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Niazi S, Doroodgar F, Nazari SH, Rahimi Y, Del Barrio JLA, Gatzioufas Z, Findl O, Vinciguerra P, Vinciguerra R, Moshirfar M, Ambrósio R, Alio JL. Refractive surgical approaches to keratoconus: A systematic review and network meta-analysis. Surv Ophthalmol 2024:S0039-6257(24)00045-6. [PMID: 38710236 DOI: 10.1016/j.survophthal.2024.04.008] [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: 10/25/2023] [Revised: 04/25/2024] [Accepted: 04/29/2024] [Indexed: 05/08/2024]
Abstract
Advancements in diagnostic methods and surgical techniques for keratoconus (KC) have increased non-invasive treatment options. Successful surgical planning for KC involves a combination of clinical science, empirical evidence, and surgical expertise. Assessment of disease progression is crucial, and halting the progression should be the focus if it is progressive. While surgeons used to rely on experience alone to decide the surgical method, comparing the network of primary factors, such as visual acuity, across studies can help them choose the most appropriate treatments for each patient and achieve optimal outcomes. Meticulous tabulation methods facilitate interpretation, highlighting the importance of selecting the correct surgical and rehabilitation approach based on each patient's condition and stage of the disease. We detail the outcomes of a comprehensive network meta-analysis comparing the effectiveness of various combined therapeutic refractive treatments for KC at identical stages of the disease, spanning four distinct follow-up intervals. Additionally, the comprehensive analysis suggests that for corneas with optimal best corrected visual acuity (BCVA) preoperatively (classified as regular), combining phakic intraocular lenses with intracorneal ring segments (ICRS) and corneal cross-linking (CXL) could offer the best therapeutic approach provided the disease stage does not exceed stage 3. For irregular corneas, although initial follow-ups show a significant difference in BCVA with surface ablation, longer-term follow-ups recommend combining surface ablation with ICRS and CXL, especially at higher stages.
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Affiliation(s)
- Sana Niazi
- Negah Aref Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Farideh Doroodgar
- Negah Aref Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
| | - Saeed Hashemi Nazari
- Prevention of Cardiovascular Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Yekta Rahimi
- Student Research Committee, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Jorge L Alió Del Barrio
- Vissum Miranza, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
| | | | - Oliver Findl
- Vienna Institute for Research in Ocular Surgery (VIROS), A Karl Landsteiner Institute, Hanusch Hospital, 1140, Vienna, Austria
| | - Paolo Vinciguerra
- Biomedical Sciences, Humanitas University, Milan, Italy; IRCCS Humanitas Research Hospital, Rozzano, Italy
| | | | - Majid Moshirfar
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Renato Ambrósio
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil; Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil; BrAIN: Brazilian Artificial Intelligence Networking in Medicine, Rio de Janeiro & Maceió, Brazil; Department of Ophthalmology, Federal University the state of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil; Department of Ophthalmology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Jorge L Alio
- Vissum Miranza, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
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Niazi S, Gatzioufas Z, Doroodgar F, Findl O, Baradaran-Rafii A, Liechty J, Moshirfar M. Keratoconus: exploring fundamentals and future perspectives - a comprehensive systematic review. Ther Adv Ophthalmol 2024; 16:25158414241232258. [PMID: 38516169 PMCID: PMC10956165 DOI: 10.1177/25158414241232258] [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: 04/07/2023] [Accepted: 01/22/2024] [Indexed: 03/23/2024] Open
Abstract
Background New developments in artificial intelligence, particularly with promising results in early detection and management of keratoconus, have favorably altered the natural history of the disease over the last few decades. Features of artificial intelligence in different machine such as anterior segment optical coherence tomography, and femtosecond laser technique have improved safety, precision, effectiveness, and predictability of treatment modalities of keratoconus (from contact lenses to keratoplasty techniques). These options ingrained in artificial intelligence are already underway and allow ophthalmologist to approach disease in the most non-invasive way. Objectives This study comprehensively describes all of the treatment modalities of keratoconus considering machine learning strategies. Design A multidimensional comprehensive systematic narrative review. Data sources and methods A comprehensive search was done in the five main electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane), without language and time or type of study restrictions. Afterward, eligible articles were selected by screening the titles and abstracts based on main mesh keywords. For potentially eligible articles, the full text was also reviewed. Results Artificial intelligence demonstrates promise in keratoconus diagnosis and clinical management, spanning early detection (especially in subclinical cases), preoperative screening, postoperative ectasia prediction after keratorefractive surgery, and guiding surgical decisions. The majority of studies employed a solitary machine learning algorithm, whereas minor studies assessed multiple algorithms that evaluated the association of various keratoconus staging and management strategies. Last but not least, AI has proven effective in guiding the implantation of intracorneal ring segments in keratoconus corneas and predicting surgical outcomes. Conclusion The efficient and widespread clinical translation of machine learning models in keratoconus management is a crucial goal of potential future approaches to better visual performance in keratoconus patients. Trial registration The article has been registered through PROSPERO, an international database of prospectively registered systematic reviews, with the ID: CRD42022319338.
