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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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Nacaroglu SA, Yesilkaya EC, Perk FFNK, Tanriverdi C, Taneri S, Kilic A. Efficacy and safety of intracorneal allogenic ring segment implantation in keratoconus: 1-year results. Eye (Lond) 2023; 37:3807-3812. [PMID: 37328510 PMCID: PMC10698022 DOI: 10.1038/s41433-023-02618-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 05/15/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND To evaluate the safety and efficacy of corneal allogenic intrastromal ring segments in the management of keratoconus patients. METHODS The retrospective, nonrandomized, interventional case series consisted of 65 keratoconic eyes of 49 consecutive patients who had ring segment-shaped corneal allografts (KeraNatural®) implanted in intrastromal tunnels created using a femtosecond laser. The main outcome measures were uncorrected visual acuity (UCVA), corrected distant visual acuity (CDVA), refraction, keratometry, and pachymetry. Computed tomography scans of the corneal surfaces were also performed preoperatively as well as 3, 6 and 12 months postoperatively. RESULTS Mean age was 29.5 ± 7.3 years (median 29, range: 20-52 years). The mean UCVA improved from 0.91 ± 0.50 logMAR preoperatively to 0.40 ± 0.24 logMAR postoperatively at 6 month follow-up (p < 0.01) and the mean CDVA improved from 0.87 ± 0.20 logMAR preoperatively to 0.27 ± 0.06 logMAR postoperatively (p < 0.01). The mean spherical equivalent improved from -8.82 ± 4.57 to -3.45 ± 4.81D (p < 0.01). Average Keratometry decreased from 49.23 ± 5.22 preoperatively to 45.63 ± 4.89 D postoperatively (p < 0.01). Mean anterior and posterior maximum elevation were also decreased significantly (p < 0.01). In one patient, dislocation of the graft towards the tunnel incision site and dehiscense at the tunnel entrance were observed in the first week of the operation. Yellow-white deposits were observed in the segment tunnels in five cases after 6 months. CONCLUSION This study demonstrated that implantation of corneal allograft ring segments is a viable alternative treatment for keratoconus with safety and good visual results.
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Affiliation(s)
- Senay Asik Nacaroglu
- Faculty of Medicine, Ophthalmology Department, Istanbul Medipol University, Istanbul, Turkey.
| | - Elif Ceren Yesilkaya
- Şişli Hamidiye Etfal Training and Research Hospital, Department of Ophthalmology, University of Health Sciences, Istanbul, Turkey
| | | | - Cafer Tanriverdi
- Faculty of Medicine, Ophthalmology Department, Istanbul Medipol University, Istanbul, Turkey
| | - Suphi Taneri
- Ophthalmology Department, Augenzentrum am St. Franziskus Hospital, Munster, Germany
| | - Aylin Kilic
- Faculty of Medicine, Ophthalmology Department, Istanbul Medipol University, Istanbul, Turkey
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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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Bagheri NM, Kadkhodaei M, Pirhadi S, Mosaddegh P. Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis. Sci Rep 2021; 11:14433. [PMID: 34257343 PMCID: PMC8277910 DOI: 10.1038/s41598-021-93821-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 06/30/2021] [Indexed: 11/08/2022] Open
Abstract
The implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ([Formula: see text]) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower [Formula: see text] value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient's keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.
