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Ibares-Frías L, Fernández-Vega-Cueto L, Alfonso-Bartolozzi B, Poo-López A, Madrid-Costa D, Alfonso JF. Long-Term Follow-Up of a 150° Arc-Length Intrastromal Corneal Ring Segment Implantation in Post-LASIK Ectasia. Curr Eye Res 2022; 48:365-370. [PMID: 36524598 DOI: 10.1080/02713683.2022.2159983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE To evaluate the outcomes of implanting a 150° arc-length intrastromal corneal ring segment (ICRS) using a femtosecond laser in patients with post-LASIK ectasia throughout a 5-year follow-up period. METHODS This study enrolled 45 eyes of 45 patients diagnosed with post-LASIK ectasia who underwent a 150° arc-length Ferrara-type ICRS implantation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, residual refractive errors, and root mean square (RMS) for coma-like aberration were evaluated preoperatively and at 6-, 12-, 36, and 60 months postoperatively. RESULTS Mean UDVA (logMAR) ameliorated from 0.53 ± 0.33 preoperatively to 0.26 ± 0.24 at 6 months postoperatively (p < 0.0001). Mean CDVA improved from 0.12 ± 0.13 to 0.04 ± 0.06 (p < 0.0001). Mean UDVA and CDVA remained stable throughout the 5-year follow-up (p > 0.1). No eyes lost lines of CDVA at any follow-up visit compared to preoperatively, and most eyes gained lines. The eyes with a refractive cylinder ≤ 2.00 D varied from 26.7% preoperatively to more than 75% at all postoperative follow-up visits. The maximum keratometry was significantly flattened (p < 0.0001), and the RMS for corneal coma-like aberration was halved (p < 0.0001). 93.3% of the eyes did not show signs of disease progression or regression of the visual or refractive outcomes at any follow-up visits. CONCLUSION These results suggest that implanting a single 150° arc-length Ferrara-type ICRS is a safe, effective and stable procedure for visual restoration in post-LASIK ectasia. In very few cases, visual and/or refractive instability was experienced throughout the follow-up.
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Affiliation(s)
- Lucía Ibares-Frías
- Fernández-Vega Ophthalmological Institute, Oviedo, Spain
- Department of Ophthalmology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | | | | | | | - David Madrid-Costa
- Clinical and Experimental Eye Research (CEER). Optometry and Vision Department, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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Hashemian SJ, Abdolalizadeh P, Ghiasian L, Aghaei H, Hadavandkhani A, Semnani FN, Jafari ME, Hashemian SM, Hashemian MS. Outcomes of a Single-Segment Intrastromal Corneal Ring in Early Keratoconus and Early Pellucid Marginal Degeneration. Int Ophthalmol 2022; 42:2987-2996. [PMID: 35389172 DOI: 10.1007/s10792-022-02284-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 03/12/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the effect of a single-segment intrastromal corneal ring segment (ICRS; Intacs SK) on early keratoconus (KCN) and pellucid marginal degeneration (PMD). METHODS It is a prospective interventional study. One hundred twenty-four eyes (99 patients) with KCN and 36 eyes (26 patients) with PMD at early stage (the maximum keratometric reading less than 55 diopters) were included to ICRS implantation using femtosecond laser at a tertiary university-based hospital and a private outpatient center. The uncorrected distance and spectacle-corrected visual acuity (UDVA and SCDVA), manifest spherical and cylindrical refractions, and keratometry indices were measured preoperatively and postoperatively, 1 week, 2 and 6 months. RESULTS One week after surgery, significant improvements were observed in UDVA, SCDVA, cylinder and keratometry readings of both KCN and PMD groups (all P < 0.05) with no significant changes afterward. No significant change occurred in the sphere refraction of PMD group (P = 0.10) in contrast to KCN group (P < 0.001). Corneal irregularity of KCN group in central 3 and 5 mm zones increased at 1 week (both P < 0.001) and then started to decrease up to 6 months. However, the corneal irregularity of PMD group had significant reduction only at 1 week in 5-mm zone (P = 0.02) and 2 months in 3-mm zone (P = 0.01) postoperatively. The final efficacy indexes were 1.44 ± 0.71 and 0.87 ± 0.40 in KCN and PMD groups, respectively. CONCLUSION Visual acuity, refractive errors and keratometry values have been improved after one-segment Intacs SK implantation in early KCN and PMD patients.
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Affiliation(s)
- Seyed Javad Hashemian
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Parya Abdolalizadeh
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Leila Ghiasian
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Hossein Aghaei
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Hadavandkhani
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Nadjafi Semnani
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ebrahim Jafari
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mahsa Sadat Hashemian
- Eye Research Center, Eye Department, The Five Senses health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Moshirfar M, Tukan AN, Bundogji N, Liu HY, McCabe SE, Ronquillo YC, Hoopes PC. Ectasia After Corneal Refractive Surgery: A Systematic Review. Ophthalmol Ther 2021; 10:753-776. [PMID: 34417707 PMCID: PMC8589911 DOI: 10.1007/s40123-021-00383-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/02/2021] [Indexed: 01/03/2023] Open
Abstract
INTRODUCTION The incidence of ectasia following refractive surgery is unclear. This review sought to determine the worldwide rates of ectasia after photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) based on reports in the literature. METHODS A systematic review was conducted according to modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Publications were identified by a search of eight electronic databases for relevant terms between 1984 and 2021. Patient characteristics and preoperative values including manifest refractive spherical refractive equivalent (MRSE), central corneal thickness (CCT), anterior keratometry, postoperative residual stromal bed (RSB), and percent tissue altered (PTA) were summarized. In addition, annual rates of each refractive surgery were determined, and incidence of post-refractive ectasia for each type was calculated using the number of ectatic eyes identified in the literature. RESULTS In total, 57 eyes (70 eyes including those with preoperative risk factors for ectasia) were identified to have post-PRK ectasia, while 1453 eyes (1681 eyes including risk factors) had post-LASIK ectasia, and 11 eyes (19 eyes including risk factors) had post-SMILE ectasia. Cases of refractive surgery performed annually were estimated as 283,920 for PRK, 1,608,880 for LASIK, and 96,750 for SMILE. Reported post-refractive ectasia in eyes without preoperative identifiable risk factors occurred with the following incidences: 20 per 100,000 eyes in PRK, 90 per 100,000 eyes in LASIK, and 11 per 100,000 eyes in SMILE. The rate of ectasia in LASIK was found to be 4.5 times higher than that of PRK. CONCLUSION Post-refractive ectasia occurs at lower rates in eyes undergoing PRK than LASIK. Although SMILE appears to have the lowest rate of ectasia, the number of cases already reported since its recent approval suggests that post-SMILE ectasia may become a concern. Considering that keratoconus is a spectrum of disease, pre-existing keratoconus may play a larger role in postoperative ectasia than previously accounted for in the literature.
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Affiliation(s)
- Majid Moshirfar
- Hoopes Vision Research Center, Hoopes Vision, 11820 S. State Street Suite #200, Draper, UT, 84020, USA.
- John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, USA.