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Affiliation(s)
- Sana Niazi
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zisis Gatzioufas
- Department of Ophthalmology, University Eye Hospital Basel, Basel, Switzerland
| | - Farideh Doroodgar
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran Province, Tehran, District 6, Pour Sina St, P94V+8MF, Tehran 1416753955, Iran
- Negah Aref Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Oliver Findl
- Department of Ophthalmology, Hanusch Hospital, Vienna Institute for Research in Ocular Surgery (VIROS), Vienna, Austria
| | - Alireza Baradaran-Rafii
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jacob Liechty
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Majid Moshirfar
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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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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Berty MM, Eliwa TF, Gaafar AAM, Mousa AS. Effect of intracorneal ring segments on posterior corneal topography in eyes with keratoconus. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2022; 97:424-431. [PMID: 35752595 DOI: 10.1016/j.oftale.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/15/2021] [Indexed: 06/15/2023]
Abstract
PURPOSE To analyze the changes in the anterior and posterior corneal surfaces measured with a Scheimpflug imaging device in keratoconus patients implanted with intracorneal ring segments (ICRS) and to correlate those changes with the visual outcomes. METHODS This prospective interventional case series study included 92 eyes of 60 patients with keratoconus who underwent Kerarings (Mediphacos, Belo Horizonte, Brazil) ICRS implantation. Keratometric (K) readings, corneal asphericity (Q value) and elevations of both anterior and posterior corneal surfaces were evaluated using a Scheimpflug imaging device preoperatively and at 1, 3, 6 and 12 months after surgery. RESULTS The mean best corrected visual acuity (BCVA) improved from 0.61 to 0.19 logMAR at 12 months after surgery. Both anterior and posterior corneal surfaces showed significant flattening with statistically significant reduction of the mean anterior K reading by 3.39 D and the mean posterior K reading by 0.39 D (p<0.001) at 12 months. Statistically significant change of the anterior Q to a less negative value (from -1.05 to -0.36) was observed (p<0.001) with no significant change of the posterior Q value. Improvement of the anterior Q was significantly correlated to better postoperative BCVA (p=0.03). Better postoperative BCVA significantly correlated to better preoperative BCVA, flatter preoperative anterior and posterior K, less prolate anterior Q value and lower anterior elevations. CONCLUSIONS ICRS implantation has a significant flattening effect on both anterior and posterior corneal surfaces. Improvement of corneal asphericity is correlated to better visual outcome. Certain preoperative parameters were predictive factors of the postoperative visual improvement.
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Affiliation(s)
- M M Berty
- Assistant Lecturer of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
| | - T F Eliwa
- Assistant Professor of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - A A M Gaafar
- Professor of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - A S Mousa
- Professor of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt
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Kammoun H, Piñero DP, Álvarez de Toledo J, Barraquer RI, García de Oteyza G. Clinical Outcomes of Femtosecond Laser-Assisted Implantation of Asymmetric ICRS in Keratoconus With No Coincidence of Topographic and Comatic Axes. J Refract Surg 2021; 37:693-699. [PMID: 34661475 DOI: 10.3928/1081597x-20210712-04] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To analyze the clinical outcomes obtained with asymmetric intracorneal corneal ring segments (ICRS) of variable thickness and width in patients with keratoconus, identifying predictive parameters of the final visual outcome. METHODS This prospective, longitudinal, non-comparative clinical trial enrolled 35 eyes of 27 patients with keratoconus with a significant difference among corneal topographic and comatic axes. All eyes underwent implantation of AJL-pro+ ICRS (AJL Ophthalmic). Visual, refractive, corneal topographic and aberrometric, and pachymetric changes were evaluated during a 3-month follow-up. RESULTS Significant changes were detected at 3 months after surgery in manifest sphere and cylinder, spherical equivalent, overall blur strength, and corrected distance visual acuity (CDVA) (P < .001). No losses of two or more lines of CDVA were observed, whereas 94.3% (33) of eyes gained one or more lines of CDVA. Keratometric readings and the magnitude of anterior corneal astigmatism were significantly reduced with surgery (P < .001), as well as the levels of corneal coma (P < .001) and spherical aberration (P = .007). Likewise, a significant change toward less prolateness was observed (P < .001). Significant correlations were found among the change in CDVA and preoperative CDVA (r = -0.532, P = .001), and between the change in primary coma root mean square and the preoperative level of spherical aberration (r = -0.542, P = .001) and coma root mean square (r = -0.719, P < .001). CONCLUSIONS The implantation of the ICRS evaluated in keratoconus with no coincidence between topographic and comatic axes regularizes the corneal shape and reduces the level of higher order aberrations, inducing a significant visual improvement. [J Refract Surg. 2021;37(10):693-699.].