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Affiliation(s)
- Niksa Mohammadi Bagheri
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Mahmoud Kadkhodaei
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Shiva Pirhadi
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, 14778-93855, Iran
| | - Peiman Mosaddegh
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
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Tabatabaei SA, Soleimani M, Mirghorbani M, Tafti ZF, Rahimi F. Microbial keratitis following intracorneal ring implantation. Clin Exp Optom 2021; 102:35-42. [DOI: 10.1111/cxo.12810] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 04/12/2018] [Accepted: 06/17/2018] [Indexed: 11/26/2022] Open
Affiliation(s)
- Seyed Ali Tabatabaei
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | - Mohammad Soleimani
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | - Masoud Mirghorbani
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | | | - Firoozeh Rahimi
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
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Ibares-Frías L, Gallego-Muñoz P, Orive G, Anitua E, Cantalapiedra-Rodríguez R, Merayo-Lloves J, Martínez-García M. Potential Effect of Plasma Rich in Growth Factors-Endoret in Stromal Wound Healing in Additive Surgery. Ophthalmic Res 2019; 63:203-212. [DOI: 10.1159/000501507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 06/17/2019] [Indexed: 11/19/2022]
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Garcia-Ferrer FJ, Akpek EK, Amescua G, Farid M, Lin A, Rhee MK, Varu DM, Musch DC, Mah FS, Dunn SP. Corneal Ectasia Preferred Practice Pattern®. Ophthalmology 2019; 126:P170-P215. [DOI: 10.1016/j.ophtha.2018.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 02/07/2023] Open
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Puell MC, Carballo-Álvarez J. Forward light scatter and visual acuity before and after intrastromal corneal ring segment implantation at different stages of keratoconus. Acta Ophthalmol 2016; 94:e738-e743. [PMID: 27129433 DOI: 10.1111/aos.13056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/15/2016] [Indexed: 12/01/2022]
Abstract
PURPOSE To assess forward light scatter (stray light) before and after intrastromal corneal ring segment (ICRS) implantation at different stages of keratoconus and to examine correlation between postoperative stray light and visual acuity (VA). METHODS In 27 eyes of 27 subjects with keratoconus, stray light was determined using the compensation comparison technique before and 6 months after ICRS implantation. Monocular corrected distance VA (CDVA) was measured using a high-contrast logMAR letter chart. Corneal higher-order aberrations (HOAs), contrast sensitivity (CS) and minimum corneal thickness (CT) were also measured. RESULTS Mean CDVA was 0.42 ± 0.28 preoperatively and 0.24 ± 0.15 logMAR postoperatively (p < 0.01). Mean corneal coma-like aberration decreased postoperatively (RMS 0.55 ± 1.18 μm, p < 0.01). Minimum CT increased 25.31 ± 18.59 μm (p < 0.01). Mean preoperative and postoperative stray light were 1.36 ± 0.31 and 1.48 ± 0.32 log units, respectively (p < 0.01). Mean changes produced in stray light (worsening) were 0.03 ± 0.21 (p > 0.05) for stage I, 0.13 ± 0.14 (p = 0.013) for stage II and 0.18 ± 0.21 (p = 0.023) for stage III. Significant positive correlation (r = 0.47, p = 0.01) was detected between postoperative stray light and postoperative CDVA such that as stray light increased, CDVA worsened (higher logMAR values). Postoperative stray light was neither associated with HOAs, CS nor minimum CT. CONCLUSIONS Stray light values in these patients with keratoconus were higher than normal preoperatively. In eyes with stage II and III keratoconus, stray light increased 6 months after ICRS placement. Higher postoperative stray light was correlated with a worse visual acuity outcome.
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Affiliation(s)
- María Cinta Puell
- Applied Vision Research Group; Faculty of Optics and Optometry; Complutense University of Madrid; Madrid Spain
| | - Jesús Carballo-Álvarez
- Applied Vision Research Group; Faculty of Optics and Optometry; Complutense University of Madrid; Madrid Spain
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Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation. J Ophthalmol 2016; 2016:7127534. [PMID: 27795856 PMCID: PMC5066027 DOI: 10.1155/2016/7127534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 08/02/2016] [Indexed: 12/02/2022] Open
Abstract
Purpose. To evaluate surgically induced astigmatism (SIA) and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS) implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was used to evaluate the SIA. Hotelling's trace test was used to compare intraindividual changes. Results. Three months postoperatively, the combined mean polar value for SIA changed significantly (Hotelling's T2 = 0.375; P = 0.006). The SIA was 1.54 D at 99° and the average corneal power decreased significantly by 3.8 D. Conclusion. Intacs SK ICRS placement decreased the average corneal power and corneal astigmatism compared to the preoperative corneal power and astigmatism when the corneal pocket incision was made at the preoperative steep meridian.
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Vega-Estrada A, Alio JL. The use of intracorneal ring segments in keratoconus. EYE AND VISION 2016; 3:8. [PMID: 26981548 PMCID: PMC4791885 DOI: 10.1186/s40662-016-0040-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 03/06/2016] [Indexed: 12/31/2022]
Abstract
Keratoconus is a corneal degeneration that usually appears during puberty and may seriously deteriorate the quality of life of the patients. This corneal disease is today the first indication of corneal transplantation in young patients. Until the last decade of the XX century, keratoplasty procedures were the only alternative to treat this pathological condition. In the beginning of the XXI century, intracorneal ring segments implantation was proposed as a therapeutic choice for treating keratoconus patients. Since then, several published articles have reported the benefits of this surgical procedure in treating this type of corneal ectatic disorder. The purpose of the present investigative work is to summarize the characteristic of the intracorneal ring segments and also to review the different features published in the literature in relation to this surgical technique for the treatment of keratoconus patients.
