environmental Research Institute Singapore Singapore
| | - Gerard Kwang Ming Nah
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- W Eye Clinic Singapore Singapore
| | - Paul Song Bo Zhao
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- Department of Ophthalmology National University Health System Singapore Singapore
| | - Marcus Chiang Lee Tan
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- Department of Ophthalmology Jurong Health Services Singapore Singapore
- Raffles Hospital Raffles Medical Group Singapore Singapore
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Endothelial cell changes after photorefractive keratectomy with graded usage of mitomycin C. Int Ophthalmol 2017; 38:1211-1217. [PMID: 28612330 DOI: 10.1007/s10792-017-0584-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 06/05/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To compare differences in the endothelial cells before and after photorefractive keratectomy (PRK) for myopia with refractive error graded mitomycin C (MMC) application. METHODS In a prospective randomized clinical trial, forty-eight myopic patients referred to Khatam-al-Anbia Eye Hospital, Mashhad, Iran, for PRK. Patients were treated with PRK by a Bausch and Lomb Technolas 217z excimer laser (Bausch and Lomb, Rochester, NY). MMC was applied after PRK 5 s for each diopter of spherical equivalent myopic refractive error corrected. The manifest refraction, visual acuity, MMC treatment length, corneal pachymetry and specular microscopy were evaluated preoperatively and at 1 and 6 months postoperatively. RESULTS A total of 48 cases (96 eyes, 68.75% female) were treated, with a mean age of 26.70 ± 4.89 years (range, 18-34 years). Postoperative cell density, cell size and polymegathism did not significantly change. On the other hand, standard deviation (SD) of cell size (P = 0.008), pleomorphism (P = 0.003) and coefficient of variation (CV) (P = 0.016) were significantly increased. None of these parameters was related to the length of MMC application. Corneal thickness decreased significantly after the operation but it increased 6 months postoperatively compared with the first month (P < 0.001). CONCLUSION MMC application for PRK in myopia can affect the endothelial cells, but in early follow-ups, it does not affect the cell density or size. Cell size was changed but it was obvious not in mean cell size, but in SD and CV. MMC time below the 30 s was not significant on endothelial cell changes.
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A Review of Mitomycin Use in Ophthalmic Surgery: Clarification of Safety Standards for Patients and Hospital Personnel. CURRENT OPHTHALMOLOGY REPORTS 2016. [DOI: 10.1007/s40135-016-0111-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Fu GL, Alexander JL, Saeedi OJ. Persistent Corneal Edema Associated With Subconjunctival 5-fluorouracil in an Infant With Primary Congenital Glaucoma. J Pediatr Ophthalmol Strabismus 2016; 53:e54-e57. [PMID: 27783089 PMCID: PMC5291828 DOI: 10.3928/01913913-20161003-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 06/17/2016] [Indexed: 11/20/2022]
Abstract
A 3-month-old boy with primary congenital glaucoma developed a transient corneal endothelial opacity after needle bleb revision with adjunctive 5-fluorouracil. This case presents a rare toxicity that, although transient, is concerning due to the potential of amblyopia. The authors review prior cases of corneal opacity associated with 5-fluorouracil. [J Pediatr Ophthalmol Strabismus. 2016;53:e54-e57.].
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Affiliation(s)
- Gregory L Fu
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Janet L Alexander
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland
| | - Osamah J Saeedi
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland
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Tomás-Juan J, Murueta-Goyena Larrañaga A, Hanneken L. Corneal Regeneration After Photorefractive Keratectomy: A Review. JOURNAL OF OPTOMETRY 2015; 8:149-69. [PMID: 25444646 PMCID: PMC4502084 DOI: 10.1016/j.optom.2014.09.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 08/01/2014] [Indexed: 05/20/2023]
Abstract
Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.
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Affiliation(s)
- Javier Tomás-Juan
- Department of Visual Science, VallmedicVision International Eye Clinic, Andorra.
| | | | - Ludger Hanneken
- Department of Visual Science, VallmedicVision International Eye Clinic, Andorra
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Abstract
Background Our aim was to describe the demographics, risk factors, clinical signs, severity, and outcome of ocular surface disease (OSD) in 12 patients who had undergone trabeculectomy augmented with mitomycin C (MMC). Methods Twelve glaucoma patients were referred to the Dry Eye Clinic (Singapore National Eye Centre) for further management of clinically significant OSD. Results Of the 15 eyes from 12 patients, 14 were treated with MMC and one with 5-fluorouracil. Mean age was 69.3±10.6 years and two-thirds were male. The median interval before onset of dry eye symptoms after surgery was 13.5 months. Mean tear breakup time (TBUT) was 5.32 seconds and mean Schirmer score was 6.14 mm/5 min. Possible major risk factors for OSD in the cases include limbal stem cell deficiency occurring from exposure to antimetabolites, chronic use of antiglaucoma medications prior to surgery, and the preoperative status of the ocular surface prior to disease onset. Treatment of OSD resulted in improved best corrected visual acuity (BCVA) in 50% of the patients, with a median gain of two-line improvement in BCVA. Conclusion OSD is a clinical problem often overlooked in patients who undergo antimetabolite-augmented filtration surgery. Recognition of the condition and appropriate treatment can improve patient symptoms and reduce health-care burdens on the economy.