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Ferrara Rings for Visual Rehabilitation in Eyes with Keratoconus and Previous Cross-Linking Using the Ferrara Ring Nomogram. Vision (Basel) 2021; 5:vision5040045. [PMID: 34698306 PMCID: PMC8544695 DOI: 10.3390/vision5040045] [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: 08/24/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To report the visual, refractive and tomographic outcomes following the implantation of intrastromal corneal ring segments (ICRS) (Ferrara rings, AJL Ophthalmics, Miñano, Spain) in eyes with a history of keratoconus and corneal cross-linking using the Ferrara ring nomogram. METHODS Retrospective, interventional case series performed at the Corneoplastics Unit, Queen Victoria Hospital, East Grinstead, United Kingdom. RESULTS 21 eyes of 19 patients with a history of keratoconus and prior corneal collagen cross-linking had Ferrara Intrastromal Corneal Ring Segments implanted between December 2015 and October 2017. The number, thickness and length of ring segments was chosen based on the Ferrara ring company nomogram. Mean uncorrected visual acuity (UDVA) improved from 0.88 to 0.52 logMAR (p < 0.001). Mean corrected visual acuity (CDVA) improved from 0.47 to 0.36 logMAR (p = 0.046). The percentage of eyes achieving 20/40 UDVA and CDVA increased from 5% to 38% and from 38% to 67%, respectively. Of the eyes, 52.3% gained at least two lines of CDVA. The spherical equivalent improved from -7.51D to -3.76D (p < 0.001) and the refractive astigmatism magnitude improved from 5.14D to 2.76D (p = 0.004). There were significant improvements in the corneal tomography with mean keratometry (KM) improving from 50.40D (3.53) to 48.24D (3.00) (p = 0.01) and keratometric astigmatism magnitude improving from 5.14D (2.91) to 2.76D (1.67) (p = 0.004). CONCLUSION Insertion of Ferrara rings in keratoconic eyes with a history of prior cross-linking using the company nomogram results in significant improvements in visual, refractive and tomographic outcomes.
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Fernández J, Peris-Martínez C, Pérez-Rueda A, Hamida Abdelkader SM, Roig-Revert MJ, Piñero DP. Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus. Int J Ophthalmol 2021; 14:1371-1383. [PMID: 34540613 DOI: 10.18240/ijo.2021.09.12] [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: 11/02/2020] [Accepted: 02/25/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations. Visual, refractive, corneal topographic, aberrometric, and pachymetric changes after surgery were evaluated during a 3-month follow-up. RESULTS The implants induced a significant refractive change as well as an improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA of 0.10 logMAR or better was achieved in 28.4% and 46.5% of eyes, respectively. Two eyes (2.3%) lost two or more lines of CDVA whereas a total of 53.5% of eyes gained lines of CDVA. A significant central anterior and posterior corneal flattening was induced (P≤0.003), with a significant reduction of anterior (P<0.001) and posterior corneal astigmatisms (P=0.048), and a change in anterior asphericity (P<0.001). Total primary coma (6 mm pupil) change was also statistically significant (preoperative 3.66±3.04 µm vs postoperative 2.33±2.26 µm, P<0.001). No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques (P≥0.101). CONCLUSION The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus, with a relevant control of primary coma aberration.