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Affiliation(s)
- Alfredo Vega-Estrada
- Keratoconus Unit, Vissum Alicante, Calle Cabañal, 1 Edificio Vissum, 03016 Alicante, Spain ; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
| | - Jorge L Alio
- Keratoconus Unit, Vissum Alicante, Calle Cabañal, 1 Edificio Vissum, 03016 Alicante, Spain ; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
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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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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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Kramer EG, Boshnick EL. Scleral lenses in the treatment of post-LASIK ectasia and superficial neovascularization of intrastromal corneal ring segments. Cont Lens Anterior Eye 2015; 38:298-303. [DOI: 10.1016/j.clae.2015.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 02/02/2015] [Indexed: 10/23/2022]
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A review of collagen cross-linking in cornea and sclera. J Ophthalmol 2015; 2015:289467. [PMID: 25922758 PMCID: PMC4398937 DOI: 10.1155/2015/289467] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/25/2015] [Indexed: 11/18/2022] Open
Abstract
Riboflavin/UVA cross-linking is a technique introduced in the past decades for the treatment of keratoconus, keratectasia, and infectious keratitis. Its efficacy and safety have been investigated with clinical and laboratory studies since its first clinical application by Wollensak for the treatment of keratoconus. Although its complications are encountered during clinical practice, such as infection inducing risk, minimal invasion merits a further investigation on its future application in clinical practice. Recently, collagen cross-linking in sclera shows a promising prospect. In present study, we summarized the representative studies describing the clinical and laboratory application of collagen cross-linking published in past decades and provided our opinion on the positive and negative results of cross-linking in the treatment of ophthalmic disorders.
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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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Dexl AK, Jell G, Strohmaier C, Seyeddain O, Riha W, Rückl T, Bachernegg A, Grabner G. Long-term outcomes after monocular corneal inlay implantation for the surgical compensation of presbyopia. J Cataract Refract Surg 2015; 41:566-75. [PMID: 25726504 DOI: 10.1016/j.jcrs.2014.05.051] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 05/05/2014] [Accepted: 05/08/2014] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate long-term outcomes of small-aperture corneal inlay implantation for the surgical compensation of presbyopia. SETTING Paracelsus Medical University, Salzburg, Austria. DESIGN Prospective interventional cohort study. METHODS Monocular implantation of a Kamra small-aperture inlay (model ACI7000) (1.6 mm central aperture) was performed in emmetropic presbyopic eyes. The preoperative and postoperative parameters included monocular and binocular uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected intermediate visual acuity (UIVA), and uncorrected (UNVA) and corrected (CNVA) near visual acuities; refraction; patient satisfaction; and complications. RESULTS From September 4, 2006, to May 21, 2007, a small-aperture inlay (1.6 mm central aperture) was implanted in 32 emmetropic presbyopic eyes. The mean binocular uncorrected visual acuities improved as follows: UNVA from Jaeger (J) 6 ± 1.2 lines (∼20/50) to J2 ± 1.8 lines (∼20/25) (P < .001) and UIVA from 0.2 logMAR ± 1.3 lines (∼20/32) to 0.1 logMAR ± 1.3 lines (∼20/25) (P = .04). The UDVA decreased from -0.2 logMAR ± 0.2 lines (∼20/12.5) to -0.1 logMAR ± 0.6 lines (∼20/16) (P < .001). At 60 months, 74.2% of patients had a UNVA of J3 (∼20/32) or better, 87.1% had a UIVA of 0.2 logMAR (∼20/32) or better, and 93.5% had a UDVA of 0.0 logMAR (∼20/20) or better. One inlay was removed after 36 months because of patient dissatisfaction with vision after a hyperopic shift in the surgical eye, with no loss of CDVA or CNVA 2 years after removal. CONCLUSION Long-term results of monocular corneal inlay implantation indicate increased UNVA and UIVA and slightly compromised UDVA in emmetropic presbyopic eyes. FINANCIAL DISCLOSURE Dr. Grabner was reimbursed for travel expenses from Acufocus. Dr. Riha is a consultant to Acufocus. No other author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Alois K Dexl
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria.
| | - Gerlinde Jell
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Clemens Strohmaier
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Orang Seyeddain
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Wolfgang Riha
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Theresa Rückl
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Alexander Bachernegg
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
| | - Günther Grabner
- From the Department of Ophthalmology, Paracelsus Medical University in Salzburg, Salzburg, Austria
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Arlt EM, Krall EM, Moussa S, Grabner G, Dexl AK. Implantable inlay devices for presbyopia: the evidence to date. Clin Ophthalmol 2015; 9:129-37. [PMID: 25609913 PMCID: PMC4298303 DOI: 10.2147/opth.s57056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
By 2020, it is estimated that 2.1 billion people will be presbyopic, and the demand for spectacle independence in this group is growing. This review article provides an overview of the three commercially available corneal inlays for the correction of presbyopia. Safety, efficacy, visual outcomes, and complications are analyzed for all three inlays according to published peer-reviewed data.
