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Kapelushnik N, Werner L, Levinger N, Levinger S, Barequet IS. Ex Vivo Histological Analysis of Corneas with Manually Implanted Intracorneal Stromal Ring Segments. J Clin Med 2024; 13:3350. [PMID: 38893062 PMCID: PMC11172415 DOI: 10.3390/jcm13113350] [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: 01/30/2024] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/21/2024] Open
Abstract
Backgrond: Intracorneal ring segments (ICRSs) are utilized to correct refractive changes impacting visual acuity, commonly implanted via femtosecond laser but can also inserted manually. Corneal deposits alongside the ICRS channels are seen commonly. Methods: This study explores the histological characteristics of corneal deposits following manual ICRS implantation, comparing them to previously published articles describing femtosecond laser-assisted cases. Results: This is a retrospective analysis of three cases involving manual ICRS implantation, accumulation of whitish deposits and later explanation of the corneas due to penetrating keratoplasty (PKP). Patient demographics, ocular history, and surgical details were collected. Histological analysis employed Hematoxylin and Eosin (H&E) and Masson's trichrome staining. Whitish deposits along ICRS tracts were observed in all cases, with minimal fibroblastic transformation of keratocytes adjacent to the segments. Comparing these cases of manual to femtosecond laser-assisted ICRS implantation, in most cases, similar deposits were identified, indicating the deposits' association with the stromal tissue reaction to the ring segment and not to the surgical technique. Conclusions: This study contributes insights into the histopathology of manually implanted ICRS, emphasizing the shared nature of deposits in both insertion methods. The findings highlight the link between deposits and the stromal tissue reaction to the ring segment, irrespective of the insertion technique.
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Affiliation(s)
- Noa Kapelushnik
- Goldschleger Eye Institute, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo 6997801, Israel;
| | - Liliana Werner
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT 84112, USA
| | - Nadav Levinger
- Enaim Refractive Surgery Center, Jerusalem 9438307, Israel (S.L.)
| | - Samuel Levinger
- Enaim Refractive Surgery Center, Jerusalem 9438307, Israel (S.L.)
| | - Irina S. Barequet
- Goldschleger Eye Institute, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo 6997801, Israel;
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Goñi N, Martínez-Soroa I, Ibarrondo O, Azkargorta M, Elortza F, Galarreta DJ, Acera A. Tear proteome profile in eyes with keratoconus after intracorneal ring segment implantation or corneal crosslinking. Front Med (Lausanne) 2022; 9:944504. [PMID: 36203781 PMCID: PMC9531826 DOI: 10.3389/fmed.2022.944504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeKeratoconus (KC) is a corneal ectasia characterized by structural changes, resulting in progressive thinning and biomechanical weakening that can lead to worsening visual acuity due to irregular astigmatism. Corneal collagen Crosslinking (CXL) and Intracorneal Ring Segment (ICRS) are widely used treatments in KC disease, but the alterations they cause in biomechanical mediators are still poorly understood. The aim of this study was to analyze the tear proteome profile before and after treatments to identify biomarkers altered by surgery.Materials and methodsAn observational, prospective, case-control pilot study was conducted, analyzing tear samples from KC patients by nano-liquid chromatography-mass spectrometry (nLC-MS/MS). Data are available via ProteomeXchange with identifier PXD035655. Patients with KC who underwent ICRS surgery (n = 4), CXL (n = 4), and healthy subjects (Ctrl, n = 4) were included in this study. Clinical parameters were measured and tear samples were collected before and 18 months after surgery. Proteins with ≥2 expression change and p-value < 0.05 between groups and times were selected to study their role in post-operative corneal changes.ResultsThese analyses led to the identification of 447 tear proteins, some of which were dysregulated in KC patients. In comparisons between the two surgical groups and Ctrls, the biological processes that were altered in KC patients at baseline were those that were dysregulated as a consequence of the disease and not of the surgical intervention. Among the biological processes seen to be altered were: immune responses, cytoskeleton components, protein synthesis and metabolic reactions. When comparing the two treatment groups (ICRS and CXL), the process related to cytoskeleton components was the most altered, probably due to corneal thinning which was more pronounced in patients undergoing CXL.ConclusionThe changes observed in tears after 18 months post-operatively could be due to the treatments performed and the pathology. Among the deregulated proteins detected, A-kinase anchor protein 13 (AKAP-13) deserves special attention for its involvement in corneal thinning, and for its strong overexpression in the tears of patients with more active KC and faster disease progression. However, it should be kept in mind that this is a pilot study conducted in a small number of patients.
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Affiliation(s)
- Nahia Goñi
- Department of Ophthalmology, Hospital Universitario Donostia, San Sebastian, Spain
- Department of Ophthalmology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Itziar Martínez-Soroa
- Department of Ophthalmology, Hospital Universitario Donostia, San Sebastian, Spain
- Department of Ophthalmology, University of the Basque Country UPV/EHU, Leioa, Spain
| | | | - Mikel Azkargorta
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), CIBERehd, Derio, Spain
| | - Felix Elortza
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), CIBERehd, Derio, Spain
| | - David J. Galarreta
- Department of Ophthalmology, Hospital Clínico Universitario de Valladolid, Valladolid, Spain
| | - Arantxa Acera
- Department of Cell Biology and Histology, Experimental Ophthalmo-Biology Group (GOBE:www.ehu.eus/gobe), University of the Basque Country UPV/EHU, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- *Correspondence: Arantxa Acera,
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Hamon L, Schlötzer-Schrehardt U, Flockerzi FA, Seitz B, Daas L. Morphological characterization and clinical effects of stromal alterations after intracorneal ring segment implantation in keratoconus. Graefes Arch Clin Exp Ophthalmol 2022; 260:2299-2308. [PMID: 35106630 PMCID: PMC9203383 DOI: 10.1007/s00417-022-05572-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/16/2022] [Accepted: 01/20/2022] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To analyze the histological and (ultra)structural stromal tissue changes after femtosecond (Fs) laser-assisted intracorneal ring segment (ICRS) implantation and their refractive and topographic effects in patients with keratoconus. METHODS This monocentric retrospective case series included 15 consecutive patients with clinical peri-segmental lamellar channel deposits after treatment with Fs-ICRS implantation for keratoconus. The stromal changes were investigated using in vivo confocal microscopy. Two patients underwent a penetrating keratoplasty after the Fs-ICRS implantation; the explanted corneas were processed for histopathology and transmission electron microscopy (TEM). Refractive and topographic effects were investigated comparing the uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent (SE), flat (K1), steep (K2), and steepest (Kmax) keratometry before and after detection of lamellar channel deposits. RESULTS In vivo confocal microscopy revealed diffuse linear and focal granular hyperreflective structures. Histologically, there was mild proliferation of fibroblasts and fibrosis. TEM demonstrated focal accumulations of degenerated keratocytes with cytoplasmic lipid inclusions. There were no significant changes for UDVA (Δ = 0.0 ± 0.2 logMAR; p = 0.67), CDVA (Δ = 0.0 ± 0.1 logMAR; p = 0.32), SE (Δ 0.1 ± 0.9 D; p = 0.22), K1 (Δ = 0.3 ± 1.0 D; p = 0.28), K2 (Δ = 0.1 ± 0.9 D; p = 0.51), and Kmax (Δ = 0.3 ± 1.5 D; p = 0.17). CONCLUSIONS Two types of structural stromal changes were identified: (1) diffuse peri-segmental fibrosis and (2) lamellar channel deposits. These structural changes showed no evidence of a relevant refractive or topographic effect.