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Affiliation(s)
- Joaquín Fernández
- Department of Ophthalmology (Qvision), Vithas Virgen del Mar Hospital, Almería 04120, Spain.,Department of Ophthalmology, Torrecárdenas Hospital Complex, Almería 04009, Spain
| | - Cristina Peris-Martínez
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia 46015, Spain.,Aviño Peris Eye Clinic, Valencia 46001, Spain.,Department of Surgery, Ophthalmology, University of Valencia, Valencia 46010, Spain
| | - Antonio Pérez-Rueda
- Department of Ophthalmology, Torrecárdenas Hospital Complex, Almería 04009, Spain
| | | | - María José Roig-Revert
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia 46015, Spain.,Department of Surgery, Ophthalmology, University of Valencia, Valencia 46010, Spain
| | - David P Piñero
- Department of Optics, Pharmacology, and Anatomy, University of Alicante, Alicante 03690, Spain
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García de Oteyza G, Álvarez de Toledo J, Barraquer RI, Kling S. Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: A 2D finite-element model. PLoS One 2021; 16:e0257222. [PMID: 34525102 PMCID: PMC8443075 DOI: 10.1371/journal.pone.0257222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/25/2021] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To evaluate the local geometric effects of a unilateral intrastromal ring segment with a combined variation of ring thickness and base width in a finite element simulation, and to compare it against the isolated effect of thickness or base width variation alone. METHODS A two-dimensional finite-element model of a transversely isotropic cornea was created assuming either axisymmetric stress or plane strain condition. The model geometry was composed of a three-layered corneal tissue (epithelium, anterior and posterior stroma) fixed at the limbus. The implantation of a triangular-shape asymmetric ring segment with varying ring thickness (150 to 300 μm) and base width (600 to 800 μm) was simulated. Also, changes induced by thickness or base width alone were studied and compared their combined effect in the asymmetric ring segment. Geometrical deformation of the simulated cornea and sagittal curvature were the main parameters of study. RESULTS Increasing ring thickness and base width along the arc of the asymmetric ring segment produced a more pronounced flattening in this part of the ring. The asymmetric design did find a good balance between maximizing corneal flattening at one end and minimizing it at the other end, compared to the isolated effect of ring thickness and width. Ring thickness was the most robust parameter in flattening both, the central and peripheral cornea. CONCLUSION The finite-element model permitted a theoretical study of corneal deformation undergoing implantation of realistic and hypothetical ring geometries. Intracorneal asymmetric ring segments with varying thickness and base width can be a good alternative in corneas with asymmetric keratoconus phenotypes.
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Affiliation(s)
- Gonzalo García de Oteyza
- Clínica Oftalmológica García de Oteyza, Barcelona, Spain
- Escuela de Doctorado, Universidad Autónoma de Barcelona (UAB), Barcelona, Spain
| | | | - Rafael I. Barraquer
- Centro de Oftalmología Barraquer, Barcelona, Spain
- Universitat Internacional de Catalunya (UIC), Barcelona, Spain
| | - Sabine Kling
- Department of Information Technology and Electrical Engineering, OPTIC Team, Computer-assisted Applications in Medicine Group, ETH Zurich, Zurich, Switzerland
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Clinical evaluation of the effectiveness of asymmetric intracorneal ring with variable thickness and width for the management of keratoconus. J Cataract Refract Surg 2021; 47:722-730. [PMID: 33278234 DOI: 10.1097/j.jcrs.0000000000000525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/07/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the short-term clinical outcomes obtained with a new model of asymmetric intracorneal ring segments (ICRS) with variable thickness and base width in keratoconus. SETTING Four ophthalmologic centers in Spain. DESIGN Prospective multicenter longitudinal noncomparative clinical trial. METHODS Thirty-one keratoconus eyes of 25 patients (aged 15 to 50 years) that underwent implantation of ICRS of variable thickness and base (AJL-pro+) in 4 Spanish centers were enrolled. Visual, refractive, topographic, aberrometric, and pachymetric changes were evaluated during a 3-month follow-up. Complications were also recorded. RESULTS Statistically significant changes after surgery were observed in uncorrected distance visual acuity (P = .002) and corrected distance visual acuity (CDVA) (P = .005), as well as in spherical equivalent (P = .006). At 3 months postoperatively, no loss of 2 or more lines of CDVA was observed, whereas 48.4% (15) of eyes gained ≥1 line. Statistically significant changes were observed in the steepest and mean keratometric values (P ≤ .047) and in the magnitude of astigmatism (P < .001) of both anterior and posterior corneal surfaces. Likewise, a change to a less prolate shape of the anterior surface was found (P = .011). Primary coma was also reduced significantly at 1 month postoperatively (P = .001, mean reduction 40.1%). No serious implant-related complications occurred during the follow-up. CONCLUSIONS The implantation of intrastromal asymmetric ring segments of variable thickness and base width in keratoconus corneas induces a significant anterior corneal flattening, leading to refractive changes, a significant reduction of its prolate shape and irregularity, and improvement in patient CDVA.