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Affiliation(s)
- EM Arlt
- Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - EM Krall
- Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - S Moussa
- Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - G Grabner
- Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - AK Dexl
- Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria
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Intracorneal Ring Segment Explantation After Intracorneal Ring Segment Implantation Combined With Same-Day Corneal Collagen Crosslinking in Keratoconus. Cornea 2013; 32:1617-20. [DOI: 10.1097/ico.0b013e3182a738ba] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Yeung SN, Ku JY, Lichtinger A, Low SA, Kim P, Rootman DS. Efficacy of single or paired intrastromal corneal ring segment implantation combined with collagen crosslinking in keratoconus. J Cataract Refract Surg 2013; 39:1146-51. [DOI: 10.1016/j.jcrs.2013.03.022] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 03/04/2013] [Accepted: 03/08/2013] [Indexed: 11/29/2022]
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23
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Rho CR, Na KS, Yoo YS, Pandey C, Park CW, Joo CK. Changes in Anterior and Posterior Corneal Parameters in Patients with Keratoconus After Intrastromal Corneal-ring Segment Implantation. Curr Eye Res 2013; 38:843-50. [DOI: 10.3109/02713683.2013.788723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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24
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Seyeddain O, Bachernegg A, Riha W, Rückl T, Reitsamer H, Grabner G, Dexl AK. Femtosecond laser–assisted small-aperture corneal inlay implantation for corneal compensation of presbyopia: Two-year follow-up. J Cataract Refract Surg 2013; 39:234-41. [DOI: 10.1016/j.jcrs.2012.09.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 09/05/2012] [Accepted: 09/14/2012] [Indexed: 11/30/2022]
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Niknam S, Shamshiri M, Shahrzad SS, Alipour A, Rajabi MB, Rajabi MT. Treatment of moderate to severe keratoconus with 6-mm Intacs SK. Int J Ophthalmol 2012; 5:513-6. [PMID: 22937516 DOI: 10.3980/j.issn.2222-3959.2012.04.21] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 06/25/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To evaluate the effect of Intacs SK corneal ring segment implant for treatment of patients with moderate to severe keratoconus, who have clear central cornea and cannot tolerate contact lens. METHODS In this prospective, non-comparative, interventional case series study performed in Dena Hospital, Shiraz, Iran, thirty-seven eyes of thirty-six patients with moderate to severe keratoconus, clear central cornea, and contact lens intolerance were enrolled and underwent Intacs SK corneal ring segment implantation. Preoperatively, uncorrected distance visual acuity (UCDVA), best-corrected distance visual acuity (BCDVA), central corneal thickness(CCT) and average keratometry (Av-K) were measured and compared with post-operative results at one week, one month, three months, and six months. RESULTS Mean preoperative UCDVA and BCDVA were (1.32±0.31)logMAR and (1.07±0.27)logMAR, respectively. Av-K was (52.13±0.39)D, and the CCT was (432±39.5)µm. Post-operative examinations showed a clinically significant improvement in both UCDVA and BCDVA (P<0.001). There was also a significant effect based on the time of assessment on both UCDVA and BCDVA and both parameters had a continuous improvement during the follow-up period. Three months after operation there was a statistical significant reduction of Av-K (P=0.0001), but there were no significant changes in CCT (P=0.149). CONCLUSION Intacs SK corneal ring segment implants seem to be a safe and effective treatment option for patients who have keratoconus, clear central cornea, and contact lens intolerance.
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Affiliation(s)
- Sasan Niknam
- Cornea Unit, Dr Khodadoust Eye Hospital, Shiraz, Iran
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26
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Al-Amry M, Alkatan HM. Histopathologic findings in two cases with history of intrastromal corneal ring segments insertion. Middle East Afr J Ophthalmol 2012; 18:317-9. [PMID: 22224023 PMCID: PMC3249820 DOI: 10.4103/0974-9233.90136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Intrastromal corneal ring segments (INTACS) implantation for mild myopia or keratoconus is simple and effective in most cases. Rarely, major complications can occur due to implantation. In this case report, we present two examples of possible intraoperative and postoperative complications of INTACS. The first case had histopathologic documentation of Descemet's membrane perforation as an intraoperative complication and the second case had accumulation of foamy histiocytes along the lamellar channels which has not been previously reported. These complications suggest further study is required on the long term effect of INTACS implantation on corneal tissue.