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Affiliation(s)
- Loïc Hamon
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Fidelis A. Flockerzi
- Department of Pathology, Saarland University Medical Center (UKS), Homburg, Saar Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
| | - Loay Daas
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
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Hamon L, Seitz B, Daas L. Intrastromal fibrosis and lipid deposits twenty years after intracorneal ring segments implantation for treatment of mild myopia. J Fr Ophtalmol 2021; 45:147-150. [PMID: 34802752 DOI: 10.1016/j.jfo.2021.06.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 10/19/2022]
Affiliation(s)
- L Hamon
- Centre Hospitalier Universitaire de la Sarre (UKS), Homburg/Saar, Germany.
| | - B Seitz
- Centre Hospitalier Universitaire de la Sarre (UKS), Homburg/Saar, Germany
| | - L Daas
- Centre Hospitalier Universitaire de la Sarre (UKS), Homburg/Saar, Germany
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David C, Kallel S, Trinh L, Goemaere I, Borderie V, Bouheraoua N. [Intracorneal ring segments in keratoconus management]. J Fr Ophtalmol 2021; 44:882-898. [PMID: 33895029 DOI: 10.1016/j.jfo.2020.10.021] [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: 04/19/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 11/25/2022]
Abstract
Intracorneal ring segments (ICRS), used in the management of keratoconus since the 2000s, have enjoyed significant technological development. Various types of ICRS exist, whose arc length, thickness, and diameter can be chosen according to the desired effect on the spherical equivalent, keratometry and asphericity. Individualized implantation strategies, based on each patient's topographic and tomographic pattern, are constantly evolving. The surgical procedure is standardized, and complications remain very rare. Combined procedures (corneal collagen cross-linking and refractive photokeratectomy±topo-guided, phakic and pseudophakic intraocular lenses) are increasingly used and require a good knowledge of the effect of ICRS alone on the keratoconic cornea. The objective of this review is to summarize clinical practices used in the visual rehabilitation of keratoconic patients using the ICRS+- combined procedures.
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Affiliation(s)
- C David
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France
| | - S Kallel
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France
| | - L Trinh
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France
| | - I Goemaere
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France
| | - V Borderie
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France; Inserm, CNRS, Sorbonne université, institut de la Vision, 17, rue Moreau, 75012 Paris, France
| | - N Bouheraoua
- INSERM-DGOS CIC 1423, CHNO des Quinze-Vingts, IHU ForeSight, 28, rue de Charenton, 75012 Paris, France; Inserm, CNRS, Sorbonne université, institut de la Vision, 17, rue Moreau, 75012 Paris, France.
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D'Oria F, Abdelghany AA, Ledo N, Barraquer RI, Alio JL. Incidence and Reasons for Intrastromal Corneal Ring Segment Explantation. Am J Ophthalmol 2021; 222:351-358. [PMID: 33011155 DOI: 10.1016/j.ajo.2020.09.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE To determine the main causes of intrastromal corneal ring segment (ICRS) explantation and define the incidence rate. DESIGN Multicenter, observational consecutive case series. METHODS Consecutive cases of ICRSs explanted in the last 10 years were reviewed. Clinical data included age of the patients at explantation, reasons for implantation and explantation, date of implantation and explantation, tunnel creation technique, and ICRS type. Main outcomes measures were the reasons for ICRS removal and the incidence rate. RESULTS During the study period, 121 ICRSs (119 patients) were explanted, with an explantation rate of 5.60%. Functional failure (74 eyes, 61.16%) represents the main cause for ICRS removal: of them, 48 (39.67%) ICRSs were removed for refractive failure and 26 (21.49%) in the setting of a keratoplasty related to poor visual performance of the implanted eye. In addition, 47 eyes (38.84%) had ICRS removal for anatomic failure: among them, 36 (29.75%) were explanted for spontaneous extrusion (overall extrusion rate: 1.58%), 7 (5.79%) for suspected infectious keratitis, 3 (2.48%) for corneal melting, and 1 (0.83%) for corneal perforation. Mild cases of keratoconus were more prone to be explanted because of a loss of the initial improved visual acuity, whereas spontaneous extrusion happened often in advanced cases of keratoconus. CONCLUSIONS We report the largest series of ICRS explantation as of this writing. The main cause of explantation was functional refractive failure followed by spontaneous extrusion of the ICRS, that is, correlated to an anatomic failure at the site of implantation in an advanced disease.
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Affiliation(s)
- Francesco D'Oria
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain; Section of Ophthalmology, Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari, Bari, Italy
| | - Ahmed A Abdelghany
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain; Ophthalmology department, Faculty of Medicine, Minia University, Minia, Egypt
| | - Natalia Ledo
- Instituto Universitario Barraquer, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rafael I Barraquer
- Instituto Universitario Barraquer, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jorge L Alio
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.
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Vastardis I, Gatzioufas Z, McLintock C, Kohlhaas M, Hamada S, Lake D, Elalfy M. Tear film parameters before and after intracorneal ring segment implantation in keratoconic eyes. Eur J Ophthalmol 2020; 31:2213-2218. [PMID: 32951440 DOI: 10.1177/1120672120958301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To assess signs of dry eye syndrome in keratoconic eyes following intracorneal ring segment (ICRS) implantation. PATIENT AND METHODS Twenty eyes of 20 consecutive patients with keratoconus were assessed for tear film changes following ICRS implantation at 6 months postoperatively. Evaluated parameters included tear osmolarity, non-invasive tear breakup time test (NI-BUT test) and Schirmer test I and II before and after treatment. RESULTS No significant changes were found with respect to osmolarity, Schirmer I and II (p = 0.9, p < 0.64, and p < 0.91, respectively). The NITUBT was significantly lower after surgery (p = 0.04). CONCLUSION Our results suggest that implantation of ICRS does not result in a significant change in tear film osmolarity, or tear film volume nor improves the tear film stability.
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Affiliation(s)
| | - Zisis Gatzioufas
- Corneo-Plastic Unit, Queen Victoria Hospital, East Grinstead, UK.,Department of Ophthalmology, University Hospital Basel, Switzerland
| | - Cameron McLintock
- Corneo-Plastic Unit, Queen Victoria Hospital, East Grinstead, UK.,Princess Alexandra Hospital, Brisbane, Australia
| | | | - Samer Hamada
- Corneo-Plastic Unit, Queen Victoria Hospital, East Grinstead, UK
| | - Damian Lake
- Corneo-Plastic Unit, Queen Victoria Hospital, East Grinstead, UK
| | - Mohamed Elalfy
- Corneo-Plastic Unit, Queen Victoria Hospital, East Grinstead, UK.,The Research Institute of Ophthalmology, Cairo, Egypt
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Bautista-Llamas MJ, Sánchez-González MC, López-Izquierdo I, López-Muñoz A, Gargallo-Martínez B, De-Hita-Cantalejo C, Sánchez-González JM. Complications and Explantation Reasons in Intracorneal Ring Segments (ICRS) Implantation: A Systematic Review. J Refract Surg 2019; 35:740-747. [DOI: 10.3928/1081597x-20191010-02] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/10/2019] [Indexed: 11/20/2022]
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Confocal biomicroscopic changes of the corneal layers following femtosecond laser-assisted MyoRing implantation in keratoconus. J Curr Ophthalmol 2016; 29:182-188. [PMID: 28913508 PMCID: PMC5587231 DOI: 10.1016/j.joco.2016.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 11/19/2016] [Accepted: 11/28/2016] [Indexed: 11/20/2022] Open
Abstract
Purpose To evaluate the effect of the femtosecond laser-assisted MyoRing implantation on the confocal biomicroscopic findings in different corneal layers of the patients with keratoconus. Methods Twelve eyes of 12 patients with mild to moderate keratoconus (keratometry between 48 and 52 diopters) and intolerance to hard contact lens entered the study. All the included patients underwent femtosecond laser-assisted MyoRing (Dioptex GmBH, Linz, Austria) implantation. The confocal biomicroscopy of the cornea was performed for all corneal layers in the center and periphery preoperatively and 3 and 6 months postoperatively. The cell counts and the qualitative findings in each layer of the cornea were compared between preoperative and 3 and 6 months postoperative images. Results Compared with preoperative values, the central epithelial and the central and peripheral midstromal cell counts were significantly decreased 6 months after MyoRing implantation (P = 0.015, P = 0.010 and 0.005, respectively). Furthermore, compared with preoperative values, the peripheral posterior stromal cell count was significantly decreased 3 months after MyoRing implantation (P = 0.033). In the qualitative analysis, highly reflective nuclei in the basal epithelium, transient disruption in the subepithelial nerve plexus, increase in the reflectivity of the stromal keratocyte, and normal endothelial cell morphology were seen. Conclusions Our study demonstrated some findings similar to that reported in intrastromal corneal ring segments (ICRS): decreased central epithelial cell counts, highly reflective nuclei in the basal epithelium, transient disruption in the subepithelial nerve plexus, and normal endothelial cell count and morphology. In addition, a decrease in the central and peripheral midstromal, transient decrease in posterior stromal cell counts, and absence of amorphous depositions were in contrast with the findings reported in ICRS.