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Affiliation(s)
- Janice Lam
- Singapore National Eye Centre, Singapore ; Singapore Eye Research Institute, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, Singapore ; Singapore Eye Research Institute, Singapore ; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore ; School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Louis Tong
- Singapore National Eye Centre, Singapore ; Singapore Eye Research Institute, Singapore ; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore ; Office of Clinical Sciences, Duke-National University of Singapore Graduate Medical School, Singapore
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Moshirfar M, Fenzl CR. December consultation #2. J Cataract Refract Surg 2014. [DOI: 10.1016/j.jcrs.2014.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Figuerola AA, Graue-Hernández EO. December consultation #4. J Cataract Refract Surg 2014. [DOI: 10.1016/j.jcrs.2014.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Gibson DJ, Pi L, Sriram S, Mao C, Petersen BE, Scott EW, Leask A, Schultz GS. Conditional knockout of CTGF affects corneal wound healing. Invest Ophthalmol Vis Sci 2014; 55:2062-70. [PMID: 24627144 DOI: 10.1167/iovs.13-12735] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study aimed to elucidate the role of connective tissue growth factor (CTGF) in healthy eyes and wounded corneas of mice and rabbits. Conditional knockout mice were used to determine the role of CTGF in corneal healing. METHODS CTGF expression was determined using transgenic mice carrying CTGF promoter driven-eGFP, quantitative RT-PCR, and immunofluorescent staining. Mice that carried two floxed CTGF alleles and a Cre/ERT2 transgene under the control of human ubiquitin C (ubc) promoter were used to conditionally delete CTGF gene in a tamoxifen-inducible manner. Phototherapeutic keratectomy (PTK) was used to generate an acute corneal wound and corneal re-epithelialization was assessed by fluorescein staining. RESULTS Connective tissue growth factor expression was found in multiple ocular tissues with relatively high levels in the corneal endothelium, lens subcapsular epithelium, and in the vasculature of the iris and retina. Wounded corneas responded with an immediate upregulation of CTGF in the epithelium at the wound margin and a sustained CTGF induction during re-epithelialization. At the onset of haze formation, CTGF protein becomes more focused in the basal epithelium. Deletion of the CTGF gene caused a 40% reduction (P < 0.01) in the cornea re-epithelialization rate in knockout mice compared with wild-type mice. CONCLUSIONS Connective tissue growth factor is expressed in the naïve cornea, lens, iris, and retina, and is expressed immediately after epithelial injury. Loss of CTGF impairs efficient re-epithelialization of corneal wounds.
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Affiliation(s)
- Daniel J Gibson
- Institute for Wound Research, University of Florida, Gainesville, Florida, United States
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Gibson DJ, Tuli SS, Schultz GS. The progression of haze formation in rabbit corneas following phototherapeutic keratectomy. Invest Ophthalmol Vis Sci 2013; 54:4776-81. [PMID: 23800768 DOI: 10.1167/iovs.13-11976] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the topographical location and time course of development of corneal haze in a phototherapeutic keratectomy model using slit lamp examination, macrophotography, quantitative image analysis, and immunofluorescence staining of corneal sections. METHODS Rabbit corneas were ablated with an excimer laser and were observed and graded for haze via slit lamp, imaged, and graded by macrophotography. Corneal sections were stained for α-smooth muscle actin (α-SMA) and tenascin-C (TNC). The distribution of haze imaged in the macrophotographs and density of α-SMA and TNC staining were compared. A daily image time course of haze formation was generated using macrophotography. RESULTS The first signs of corneal haze were apparent shortly after reepithelialization. The haze was distributed as a ring at the wound margin in all cases, while nearly all corneas also had some central islands of haze initiation. With time, the haze spread within the ablated zone and intensified. The pattern of immunofluorescent staining for α-SMA and TNC at the wound margin mirrored the haze distribution, spread, and intensification with time. CONCLUSIONS The initiation and spread of subepithelial haze begins shortly after reepithelialization. The haze then spreads from the loci of initiation and becomes more dense with time, maturing as early as 14 days after wounding. The improved temporal and spatial resolution provided by these data improve the current model of light-scattering haze formation in wounded corneas, which will improve the design of studies aimed at maintaining corneal clarity following acute injury or surgery.