- Utah Lions Eye Bank, Murray, UT, USA.
| | - Alyson N Tukan
- University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Nour Bundogji
- University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Harry Y Liu
- McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Shannon E McCabe
- Hoopes Vision Research Center, Hoopes Vision, 11820 S. State Street Suite #200, Draper, UT, 84020, USA
- Mission Hills Eye Center, Pleasant Hill, CA, USA
| | - Yasmyne C Ronquillo
- Hoopes Vision Research Center, Hoopes Vision, 11820 S. State Street Suite #200, Draper, UT, 84020, USA
| | - Phillip C Hoopes
- Hoopes Vision Research Center, Hoopes Vision, 11820 S. State Street Suite #200, Draper, UT, 84020, USA
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Ormonde S. Refractive surgery for keratoconus. Clin Exp Optom 2021; 96:173-82. [DOI: 10.1111/cxo.12051] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 01/31/2013] [Accepted: 02/03/2013] [Indexed: 11/28/2022] Open
Affiliation(s)
- Sue Ormonde
- Department of Ophthalmology, University of Auckland, Auckland, New Zealand,
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Utine CA, Özizmirliler D, Kayabaşı M, Günenç Ü. The number of intracorneal ring segments in asymmetric and central cones. EYE AND VISION (LONDON, ENGLAND) 2021; 8:10. [PMID: 33785054 PMCID: PMC8010988 DOI: 10.1186/s40662-021-00234-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/07/2021] [Indexed: 12/03/2022]
Abstract
Background To compare the results of single versus double intracorneal ring segment (ICRS) (KeraRing) implantation in keratoconus with respect to different cone locations. Methods Twenty-two eyes of 18 patients with totally asymmetric cones (20–80% or 0–100% distribution along steep axis) were implanted with single ICRS (Group 1), 38 eyes of 32 patients with central or partially asymmetric cones (50–50% or 40–60% distribution along steep axis) were implanted with double ICRS (Group 2), at a depth of 80% of the site of implantation, in channels created with femtosecond laser device. All patients had uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively) of ≤ 0.3 Snellen lines. Results In both groups, patients had median UDVA and CDVA gain of 3 Snellen lines (P > 0.05). Postoperative improvement in indices of vertical asymmetry and height decentration in Group 1; simulated keratometry, corneal astigmatism and anterior corneal asphericity values in Group 2 were greater (P < 0.05). A total of 10 eyes (45.5%) in Group 1 were recommended double ring implantation by the manufacturer’s nomogram, but underwent single ICRS implantation and achieved visual, refractive, tomographic outcomes comparable to that in Group 2, although corneal cylindrical correction was less and final topographic astigmatism was greater. Conclusion Double ICRS implantation seems to be superior in terms of keratometry, corneal astigmatism and anterior corneal asphericity improvement. Single ICRS implantation in totally asymmetric cones seems to provide satisfactory visual, refractive and tomographic results, similar to double ICRS implantation in central and partially asymmetric cones, by inducing central shift of the cone.
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Affiliation(s)
- Canan Asli Utine
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Mithatpasa cad, No:1606 Inciraltı Kampusu, Balcova, 35330, Izmir, Turkey. .,Izmir Biomedicine and Genome Center, Izmir, Turkey.
| | - Denizcan Özizmirliler
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Mithatpasa cad, No:1606 Inciraltı Kampusu, Balcova, 35330, Izmir, Turkey
| | - Mustafa Kayabaşı
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Mithatpasa cad, No:1606 Inciraltı Kampusu, Balcova, 35330, Izmir, Turkey
| | - Üzeyir Günenç
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Mithatpasa cad, No:1606 Inciraltı Kampusu, Balcova, 35330, Izmir, Turkey
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Intracorneal ring segments followed by toric pseudoaccomodating IOL for treatment of patients with corneal ectasia and cataract. Am J Ophthalmol Case Rep 2020; 18:100693. [PMID: 32368687 PMCID: PMC7184316 DOI: 10.1016/j.ajoc.2020.100693] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/21/2018] [Accepted: 04/02/2020] [Indexed: 12/05/2022] Open
Abstract
Purpose Surgical management of keratoconus aims to improve corneal curvature, prevent progression of corneal ectasia, and manage refractive error. In older individuals with concurrent cataracts, management can be challenging due to topographic irregularity and difficult-to-interpret IOL calculations. We describe a sequential combination of two surgical techniques—intrastromal corneal ring segments (e.g. intacs) insertion and toric pseudoaccomodating lens implantation—to successfully manage concurrent keratoconus and cataracts. Observations In this case series, we present three eyes with corneal ectasia in two cataractous patients successfully managed by (1) Intacs placement to normalize corneal contour/asymmetry and enable more regular keratometry measurements, followed by (2) correction of astigmatism and presbyopia by placement of toric pseudoaccommodating IOL (Trulign) after cataract extraction. Conclusions and Importance This is the first description, to the authors’ knowledge, of the use of intraocorneal ring segments + toric pseudoaccommodating intraocular lenses for the management of concurrent keratoconus, cataract, and presbyopia.
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Sheludchenko VM, Osipyan GA, Yusef NY, Khraystin K, Alharki L, Dzhalili RA. [Bandage lamellar-optical keratoplasty for post-excimer laser keratectasia]. Vestn Oftalmol 2019; 135:171-176. [PMID: 31691656 DOI: 10.17116/oftalma2019135052171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION According to various sources, occurrence rate of keratectasia (KE) after Laser in situ Keratomileusis (LASIK) ranges from 0.04 to 0.2%. No known technique for keratorefractive surgery eliminates the probability. Neither corneal cross-linking, nor implantation of polymeric segments can completely prevent its development. PURPOSE To treat KE after LASIK with bandage lamellar-optical keratoplasty (BLOK) surgery and to evaluate the results. MATERIAL AND METHODS The study included 22 patients with KE after LASIK divided into two groups. The first group consisted of 6 patients; they underwent BLOK surgery using a segment transplant 1.5 mm in width and 180-220 µm in thickness. The second group included 16 patients who underwent BLOK surgery using 2.75 mm wide, 290-350 µm thick allogeneic transplant of individual length. The follow-up lasted 4 years. RESULTS In the first group, uncorrected visual acuity (UCVA) improved by 0.4±007, in the second group - by 0.46±0.15. After two years, two patients had their transplant exchanged for a wider one due to ectasia progression. Corneal refraction was stable at 45.36±1.47 Diopters in all other patients of the first group. In the second group, it was consistently between 40.6 and 45.7 Diopters. The main complication of the BLOK surgery was displacement of the edge of the corneal flap formed during LASIK - occurred in 4 patients. CONCLUSION Bandage lamellar-optical keratoplasty proved effective in treating patients with KE after LASIK, leading to improvement of visual acuity, strengthening of the cornea and normalization of its surface; it slows further progression of ectasia.
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Affiliation(s)
- V M Sheludchenko
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - G A Osipyan
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021; Center Vision Recovery, 108 Lobachevskogo St., Moscow, Russian Federation, 119361
| | - N Yu Yusef
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021; Center Vision Recovery, 108 Lobachevskogo St., Moscow, Russian Federation, 119361
| | - Kh Khraystin
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - L Alharki
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - R A Dzhalili
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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Sakellaris D, Balidis M, Gorou O, Szentmary N, Alexoudis A, Grieshaber MC, Sagri D, Scholl H, Gatzioufas Z. Intracorneal Ring Segment Implantation in the Management of Keratoconus: An Evidence-Based Approach. Ophthalmol Ther 2019; 8:5-14. [PMID: 31605316 PMCID: PMC6789055 DOI: 10.1007/s40123-019-00211-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Indexed: 01/19/2023] Open
Abstract
Intracorneal ring segment (ICRS) implantation represents a modern, minimally invasive, surgical option for visual improvement in patients with keratoconus. ICRS modify the corneal geometry in a manner that enhances its refractive properties and thereby, they improve visual acuity. It is well-documented that implantation of ICRS decreases the keratometric readings, spherical equivalent and cylinder, reduces high-order aberrations and improves uncorrected distance visual acuity (UDVA) and best-corrected distance visual acuity (BCDVA) in patients with keratoconus. Success rate after ICRS implantation is high, depending on appropriate patient selection and adherence to suitable implantation nomograms, and most important, the overall complication rate is very low. This review is summarizing current indications/contra-indications for ICRS implantation, implantation techniques, clinical outcomes and potential complications, shedding light on myths and realities related to this innovative surgical option.