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Carracedo G, Recchioni A, Alejandre-Alba N, Martin-Gil A, Batres L, Morote IJA, Pintor J. Signs and Symptoms of Dry Eye in Keratoconus Patients Before and After Intrastromal Corneal Rings Surgery. Curr Eye Res 2016; 42:513-519. [PMID: 27450910 DOI: 10.1080/02713683.2016.1200098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE Based on the relationship between keratoconus and dry eye, the aim of this study was to evaluate changes in signs and symptoms of dry eye in keratoconus patients before and after intrastromal corneal ring surgery. METHODS Fifteen keratoconus patients were enrolled in Fundación Jiménez-Díaz of Madrid and University Clinic of Optometry of the Universidad Complutense de Madrid (Madrid, Spain). Tear break up time (TBUT), Schirmer test without anesthesia, corneal staining, diadenosine tetraphosphate (Ap4A) concentration, and ocular surface disease index (OSDI) were evaluated. Impression cytology combined with laser confocal microscopy was performed to evaluate goblet cell density, mucin cloud height (MCH), and cell layer thickness (CLT). All measurements were performed before (pre) surgery, 1 month (post) and 6 months after surgery (post6m). RESULTS We found no statistical differences in time in Schirmer test, TBUT, and corneal staining. OSDI scores were 44.96 ± 8.65, 26.30 ± 6.79, and 19.31 ± 4.28 for (pre), (post), and (post6m) surgery, respectively (p < 0.001). Impression cytology showed a decrease in cell density at (post6m) compared with presurgery (47.36 ± 35.15 cells/mm2 and 84.88 ± 32.08 cells/mm2, respectively, p = 0.04). At post6m, the MCH increased compared with presurgery values (13.97 ± 4.26 µm and 6.77 ± 2.51 µm, respectively, p < 0.001). There was a statistically significant increase in CLT in time. Ap4A tear concentrations were lower post6m than presurgery (1.02 ± 0.65 and 2.56 ± 1.10 µM, respectively, p < 0.001). CONCLUSION Intrastromal corneal ring surgery induces changes improving dry eye symptoms but no changes were found in signs of dry eye after surgery in keratoconus patients except for the MCH that increases drastically. More studies are needed to clarify the reason of its improvement.
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Affiliation(s)
- Gonzalo Carracedo
- a Department of Optics II (Optometry and Vision) , Faculty of Optics and Optometry, Universidad Complutense de Madrid , Madrid , Spain
| | - Alberto Recchioni
- a Department of Optics II (Optometry and Vision) , Faculty of Optics and Optometry, Universidad Complutense de Madrid , Madrid , Spain
| | | | - Alba Martin-Gil
- c Department of Biochemistry and Molecular Biology IV , Faculty of Optics and Optometry, Universidad Complutense de Madrid , Madrid , Spain
| | - Laura Batres
- a Department of Optics II (Optometry and Vision) , Faculty of Optics and Optometry, Universidad Complutense de Madrid , Madrid , Spain
| | | | - Jesús Pintor
- c Department of Biochemistry and Molecular Biology IV , Faculty of Optics and Optometry, Universidad Complutense de Madrid , Madrid , Spain
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Malandrini A, Martone G, Menabuoni L, Catanese AM, Tosi GM, Balestrazzi A, Corsani C, Fantozzi M. Bifocal refractive corneal inlay implantation to improve near vision in emmetropic presbyopic patients. J Cataract Refract Surg 2016; 41:1962-72. [PMID: 26603405 DOI: 10.1016/j.jcrs.2015.01.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 01/03/2015] [Accepted: 01/07/2015] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the safety and effectiveness of the Flexivue Microlens corneal inlay for the improvement of near vision in emmetropic presbyopic patients. SETTING Ophthalmology Department, Misericordia e Dolce Hospital, Prato, Italy. DESIGN Prospective interventional case series. METHODS Corneal inlay implantation was performed in nondominant eyes using a 150 kHz femtosecond laser (iFS). Refraction, uncorrected (UNVA) and corrected (CNVA) near visual acuities, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, slitlamp evaluation, wavefront aberrometry, photopic and mesopic contrast sensitivity, anterior segment optical coherence tomography, endothelial cell density, and central corneal thickness measurements were assessed preoperatively and at each postoperative visit. RESULTS The study evaluated 81 eyes. In 26 eyes, the mean preoperative UNVA and UDVA were 0.76 logMAR and 0.00 logMAR, respectively, compared with 0.10 logMAR and 0.15 logMAR, respectively, 36 months postoperatively. Sixteen (62%) of 26 treated eyes lost more than 1 line of UDVA, and 5 (19%) lost more than 2 lines of UDVA. Two eyes (8%) lost more than 1 line of CDVA at 36 months. The mean binocular UDVA was 0.00 logMAR preoperatively and 0.02 logMAR at 36 months. The mean spherical aberration increased after surgery. Statistically significant differences in the mean mesopic and photopic contrast sensitivities at higher spatial frequencies were found between treated eyes and nontreated eyes. Explantation was performed in 6 treated eyes because of halos, glare, and a reduced UDVA. CONCLUSION The corneal inlay might be a safe and effective method of improving UNVA in emmetropic presbyopic patients. FINANCIAL DISCLOSURE Dr. Fantozzi is a member of the Presbia medical advisory board. No other author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Alex Malandrini
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Gianluca Martone
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy.
| | - Luca Menabuoni
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Anna Maria Catanese
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Gian Marco Tosi
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Angelo Balestrazzi
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Chiara Corsani
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
| | - Marco Fantozzi
- From the Ophthalmology Department (Malandrini, Menabuoni, Catanese, Corsani, Fantozzi), Misericordia e Dolce Hospital, Prato, and the Ophthalmology Department (Martone, Tosi, Balestrazzi), University of Siena, Siena, Italy
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Ibares-Frías L, Gallego P, Cantalapiedra-Rodriguez R, Merayo-Lloves J, Martínez-García MC. Clinical, Refractive and Histological Reversibility of Corneal Additive Surgery in Deep Stroma in an Animal Model. Curr Eye Res 2016; 41:1192-201. [PMID: 26889567 DOI: 10.3109/02713683.2015.1114652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The aim was to evaluate the reversibility of the clinical and histological changes induced in the corneas of an animal model after removing an intracorneal ring segment (ICRS). METHODS Surgery for this study was performed in 38 eyes of an experimental animal model (Gallus domesticus) for ICRS surgery (Ferrara technique). The animals without complications were randomized to two groups; in all of them, 1 segment was implanted in each eye and later removed at different times (1 and 3 months after implantation). In each group, after explantation, corneas were processed at different times for histological analysis with hematoxylin and eosin (H&E) stain and electronic microscopy. The refractive state of the eyes was also measured. RESULTS In corneas without complications (88.23%), explantation was performed correctly. During the first few days, around the area where the ICRS was implanted we observed deposits of cells and a moderate degree of corneal opacity (haze). These signs decreased progressively without disappearing completely. Histologically, at 7 days, we observed hyperplasia and abnormal arrangement of collagen fibers. Later, these findings also decreased in both groups, albeit at a faster rate in group 1. Minimal changes were observed in electron microscopy up to the end of the study in both groups. Preoperative refractive state was achieved at 1 month after explantation in both groups. CONCLUSIONS ICRS can safely be explanted from the cornea. Refractive reversibility was achieved at 1 month after explantation. However, the clinical and histological findings after ICRS explantation depend on the time from implantation to explantation.