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Affiliation(s)
- Mohammad Al-Amry
- Anterior Segment Division and Emergency Room, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia
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27
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Kim SB, Chang MH. A Case of Fungal Keratitis after Intracorneal Ring Segment Implantation for Keratoconus. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2012. [DOI: 10.3341/jkos.2012.53.6.866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Si Bum Kim
- Department of Ophthalmology, Dankook University Medical College, Cheonan, Korea
| | - Moo Hwan Chang
- Department of Ophthalmology, Dankook University Medical College, Cheonan, Korea
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28
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Kim EJ, Koo SH, Lee GJ, Lee KW, Park YJ. The Clinical Results of Intacs® Ring Implantation by Manual Tunnel Creation in Patients with Keratoconus. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2012. [DOI: 10.3341/jkos.2012.53.12.1756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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29
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Dexl AK, Seyeddain O, Riha W, Hohensinn M, Rückl T, Reischl V, Grabner G. One-year visual outcomes and patient satisfaction after surgical correction of presbyopia with an intracorneal inlay of a new design. J Cataract Refract Surg 2011; 38:262-9. [PMID: 22138501 DOI: 10.1016/j.jcrs.2011.08.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 05/29/2011] [Accepted: 08/06/2011] [Indexed: 11/18/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of the third-generation Kamra corneal inlay (ACI 7000PDT) implanted monocularly in corneal pockets of emmetropic presbyopic patients to improve near and intermediate vision. SETTING University Eye Clinic, Paracelsus Medical University, Salzburg, Austria. DESIGN Cohort study. METHODS The corneal inlay was implanted in the nondominant eye over the line of sight by creating a corneal pocket with a femtosecond laser. The minimum postoperative follow-up was 12 months. Distance, intermediate, and near visual acuities were assessed over the follow-up. Other examinations included slitlamp evaluation, central keratometry, computerized corneal topography, endothelial cell count, and central corneal thickness. Patients completed satisfaction questionnaires preoperatively and 3, 6, and 12 months postoperatively. RESULTS The study evaluated 24 patients. After a mean follow-up of 12 months, 92% of patients read Jaeger (J) 3 or better with the surgical eye, the mean binocular uncorrected near visual acuity improved from J5 preoperatively to J2, and the mean binocular uncorrected intermediate visual acuity was 20/20 (67% ≥ 20/20). At 12 months, the mean uncorrected distance visual acuity was 20/20 in the surgical eye and 20/16 binocularly. Patients reported no change in distance vision, and their need for reading glasses decreased significantly (P<.001). No inlay was explanted and or recentered during the reported follow-up. CONCLUSION The new corneal inlay was a safe and effective treatment for presbyopia over a 1-year follow-up.
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Affiliation(s)
- Alois K Dexl
- University Eye Clinic, Paracelsus Medical University, Salzburg, Austria.
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30
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Seyeddain O, Hohensinn M, Riha W, Nix G, Rückl T, Grabner G, Dexl AK. Small-aperture corneal inlay for the correction of presbyopia: 3-year follow-up. J Cataract Refract Surg 2011; 38:35-45. [PMID: 22018596 DOI: 10.1016/j.jcrs.2011.07.027] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 07/21/2011] [Accepted: 07/25/2011] [Indexed: 11/16/2022]
Abstract
PURPOSE To report the 3-year postoperative safety and efficacy outcomes of the Acufocus corneal inlay. SETTING University Eye Clinic, Paracelsus Medical University, Salzburg, Austria. DESIGN Prospective nonrandomized noncomparative cohort study. METHODS The corneal inlay was implanted in the nondominant eye of naturally emmetropic presbyopic patients. Refraction, uncorrected near (UNVA), intermediate (UIVA), and distance (UDVA) visual acuities; corrected distance visual acuity (CDVA); contrast sensitivity; visual fields; subjective patient satisfaction and symptoms; and operative and postoperative adverse events and complications were evaluated. RESULTS The study enrolled 32 patients. The mean UNVA improved from Jaeger (J) 6 preoperatively to J1 at 3 years and the mean UIVA, from 20/40 to 20/25, respectively. At 3 years, 97% of eyes had a UNVA of J3 or better and 91% had a UIVA of 20/32 or better. The mean UDVA was 20/20, with all eyes achieving 20/32 or better. Nine eyes (28.3%) lost 1 line of CDVA, 1 eye (3.1%) lost more than 2 lines (3.8 lines), and 3 eyes (9.3%) gained 1 line. No inlay was explanted, and no inflammatory reactions were observed. At 3 years, 15.6% of patients reported severe night-vision problems and 6.3% (versus 87.5% preoperatively) reported being dependent on reading glasses. CONCLUSIONS These 3-year results support the safety and efficacy of the corneal inlay to correct presbyopia in naturally emmetropic presbyopic patients. However, despite a significant gain in UNVA and UIVA, 28.3% of patients lost 1 line of CDVA.