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Affiliation(s)
| | | | - Olga Gorou
- Ophthalmica Institute, Thessaloniki, Greece
| | - Nora Szentmary
- Department of Ophthalmology, University Clinic Saarland, Homburg, Saarland, Germany
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Antonios Alexoudis
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | | | | | - Hendrik Scholl
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Zisis Gatzioufas
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland.
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McMillan J. Spectrum of Darkness, Agent of Light: Myopia, Keratoconus, Ocular Surface Disease, and Evidence for a Profoundly Vitamin D-dependent Eye. Cureus 2018; 10:e2744. [PMID: 30087820 PMCID: PMC6075645 DOI: 10.7759/cureus.2744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Serial observations obtained over more than eight years and 10,000 patient encounters in a general ophthalmology practice serving a population highly prone to chronic vitamin D (D3) deficiency, facilitated by the Oculus Pentacam Scheimpflug imaging system (Oculus Optikgeräte GmbH, Wetzlar, Germany), resulted in the recognition of consistent, predictable, and highly reproducible patterns of mechanical, optical, and physiologic change in the cornea and other ocular structures correlated to adequate vs. inadequate vitamin D availability. These patterns were identified from an analysis of more than 20,000 topographical and digital imaging studies, manifest refraction results, and other clinical ophthalmic exam findings recorded during patient visits. The main outcome measures included improved corneal and global optical quality and function, decreased ametropia, improved stability, and decreased subjective symptoms of compromised acuity and comfort. Adequate D3 replacement consistently yielded some degree of objective structural improvement in all subjects observed. The rate of improvement varied and synergistic interaction with cofactors was also suggested in particular topical steroids. A plausible explanation for the cause and mechanism of most myopia emerged and keratoconus, in particular, appears to be the extreme presentation of otherwise common corneal disturbances associated with inadequate vitamin D availability. Emmetropization mechanisms appear to awaken and reactivate with adequate D3. Intraocular pressure control likewise shows evidence of being vitamin D regulated and may play a significant interactive role in emmetropization and relief from ametropia. Ocular surface disease and inflammatory activity can be markedly alleviated in addition. As the findings are most readily appreciated via topographical map changes, a series of case reports are presented, selected from the mass of similar data, to illustrate specific aspects of these findings in the hope of inspiring controlled trials to better delineate their significance. Taken as a whole, these observations suggest the human eye may be profoundly dependent upon adequate vitamin D availability for many critical optical, structural, and physiologic properties. Myopia may represent the end result of adverse emmetropization feedback generated by low vitamin D-related irregular corneal astigmatism.
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Abreu AC, Malheiro L, Coelho J, Neves MM, Gomes M, Oliveira L, Menéres P. Implantation of intracorneal ring segments in pediatric patients: long-term follow-up. Int Med Case Rep J 2018; 11:23-27. [PMID: 29445305 PMCID: PMC5808705 DOI: 10.2147/imcrj.s151383] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To analyze the long-term outcomes of intracorneal ring segments (ICRS) implantation for keratoconus management in pediatric patients. Methods Retrospective case series review of the long-term (>5 years) outcomes of Intacs® ICRS implantation for keratoconus in pediatric patients (age <18 years old at the time of surgery) between January 2008 and December 2011 at Ophthalmology Department of Hospital de Santo António. Demographic data, follow-up time, preoperative and postoperative uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) in decimal scale, and corneal topography were evaluated. Statistical analysis was done using SPSS for windows (version 24). Significance was set at p<0.0125. Results Fourteen eyes of 14 patients, with a mean age of 15.36 years (range 10-18 years), were included in this study. All patients had been diagnosed with keratoconus with reported progression in the 6 months prior to surgery. Follow-up time was 6.36±0.97 years. UCVA and BCVA improved after ICRS implantation (p<0.0125). Keratometry (K) minimum (Kmin) and K maximum (Kmax) decreased after surgery (p<0.0125). During follow-up, UCVA, BCVA, Kmin, and Kmax values ranged, showing a tendency to worsen at the end of follow-up. However, statistically significant differences were not observed. Conclusion ICRS implantation showed good visual and topographic results in pediatric patients. Long-term follow-up suggests that, despite ICRS implantation, there is still progression of keratoconus. To the best of our knowledge, there are no reports regarding the long-term efficacy of ICRS implantation in pediatric patients.
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Affiliation(s)
- Ana Carolina Abreu
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - Luisa Malheiro
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - João Coelho
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - Miguel Mesquita Neves
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - Miguel Gomes
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal.,Ophthalmology Department, Instituto de Ciências Biomédicas Abel Salazar (ICBAS) - Universidade do Porto, Porto, Portugal
| | - Luis Oliveira
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal.,Ophthalmology Department, Instituto de Ciências Biomédicas Abel Salazar (ICBAS) - Universidade do Porto, Porto, Portugal
| | - Pedro Menéres
- Ophthalmology Department of Hospital de Santo António - Centro Hospitalar do Porto, Porto, Portugal.,Ophthalmology Department, Instituto de Ciências Biomédicas Abel Salazar (ICBAS) - Universidade do Porto, Porto, Portugal
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Affiliation(s)
- Davin Johnson
- Department of Ophthalmology, CHUM-Notre Dame Hospital, Montreal, Canada
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Giacomin NT, Mello GR, Medeiros CS, Kiliç A, Serpe CC, Almeida HG, Kara-Junior N, Santhiago MR. Intracorneal Ring Segments Implantation for Corneal Ectasia. J Refract Surg 2016; 32:829-839. [DOI: 10.3928/1081597x-20160822-01] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 07/05/2016] [Indexed: 12/20/2022]
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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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Hashemi H, Amanzadeh K, Miraftab M, Asgari S. Femtosecond-assisted intrastromal corneal single-segment ring implantation in patients with keratoconus: a 12-month follow-up. Eye Contact Lens 2016; 41:183-6. [PMID: 25603435 DOI: 10.1097/icl.0000000000000106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine visual rehabilitation in patients with keratoconus who received femtosecond-assisted intrastromal corneal single-segment ring implantation. METHODS This prospective study was conducted on 62 eyes of 45 patients with keratoconus who received single-segment Intacs. The FS200 femtosecond laser was used for tunnel creation. Patients were examined for astigmatism, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and manifest refraction spherical equivalent (MRSE) before the operation and 1, 6, and 12 months after operation. Scheimpflug imaging including minimum keratometry reading (min-K), maximum keratometry reading (max-K), average of minimum and maximum keratometry readings (mean-K), central corneal thickness (CCT), asphericity (Q-value), index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), center keratoconus index (CKI), index of height asymmetry (IHA), index of height decentration (IHD), and minimum sagittal curvature (Rmin) was performed before and 12 months after the operation. RESULTS The mean preoperative UCVA was 20/130, which increased to 20/62 1 year after the operation (P < 0.001). The mean BCVA in the last follow-up was 20/32, which improved when compared with preoperative BCVA (20/40) (P = 0.008). One year after the operation, MRSE and cylinder decreased to 1.33 ± 1.90 diopter (D) and 0.46 ± 1.50 D, respectively (P < 0.001 for both). Min-K, max-k, and mean-k reduced to 1.67 ± 0.1.40 D, 2.08 ± 1.84 D, and 1.85 ± 1.30 D (P < 0.001 for all). Q-value decreased to 0.81 ± 1.14 (P < 0.001). In contrast, CKI had a significant increase of 0.02 (P = 0.002). Other evaluated indexes did not show any significant differences. CONCLUSION Implantation of the single-segment ring in patients with keratoconus improved vision because of regularizing the cornea and centralization of the corneal cone.