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Affiliation(s)
- Lucía Ibares-Frías
- a Optical Diagnostic Techniques Group, Theoretical, Atomic and Optical Physics Department , University of Valladolid , Valladolid , Spain.,b Ophthalmology Department , Hospital Clínico Universitario de Valladolid , Valladolid , Spain
| | - Patricia Gallego
- a Optical Diagnostic Techniques Group, Theoretical, Atomic and Optical Physics Department , University of Valladolid , Valladolid , Spain.,c Cell Biology, Histology and Pharmacology Department , Faculty of Medicine, University of Valladolid , Valladolid , Spain
| | | | - Jesús Merayo-Lloves
- a Optical Diagnostic Techniques Group, Theoretical, Atomic and Optical Physics Department , University of Valladolid , Valladolid , Spain.,d Instituto Universitario Fernandez-Vega, Universidad de Oviedo , Oviedo , Spain
| | - María Carmen Martínez-García
- a Optical Diagnostic Techniques Group, Theoretical, Atomic and Optical Physics Department , University of Valladolid , Valladolid , Spain.,c Cell Biology, Histology and Pharmacology Department , Faculty of Medicine, University of Valladolid , Valladolid , Spain
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Morral M, Güell JL, El Husseiny MA, Elies D, Gris O, Manero F. Paired-eye comparison of corneal endothelial cell counts after unilateral iris-claw phakic intraocular lens implantation. J Cataract Refract Surg 2016; 42:117-26. [DOI: 10.1016/j.jcrs.2015.08.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/03/2015] [Accepted: 08/04/2015] [Indexed: 01/18/2023]
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Reshaping procedures for the surgical management of corneal ectasia. J Cataract Refract Surg 2015; 41:842-72. [PMID: 25840308 DOI: 10.1016/j.jcrs.2015.03.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 12/31/2022]
Abstract
UNLABELLED Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography-guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Ibares-Frías L, Gallego P, Cantalapiedra-Rodríguez R, Valsero MC, Mar S, Merayo-Lloves J, Martínez-García MC. Tissue reaction after intrastromal corneal ring implantation in an experimental animal model. Graefes Arch Clin Exp Ophthalmol 2015; 253:1071-83. [PMID: 25744328 DOI: 10.1007/s00417-015-2959-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 01/22/2015] [Accepted: 01/27/2015] [Indexed: 01/04/2023] Open
Abstract
PURPOSE To evaluate corneal wound healing in the hen animal model after additive surgery with an intracorneal ring segment (ICRS). METHODS We implanted one ICRS in each eye of 76 hens. In control group 1 (n = 22 hens), the stromal channel was prepared but no ICRS was inserted. In control group 2 (n = 2 hens), no surgery was performed. Animals were randomly separated into groups and euthanized after clinical follow-up of 4 and 12 hours, 1, 2, 3, and 7 days, and 1, 2, 3, 4, and 6 months. Corneas were stained with hematoxylin-eosin. Apoptosis was measured by terminal uridine nick end-labeling assays. Cell proliferation and myofibroblast-like differentiation were assayed by BrdU and α-smooth muscle actin immunofluorescence microscopy. Stromal matrix changes were documented by electron microscopy. RESULTS Epithelial and stromal cell apoptosis around the ICRS-implanted and control group 1 eyes peaked at 12 hours, but continued for 72 hours. In ICRS-implanted eyes, epithelial and stromal proliferation was present at 12 and 24 hours, respectively, and peaked at 7 days and 72 hours, respectively. Some proliferation in the ICRS-implanted group continued through the 6-month follow-up, and myofibroblast-like cells differentiated one to three months after ICRS implantation. The segments rotated within the stroma as the limbal inferior angle approached the epithelium. CONCLUSIONS Wound healing after ICRS implantation in hen corneas was similar to that of other corneal surgical wounds in stages. However, there were some specific features related to the small size of the epithelial wound and the device permanently implanted inside the cornea.
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Affiliation(s)
- Lucía Ibares-Frías
- Group of Optical Diagnostic Techniques, Theorist, Atomic and Optical Physics Department, Faculty of Science, University of Valladolid, Valladolid, Spain,
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Parker JS, van Dijk K, Melles GRJ. Treatment options for advanced keratoconus: A review. Surv Ophthalmol 2015; 60:459-80. [PMID: 26077628 DOI: 10.1016/j.survophthal.2015.02.004] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.
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Affiliation(s)
- Jack S Parker
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; UAB Callahan Eye Hospital, Birmingham, Alabama, USA
| | - Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Gerrit R J Melles
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; Amnitrans EyeBank, Rotterdam, The Netherlands.
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Malandrini A, Martone G, Canovetti A, Menabuoni L, Balestrazzi A, Fantozzi C, Lenzetti C, Fantozzi M. Morphologic study of the cornea by in vivo confocal microscopy and optical coherence tomography after bifocal refractive corneal inlay implantation. J Cataract Refract Surg 2014; 40:545-57. [PMID: 24680518 DOI: 10.1016/j.jcrs.2013.08.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 08/24/2013] [Accepted: 08/27/2013] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the biocompatibility of the Flexivue Microlens intracorneal inlay based on healing of corneal wounds and analysis of corneal structural features using in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT). SETTING Ophthalmology Department, Misericordia e Dolce Hospital, Prato, Italy. DESIGN Case series. METHODS The intracorneal inlay was inserted in a stromal pocket created in the nondominant eye of emmetropic presbyopic patients using a femtosecond laser. In vivo confocal microscopy and AS-OCT examinations were performed preoperatively and 1, 6, and 12 months postoperatively. RESULTS The mean follow-up was 7.6 months. In the early postoperative period, IVCM showed intense cellular activity in the stroma around the inlay, edema, inflammation, and degenerative material deposition but normal regularity after 12 months. Anterior segment OCT showed a regular planar shape of the corneal pocket in all eyes. The mean of the side-cut angles was 30.7 degrees. The mean difference between the measured and planned pocket depth was 9.77 μm. At 1 month, hyperreflective areas beneath the inlay and microfolds were observed in 21 of the 52 eyes. After 12 months, the anterior segment profile was regular and interface pocket reflectivity decreased over time. Six patients had inlay removal postoperatively (3 before 6 months; 3 before 12 months); after removal, IVCM and AS-OCT showed clear corneas without signs of irregularity. CONCLUSION In vivo confocal microscopy and AS-OCT analysis showed that the inlay elicited a low-level wound-healing response in its immediate vicinity with no alteration in the corneal structures. FINANCIAL DISCLOSURE Dr. M. Fantozzi is a member of the Presbia medical advisory board. No other author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Alex Malandrini
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy.
| | - Gianluca Martone
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Annalisa Canovetti
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Luca Menabuoni
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Angelo Balestrazzi
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Chiara Fantozzi
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Chiara Lenzetti
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
| | - Marco Fantozzi
- From the Department of Ophthalmology (Malandrini, Canovetti, Menabuoni, C. Fantozzi, M. Fantozzi, Lenzetti), Misericordia e Dolce Hospital, Prato, and the Department of Ophthalmology (Martone, Balestrazzi), University of Siena, Siena, Italy
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Tomita M, Huseynova T. Evaluating the short-term results of KAMRA inlay implantation using real-time optical coherence tomography-guided femtosecond laser technology. J Refract Surg 2014; 30:326-9. [PMID: 24893357 DOI: 10.3928/1081597x-20140416-06] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 03/04/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the outcomes from using real-time optical coherence tomography (OCT)-guided femtosecond laser technology for pocket creation for KAMRA inlay (Acufocus, Inc., Irvine, CA) implantation surgery. METHODS One hundred fifty-one eyes underwent KAMRA inlay implantation using the real-time OCT-guided femtosecond laser for pocket creation. All patients had a history of prior LASIK. Uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, corrected near visual acuity, and manifest refraction spherical equivalent were evaluated preoperatively and postoperatively. The follow-up period was 3 months. RESULTS Mean manifest refraction spherical equivalent, uncorrected distance visual acuity, and uncorrected near visual acuity changed from -0.18 ± 0.33 to -0.95 ± 0.64, 20/16 to 20/20, and J8 to J2, respectively. Corrected distance visual acuity and corrected near visual acuity remained stable before and after KAMRA inlay implantation, 20/12 and J1, respectively. CONCLUSIONS Using real-time OCT-guided femtosecond laser technology increases the safety and accuracy of corneal KAMRA inlay implantation surgery with a history of prior LASIK with excellent visual and refractive outcomes.
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Biomaterials for refractive correction: corneal onlays and inlays. Sci China Chem 2014. [DOI: 10.1007/s11426-014-5083-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Messmer EM. Confocal microscopy: when is it helpful to diagnose corneal and conjunctival disease? EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/17469899.3.2.177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Salustiano R, Avila MP, Silva DS, Rannouche RZ, Salustiano LX, Paula AC. Endothelial analysis in patients having corneal intrastromal surgery with Cornealring for correction of Keratoconus. Semin Ophthalmol 2013; 28:19-24. [PMID: 23305435 DOI: 10.3109/08820538.2012.730096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Evaluate corneal endothelium by means of specular microscopy exam in patients with Keratoconus, before and after Cornealring® corneal intrastromal ring surgery. METHODS One hundred and two eyes of 67 patients, aged between 12 and 45, with the average age of 27.31 ± 8.15 years, 30 females and 37 males, were selected to be submitted to the implant of Cornealring® corneal ring segments in pre- and post-surgery (six months after the procedure) in the External Diseases and Cornea Ward of the Instituto Panamericano da Visão. RESULTS Of the 102 eyes treated, only those that received two rings of equal thickness up to 250 µ showed statistical significance between the initial and final mean number of endothelial cells (P = 0.008), a decrease of 10.1% in the mean coefficient of variation (P = 0.003), and a 9.75% decrease in initial and final hexagonal cell counts. The other eyes receiving rings of other thicknesses showed no statistically significant differences between the mean initial and final SM examinations. CONCLUSION A longer segment is necessary for the confirmation or not of the alterations found in this study, particularly regarding the thickness of the ring used, because with the new technologies and the improvement in the result of deep lamellar transplantation, the decrease in the cell count might represent a problem in the indication of this procedure following thick corneal ring implants.