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Affiliation(s)
- Orang Seyeddain
- University Eye Clinic, Paracelsus Medical University, Salzburg, Austria.
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31
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Espandar L, Meyer J. Keratoconus: overview and update on treatment. Middle East Afr J Ophthalmol 2011; 17:15-20. [PMID: 20543932 PMCID: PMC2880369 DOI: 10.4103/0974-9233.61212] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Keratoconus is a non-inflammatory, progressive thinning process of the cornea. It is a relatively common disorder of unknown etiology that can involve each layer of the cornea and often leads to high myopia and astigmatism. Computer- assisted corneal topography devices are valuable diagnostic tools for the diagnosis of subclinical keratoconus and for tracking the progression of the disease. The traditional conservative management of keratoconus begins with spectacle correction and contact lenses. Several newer, more invasive, treatments are currently available, especially for contact lens-intolerant patients. Intrastromal corneal ring segments can be used to reshape the abnormal cornea to improve the topographic abnormalities and visual acuity. Phakic intraocular lenses such as iris-fixated, angle-supported, posterior chamber implantable collamer and toric lenses are additional valuable options for the correction of refractive error. Corneal cross-linking is a relatively new method of stiffening the cornea to halt the progression of the disease. The future management of keratoconus will most likely incorporate multiple treatment modalities, both simultaneous and sequential, for the prevention and treatment of this disease.
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Affiliation(s)
- Ladan Espandar
- Department of Ophthalmology, Tulane University, New Orleans, LA, USA
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32
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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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Renesto ADC, Campos M. Intrastromal Corneal Ring Segments. Cornea 2011. [DOI: 10.1016/b978-0-323-06387-6.00176-8] [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]
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Pérez-Merino P, Parra F, Ibares-Frías L, Gallego P, Vázquez-Lasa B, Benito L, San Román J, Martínez-García C, Merayo-Lloves J. Clinical and pathological effects of different acrylic intracorneal ring segments in corneal additive surgery. Acta Biomater 2010; 6:2572-9. [PMID: 20080217 DOI: 10.1016/j.actbio.2010.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 12/17/2009] [Accepted: 01/11/2010] [Indexed: 11/19/2022]
Abstract
The objective of this work was to evaluate the potential use of less stiff materials based on acrylic copolymers of methyl methacrylate/2-ethylhexyl acrylate (MMA/EHA) as devices to correct, stabilize and improve the effect of poly(methyl methacrylate) (PMMA) intracorneal ring segments. MMA/EHA and PMMA intracorneal ring segments were surgically implanted in the corneas of Lohmann Classic hens. The effects of the intracorneal ring segments were assessed by optical measurements and corneal tolerance was evaluated through biomicroscopic examination over a 90-day observation period and by conventional histology. The experimental results demonstrated that the intracorneal ring segments made of MMA/EHA copolymers provided a significant change in the corneal curvature and an improved in vivo response compared to those obtained for PMMA rings, which was attributed to the higher flexibility of the copolymeric materials, indicating that these systems might be considered suitable as an alternative to those currently used, for application in clinical practice.