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Affiliation(s)
- Hassan Hashemi
- Noor Ophthalmology Research Center (H.H., K.A., M.M.), Noor Eye Hospital, Tehran, Iran; and Department of Epidemiology and Biostatistics (S.A.), School of Public Health, Tehran University of Medical Sciences, International Campus (TUMS-IC), Tehran, Iran
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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: 77] [Impact Index Per Article: 8.6] [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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Refractive and topographic effects of single-segment intrastromal corneal ring segments in eyes with moderate to severe keratoconus and inferior cones. J Cataract Refract Surg 2015; 41:1434-40. [DOI: 10.1016/j.jcrs.2014.10.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/24/2014] [Accepted: 10/26/2014] [Indexed: 11/18/2022]
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Abstract
OBJECTIVES To review and summarize relevant studies on combined use of corneal crosslinking and intracorneal ring segments (ICRS) for the treatment of corneal ectasia. METHODS A literature search was performed using the key words "corneal collagen cross-linking" and "intra-corneal ring segments." RESULTS Crosslinking is a well-accepted treatment option for corneal ectasia and can be combined with corneal ICRS insertion as needed. The advent of crosslinking has dramatically reduced the number of corneal transplants performed for patients with keratoconus or postrefractive ectasia. Intracorneal ring segments, although flatten the corneal surface, do not prevent the progression of corneal ectasia. This is why the combination of crosslinking and ICRS is potentially synergistic. Previous studies reported that combining these two complementary interventions has been shown to be safe and effective. CONCLUSIONS The effects of ICRS are enhanced and stabilized by crosslinking, but the ideal combined technique is not known at present.
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Hashemian MN, Zare MA, Mohammadpour M, Rahimi F, Fallah MR, Panah FK. Outcomes of Single Segment Implantation of Conventional Intacs versus Intacs SK for Keratoconus. J Ophthalmic Vis Res 2015; 9:305-9. [PMID: 25667729 PMCID: PMC4307661 DOI: 10.4103/2008-322x.143359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 02/15/2014] [Indexed: 11/09/2022] Open
Abstract
Purpose: To compare the visual, refractive, and keratometric outcomes of single-segment conventional and severe keratoconus (SK) types of Intacs for correction of inferior keratoconus (KCN). Methods: A total number of 41 consecutive eyes of 23 patients with a diagnosis of inferior KCN underwent Intacs implantation. Eight eyes were excluded due to postoperative complications (4 eyes) and loss to follow-up (4 eyes) and finally 33 eyes underwent statistical analysis. Two groups were created according to Intacs type insertion; conventional group (17 eyes) and SK groups (16 eyes). Intracorneal ring segments (ICRS) implantation was indicated in keratoconic patients with contact-lens intolerance or reduced best spectacle-corrected visual acuity (BSCVA). Results: In the conventional group, mean uncorrected distance visual acuity (UCDVA) improved from 0.45 ± 0.41 preoperatively to 0.69 ± 0.39 six months after surgery representing a gain of 2 Snellen lines, and in the SK group mean UCDVA changed from 0.40 ± 0.35 preoperatively to 0.58 ± 0.48 equivalent to two Snellen lines improvement 6 months after operation (P = 0.48). Mean preoperative BSCVA in the conventional group improved from 0.72 ± 0.41 to 0.86 ± 0.39 (2 lines improvement) postoperatively and in the SK group improved from 0.71 ± 0.69 to 0.75 ± 0.45 (0.50 line improvement) (P = 0.29). Mean preoperative spherical equivalent (SE) decreased from −4.86 ± 2.26 D to −3.57 ± 2.21 D (conventional group) and from −4.20 ± 1.82 D to −3.60 ± 1.89 D (P = 0.34), mean astigmatism (AST) decreased from −5.20 ± 2.07 D and −4.50 ± 2.26 D to −4.02 ± 2.57 D and − 3.18 ± 2.14 D in the conventional and SK groups, respectively (P = 0.68). Finally, mean K min decreased from 47.11 ± 2.51 D to 45.40 ± 3.30 D in the conventional group and from 45.05 ± 2.59 D to 44 ± 3.88 D in the SK group (P = 0.63) and mean K max was decreased from 52.82 ± 3.23 D to 50.52 ± 3.57 D and from 49.72 ± 3.17 D to 48.55 ± 4.50 D, respectively (P = 0.48). Conclusion: Single-segment implantation of conventional and SK Intacs improved UCDVA and BSCVA, decreased corneal AST and keratometry in both groups with comparable outcomes.
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Affiliation(s)
- Mohammad Nasser Hashemian
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ali Zare
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Mohammadpour
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Firouzeh Rahimi
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Fallah
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Fereydoun Keramat Panah
- Cornea Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Intrastromal corneal ring segment implantation (keraring 355°) in patients with central keratoconus: 6-month follow-up. J Ophthalmol 2015; 2015:916385. [PMID: 25685395 PMCID: PMC4313675 DOI: 10.1155/2015/916385] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/27/2014] [Accepted: 11/28/2014] [Indexed: 11/17/2022] Open
Abstract
We evaluate the efficacy and safety of Keraring 355° intrastromal corneal ring segment (ICRS) implantation aided by PocketMaker microkeratome for the correction of keratoconus. Patients underwent ICRS insertion using mechanical dissection with PocketMaker microkeratome and completed 6 months of follow-up. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, topographic findings, safety, efficacy index, and adverse events were reported for six months postoperatively. We evaluated 15 eyes of 15 patients (12 men) with a mean age of 28.87 ± 6.94 years (range 21–49 years). At final postoperative examination, there was a statistically significant reduction in the spherical equivalent refractive error compared to preoperative measurements (−5.46 ± 1.52 to −2.01 ± 1.63 D, P < 0.001). Mean preoperative UCVA (logMAR) before implantation was 0.79 ± 0.48, and postoperative UCVA was 0.28 ± 0.15, P = 0.001. Mean preoperative BSCVA (logMAR) before implantation was 0.36 ± 0.21; at final follow-up examination BSCVA was 0.18 ± 0.9, P = 0.009. Mean K decreased from 48.33 to 43.31 D, P < 0.001. All patients were satisfied with ICRS implantation; 86.7% were moderately to very happy with the results. No intraoperative or postoperative complications were demonstrated. This preliminary study shows that ICRS (Keraring 355°) implantation is an efficient, cost-effective, and minimally invasive procedure for improving visual acuity in nipple type keratoconic corneas.
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Gross cystic disease fluid protein-15/prolactin-inducible protein as a biomarker for keratoconus disease. PLoS One 2014; 9:e113310. [PMID: 25405607 PMCID: PMC4236164 DOI: 10.1371/journal.pone.0113310] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/21/2014] [Indexed: 12/14/2022] Open
Abstract
Keratoconus (KC) is a bilateral degenerative disease of the cornea characterized by corneal bulging, stromal thinning, and scarring. The etiology of the disease is unknown. In this study, we identified a new biomarker for KC that is present in vivo and in vitro. In vivo, tear samples were collected from age-matched controls with no eye disease (n = 36) and KC diagnosed subjects (n = 17). Samples were processed for proteomics using LC-MS/MS. In vitro, cells were isolated from controls (Human Corneal Fibroblasts-HCF) and KC subjects (Human Keratoconus Cells-HKC) and stimulated with a Vitamin C (VitC) derivative for 4 weeks, and with one of the three transforming growth factor-beta (TGF-β) isoforms. Samples were analyzed using real-time PCR and Western Blots. By using proteomics analysis, the Gross cystic disease fluid protein-15 (GCDFP-15) or prolactin-inducible protein (PIP) was found to be the best independent biomarker able to discriminate between KC and controls. The intensity of GCDFP-15/PIP was significantly higher in healthy subjects compared to KC-diagnosed. Similar findings were seen in vitro, using a 3D culture model. All three TGF-β isoforms significantly down-regulated the expression of GCDFP-15/PIP. Zinc-alpha-2-glycoprotein (AZGP1), a protein that binds to PIP, was identified by proteomics and cell culture to be highly regulated. In this study by different complementary techniques we confirmed the potential role of GCDFP-15/PIP as a novel biomarker for KC disease. It is likely that exploring the GCDFP-15/PIP-AZGP1 interactions will help better understand the mechanism of KC disease.