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Affiliation(s)
- R Salustiano
- Department of Medicine, Service of Cornea and External Diseases, Federal University of Goiás - Centre for Excellence in Ophthalmology, Goiânia, Brazil
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Bedi R, Touboul D, Pinsard L, Colin J. Refractive and Topographic Stability of Intacs in Eyes With Progressive Keratoconus: Five-year Follow-up. J Refract Surg 2012; 28:392-6. [DOI: 10.3928/1081597x-20120509-01] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 04/24/2012] [Indexed: 11/20/2022]
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Gorgun E, Kucumen RB, Yenerel NM, Ciftci F. Assessment of Intrastromal Corneal Ring Segment Position With Anterior Segment Optical Coherence Tomography. Ophthalmic Surg Lasers Imaging Retina 2012; 43:214-21. [DOI: 10.3928/15428877-20120301-01] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 02/01/2012] [Indexed: 11/20/2022]
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Touboul D, Pinsard L, Mesplier N, Smadja D, Colin J. Correction des astigmatismes irréguliers par anneaux intra cornéens. J Fr Ophtalmol 2012; 35:212-9. [DOI: 10.1016/j.jfo.2011.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/23/2011] [Accepted: 08/25/2011] [Indexed: 11/28/2022]
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Refractive and Keratometric Outcomes of Intacs Continue to Improve Until 6 Months. Cornea 2011; 30:1068; author reply 1068-9. [DOI: 10.1097/ico.0b013e3181eeb45f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Corneal Melt of Incisions Overlying Corneal Ring Segments: Case Series and Literature Review. Cornea 2011; 30:968-71. [DOI: 10.1097/ico.0b013e3182031ca0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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Kaufman MB, Dhaliwal DK. Spontaneous Improvement of Channel Deposits Following Intacs Implantation. J Refract Surg 2011; 27:303-5. [DOI: 10.3928/1081597x-20100804-03] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 07/08/2010] [Indexed: 11/20/2022]
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Verity SM, McCulley JP, Bowman RW, Cavanagh HD, Petroll WM. Outcomes of PermaVision intracorneal implants for the correction of hyperopia. Am J Ophthalmol 2009; 147:973-7. [PMID: 19268889 DOI: 10.1016/j.ajo.2008.12.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 12/17/2008] [Accepted: 12/18/2008] [Indexed: 11/15/2022]
Abstract
PURPOSE To report the clinical and visual outcomes of a series of patients implanted with the PermaVision intracorneal lens (ReVision Optics Inc, Lake Forest, California, USA) for correction of hyperopia. DESIGN Prospective, nonrandomized, clinical trial study. METHODS Fifteen patients were implanted with the intracorneal lens for correction of spherical hyperopic refractive errors ranging from 1.00 to 5.00 diopters (D) (mean, 2.45 D). All eyes were correctable to 20/20 before surgery. Patients were followed up to 3 years with measurements of residual refractive error, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA). RESULTS For patients with follow-up of 1 year or more, the mean logarithm of the minimum angle of resolution BSCVA was 0.15 (20/28 Snellen equivalent; range, 0.1 to 0.6) with an average change of -2.5 lines of BSCVA (range, 1 to -6 lines). Only 3 eyes (25%) achieved 20/20 or better UCVA. Two patients experienced early adverse events and 1 patient experienced a late-onset adverse event requiring eventual removal of the implant. Nine patients elected to have the implant removed, with dissatisfaction with the quality of vision as the most frequent reason for removal. CONCLUSIONS The quality of visual and refractive outcomes with this device was less than satisfactory for most of the patients in our series. Although the problems of early onset migration or extrusion of the device are possible, late-onset ulceration noted in one of our patients most likely represents a neurotropic melt. Further research to improve the safety and quality of refractive result with intracorneal implants is needed.
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Affiliation(s)
- Steven M Verity
- Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA.
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Kojima T, Primack JD, Azar DT. Intrastromal Corneal Ring Segments for Low and High Myopia. Ophthalmology 2009. [DOI: 10.1016/b978-0-323-04332-8.00023-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Alterations of extracellular matrix components and proteinases in human corneal buttons with INTACS for post-laser in situ keratomileusis keratectasia and keratoconus. Cornea 2008; 27:565-73. [PMID: 18520507 DOI: 10.1097/ico.0b013e318165b1cd] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE To perform an immunohistochemical evaluation of corneas with INTACS for post-laser in situ keratomileusis (LASIK) keratectasia and keratoconus, obtained after corneal transplantation. METHODS Corneas from 1 patient with INTACS for post-LASIK keratectasia and 2 patients with INTACS for keratoconus were obtained within 3 hours after penetrating keratoplasty, and cryostat sections were analyzed by immunostaining for 35 extracellular matrix (ECM) components and proteinases. RESULTS In the stroma of all corneas next to an INTACS implant, ECM components typically associated with fibrosis were observed. These included tenascin-C, fibrillin-1, and types III, IV (alpha1/alpha2 chains), and XIV collagen. Also, significant deposition of perlecan, nidogen-2, and cellular fibronectin was revealed in the same locations. The keratoconus cases displayed typical Bowman layer breaks and subepithelial fibrosis with deposition of various ECM components. In all cases, some keratocytes around INTACS were positive for specific proteinases associated with stromal remodeling, including cathepsins F and H, matrix metalloproteinase (MMP)-1, MMP-3, and MMP-10. Staining for MMP-7 was variable; MMP-2 and MMP-9 were mostly negative. Patterns of type IV collagen alpha 3, alpha 4, and alpha 6 chains; types VI and VIII collagen; laminin-332, alpha 4, alpha 5, beta1, beta2, and gamma 1 laminin chains; vitronectin; thrombospondin-1; urokinase; EMMPRIN; and cathepsins B and L were unchanged around INTACS in all 3 cases compared with normal. CONCLUSIONS Abnormal accumulation of fibrotic ECM components and proteinases near INTACS suggests ongoing lysis and remodeling of corneal stroma. Specific changes observed in each case may be related to underlying pathology.
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Myung D, Farooqui N, Waters D, Schaber S, Koh W, Carrasco M, Noolandi J, Frank CW, Ta CN. Glucose-permeable interpenetrating polymer network hydrogels for corneal implant applications: a pilot study. Curr Eye Res 2008; 33:29-43. [PMID: 18214741 DOI: 10.1080/02713680701793930] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Epithelialization of a keratoprosthesis requires that the implant material be sufficiently permeable to glucose. We have developed a poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) interpenetrating polymer network (IPN) hydrogel that can provide adequate passage of glucose from the aqueous humor to the epithelium in vivo. A series of PEG/PAA IPNs with varying PEG macromonomer molecular weights were synthesized and evaluated through swelling studies to determine their water content and diffusion experiments to assess their permeability to glucose. One of the PEG/PAA hydrogels prepared in this study had a glucose diffusion coefficient nearly identical to that of the human cornea (approximately 2.5 x 10(-6) cm(2)/sec). When implanted intrastromally in rabbit corneas, this hydrogel was retained and well-tolerated in 9 out of 10 cases for a period of 14 days. The retained hydrogels stayed optically clear and the epithelium remained intact and multilayered, indicating that the material facilitated glucose transport from the aqueous humor to the anterior part of the eye. The results from these experiments indicate that PEG/PAA hydrogels are promising candidates for corneal implant applications such as keratoprostheses and intracorneal lenses, and that the PEG/PAA IPN system in general is useful for creating permeable substrates for ophthalmic and other biomedical applications.