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Affiliation(s)
- Daniel J Gibson
- Institute of Wound Research, University of Florida, Gainesville, Florida 32610-0294, USA.
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O'Brart DPS. Excimer laser surface ablation: a review of recent literature. Clin Exp Optom 2013; 97:12-7. [PMID: 23656608 DOI: 10.1111/cxo.12061] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 12/25/2012] [Accepted: 01/08/2013] [Indexed: 11/27/2022] Open
Abstract
The aim was to review the recently published literature on excimer laser surface ablation procedures, including photorefractive keratectomy (PRK), laser sub-epithelial keratomileusis (LASEK), microkeratome-assisted PRK (epi-LASIK) and trans-epithelial (laser-assisted) PRK, to help elucidate where and how surface ablation may best fit into current refractive surgical practice. The emphasis was on publications within the last three years and included systemic reviews, meta-analyses and randomised controlled trials. Where such evidence did not exist, selective large series cohort studies, case-controlled studies and case series with follow-up preferably greater than six months were examined and included. Refractive and visual outcomes are excellent and comparable to those after LASIK even in complex cases after previous corneal surgery. Indeed, surface ablation combined with corneal collagen cross-linking may be used in selected eyes with biomechanical instability, where LASIK is contraindicated. In addition, there is evidence to suggest that there may be less induction of higher order aberrations with surface techniques. Long-term stability and safety appear to be extremely satisfactory. The literature supports the use of modern excimer laser surface treatments, with outcomes comparable to those after LASIK and evidence of less induction of higher-order aberrations. Follow-up studies at 10 to 20 years indicate excellent stability and safety.
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Affiliation(s)
- David P S O'Brart
- Keratoconus Research Institute, Department of Ophthalmology, St. Thomas Hospital, London, United Kingdom.
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15
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Meta-analysis of Randomized Controlled Trials Comparing Excimer Laser and Phakic Intraocular Lenses for Myopia Between 6.0 and 20.0 Diopters. Cornea 2012; 31:454-61. [DOI: 10.1097/ico.0b013e31823f0b29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
PURPOSE To provide an overview of the safety and efficacy of mitomycin C (MMC) as adjuvant therapy after refractive surgery procedures. METHODS Literature review. RESULTS Over the past 10 years, MMC has been used by refractive surgeons to prophylactically decrease haze after surface ablation procedures and therapeutically in the treatment of preexisting haze. Development of MMC treatments has had a significant role in the revival of surface ablation techniques. We reviewed the literature regarding mechanism of action of MMC, its role in modulating wound healing after refractive surgery, and its safety and efficacy as adjuvant therapy applied after primary photorefractive keratectomy surgery or after photorefractive keratectomy re-treatment after laser in situ keratomileusis and other corneal surgeries and disorders. The drug is a potent mitotic inhibitor that effectively blocks keratocyte activation, proliferation, and myofibroblast differentiation. Many studies have suggested that MMC is safe and effective in doses used by anterior surface surgeons, although there continue to be concerns regarding long-term safety. After initial depletion of anterior keratocytes, keratocyte density seems to return to normal 6 to 12 months after the use of MMC when corneas are examined with the confocal microscope. Most clinical studies found no difference between preoperative and postoperative corneal endothelial cell densities when MMC 0.02% was applied during refractive surgery, with exposure time of 2 minutes or less. CONCLUSIONS After more than 10 years of use, MMC has been found to be effective when used for prevention and treatment of corneal haze. Questions remain regarding optimal treatment parameters and long-term safety.