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Karamichos D, Hjortdal J. Keratoconus: tissue engineering and biomaterials. J Funct Biomater 2014; 5:111-34. [PMID: 25215423 PMCID: PMC4192608 DOI: 10.3390/jfb5030111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 08/26/2014] [Accepted: 09/03/2014] [Indexed: 12/20/2022] Open
Abstract
Keratoconus (KC) is a bilateral, asymmetric, corneal disorder that is characterized by progressive thinning, steepening, and potential scarring. The prevalence of KC is stated to be 1 in 2000 persons worldwide; however, numbers vary depending on size of the study and regions. KC appears more often in South Asian, Eastern Mediterranean, and North African populations. The cause remains unknown, although a variety of factors have been considered. Genetics, cellular, and mechanical changes have all been reported; however, most of these studies have proven inconclusive. Clearly, the major problem here, like with any other ocular disease, is quality of life and the threat of vision loss. While most KC cases progress until the third or fourth decade, it varies between individuals. Patients may experience periods of several months with significant changes followed by months or years of no change, followed by another period of rapid changes. Despite the major advancements, it is still uncertain how to treat KC at early stages and prevent vision impairment. There are currently limited tissue engineering techniques and/or "smart" biomaterials that can help arrest the progression of KC. This review will focus on current treatments and how biomaterials may hold promise for the future.
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Affiliation(s)
- Dimitrios Karamichos
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, DMEI PA-409, Oklahoma City, OK 73104, USA.
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus C DK-800, Denmark.
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Shetty R, D'Souza S, Ramachandran S, Kurian M, Nuijts RMMA. Decision making nomogram for intrastromal corneal ring segments in keratoconus. Indian J Ophthalmol 2014; 62:23-8. [PMID: 24492498 PMCID: PMC3955066 DOI: 10.4103/0301-4738.126170] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Purpose: To create a nomogram for the insertion of intrastromal corneal ring segments (ICRS) (Intacs® ) in eyes with keratoconus. Setting: Tertiary eye care center in South India. Materials and Methods: This prospective, non-randomized, interventional case series used a self-designed decision-making nomogram for the selection of ICRS in keratoconus patients based on the centration of the cone, mean refractive spherical equivalent (MRSE), and mean keratometry (Km) values. The 3, 6, and 12 months clinical outcomes were compared to historical controls. Primary endpoints were improvement in uncorrected and best-corrected vision and change in the keratometric values. Results: Group A comprised of 52 eyes of 50 patients that followed the nomogram, while Group B comprised of 25 eyes of 23 non-nomogram historical controls matched for baseline parameters. In Group A, the uncorrected distance visual acuity (UDVA) improved from 0.16 ± 0.15 to 0.25 ± 0.16 (P < 0.001), corrected distance visual acuity (CDVA) from 0.58 ± 0.2 to 0.69 ± 0.21 (P = 0.022), MRSE from -5.41 ± 4.94 to -1.71 ± 2.88 (P < 0.001), Km from 51.77 ± 5.45 to 48.63 ± 4.37 (P < 0.001), and astigmatism reduced from 5.86 ± 2.61 to 4.91 ± 2.72 diopters (P < 0.001).In Group B, improvement in the average MRSE was from -6.44 ± 5.32 to -3.26 ± 2.82 (P < 0.013) and in the average Km from 53.64 ± 5.32 to 50.31 ± 5.02 (P < 0.001). Other parameters did not improve significantly. A statistically significant difference was present in the percentage of patients achieving a good clinical outcome between the two groups (P < 0.001; Chi-square). Conclusion: The nomogram provides a means to choose the appropriate ICRS, hence improving the outcome in patients with keratoconus.
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Affiliation(s)
- Rohit Shetty
- Head of Department, Refractive Surgery, Narayana Nethralaya Superspeciality Eye Institute, Bangalore, Karnataka, India
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Moshirfar M, Edmonds JN, Behunin NL, Christiansen SM. Current Options in the Management of Pellucid Marginal Degeneration. J Refract Surg 2014; 30:474-85. [DOI: 10.3928/1081597x-20140429-02] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 03/11/2014] [Indexed: 11/20/2022]
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Jabbarvand M, Hashemian M, Hashemian H, Bazvand F, Khodaparast M. Femtosecond Laser-Assisted MyoRing Implantation in Postoperative LASIK Ectasia. J Refract Surg 2014; 30:462-6. [DOI: 10.3928/1081597x-20140521-02] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/04/2014] [Indexed: 11/20/2022]
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Ganesh S, Shetty R, D'Souza S, Ramachandran S, Kurian M. Intrastromal corneal ring segments for management of keratoconus. Indian J Ophthalmol 2014; 61:451-5. [PMID: 23925336 PMCID: PMC3775086 DOI: 10.4103/0301-4738.116065] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Keratoconus is a progressive corneal ectasia, which can be managed both by conservative measures like glasses or contact lenses in non-progressive cases or surgical procedures like collagen crosslinking (CXL) with or without adjuvant measures like intrastromal corneal rings segments (ICRS) or topography guided ablation. Various kinds of ICRS are available to the surgeon, but it is most essential to be able to plan the implantation of the ring to optimize outcomes.
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Affiliation(s)
- Sri Ganesh
- Department of Refractive Surgery, Narayana Nethralaya, Superspeciality Eye Institute, Bangalore, Karnataka, India
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Hashemi H, Yazdani-Abyaneh A, Beheshtnejad A, Jabbarvand M, Kheirkhah A, Ghaffary SR. Efficacy of intacs intrastromal corneal ring segment relative to depth of insertion evaluated with anterior segment optical coherence tomography. Middle East Afr J Ophthalmol 2014; 20:234-8. [PMID: 24014988 PMCID: PMC3757634 DOI: 10.4103/0974-9233.114800] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
AIM To evaluate the effect of implantation depth of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, California) on visual and topographic outcomes in patients with post- laser-assisted in situ keratomileusis (LASIK) ectasias. SETTINGS AND DESIGN Retrospective, observational case series. MATERIALS AND METHODS In this case series, 16 eyes of 12 patients were evaluated. All cases were post-LASIK ectasia that had undergone intrastromal corneal ring segment (ICRS) implantation. The planned insertion depth was 70% of stromal thickness using a manual dissector. At least 12 months postoperatively, all eyes underwent Visante (Carl Zeiss Meditec) AS-OCT to determine insertion depth. Cases were categorized into 3 groups based on the measured implantation depth: 40-59% thickness; 60-79% thickness; and ≥80% thickness. Visual, refractive and topographic outcomes were evaluated relative to implantation depth. RESULTS The lowest improvement in the study parameters ocurred when the implantation depth was ≥80%. In this group, uncorrected visual acuity (UCVA) and best spectacle corrected VA (BSCVA) improved less than 0.5 lines. Manifest refractive spherical equivalent (MRSE) and mean keratometry (Km) change was less than 0.5 diopters (D). The greatest improvements were observed with implantation depth of 60-79% where UCVA and BSCVA increased by 4.5 and 2.5 lines respectively, and MRSE and Km changed by approximately 2.00 D. Less improvement was found when ICRS were implanted between 40-59% of stromal thickness. CONCLUSION Implantation of ICRS greater than 80% of stromal thickness may have no effect on visual and topographic status.