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Affiliation(s)
- David Myung
- Department of Ophthalmology, Stanford University, Stanford, California 94305, USA
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Sweeney DF, Vannas A, Hughes TC, Evans MD, McLean KM, Xie RZ, Pravin VK, Prakasam RK. Synthetic corneal inlays. Clin Exp Optom 2008; 91:56-66. [PMID: 18045251 DOI: 10.1111/j.1444-0938.2007.00198.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
This review is based on the activities of the Vision Cooperative Research Centre (previously Cooperative Research Centre for Eye Research and Technology) Corneal Implant team from 1991 to 2007. The development of a synthetic polymer of perfluoropolyether (PFPE), meeting essential physical and biological requirements, for use as a corneal inlay is presented. Each inlay was placed in a corneal flap created with a microkeratome and monitored over a two-year period in a rabbit model. The results indicate that the PFPE implant shows excellent biocompatibility and biostability. As a result, a Phase 1 clinical trial is being conducted. Three years post-implantation, the PFPE inlays are exhibiting continued excellent biocompatibility. Corneal inlays made from PFPE are biocompatible with corneal tissue in the long term and offer a safe and biologically-acceptable alternative to other forms of refractive surgery.
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Samimi S, Leger F, Touboul D, Colin J. Histopathological findings after intracorneal ring segment implantation in keratoconic human corneas. J Cataract Refract Surg 2007; 33:247-53. [PMID: 17276265 DOI: 10.1016/j.jcrs.2006.08.059] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Accepted: 08/25/2006] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate histopathological changes induced in keratoconic corneas after implantation of Intacs intracorneal ring segments (Addition Technology, Inc.). SETTING Departments of Ophthalmology and Pathology, Hospital Pellegrin, Bordeaux, France. METHODS This retrospective study included 8 keratoconic, contact-lens-intolerant eyes of 8 patients who had penetrating keratoplasty (PKP) after removal of Intacs inserts because of a poor refractive outcome or insert extrusion. Light microscopy was performed on all specimens after conventional staining. Immunohistochemistry was performed to identify cell types located next to the tunnel using AE1/AE3 cytokeratins, CD34, vimentin, collagen IV, and alpha-smooth muscle actin monoclonal antibodies. RESULTS Conventional histology showed hypoplasia of the epithelium immediately surrounding the channel. There was no evidence of an inflammatory response or foreign-body granuloma. Keratocyte density was decreased above and below the tunnel, and collagen IV synthesis was seen in the scar area. All samples stained negatively with alpha-smooth muscle actin, indicating that myofibroblasts were not present. These changes were no longer visible when PKP was performed more than 6 months after Intacs explantation. CONCLUSIONS Intacs induced keratocyte apoptosis, probably through a switch to a collagenous synthetic phenotype. Although histological changes seem to be entirely reversible after implant removal, longer follow-up is necessary to determine whether they accelerate corneal thinning and keratoconus progression via apoptosis and release of metalloprotease.
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Affiliation(s)
- Sépideh Samimi
- Ophthalmology and Pathology Departments, Hospital Pellegrin, Bordeaux, France
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Kymionis GD, Siganos CS, Tsiklis NS, Anastasakis A, Yoo SH, Pallikaris AI, Astyrakakis N, Pallikaris IG. Long-term follow-up of Intacs in keratoconus. Am J Ophthalmol 2007; 143:236-244. [PMID: 17184717 DOI: 10.1016/j.ajo.2006.10.041] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2006] [Revised: 10/15/2006] [Accepted: 10/16/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate long-term follow-up of Intacs microthin prescription inserts (Addition Technology, Inc, Fremont, California, USA) for the management of keratoconus. DESIGN A long-term (five years) retrospective, follow-up study. METHODS Seventeen eyes of 15 patients with keratoconus ages 24 to 52 years (mean age +/- standard deviation [SD], 34.0 +/- 10.5 years) who had completed five years of follow-up (mean follow-up +/- SD, 67.2 +/- 7.5 months; range, 58 to 78 months) were included. Two Intacs segments of 0.45-mm thickness were inserted in the cornea of each eye, aiming at embracing the keratoconus area to try to achieve maximal flattening. RESULTS No late postoperative complications occurred in this series of patients. At five years, the spherical equivalent error was statistically significantly reduced (pre-Intacs, mean +/- SD -5.54 +/- 5.02 diopters [D]; range, -12.50 to 3.63 D; -3.02 +/- 2.65 D; range, -8.25 to 1.88 D) (P = .01). Pre-Intacs uncorrected visual acuity (UCVA) was 20/50 or worse in all eyes (range, counting fingers to 20/50), whereas, at the last follow-up examination, 10 (59%) of 17 eyes had UCVA of 20/50 or better (range, counting fingers to 20/32). Six eyes (35%) maintained the pre-Intacs best spectacle-corrected visual acuity (BSCVA) and one eye lost 3 lines of BSCVA, whereas the rest of the 10 eyes (59%) experienced a gain of one up to 8 lines. CONCLUSIONS After five years, intracorneal ring segments implantation improved UCVA, BSCVA, and refraction in the majority of the keratoconus patients. There was no evidence of progressive sight-threatening complications in this study.
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Affiliation(s)
- George D Kymionis
- Department of Ophthalmology, Institute of Vision and Optics, University of Crete, Crete, Greece.
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Lai MM, Tang M, Andrade EMM, Li Y, Khurana RN, Song JC, Huang D. Optical coherence tomography to assess intrastromal corneal ring segment depth in keratoconic eyes. J Cataract Refract Surg 2006; 32:1860-5. [PMID: 17081869 PMCID: PMC1802100 DOI: 10.1016/j.jcrs.2006.05.030] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Accepted: 05/07/2006] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate intrastromal corneal ring segment depth with a high-speed corneal optical coherence tomography (OCT) system. SETTING Doheny Eye Institute, University of Southern California, Los Angeles, California, USA. METHODS A prospective observational case series comprised 4 eyes of 4 patients receiving Intacs intrastromal corneal ring segments (Addition Technology, Inc.) for keratoconus. Optical coherence tomography (OCT) was performed between 7 days and 43 days after implantation. RESULTS The slitlamp impression of intrastromal corneal ring segment implantation depth did not correlate well with OCT measurements (r(2) = 0.68). The fractional implantation depth was correlated with several surgical variables using a stepwise multivariate regression model, and 2 statistically significant correlations were found. The position of the distal portions of the ring segments was shallower than that of the portion closer to the insertion site (P = .003). Segments placed in the inferior cornea (P = .008) experienced more distal shallowing. Shallower depth was associated with greater fractional anterior stromal compression (P = .04). CONCLUSIONS Shallower placement of intrastromal corneal ring segments may result in more complications, such as epithelial-stromal breakdown and extrusion, because of the greater anterior stromal tensile strain. The distal and inferior portions of intrastromal corneal ring segments tended to be placed at a shallower depth. Optical coherence tomography provided precise measurement of ring segment depth and may help identify implants that pose a greater risk for depth-related complications.
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Affiliation(s)
- Michael M Lai
- Doheny Eye Institute and Department of Ophthalmology, University of Southern California, Los Angeles, California, USA
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Katsoulis K, Sarra GM, Schittny JC, Frueh BE. Bilateral Central Crystalline Corneal Deposits Four Years After Intacs for Myopia. J Refract Surg 2006; 22:910-3. [PMID: 17124888 DOI: 10.3928/1081-597x-20061101-13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To report a case of bilateral central crystalline keratopathy in the anterior stroma occurring 4 years after Intacs implantation. METHODS A 45-year-old woman underwent bilateral uncomplicated Intacs implantation for myopia. The postoperative course was uneventful. However, between 3 and 4 years after surgery, the patient developed central opacifications of the anterior stroma in both eyes, reducing best spectacle-corrected visual acuity. RESULTS Intacs were explanted. Confocal microscopy, electron microscopy of the explanted ring segments, and microbiology studies were performed. Opacities were still detectable at the slit-lamp microscope up to 8 months after explantation. CONCLUSIONS This is the first report on central corneal opacifications after Intacs implantation for myopia. The opacities could be the result of chronic metabolic stress or the beginning of lipid-like changes in another more central corneal localization.