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McLintock CA, McKelvie J, Miraflores Gomez S, Gatzioufas Z, Elalfy M, Hamada S. Outcomes of sequential intracorneal ring segment and phakic intraocular lens insertion for visual rehabilitation in keratoconus. Eur J Ophthalmol 2020; 31:2219-2226. [PMID: 33135490 DOI: 10.1177/1120672120969600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To report the visual and refractive outcomes of sequential intracorneal ring segment (ICRS) and toric phakic intraocular lens (IOL) insertion for visual rehabilitation in keratoconus. METHODS A retrospective interventional cohort study was performed through the Corneoplastics unit and Eye Bank, Queen Victoria Hospital, East Grinstead, United Kingdom. RESULTS 14 eyes of 12 patients had sequential ICRS and phakic IOL implantation for visual rehabilitation of keratoconus between June 2014 and February 2018. After at least 6 months follow-up, the number of eyes with an uncorrected distance visual acuity (UDVA) of 20/40 UDVA or better increased from zero (0%) to 10 (71%). 12 (85.7%) eyes achieved a post-operative UDVA equal to or better than the pre-operative corrected distance visual acuity (CDVA). The number percentage of eyes with a CDVA of 20/40 or better increased from 3 (31%) to 14 (100%). The mean final spherical equivalent improved from -4.07 to -0.17 (p ⩽ 0.001). The mean refractive astigmatism magnitude improved from 4.76D to 1.23D (p = 0.002). Seven (50%) eyes had 1.0D or less of refractive astigmatism post-operatively. CONCLUSION In this cohort of eyes with keratoconus, sequential ICRS and phakic IOL implantation resulted in excellent visual and refractive outcomes after at least 6 months.
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Affiliation(s)
- Cameron A McLintock
- Corneoplastic unit and Eye Bank, Queen Victoria Hospital, NHS Trust, East Grinstead, West Sussex, UK.,Department of Ophthalmology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - James McKelvie
- Corneoplastic unit and Eye Bank, Queen Victoria Hospital, NHS Trust, East Grinstead, West Sussex, UK.,Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | - Zisis Gatzioufas
- Corneoplastic unit and Eye Bank, Queen Victoria Hospital, NHS Trust, East Grinstead, West Sussex, UK.,Department of Ophthalmology, University Hospital Basel, Basel, BS, Switzerland
| | - Mohamed Elalfy
- Corneoplastic unit and Eye Bank, Queen Victoria Hospital, NHS Trust, East Grinstead, West Sussex, UK.,Cornea Unit, The Research Institute of Ophthalmology, Giza, Egypt
| | - Samer Hamada
- Corneoplastic unit and Eye Bank, Queen Victoria Hospital, NHS Trust, East Grinstead, West Sussex, UK
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Sedaghat MR, Momeni-Moghaddam H, Belin MW, Piñero DP, Akbarzadeh R, Ambrósio R, Hosseini SR. Comparative analysis of two different types of intracorneal implants in keratoconus: A corneal tomographic study. Eur J Ophthalmol 2020; 31:1517-1524. [PMID: 33124461 DOI: 10.1177/1120672120963449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To evaluate changes in visual acuity and corneal tomographic outcomes at 6 months after femtosecond-laser assisted implantation of two different types of intracorneal implants in keratoconus. METHODS A total of 39 keratoconus eyes implanted with two segments KeraRing (n = 22 eyes) or MyoRing (n = 17 eyes) were enrolled. Tomographic data (Pentacam system, Oculus) were analyzed and correlated with enhancement in uncorrected (UDVA) and corrected distance visual acuity (CDVA). The tomographic indices were front maximum keratometry (Kmax), corneal asphericity (Q-value) on both surfaces, average pachymetric progression indices (PPI), maximum Ambrosio relational thickness (ARTmax), Belin-Ambrósio enhanced ectasia total deviation index (BAD-D), index of surface variance (ISV), vertical asymmetry (IVA), height asymmetry (IHA) and height decentration (IHD). RESULTS LogMAR UDVA and CDVA improved 2.1 (p = 0.003) and 0.7 (p = 0.074) lines with KeraRing, and 8 and 2.5 lines with MyoRing (p = 0.001). The highest and lowest mean differences in the tomographic indices between both groups were related to ISV and IHD, respectively. Changes in all indices differed significantly between two groups except for changes in front corneal astigmatism, ARTmax, ISV, IVA, IHD and IHA (p > 0.05). Correlation of changes in CDVA with changes in other parameters was statistically significant only for IHD in the KeraRing group, while changes in in UDVA were significantly correlated with changes in spherical equivalent, back Q-value, ISV, IVA, and IHA only in the MyoRing group. CONCLUSION Both implants promote corneal shape regularization and an enhancement in UDVA in keratoconus. A considerable flattening effect and reduction in prolateness in the front corneal surface were observed with MyoRing.