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Affiliation(s)
- Hassan Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran ; Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Sánchez-Thorin JC, Navarro PI. Single-Segment Intacs Severe Keratoconus 80% Stromal Depth Insertion With a Femtosecond Laser for Asymmetric Keratoconus: A Case Series. Asia Pac J Ophthalmol (Phila) 2014; 3:23-6. [PMID: 26107303 DOI: 10.1097/apo.0b013e318299068a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To study the efficacy of inferior, single-segment, 80% stromal depth Intacs severe keratoconus (SK) intracorneal ring segment implantation. DESIGN A prospective case series. METHODS Eighteen eyes from 15 patients with asymmetric keratoconus underwent 80% stromal depth Intacs SK single inferior segment implantation, using an IntraLase femtosecond laser for tunnel creation. Parameters studied included preoperative and postoperative uncorrected and best-corrected visual acuity (VA), manifest refraction and elevation-based computerized corneal topography. RESULTS Patients' VA was tested with Early Treatment Diabetic Retinopathy Study (ETDRS) chart. All the eyes demonstrated a significant ETDRS line improvement of 5.4 ± 2.0 after a follow-up period of 8.9 ± 3.9 months. Thirteen eyes (72%) showed a line improvement of 4 or more. Best-corrected VA remained unchanged in 8 eyes (44%) while 7 eyes (39%) showed a line improvement of 1 to 8. Sixteen eyes (89%) had a significant change in manifest cylinder [3.0 ± 2.2 diopters (D)]. Of the 18 eyes, astigmatism reduction was 3.44 ± 1.98 D, from 5.6 ± 2.2 D preoperatively to 2.5 ± 1.5 D postoperatively (P < 0.05). Implant placement reduced both preexisting hyperopic and myopic spheres in 14 cases (78%). Although one case showed a significant postoperative regression of the obtained correction, Intacs SK implantation was safe and effective in all the other cases. CONCLUSIONS Femtosecond laser-assisted single-segment Intacs SK (80% depth intrastromal placement) is a safe and effective technique for improving uncorrected and best-corrected VA and correcting both spherical and cylindrical refractive errors in eyes with severe asymmetric keratoconus.
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Affiliation(s)
- Juan Camilo Sánchez-Thorin
- From the *Sección de Oftalmología, Fundación Santa Fe de Bogotá; and †Córnea y Cirugía Refractiva, Centro Médico de los Andes, Bogotá, Colombia
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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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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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Yeung SN, Low SAW, Ku JYF, Lichtinger A, Kim P, Teichman J, Iovieno A, Rootman DS. Transepithelial phototherapeutic keratectomy combined with implantation of a single inferior intrastromal corneal ring segment and collagen crosslinking in keratoconus. J Cataract Refract Surg 2013; 39:1152-6. [PMID: 23706927 DOI: 10.1016/j.jcrs.2013.03.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 03/11/2013] [Accepted: 03/11/2013] [Indexed: 11/19/2022]
Abstract
PURPOSE To evaluate the efficacy of phototherapeutic keratectomy (PTK) combined with implantation of a single inferior intrastromal corneal ring segment (ICRS) and riboflavin with ultraviolet-A collagen crosslinking (CXL) performed sequentially on the same day in the management of keratoconus. SETTING Cornea Unit, Toronto Western Hospital, Toronto, Ontario, Canada. DESIGN Case series. METHODS This retrospective review comprised consecutive patients with progressive keratoconus having transepithelial PTK followed by femtosecond laser-enabled placement of a single inferior ICRS and CXL on the same day by the same surgeon between December 2010 and August 2011. The main outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), mean refraction spherical equivalent, keratometry (K), and total higher-order aberrations. RESULTS Sixteen eyes of 13 patients were included in the study. Six months after same-day PTK combined with implantation of a single inferior ICRS and CXL, there was a significant improvement in UDVA, CDVA, and the mean and steep K values. No patient lost CDVA lines. CONCLUSION Phototherapeutic keratectomy combined with implantation of a single inferior ICRS and CXL on the same day was a safe, effective treatment for improving visual acuity in select patients with progressive keratoconus.
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Affiliation(s)
- Sonia N Yeung
- Yonge Eglinton Laser Eye Centre and the Department of Ophthalmology, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
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Karamichos D, Zareian R, Guo X, Hutcheon AE, Ruberti JW, Zieske JD. Novel in Vitro Model for Keratoconus Disease. J Funct Biomater 2012; 3:760-775. [PMID: 23888249 PMCID: PMC3719435 DOI: 10.3390/jfb3040760] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Keratoconus is a disease where the cornea becomes cone-like due to structural thinning and ultimately leads to compromised corneal integrity and loss of vision. Currently, the therapeutic options are corrective lenses for early stages and surgery for advanced cases with no in vitro model available. In this study, we used human corneal fibroblasts (HCFs) and compared them to human Keratoconus fibroblasts (HKCs) cultured in a 3-dimensional (3D) model, in order to compare the expression and secretion of specific extracellular matrix (ECM) components. For four weeks, the cells were stimulated with a stable Vitamin C (VitC) derivative ± TGF-β1 or TGF-β3 (T1 and T3, respectively). After four weeks, HKCs stimulated with T1 and T3 were significantly thicker compared with Control (VitC only); however, HCF constructs were significantly thicker than HKCs under all conditions. Both cell types secreted copious amounts of type I and V collagens in their assembled, aligned collagen fibrils, which increased in the degree of alignment upon T3 stimulation. In contrast, only HKCs expressed high levels of corneal scarring markers, such as type III collagen, which was dramatically reduced with T3. HKCs expressed α-smooth muscle actin (SMA) under all conditions in contrast to HCFs, where T3 minimized SMA expression. Fast Fourier transform (FFT) data indicated that HKCs were more aligned when compared to HCFs, independent of treatments; however, HKC’s ECM showed the least degree of rotation. HKCs also secreted the most aligned type I collagen under T3 treatment, when compared to any condition and cell type. Overall, our model for Keratoconus disease studies is the first 3D in vitro tissue engineered model that can mimic the Keratoconus disease in vivo and may be a breakthrough in efforts to understand the progression of this disease.
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Affiliation(s)
- Dimitrios Karamichos
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (X.G.); (A.H.); (J.Z.)
- Author to whom correspondence should be addressed; ; Tel.: +1-617-912-0280; Fax: +1-617-912-0107
| | - Ramin Zareian
- Mechanical & Industrial Engineering, Northeastern University, Boston, MA 02115, USA; (R.Z.); (J.W.R.)
| | - Xiaoqing Guo
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (X.G.); (A.H.); (J.Z.)
| | - Audrey E.K. Hutcheon
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (X.G.); (A.H.); (J.Z.)
| | - Jeffrey W. Ruberti
- Mechanical & Industrial Engineering, Northeastern University, Boston, MA 02115, USA; (R.Z.); (J.W.R.)
| | - James D. Zieske
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (X.G.); (A.H.); (J.Z.)