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Tandon A, Tovey JCK, Waggoner MR, Sharma A, Cowden JW, Gibson DJ, Liu Y, Schultz GS, Mohan RR. Vorinostat: a potent agent to prevent and treat laser-induced corneal haze. J Refract Surg 2012; 28:285-90. [PMID: 22386369 DOI: 10.3928/1081597x-20120210-01] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 01/03/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE This study investigated the efficacy and safety of vorinostat, a deacetylase (HDAC) inhibitor, in the treatment of laser-induced corneal haze following photorefractive keratectomy (PRK) in rabbits in vivo and transforming growth factor beta 1 (TGFβ1) -induced corneal fibrosis in vitro. METHODS Corneal haze in rabbits was produced with -9.00 diopters (D) PRK. Fibrosis in cultured human and rabbit corneal fibroblasts was activated with TGFβ1. Vorinostat (25 μm) was topically applied once for 5 minutes on rabbit cornea immediately after PRK for in vivo studies. Vorinostat (0 to 25 μm) was given to human/rabbit corneal fibroblasts for 5 minutes or 48 hours for in vitro studies. Slit-lamp microscopy, TUNEL assay, and trypan blue were used to determined vorinostat toxicity, whereas real-time polymerase chain reaction, immunocytochemistry, and immunoblotting were used to measure its efficacy. RESULTS Single 5-minute vorinostat (25 μm) topical application on the cornea following PRK significantly reduced corneal haze (P<.008) and fibrotic marker proteins (α-smooth muscle actin and f-actin; P<.001) without showing redness, swelling, or inflammation in rabbit eyes in vivo screened 4 weeks after PRK. Vorinostat reduced TGFβ1-induced fibrosis in human and rabbit corneas in vitro in a dose-dependent manner without altering cellular viability, phenotype, or proliferation. CONCLUSIONS Vorinostat is non-cytotoxic and safe for the eye and has potential to prevent laser-induced corneal haze in patients undergoing PRK for high myopia.
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Affiliation(s)
- Ashish Tandon
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri 65212, USA
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Fazel F, Roshani L, Rezaei L. Two-step versus Single Application of Mitomycin-C in Photorefractive Keratectomy for High Myopia. J Ophthalmic Vis Res 2012; 7:17-23. [PMID: 22737382 PMCID: PMC3381101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 09/04/2011] [Indexed: 10/30/2022] Open
Abstract
PURPOSE To evaluate the long-term outcomes of two-step versus single application of mitomycin-C (MMC) during photorefractive keratectomy (PRK) for high myopia. METHODS This randomized clinical trial included consecutive patients with high myopia (exceeding 7 D). Patients underwent PRK and were randomized to two methods of MMC 0.02% application as follows: in the single application group, MMC was applied for 45 seconds followed by irrigation; in the two-step group MMC was used identically followed by repeat application for another 15 seconds and corneal surface irrigation. Visual acuity, refractive error, pachymetry, topography, corneal haze and complications were compared between the two groups 18 months after surgery. RESULTS One hundred and forty patients (70 subjects in either study arm) underwent PRK according to the study protocol. Mean spherical equivalent refractive error was significantly reduced from baseline to -1.16±0.39 D in the single application group and to -1.07±0.39 D in the two-step group. Sixteen (11.5%) versus 8 (5.7%) eyes lost one or more line(s) of best corrected visual acuity in the single application group as compared to the two-step group (P=0.05). Corneal haze was observed in 18 (12.9%) and 8 (5.7%) eyes in the single application versus two-step group, respectively (P=0.04). Grade 3 corneal haze was not observed in the two-step group but occurred in five eyes (3.6%) in the single application group (P=0.03). No eyes developed corneal ectasia during the follow-up period. CONCLUSION Two-step intraoperative application of MMC 0.02% in highly myopic eyes undergoing PRK can reduce the frequency and severity of haze formation.
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Affiliation(s)
| | | | - Leila Rezaei
- Correspondence to: Leila Rezaei, MD. Ophthalmologist, Eye Research Center, Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Tel: +98 831 727 8759; e-mail:
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Woodward MA, Edelhauser HF. Corneal endothelium after refractive surgery. J Cataract Refract Surg 2011; 37:767-77. [PMID: 21420604 DOI: 10.1016/j.jcrs.2011.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/28/2010] [Accepted: 10/29/2010] [Indexed: 11/25/2022]
Abstract
UNLABELLED The endothelium is vital to the health and optical clarity of the human cornea. The safety of procedures to correct refractive errors depends on preservation of an intact corneal endothelium. Disease states and genetic and environmental factors affect the corneal endothelium; an unstable corneal endothelium can impact the success of refractive surgery. Technological advances and recent laboratory findings have improved the ability to assess the endothelium. The status of the corneal endothelium after laser in situ keratomileusis, photorefractive keratectomy, phakic intraocular lenses, and adjuvants to these treatments has been the topic of numerous clinical trials. Safety guidelines for refractive surgery procedures should be followed to minimize deleterious effects on the corneal endothelium. FINANCIAL DISCLOSURE Neither author has a financial or proprietary interest in any material or method mentioned.
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Current world literature. Refractive surgery. Corneal and external disorders. Curr Opin Ophthalmol 2010; 21:322-6. [PMID: 20548165 DOI: 10.1097/icu.0b013e32833bb58c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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