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Affiliation(s)
- P Pérez-Merino
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), University of Valladolid, Valladolid, Spain
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36
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Kubaloglu A, Cinar Y, Sari ES, Koytak A, Ozdemir B, Ozertürk Y. Comparison of 2 intrastromal corneal ring segment models in the management of keratoconus. J Cataract Refract Surg 2010; 36:978-85. [DOI: 10.1016/j.jcrs.2009.12.031] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 10/02/2009] [Accepted: 12/04/2009] [Indexed: 10/19/2022]
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37
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Ferrer C, Alió JL, Montañés AU, Pérez-Santonja JJ, Diaz del Rio MA, de Toledo JA, Teus MA, Javaloy J. Causes of intrastromal corneal ring segment explantation: Clinicopathologic correlation analysis. J Cataract Refract Surg 2010; 36:970-7. [DOI: 10.1016/j.jcrs.2009.12.042] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 11/27/2009] [Accepted: 12/03/2009] [Indexed: 10/19/2022]
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Seyeddain O, Riha W, Hohensinn M, Nix G, Dexl AK, Grabner G. Refractive surgical correction of presbyopia with the AcuFocus small aperture corneal inlay: two-year follow-up. J Refract Surg 2010; 26:707-15. [PMID: 20438021 DOI: 10.3928/1081597x-20100408-01] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 02/16/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of the AcuFocus Corneal Inlay 7000 (ACI 7000) implanted in emmetropic presbyopic patients for the improvement of near and intermediate vision over 2-year follow-up. METHODS This prospective, non-randomized, non-comparative study included 32 naturally emmetropic presbyopic patients. The intracorneal inlay was implanted in the non-dominant eye over the pupil by creating a superior-hinged flap with the IntraLase 60-kHz femtosecond laser (Abbott Medical Optics). Inlay centration was over the line of sight. Minimum postoperative follow-up was 24 months. RESULTS After mean follow-up of 24.2±0.8 months (range: 24 to 26 months), 96.9% of patients read J3 or better in the implanted eye. Mean binocular uncorrected near visual acuity improved from J6 preoperatively to J1 after 24 months. Mean binocular uncorrected intermediate visual acuity (UIVA) was 20/20 at 1 month and remained 20/20 throughout 24-month follow-up, with 71.9% of eyes reaching UIVA of 20/20 or better. At 24 months, mean uncorrected distance visual acuity was 20/20 in the implanted eye and 20/16 binocularly. No inlay was explanted during the study. Two decentered inlays were recentered after 6 months because of in-sufficient increase in near and intermediate visual acuity. Both patients' near and intermediate visual acuity improved significantly after recentration. CONCLUSIONS The ACI 7000 seems to provide a safe and effective treatment for presbyopia over follow-up of 2 years.
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Affiliation(s)
- Orang Seyeddain
- University Eye Clinic, Paracelsus Medical University, Müllner Hauptstraße 48, A-5020 Salzburg, Austria.
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Piñero DP, Alio JL. Intracorneal ring segments in ectatic corneal disease - a review. Clin Exp Ophthalmol 2010; 38:154-67. [DOI: 10.1111/j.1442-9071.2010.02197.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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40
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Intrastromal corneal ring segment implantation for high astigmatism after penetrating keratoplasty. J Cataract Refract Surg 2009; 35:1878-84. [DOI: 10.1016/j.jcrs.2009.05.060] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 05/07/2009] [Accepted: 05/11/2009] [Indexed: 11/20/2022]
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41
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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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Shetty R, Narayana KM, Mathew K, Anand D, Mhaske P, Shetty BK. Safety and efficacy of Intacs in Indian eyes with keratoconus: an initial report. Indian J Ophthalmol 2009; 57:115-9. [PMID: 19237784 PMCID: PMC2684424 DOI: 10.4103/0301-4738.44517] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Context In contact lens-intolerant keratoconus patients, intrastromal placement of Intacs is becoming a promising new modality of treatment. Aims To study the safety and efficacy of implantation of microthin corneal inserts (Intacs) in Asian-Indian keratoconus patients. Settings and Design Retrospective interventional case series, in the cornea and refractive surgery service, at a tertiary care eye hospital in South India, between May 2006 and July 2007. Materials and Methods Intacs (Addition Technology, USA) were successfully implanted by mechanically creating tunnels, in 12 eyes of 12 keratoconus patients, who were contact lens-intolerant. The patients (mean age 25.58 years, nine male and three female) had a minimum follow-up of six months. Five patients had severe keratoconus (mean K > 53 D) and nine had central cones. Results All patients improved or retained visual acuity. The uncorrected visual acuity (UCVA) improved from a mean value of 0.06, (SD ± 0.08) to 0.19 postoperatively (SD± 0.15) (P= 0.01). The change in mean best corrected visual acuity (BCVA) was from 0.51, (SD ± 0.24), to 0.69, (SD ±0.00) (P = 0.01) postoperatively. The average central keratometry reading was 52.55 D. The change in mean K from 52.84 to 49.16 and 49.15 at one and six months respectively, was statistically significant. We did not have any major intra- or early postoperative complications. Eight of 12 eyes became contact lens-tolerant post-surgery. Conclusion The procedure of Intacs implantation appears to be safe and effective in a small group of Indian population at an intermediate follow-up.
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Affiliation(s)
- Rohit Shetty
- Department of Cataract and Refractive Surgery, Narayana Nethralaya, Bangalore, India.