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Kapasi M, Rocha G. Comparison of visual and refractive outcomes following Intacs implantation in keratoconus eyes with central and eccentric cones. Can J Ophthalmol 2012; 47:354-9. [DOI: 10.1016/j.jcjo.2012.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 02/14/2012] [Accepted: 03/29/2012] [Indexed: 10/26/2022]
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Tu KL, Batterbury M, Kaye SB. Intrastromal corneal ring segments: effect of relationship between alignment and topographic keratometric meridians. J Cataract Refract Surg 2012; 38:1432-9. [PMID: 22814050 DOI: 10.1016/j.jcrs.2012.04.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 03/07/2012] [Accepted: 04/09/2012] [Indexed: 11/17/2022]
Abstract
PURPOSE To determine whether the keratometric and refractive surgical effects of paired intrastromal corneal ring segments (ICRS) depend on their alignment relative to steep and flat topographic meridians. SETTING St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom. DESIGN Comparative case series. METHODS Keratoconic patients who had two 0.3 mm Intacs ICRS inserted were retrospectively grouped depending on alignment of segments within 30 degrees either side of the steep (meridional group) or the flat (perpendicular group) topographic meridians, respectively, with the rest in the oblique group. Principal outcome measures were changes in visual acuity, refractive surgical effect, and keratometric surgical effect 4 months postoperatively. RESULTS Forty eyes of 40 patients were included. There was a significant reduction in keratometric power (flattening) (P<.01) but not in refractive error in all 3 groups. The reduction in keratometric astigmatism was significantly greater in the perpendicular group (-2.67 diopters [D]) than in the meridional group (-0.65 D) (P=.03), with the oblique group (-0.9 D) in between (P=.12). The principal reduction was flattening orthogonal to the incision site, with relative steepening in the axis of ICRS alignment. In all groups, variations in the refractive surgical effect and keratometric surgical effect were very high. CONCLUSIONS Placement of two 0.3 mm ICRS had a variable effect with limited predictability. There was predominant flattening of the cornea orthogonal to the axis of ICRS alignment. Irrespective of the location of preoperative steep and flat keratometric meridians, the maximum reduction in astigmatism occurred when the incision and the segments were placed along the flat topographic meridian. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Kyaw L Tu
- HM Stanley Hospital, St. Asaph, Liverpool, United Kingdom.
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Comparison of Astigmatism Correction Using Shorter Arc Length 90°/120° Asymmetric Intacs Severe Keratoconus Versus 150° Single-Segment Intacs Severe Keratoconus in Asymmetric Keratoconus. Cornea 2011; 30:1201-6. [DOI: 10.1097/ico.0b013e3182182bc6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tu KL, Sebastian RT, Owen M, Batterbury M, Kaye SB. Quantification of the surgically induced refractive effect of intrastromal corneal ring segments in keratoconus with standardized incision site and segment size. J Cataract Refract Surg 2011; 37:1865-70. [DOI: 10.1016/j.jcrs.2011.04.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 03/23/2011] [Accepted: 04/01/2011] [Indexed: 10/17/2022]
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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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Alio JL, Piñero DP, Daxer A. Clinical outcomes after complete ring implantation in corneal ectasia using the femtosecond technology: a pilot study. Ophthalmology 2011; 118:1282-90. [PMID: 21440940 DOI: 10.1016/j.ophtha.2010.12.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/18/2010] [Accepted: 12/12/2010] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To evaluate the clinical outcomes after implantation of the MyoRing (DIOPTEX GmBH, Linz, Austria) by means of femtosecond laser technology in eyes with corneal ectasia. DESIGN Retrospective, consecutive, nonrandomized, case series. PARTICIPANTS A total of 12 eyes of 11 patients with ages ranging from 17 to 50 years were included. All cases were diagnosed with corneal ectasia according to the standard criteria: 1 case of post-LASIK ectasia and 11 cases of keratoconus. All cases presented with reduced best spectacle-corrected visual acuity, contact lens intolerance or discomfort, and central corneal thickness of more than 350 μm. METHODS MyoRing inserts of 280 μm in thickness and 5 mm in diameter were implanted in all cases into an intrastromal corneal pocket created by means of femtosecond technology. Visual, refractive, corneal topography, and pachymetric changes were evaluated during a 6-month follow-up. In addition, corneal biomechanical changes were evaluated by means of the Ocular Response Analyzer (Reichert, Buffalo, NY). MAIN OUTCOME MEASURES Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, keratometry, corneal asphericity, corneal higher-order aberrations, pachymetry, corneal hysteresis (CH), and corneal resistance factor (CRF). RESULTS A significant improvement in UDVA was observed 1 week after surgery (P=0.001), which was consistent with the significant reduction in sphere (P=0.002) and cylinder (P=0.004). No significant changes were detected in these parameters afterward (P ≥ 0.263). Furthermore, a significant corneal flattening of a mean value of 8.03 diopters (D) was found (P=0.005). This keratometric change was correlated with the magnitude of corneal coma-like aberrations (r=0.830, P=0.003) and the CRF (r=-0.782, P=0.008). In regard to aberrometry, a statistically significant increase in primary spherical aberration was found 1 month after surgery (P=0.001). In addition, a significant reduction in higher-order corneal aberrations was found 3 to 6 months after surgery (P=0.027). Significant corneal thickening was also observed postoperatively in the central, nasal, and temporal areas (P ≤ 0.013). No statistically significant changes were detected (P ≥ 0.176) in corneal biomechanics. Explantation was performed in a very advanced keratoconus because of the extremely poor visual outcome. CONCLUSIONS MyoRing implantation using femtosecond technology in keratoconus allows successful corneal modeling, although the use of large diameters is advisable.
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Affiliation(s)
- Jorge L Alio
- Vissum/Instituto Oftalmológico de Alicante, Spain.
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Madar J, Proust H, Matonti F, Conrath J, Ridings B, Hoffart L. [New therapeutic approach of keratoconus with intracorneal ring segments aided by femtosecond laser (Tecnolas Perfect Vision): indications, operating technique and results]. J Fr Ophtalmol 2010; 34:2-9. [PMID: 21112667 DOI: 10.1016/j.jfo.2010.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Accepted: 09/20/2010] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To assess the results of intracorneal ring segment implantation assisted by the Tecnolas Perfect Vision(®) femtosecond laser (Heidelberg, Germany). SETTINGS Retrospective observational study. METHODS The patients were operated on with the Tecnolas Perfect Vision(®) femtosecond laser. The following parameters were evaluated before and after surgery: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal topography, wavefront analysis, and central corneal thickness. The Wilcoxon test was used for statistical analysis. RESULTS Seventeen eyes of 15 patients were included. The mean follow-up was 6.9±0.71 months. Significant improvement of UCVA and BCVA was observed in 82.35% (P=0.027) and 94.12% (P=0.003) of the eyes, respectively. The subjective refraction showed a significant decrease of the sphere from -10.29±5.54 to -6.5±5.03D (P=0.002). The subjective cylinder significantly decreased from 5.43±3.20 to 3.69±2.30D (P=0.026). The SAI also decreased significantly (P=0.011). CONCLUSION Femtosecond-assisted intracorneal ring segment implantation is an effective treatment for corneal ectasia. Further studies are needed to improve surgical parameters and outcomes.
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Affiliation(s)
- J Madar
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille cedex 5, France.