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Kymionis GD, Tsiklis NS, Pallikaris AI, Kounis G, Diakonis VF, Astyrakakis N, Siganos CS. Long-term Follow-up of Intacs for Post-LASIK Corneal Ectasia. Ophthalmology 2006; 113:1909-17. [PMID: 17074560 DOI: 10.1016/j.ophtha.2006.05.043] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 04/14/2006] [Accepted: 05/26/2006] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To report long-term follow-up of Intacs microthin prescription inserts for the management of post-LASIK corneal ectasia. DESIGN Long-term (5 years), retrospective, nonrandomized study. PARTICIPANTS Eight eyes of 5 patients with post-LASIK corneal ectasia (3 men and 2 women) ages 31 to 54 years (mean age+/-standard deviation [SD], 41.60+/-9.24 years) who had completed 5 years of follow-up (mean follow-up +/- SD, 60.1+/-4.9 months; range, 57-68 months). INTERVENTION Two Intacs segments, inserted in the usual fashion, were used for low myopia correction (1 each nasally and temporally), with thickness based on the residual refraction of the patients. MAIN OUTCOME MEASURES Manifest refraction, uncorrected and best spectacle-corrected visual acuity, patient satisfaction, topography, and confocal microscopy analysis. RESULTS No intraoperative or late postoperative complications occurred in this series of patients. At 5 years, the SE error was statistically significantly reduced (pre-Intacs mean+/-SD, -5.47+/-2.66 diopters [D]; range, -11.50 to -3.00 D) to -2.56+/-3.44 D (range, -9.50 to 1.5 D; P = 0.01). At the end of the first postoperative year, refractive stability was obtained and remained stable during the follow-up period with no significant changes between the interval meantime (P>0.05). Pre-Intacs uncorrected visual acuity was 20/100 or worse in all eyes (range, counting fingers-20/100), whereas at the last follow-up examination, 6 (75%) of 8 eyes had uncorrected visual acuity of 20/40 or better (range, counting fingers-20/25). Two eyes (25%) maintained the pre-Intacs best spectacle-corrected visual acuity, whereas the rest of the eyes (6 eyes; 75%) experienced a gain of 1 or 2 lines. At the end of the first postoperative year, uncorrected and best-spectacle corrected visual acuity and topographic stability were obtained and were shown to have remained stable during the follow-up period with no significant changes between the interval meantime. Lamellar channel deposits were observed in confocal microscopy at or adjacent to the intrastromal ring segment. CONCLUSIONS Refractive stability was maintained for up to 5 years in the treatment of post-LASIK corneal ectasia after Intacs implantation. There was no evidence of progressive time-dependent corneal ectasia, late regression, or sight-threatening complications in this study.
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Affiliation(s)
- George D Kymionis
- Department of Ophthalmology, Institute of Vision and Optics, University of Crete, Medical School, Crete, Greece.
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Abstract
Confocal microscopy allows non-invasive in vivo imaging of the ocular surface. Its unique physical properties enable microscopic examination of all layers of the cornea and have been used to investigate numerous corneal diseases: epithelial changes, numerous stromal degenerative or dystrophic diseases, endothelial pathologies, corneal deposits, infections, and traumatic lesions. It offers a new approach to study the physiological reactions of the cornea to different stimuli and the pathophysiologic events leading to corneal dysfunction in certain diseases. Confocal microscopy proves to be a powerful diagnostic tool and is especially of value in certain corneal diseases by allowing straightforward and non-invasive recognition of the pathologic conditions.
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Ly LT, McCulley JP, Verity SM, Cavanagh HD, Bowman RW, Petroll WM. Evaluation of intrastromal lipid deposits after intacs implantation using in vivo confocal microscopy. Eye Contact Lens 2006; 32:211-5. [PMID: 16845269 DOI: 10.1097/01.icl.0000194530.68528.14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the structure and location of intrastromal lipid deposits after implantation of Intacs by using in vivo confocal microscopy. METHODS Seven eyes of six patients were examined by in vivo confocal microscopy 5 years (n = 6) or 2 months (n = 1) after uncomplicated implantation of Intacs for the correction of mild myopia. Selected images from all corneal layers were qualitatively evaluated for structural changes, with special attention paid to areas surrounding the Intacs implants. RESULTS In the peripheral cornea of eyes examined 5 years after surgery, epithelial and endothelial cell layers appeared normal. Tandem scanning confocal microscopy showed stromal haze surrounding the implants in all eyes examined, but no keratocyte activation was seen. Reflective amorphous or crystalline structures consistent with lipid deposition were detected in all eyes with long-term implantation of Intacs. Deposits were localized to the inner and outer edges of Intacs segments and to the region anterior to the implant. Confocal microscopy did not show any deposits in the eye examined 2 months after surgery, although the region anterior to the implant appeared hazy and edematous. Areas central to the implant appeared normal in all eyes. CONCLUSIONS The mechanical and physiologic stresses introduced by the implantation of Intacs lead to the accumulation of lipid deposits in the extracellular matrix. By using in vivo confocal microscopy, the location and structure of these deposits can be determined.
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Affiliation(s)
- Linda T Ly
- University of Texas Southwestern Medical School, University of Texas Southwestern Medical Center, Dallas, TX 75390-9057, USA
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Abstract
PURPOSE OF REVIEW To summarize the known uses of in-vivo confocal microscopy in refractive surgery, highlighting the current developments in the field. RECENT FINDINGS Examination of the cornea after laser in-situ keratomileusis demonstrated that the keratocyte density within the laser in-situ keratomileusis flap and anterior residual corneal bed continued to decline during the entire 3-year period of the study. The progressive loss of keratocytes in the flap and anterior portion of the residual corneal bed could have long-term implications in terms of corneal stability, refractive stability and cellular integrity after laser in-situ keratomileusis. Additional studies showed that the density of sub-basal nerves decreased by 90% 1 month after laser in-situ keratomileusis. At some point between 3 and 6 months after laser in-situ keratomileusis, the sub-basal nerves began to recover and by 2 years they had reached approximately 50% of their original preoperative density. Analysis of sub-basal nerve density after photorefractive keratectomy reported that the nerve density completely recovered to preoperative levels by 2 years. Other confocal microscopic studies demonstrated that the microscope can detect infectious organisms in vivo, without stains or dyes. SUMMARY The confocal microscope is a unique diagnostic instrument that can be used to evaluate corneal healing, long-term stability and to assess complications after refractive surgery. The ability of the device to view in-vivo cellular detail, microorganisms, inflammatory cells, epitheliod cells, fibrosis and measure the postoperative thickness of the residual corneal bed after laser in-situ keratomileusis, in a noninvasive manner, highlights the unique capabilities of this instrument.
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Randleman JB, Dawson DG, Larson PM, Russell B, Edelhauser HF. Chronic pain after Intacs implantation. J Cataract Refract Surg 2006; 32:875-8. [PMID: 16765809 DOI: 10.1016/j.jcrs.2006.01.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Accepted: 10/12/2005] [Indexed: 10/24/2022]
Abstract
A 39-year-old woman developed corneal ectasia after laser in situ keratomileusis. Intracorneal ring segments (Intacs, Addition Technology, Inc.) were placed in the left eye in November 2004. Postoperatively, inferior topographic steepening decreased significantly and a rigid gas-permeable lens yielded 20/25 visual acuity. However, the patient reported persistent discomfort that did not improve with topical medications or a bandage contact lens. In May 2005, confocal microscopy demonstrated a corneal nerve in direct contact with the inferior segment. Both segments were removed, and after removal, the patient reported complete resolution of the pain.
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Güell JL, Velasco F, Guerrero E, Gris O, Pujol J. Confocal Microscopy of Corneas With an Intracorneal Lens for Hyperopia. J Refract Surg 2004; 20:778-82. [PMID: 15586759 DOI: 10.3928/1081-597x-20041101-04] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE We evaluated short-term results and confocal microscopic corneal changes following intracorneal lens implantation. METHODS In six eyes of three patients with hyperopia between +3.00 and +6.00 diopters (D), an intrastromal hydrogel lens (Permavision, Anamed, Anaheim, Calif) was implanted. Mean baseline hyperopia was +3.90 D. Manifest refraction, uncorrected visual acuity, and spectacle-corrected visual acuity were evaluated. We also performed confocal real-time microscopy with a water immersion objective. Corneal optical sections were recorded and reviewed frame by frame. Examinations were done at months 3, 6, and 12 after intracorneal lens implantation. RESULTS After surgery, the spherical equivalent refraction was within +/- 0.50 D in 83% (five of six eyes) at 3 months and 100% (six eyes) at 6 and 12 months. Uncorrected visual acuity (UCVA) at 3 months was within 20/40 or better in 67% (four eyes) and in 100% (six eyes) at 6 and 12 months; no eyes had 20/20 or better UCVA at 3 and 6 months. One eye (17%) had 20/20 or better UCVA at 12 months. On confocal microscopy, one eye had an amorphous deposit adjacent to the lens and presumed fibroblastic activity in the same stromal area at 6 months, which was non-progressive up to 12 months. CONCLUSION Intracorneal lenses may be a treatment option for correction of spherical hyperopia. Predictability must be improved but results in these six eyes were stable up to 1 year. Confocal miscroscopy confirmed biocompatibility and showed no abnormal changes, except two spots of hypercellularity in one eye.