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Affiliation(s)
| | - Hamed Momeni-Moghaddam
- Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.,Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Michael W Belin
- Department of Ophthalmology & Vision Science, University of Arizona, Tucson, AZ, USA
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Reyhaneh Akbarzadeh
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Renato Ambrósio
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Seyed Rafi Hosseini
- Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
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Abstract
PURPOSE OF REVIEW To review the efficacy of intrastromal corneal ring segments (ICRS) for keratoconus and with other interventions such as contacts lens, keratoplasty, and corneal collagen cross-linking. RECENT FINDINGS Changes in ICRS thickness and size, combination of procedures, and the adaptation of a more sophisticated classification system have broadened our application of ICRS. Recent studies have shown the long-term efficacy of ICRS in visual acuity, keratometry, and astigmatism. SUMMARY Studies have demonstrated the short-term and long-term efficacy of ICRS implantation in patients with keratoconus.
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Peris-Martínez C, Dualde-Beltrán C, Fernández-López E, Roig-Revert MJ, Hernández-Díaz M, Piñero DP. Effect of the variability in implantation depth of intracorneal ring segments using the femtosecond laser technology in corneal ectasia. Eur J Ophthalmol 2019; 30:668-675. [DOI: 10.1177/1120672119852026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Purpose: To analyze the impact of the depth of implantation of intracorneal ring segments on morphological, biomechanical, and clinical outcomes in ectatic corneas. Methods: This prospective longitudinal study enrolled 40 eyes of 29 patients (age 20–51 years) with corneal ectasia that underwent intracorneal ring segments implantation (KeraRing, Mediphacos). Changes in visual acuity, refraction, corneal tomography, and corneal biomechanics (Ocular Response Analyzer, Reichert) were evaluated during a 6 month follow-up. Likewise, changes in ring segment implantation depth measured by optical coherence tomography (Visante OCT, Carl Zeiss Meditec) were also evaluated. Results: Mean relative depth of implantation was 71.6 ± 5.8%, 71.5 ± 6.5%, and 71.9 ± 6.3% at 1, 3, and 6 months after surgery, respectively (p = 0.827). The difference between the real relative depth of implantation and the theoretical attempted value of 70% was not statistically significant (p = 0.072). Differences in spherical equivalent during the follow-up changed significantly depending on the level of relative depth of implantation (p = 0.036), with an increase of 0.114 D per each 1% increase in relative depth of implantation. Likewise, a decrease of –0.194 D in the steepest keratometric reading was found per each decrease of 1% in relative depth of implantation (p = 0.026). Changes in corneal thickness (p = 0.092) and biomechanics (p = 0.080) were not related to relative depth of implantation. Conclusion: The effect on visual acuity and refraction of intracorneal ring segments when implanted in corneal ectasia is less clinically relevant when the implantation is done at a very deep plane. The variability of the depth of intracorneal ring segments implantation when using femtosecond laser technology is minimal and with no clinically significant effect on clinical outcomes.
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Affiliation(s)
- Cristina Peris-Martínez
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia, Spain
- Clínica Oftalmológica Aviñó&Peris, Valencia, Spain
| | | | - Ester Fernández-López
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia, Spain
| | | | - Mikhail Hernández-Díaz
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia, Spain
- Clínica Oftalmológica Aviñó&Peris, Valencia, Spain
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
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Sedaghat MR, Momeni-Moghaddam H, Piñero DP, Akbarzadeh R, Moshirfar M, Bamdad S, Gazanchian M. Predictors of Successful Outcome following Intrastromal Corneal Ring Segments Implantation. Curr Eye Res 2019; 44:707-715. [PMID: 30868919 DOI: 10.1080/02713683.2019.1594945] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Purpose: To assess the preoperative visual, refractive, corneal topo/tomographic, aberrometric and biomechanical parameters as predictive factors of a successful outcome 6 months following intrastromal corneal ring segments implantation. Methods: Sixty-eight keratoconus eyes implanted with Keraring using femtosecond laser technology were assessed. The preoperative assessed parameters included uncorrected and corrected distance visual acuity (UDVA & CDVA), refraction, placido-disk based topography using TMS-4, Scheimplfug tomography using Pentacam HR, corneal biomechanical assessments using Ocular Response Analyzer (ORA) and the wavefront analysis using i-Trace aberrometer. Other variables were type of astigmatism based on orientation of the steep meridian, keratoconus staging based on the Amsler-Krumeich classification and the difference between the axes of refractive astigmatism, topographic astigmatism and comatic aberration based on a difference less or more than 30°. The success criterion was defined based on CDVA, a post-operative CDVA improvement at least two lines were considered as a success and otherwise were recognized as a failure following Keraring implantation. Results: Only UDVA, coincidence of the most elevated points on the front and back corneal surfaces and the difference between UDVA and CDVA showed significant difference between the eyes with successful outcomes and those with unsuccessful results (P < 0.05). Although corneal curvature and astigmatism were higher and corneal thickness was lower in the unsuccessful group, differences were not statistically significant. Conclusion: It is expected that the greater difference between the preoperative uncorrected and corrected distance visual acuity (Δ UDVA-CDVA) and more coincidence of the most elevated points in the two corneal surfaces on the elevation maps increase the rate of successful outcome following the Keraring implantation. Abbreviations: ICRS: intrastromal corneal ring segments; UDVA: uncorrected distance visual acuity; CDVA: corrected distance visual acuity; logMAR: logarithm of minimum angle of resolution; SE: spherical equivalent; IOP: intra-ocular pressure; Km: mean keratometry; CA: corneal astigmatism; WTR: with-the-rule; ATR: against-the-rule; OBL: oblique; SB: symmetric bow-tie; AB: asymmetric bow-tie; IS: inferior steepening; SRAX: skewed radial axis; Q: asphericity (Q-value); CCT: central corneal thickness; CTP: corneal thinnest point; ORA: ocular response analyzer; CH: corneal hysteresis; CRF: corneal resistance factor; HOAs: higher-orders aberrations; RMS: root mean square; SD: standard deviation; CI: confidence interval.