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Daxer A, Mahmoud H, Venkateswaran RS. Intracorneal continuous ring implantation for keratoconus: One-year follow-up. J Cataract Refract Surg 2010; 36:1296-302. [PMID: 20656151 DOI: 10.1016/j.jcrs.2010.03.039] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 01/17/2010] [Accepted: 03/09/2010] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate intracorneal continuous ring (ICCR) implantation for the treatment of keratoconus. SETTING Eye specialist centers, Europe and Middle East. METHOD This study assessed the results of implantation of a MyoRing ICCR in 15 eyes with keratoconus. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) (spectacle correction), refraction, complications, and side effects. Postoperative follow-up was up to 1 year. RESULTS The study evaluated 15 eyes of 11 patients (8 men, 3 women) with a mean age of 35 years +/- 12 (SD) (range 22 to 60 years). Preoperatively, the mean central corneal thickness was 435 +/- 41 mum (range from 350 to 485 mum) and the mean keratometry (K) readings, 48.96 +/- 3.4 diopters (D) (range 43.75 to 56.62 D). Postoperatively, there was a statistically significant improvement in the UDVA, CDVA, K readings, manifest spherical and cylindrical refractive errors, and spherical equivalent (P<.05). The mean UDVA improved by almost 10 lines, from 0.07 (1.24 +/- 0.35 logMAR) to 0.56 (0.27 +/- 0.17 logMAR), and the mean CDVA improved by almost 3 lines, from 0.42 (0.40 +/- 0.17 logMAR) to 0.77 (0.12 +/- 0.10 logMAR). The mean K reading decreased by 5.76 D, from 48.96 D to 43.20 D. No serious intraoperative complications occurred. Side effects included glare and night-vision problems. CONCLUSIONS Treatment of keratoconus with ICCR implantation significantly improved visual function. The nomogram requires grading the disease using the K readings only. The UDVA and CDVA also improved during the first postoperative year. FINANCIAL DISCLOSURE Drs. Mahmoud and Venkateswaran have no financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
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Kubaloglu A, Sari ES, Cinar Y, Koytak A, Kurnaz E, Piñero DP, Ozerturk Y. A single 210-degree arc length intrastromal corneal ring implantation for the management of pellucid marginal corneal degeneration. Am J Ophthalmol 2010; 150:185-192.e1. [PMID: 20570241 DOI: 10.1016/j.ajo.2010.03.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 03/08/2010] [Accepted: 03/10/2010] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine the visual and refractive outcomes of 210-degree arc length intrastromal corneal ring segment (ICRS) implantation in eyes with pellucid marginal corneal degeneration (PMCD). DESIGN Retrospective, consecutive case series. METHODS Sixteen consecutive eyes of 10 patients who underwent a single 210-degree ICRS implantation by femtosecond laser for the management of PMCD and completed at least 1 year follow-up were included. A complete ophthalmic examination was performed preoperatively and postoperatively, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest spherical and cylindrical refractions, spherical equivalent, and keratometric readings. RESULTS The mean follow-up period was 30.7 months (range 12 to 36 months). No intraoperative complication was observed. White deposits around the segments were noted in 2 of 16 eyes (12.5%) at the first postoperative year. The mean UCVA showed significant improvement, from 1.69 +/- 1.02 logarithm of the minimal angle of resolution (logMAR) preoperatively to 0.64 +/- 0.43 logMAR at the 36th month (n = 11, P < .001). The mean preoperative BSCVA was 0.88 +/- 0.68 logMAR; after 36 months, this improved to 0.35 +/- 0.34 (P < .001). At the 36th month, UCVA was improved in all eyes (n = 11, range: gain of 1 to 6 lines), whereas BSCVA was improved in 9 eyes (81.8%, range: gain of 2 to 7 lines) and remained unchanged in 2 eyes (18.1%); UCVA was 20/40 or better in 3 eyes (27%) and BSCVA was 20/40 or better in 8 eyes (72.7%). There was a significant reduction in the spherical equivalent refractive error, from -4.40 +/- 1.85 diopters (D) preoperatively to -1.86 +/- 0.60 D (P < .001), and the mean maximum keratometric power decreased from 49.70 +/- 4.32 D to 46.08 +/- 2.84 D (P < .001) after 36 months. The mean cylindrical refraction decreased from -4.39 +/- 1.86 D preoperatively to -2.38 +/- 1.35 D at 36 months (P < .001). CONCLUSION A single 210-degree arc length ICRS implantation using a femtosecond laser for patients with PMCD provides good visual and refractive outcomes.
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Affiliation(s)
- Anil Kubaloglu
- Dr Lütfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey
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Implantation of new intracorneal ring segments after segment explantation for unsuccessful outcomes in eyes with keratoconus. J Cataract Refract Surg 2010; 36:1303-10. [DOI: 10.1016/j.jcrs.2010.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 02/02/2010] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
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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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Feldman BH, Kim T. Enhanced effect of double-stacked intrastromal corneal ring segments in keratoconus. J Cataract Refract Surg 2010; 36:332-5. [PMID: 20152617 DOI: 10.1016/j.jcrs.2009.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Revised: 07/17/2009] [Accepted: 07/22/2009] [Indexed: 10/19/2022]
Abstract
We present a patient with poor visual acuity and contact lens intolerance due to advanced keratoconus who had femtosecond-assisted placement of two 0.35 mm intrastromal corneal ring segments (ICRS) in the right eye. Postoperatively, both rings migrated inferiorly and overlapped each other in a double-stacked formation. This resulted in a dramatic central shift of the cone and flattening of the inferior paracentral cornea with significant improvement in vision. To our knowledge, this is the first report of double-stacked ICRS in a human cornea and raises the possibility that significantly thicker segments may provide enhanced anatomic and visual effects in some keratoectatic patients.
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Mahmood H, Venkateswaran RS, Daxer A. Implantation of a complete corneal ring in an intrastromal pocket for keratoconus. J Refract Surg 2010; 27:63-8. [PMID: 20166619 DOI: 10.3928/1081597x-20100212-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 01/21/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE to evaluate the refractive and visual results of a new treatment for keratoconus using the corneal intrastromal implantation system (CISIS). METHODS six eyes of four patients with keratoconus were treated with CISIS. Follow-up was 1, 3, and 6 months. After creating an intracorneal pocket of 9-mm diameter and 300-microm depth, a flexible full-ring implant was inserted via a 4-mm-wide corneal tunnel. RESULTS no eyes showed loss of lines in uncorrected distance visual acuity (UDVA) or spectacle corrected distance visual acuity (CDVA) at any follow-up examination. Uncorrected and distance corrected visual acuity, keratometry, spherical and cylindrical refractive error as well as spherical equivalent refraction improved significantly (P<.05). Mean UDVA improved from 20/260 to 20/48 and mean CDVA improved from 20/41 to 20/27. A significant centralization and decrease of the corneal apex was found. No intra- or postoperative complications were observed. CONCLUSIONS the corneal intrastromal implantation system using a complete ring implanted in a stromal pocket can achieve significant improvements in the visual function of patients with keratoconus. Uncorrected distance visual acuity improved by more than seven lines on average and CDVA improved by two lines.
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Piñero DP, Alió JL, El Kady B, Pascual I. Corneal aberrometric and refractive performance of 2 intrastromal corneal ring segment models in early and moderate ectatic disease. J Cataract Refract Surg 2010; 36:102-9. [DOI: 10.1016/j.jcrs.2009.07.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 07/16/2009] [Accepted: 07/22/2009] [Indexed: 11/27/2022]
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Daxer A. Adjustable Intracorneal Ring in a Lamellar Pocket for Keratoconus. J Refract Surg 2010; 26:217-21. [DOI: 10.3928/1081597x-20100224-08] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Accepted: 02/03/2009] [Indexed: 11/20/2022]
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Piñero DP, Alio JL, Uceda-Montanes A, Kady BE, Pascual I. Intracorneal Ring Segment Implantation in Corneas with Post-Laser In Situ Keratomileusis Keratectasia. Ophthalmology 2009; 116:1665-74. [DOI: 10.1016/j.ophtha.2009.05.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 05/15/2009] [Accepted: 05/22/2009] [Indexed: 10/20/2022] Open
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