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Kim HS, Lee TH, Lee KH. Intracorneal Ring Segment Implantation for the Management of Keratoconus: Short-Term Safety and Efficacy. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2009. [DOI: 10.3341/jkos.2009.50.10.1505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ertan A, Colin J. Intracorneal rings for keratoconus and keratectasia. J Cataract Refract Surg 2007; 33:1303-14. [PMID: 17586391 DOI: 10.1016/j.jcrs.2007.02.048] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
Intrastromal corneal ring segments were designed to achieve refractive adjustment by flattening the cornea. Recently, they have been used to reshape keratoconic corneas to improve uncorrected visual acuity, best corrected visual acuity, and contact lens tolerance and to delay or prevent the need for keratoplasty. Intracorneal ring segments have several distinct and important advantages. New thicknesses and different ring sizes and the use of femtosecond lasers to dissect channels inside the cornea will likely improve the surgical outcomes. This article reviews the latest data published or presented at meetings on the correction of keratoconus and keratectasia by intracorneal ring segments.
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Affiliation(s)
- Aylin Ertan
- Kudret Eye Hospital, Ankara, Turkey, and the Bordeaux University, Bordeaux, France.
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Lyra JM, Trindade FC, Lyra D, Bezerra A. Outcomes of radiofrequency in advanced keratoconus. J Cataract Refract Surg 2007; 33:1288-95. [PMID: 17586389 DOI: 10.1016/j.jcrs.2007.03.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Accepted: 03/22/2007] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the use of radiofrequency energy to correct advanced keratoconus. SETTING Universidade Federal de Minas Gerais, Belo Horizonte, and Universidade de Ciências da Saúde de Alagoas, Maceió, Brazil. METHODS In this prospective comparative study, radiofrequency was applied to 25 eyes of 21 consecutive patients. One group comprised patients with a K-reading between 54.0 diopters (D) and 58.0 D; 8 thermal spots were placed at the 4.0 mm optical zone. The other group comprised patients with a K-reading greater than 58.0 D; 16 spots were applied at the 4.0 mm and 5.0 mm optical zones. The minimum follow-up was 18 months in all patients. Differences between preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), manifest refraction, and K-readings were clinically and statistically evaluated. RESULTS At end of the 18-month follow-up, the mean BSCVA in the 8-spot group improved from 20/100 (0.71+/-0.25 logMAR) preoperatively to 20/40 (0.32+/-0.11 logMAR) and in the 16-spot group, from 20/200 (1.03+/-0.30 logMAR) to 20/60 (0.62+/-0.22 logMAR). The mean manifest refractive spherical equivalent (MRSE) improved from -7.70 D+/-5.20 (SD) preoperatively to -6.82+/-4.41 D after 18 months in the 8-spot group and from -11.33+/-6.70 to -8.38+/-5.12 D, respectively, in the 16-spot group. The mean best contact lens-corrected visual acuity was 20/30 (0.18+/-0.24 logMAR) in the 8-spot group and 20/40 (0.31+/-0.19 logMAR) in the 16-spot group. A dense corneal scar was seen in 1 patient in the 16-spot group at the 6-month follow-up. CONCLUSIONS Radiofrequency appeared safe for the treatment of advanced keratoconus. Contact lens fitting was stable in all cases.
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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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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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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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Alió JL, Shabayek MH, Artola A. Intracorneal ring segments for keratoconus correction: Long-term follow-up. J Cataract Refract Surg 2006; 32:978-85. [PMID: 16814056 DOI: 10.1016/j.jcrs.2006.02.044] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Accepted: 11/29/2005] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate long-term results and stability of intracorneal ring segment (Intacs) implantation for keratoconus correction. SETTING Vissum, Instituto Oftalmológico de Alicante and University of Miguel Hernandez, Alicante, Spain. METHODS This retrospective study comprised 13 eyes operated on between April 2000 and December 2001 that had Intacs implantation for keratoconus correction. The outcomes were evaluated at 6, 12, 24, and 36 months in all eyes and at 48 months (6 eyes). RESULTS Mean best spectacle-corrected visual acuity (BSCVA) increased from 0.46 (20/50) preoperatively to 0.66 (20/30) postoperatively (P< or =.001). Mean decrease of inferior-superior (I-S) asymmetry was 2.81 diopters (D) (P< or =.02), and the average K-value was 3.13 D (P< or =.001). Mean difference between 6 and 36 months (stability) showed no significant difference regarding BSCVA (P< or =.5) and I-S asymmetry (P< or =.6). Although a significant increase was noticed in the average K by 1.67 D (P< or =.002), at 36 months it did not reach the initial preoperative values. CONCLUSION Intacs increased the BSCVA and decreased I-S asymmetry with stability up to 36 months. In spite of the decrease of the K-values at 6 months, a further significant increase was detected 36 months after surgery.
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Affiliation(s)
- Jorge L Alió
- Department of Cornea and Refractive Surgery, Instituto Oftalmológico de Alicante, Vissum, Spain.
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