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Affiliation(s)
| | - Hamed Momeni-Moghaddam
- b Health Promotion Research Center , Zahedan University of Medical Sciences , Zahedan , Iran.,c Department of Optometry, School of Paramedical Sciences , Mashhad University of Medical Sciences , Mashhad , Iran
| | - David P Piñero
- d Department of Optics, Pharmacology and Anatomy , University of Alicante , Alicante , Spain
| | - Reyhaneh Akbarzadeh
- c Department of Optometry, School of Paramedical Sciences , Mashhad University of Medical Sciences , Mashhad , Iran
| | - Majid Moshirfar
- e John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, School of Medicine , University of Utah , Salt Lake City , UT , USA.,f Utah Lions Eye Bank, University of Utah Health , Murray , UT , USA.,g HDR Research Center, Hoopes Vision , Draper , UT , USA
| | - Shahram Bamdad
- h Poostchi Ophthalmology Research Center , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Mehrdad Gazanchian
- a Eye Research Center , Mashhad University of Medical Sciences , Mashhad , Iran
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Utine CA, Ayhan Z, Durmaz Engin C. Effect of intracorneal ring segment implantation on corneal asphericity. Int J Ophthalmol 2018; 11:1303-1307. [PMID: 30140633 DOI: 10.18240/ijo.2018.08.09] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 04/17/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the visual, refractive and corneal asphericity changes after intrastromal corneal ring segment (ICRS) implantation for visual rehabilitation of keratoconus. METHODS A total of 42 eyes of 32 patients were included. After creation of intrastromal tunnels of 5.01±0.03 mm inner diameter, 5.71±0.03 mm outer diameter and at 384.21±34.12 µm depth, 1 or 2 ICRS of 150-300 µm thickness and 90°-210° arc length were implanted. Changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive errors, mean simulated keratometry readings (SimKavg), anterior and posterior corneal asphericity values (Qant and Qpost, respectively) measured with Scheimpflug topography were evaluated retrospectively. RESULTS There was a significant improvement in UDVA and CDVA, along with a significant decrease in refractive spherical equivalent (SE), cylinder and SimKavg postoperatively (P<0.001 for all). Mean Qant increased from -1.06±0.48 to -0.57±0.58 postoperatively (P<0.001). Change in mean Qpost was insignificant (P=0.92). Postoperative changes in UDVA and CDVA were not correlated with the postoperative changes in SE and cylinder (P>0.05 for all); but were correlated with the preoperative SimKavg and Qant values (P<0.001 for all). CONCLUSION ICRS implantation seems to approximate the anterior corneal asphericity of "advanced prolate" shape to "optimal prolate" shape and an "ideal Q value" of -0.46; which may have a role in improved UDVA and CDVA postoperatively, besides decreased refractive cylinder values.