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Affiliation(s)
- José L Güell
- Instituto de Microcirugía Ocular, Departamento de Cornea, c/Munner 10, 10 CP 08022, Barcelona, Spain.
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Twa MD, Kash RL, Costello M, Schanzlin DJ. Morphologic Characteristics of Lamellar Channel Deposits in the Human Eye. Cornea 2004; 23:412-20. [PMID: 15097142 DOI: 10.1097/00003226-200405000-00021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To report the histologic characteristics of lamellar channel deposits after polymethyl methacrylate intrastromal corneal ring segments in a human eye. METHODS A 34-year-old man previously diagnosed with keratoconus received photorefractive keratectomy in his left eye that exacerbated his corneal ectasia. To delay or possibly prevent corneal transplant, the patient elected to have intrastromal corneal segments implanted in the left eye. One year later the patient underwent corneal transplant. Before transplant, lamellar channel deposits were noted on clinical microscopic examination of the left eye. We performed histologic evaluation to assess changes to the patient's excised corneal tissue and to further characterize the observed lamellar channel deposits. RESULTS Lamellar channel deposits in humans are histologically similar to our previous descriptions of deposits in rabbits. These deposits primarily consist of intracellular lipid accumulations that stain positively with oil red O and filipin but not periodic acid Schiff reaction. Immunohistochemistry of cells located in the deposit region stained positively with vimentin, suggesting that these cells were keratocytes. Stains for cytokeratins 3 and 12 and for CD68 were both negative, indicating that epithelial cells and macrophages were not present in the deposit region. CONCLUSION Lamellar channel deposits are a common clinical finding after intrastromal corneal implants. This case provides further evidence to support our hypothesis that lamellar channel deposits in humans are a tissue response to corneal implants that consist of intracellular lipid accumulations. We use this case to propose a theoretical construct for the observation of stromal lipid accumulation in response to corneal injury.
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Affiliation(s)
- Michael D Twa
- College of Optometry, The Ohio State University, Columbus, OH 43210-1240, USA.
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Kaufman SC, Musch DC, Belin MW, Cohen EJ, Meisler DM, Reinhart WJ, Udell IJ, Van Meter WS. Confocal microscopy. Ophthalmology 2004; 111:396-406. [PMID: 15019397 DOI: 10.1016/j.ophtha.2003.12.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To review the available evidence for the use of confocal microscopy in diagnosing infectious keratitis and for other applications for ophthalmic practice. METHODS A MEDLINE search of the peer-reviewed literature for the years 1990 to 2001 yielded 94 citations. The search was limited to studies of human subjects published in English with abstracts. The Ophthalmic Technology Assessment Committee Cornea Panel evaluated these 94 articles for possible clinical relevance and selected 51 (54%) for content review by the panel members. Of these 51 articles, 24 were selected for the panel methodologist to review and rate according to the strength of evidence. RESULTS Of the 24 articles, 21 (87.5%) were classified as case reports or case series and were rated as level III evidence. Three articles were classified as independent, masked, or objective comparisons performed in a narrow spectrum of patients or in a nonconsecutive series of patients and were rated as level II evidence. No studies were rated as level I evidence, defined as an independent masked comparison of an appropriate spectrum of consecutive patients. CONCLUSION Confocal microscopy is a new technology with clinical applications in ophthalmology. Although confocal microscopy has been used in other fields of medicine, the optical transparency of the cornea and other structures of the eye provides a unique opportunity to apply this technology. The targeted literature review of 24 articles found no level I studies to support the use of confocal microscopy in the management of eye disorders. Three level II studies pertained to promising clinical applications of the confocal microscope and provided evidence that supports the use of confocal microscopy as an adjunctive modality for diagnosing Acanthamoeba keratitis. The remaining 21 articles, rated as level III evidence, focus on the use of confocal microscopy to facilitate the diagnosis of infectious keratitis, including amoebic and fungal, but currently there are no definitive studies of its role in the differential diagnosis of this condition. There are also level III studies that support the use of the confocal microscope in refractive surgery. Facilitating the diagnosis of infectious keratitis and applying the confocal microscope to refractive surgery may hold the greatest promise of this new technology.
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Bourges JL, Trong TT, Ellies P, Briat B, Renard G. Intrastromal corneal ring segments and corneal anterior stromal necrosis. J Cataract Refract Surg 2003; 29:1228-30. [PMID: 12842696 DOI: 10.1016/s0886-3350(02)02036-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Poly(methyl methacrylate) refractive intracorneal ring segments (ICRS) can be removed for a refractive miscorrection or for early complications after implantation. We report the first case of a woman who experienced anterior stromal necrosis 5 years after an ICRS surgical procedure.
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Wirbelauer C, Winkler J, Scholz C, Häberle H, Pham DT. Experimental Imaging of Intracorneal Ring Segments With Optical Coherence Tomography. J Refract Surg 2003; 19:367-71. [PMID: 12777035 DOI: 10.3928/1081-597x-20030501-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the imaging of corneal structures with optical coherence tomography (OCT) after implantation of intracorneal ring segments (ICRS). METHODS In an experimental study with six porcine eyes, qualitative and quantitative imaging with corneal OCT using a wavelength of 1310 nm after implantation of ICRS was performed. The optical results were compared with light microscopy of the histological sections. RESULTS In corneal OCT, the ICRS revealed marked hyporeflective intrastromal areas, which correlated well with macroscopic and microscopic findings. Corneal OCT enabled precise images of the incision depth for the implantation of ICRS, and the exact intrastromal segment position. CONCLUSIONS Noncontact slit lamp-adapted corneal optical coherence tomography could be employed to clinically monitor corneal changes after implantation of ICRS, evaluate the depth of the segments to correlate refractive changes, and quantify the stromal wound healing response.
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Twa MD, Ruckhofer J, Kash RL, Costello M, Schanzlin DJ. Histologic evaluation of corneal stroma in rabbits after intrastromal corneal ring implantation. Cornea 2003; 22:146-52. [PMID: 12605051 DOI: 10.1097/00003226-200303000-00014] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Previous refractive corneal implants have produced histologic changes characteristic of nonspecific lipid keratopathy. Intacs intrastromal corneal ring segments are polymethylmethacrylate (PMMA) corneal inserts approved for the correction of low myopia by the U.S. Food and Drug Administration. The purpose of this study was to describe histologic changes associated with these corneal implants in rabbit eyes. METHODS Two 150-degree PMMA arc segments, 0.30 mm thick, were surgically implanted through a single radial incision at two-thirds stromal depth in the mid-peripheral cornea of five New Zealand white rabbits. We collected corneas 6 months after implantation that were prepared for light and electron microscopy. We analyzed tissue with oil red O, filipin, and periodic acid-Schiff (PAS) staining. Additional studies with energy-dispersive x-ray analysis and autofluorescent microscopy were conducted. RESULTS In all samples, we observed new collagen formation with lamellar organization adjacent to the implant and increased keratocyte density. Intracellular accumulations of osmophilic and saturated lipid material corresponded to stromal opacification visible by slit-lamp microscopy. These same regions were autofluorescent and stained positively with oil red O, and filipin but negatively with PAS. Granular lipid inclusions characteristic of lipofuscinosis were absent on transmission electron microscopy. Energy-dispersive x-ray analysis demonstrated elevated levels of calcium compared with adjacent tissue. CONCLUSION Tissue response to these corneal inserts includes keratocyte activation, intracellular lipid accumulation, and new collagen formation. Our histologic findings suggest that these deposit formations are not lipofuscin accumulations.
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Affiliation(s)
- Michael D Twa
- College of Optometry, The Ohio State University, 338 West 10th Avenue, Columbus, OH 43210-1240, USA.
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