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Affiliation(s)
- Canan A Utine
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Izmir 35340, Turkey.,Izmir International Biomedicine and Genome Center, Dokuz Eylul University, Izmir 35340, Turkey
| | - Ziya Ayhan
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Izmir 35340, Turkey
| | - Ceren Durmaz Engin
- Department of Ophthalmology, Faculty of Medicine, Dokuz Eylul University, Izmir 35340, Turkey
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Lyra D, Ribeiro G, Torquetti L, Ferrara P, Machado A, Lyra JM. Computational Models for Optimization of the Intrastromal Corneal Ring Choice in Patients With Keratoconus Using Corneal Tomography Data. J Refract Surg 2018; 34:547-550. [DOI: 10.3928/1081597x-20180615-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 06/08/2018] [Indexed: 11/20/2022]
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Anterior Segment Changes After Femtosecond Laser-Assisted Implantation of a 355-Degree Intrastromal Corneal Ring Segment in Advanced Keratoconus. Cornea 2018; 37:1438-1443. [DOI: 10.1097/ico.0000000000001702] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Effects of Preoperative Topometric Indices on Visual Gain After Intracorneal Ring Segment Implantation For Keratoconus. Eye Contact Lens 2018; 44 Suppl 2:S387-S391. [PMID: 29944503 DOI: 10.1097/icl.0000000000000490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess the corneal topometric parameters that can be predictive for better visual gain after intracorneal ring segment (ICRS) implantation in eyes with keratoconus. METHODS A total of 42 eyes of 32 patients who underwent ICRS implantation at Dokuz Eylul University, Deparment of Ophthalmology, Cornea Divison were included. Changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive errors, and corneal topometric indices measured using Scheimpflug topography (Pentacam, Oculus) were evaluated retrospectively. RESULTS After creation of intrastromal tunnels of 5.01±0.03 mm inner diameter, 5.71±0.03 mm outer diameter and at 384.21±34.12 μm depth, 1 or 2 ICRS of 150 to 350 µm thickness and 90 to 210° arc length were implanted. Preoperative UDVA of 0.09±0.10 and CDVA of 0.29±0.14 Snellen lines improved postoperatively to 0.42±0.26 and 0.62±0.24, respectively (P<0.001 for both). Preoperative spherical equivalent of -6.35±4.58D and refractive astigmatism of -5.89±2.40D decreased to -3.59±3.86 and -2.25±1.66D, retrospectively (P<0.001 for both). Strong negative correlations were detected between preoperative mean simulated keratometry (SimKavg)/index of surface variance (ISV) and changes in UDVA/CDVA (P<0.01, for all). Postoperative change in ISV was positively correlated with thicknesses of implanted rings. Change in topographical keratoconus classification was positively and change in index of vertical asymmetry was negatively correlated with number of implanted rings (P<0.05 for all). CONCLUSIONS Preoperative ISV value seems to be beneficial in predicting visual gain after ICRS implantation, in addition to SimKavg. Future work on new nomograms for ICRS selection that include ISV, besides refractive, topographic, and cone location data, is warranted.
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Sandes J, Stival LRS, de Ávila MP, Ferrara P, Ferrara G, Magacho L, Araújo LPN, Torquetti L. Clinical outcomes after implantation of a new intrastromal corneal ring with 140-degree of arc in patients with corneal ectasia. Int J Ophthalmol 2018; 11:802-806. [PMID: 29862179 DOI: 10.18240/ijo.2018.05.14] [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] [Received: 09/08/2017] [Accepted: 11/14/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the clinical and tomographic outcomes after implantation of a new intrastromal corneal ring segment (ICRS) with 140-degrees of arc in eyes with corneal ectasia. METHODS We evaluated patients with corneal ectasia implanted with Ferrara 140° ICRS from April 2010 to February 2015. Outcome measures included preoperative and postoperative corrected distance visual acuity (CDVA), keratometry simulated (K) reading, tomographic astigmatism and asphericity. All patients were evaluated using the Pentacam Scheimpflug system. RESULTS The study evaluated 58 eyes. The mean follow-up was 16.81±10.8mo. The CDVA (logMAR) improved from 0.5±0.20 (20/60) to 0.3±0.21 (20/40) (P<0.01). The average K reduced from 49.87±7.01 to 47.34±4.90 D (P<0.01). The asphericity changed from -0.60±0.86 to -0.23±0.67 D (P<0.01). The mean preoperative tomographic astigmatism decreased from -8.0±3.45 to -4.53±2.52 D (P<0.01). CONCLUSION The new ICRS model with 140-degrees of arc effectively improve the visual acuity and reduce the high astigmatism usually found in patients with corneal ectasia.
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Affiliation(s)
- Jordana Sandes
- Center of Reference in Ophthalmology (CEROF), Goiânia 64605-020, Brazil
| | | | | | - Paulo Ferrara
- Paulo Ferrara Eye Clinic, Belo Horizonte-MG 30110-921, Brazil
| | | | - Leopoldo Magacho
- Center of Reference in Ophthalmology (CEROF), Goiânia 64605-020, Brazil
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Persistence of the Cone on the Posterior Corneal Surface Affecting Corneal Aberration Changes After Intracorneal Ring Segment Implantation in Patients With Keratoconus. Cornea 2017; 37:347-353. [DOI: 10.1097/ico.0000000000001492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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