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Al Bdour M, Abu-Ameerh M, Gharaibeh A, AlQudah R, Hubaishy L, AlAdwan M, AlRyalat SA. Intrastromal corneal ring segments for keratoconus patients: up to 12 years follow up. Int Ophthalmol 2024; 44:50. [PMID: 38336951 DOI: 10.1007/s10792-024-02912-5] [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: 03/01/2023] [Accepted: 12/24/2023] [Indexed: 02/12/2024]
Abstract
PURPOSE Intrastromal corneal ring segment (ICRS) implantation is a surgical technique developed with the purpose of avoiding the progression of corneal protrusion and is considered a viable option for managing patients with keratoconus as it stabilizes or improves vision thus delaying or excluding the need of more advanced surgical intervention such as penetrating keratoplasty. However, long term follow up is still limited to determine its actual success in achieving this goal. The current project aims to provide an extended follow up reporting a mean followup of around 5 years, extending up to 12.5 years. METHODS We recruited patients who performed their ICRS between 2008 and 2013. We contacted patients for a follow up exam with a possible corneal tomography. For each patient, we obtained baseline pre operative data and latest follow up data which included visual acuity, subjective refraction, clinical slit-lamp exam, and corneal tomography. We compared the change in best corrected visual acuity and maximum keratometry readings from clinical visits before ring implantation to the latest follow up. RESULTS A total of 68 eyes for 53 patients were included. The mean duration of follow up was 53.87 (± 38.8) months, with a maximum duration of 153 months. We found a significant improvement in corrected and uncorrected visual acuity, keratometries and refraction during the follow up period. On correlation analysis, strong negative significant correlation was found between duration since surgery and change in uncorrected visual acuity (p = 0.03, ρ = 0.338) and mean keratometry values (p = 0.033, ρ = 0.296). At the latest follow up for majority of patients with more than 100 weeks of follow up (12 eyes), uncorrected visual acuity were equal to or worse than baseline. CONCLUSION This study represents the largest follow up for ICRS implanted in keratoconus patients. Improvement of visual acuity following ICRS implantation can be expected in the first few years, after which, a decline occurring thereafter.
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Affiliation(s)
- Muawyah Al Bdour
- Department of Ophthalmology, The University of Jordan, Amman, 11942, Jordan
| | | | - Almutez Gharaibeh
- Department of Ophthalmology, The University of Jordan, Amman, 11942, Jordan
| | - Ruba AlQudah
- Department of Ophthalmology, The University of Jordan, Amman, 11942, Jordan.
| | - Lana Hubaishy
- Department of Ophthalmology, The University of Jordan, Amman, 11942, Jordan
| | - Mai AlAdwan
- School of Medicine, The University of Jordan, Amman, 11942, Jordan
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Jacob S, Agarwal A, Awwad ST, Mazzotta C, Parashar P, Jambulingam S. Customized corneal allogenic intrastromal ring segments (CAIRS) for keratoconus with decentered asymmetric cone. Indian J Ophthalmol 2023; 71:3723-3729. [PMID: 37991313 PMCID: PMC10788746 DOI: 10.4103/ijo.ijo_1988_23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/01/2023] [Accepted: 11/06/2023] [Indexed: 11/23/2023] Open
Abstract
Corneal allogenic intrastromal ring segments (CAIRS) refer to the intracorneal placement of fresh, unprocessed, processed, preserved, or packaged allogenic rings/segments of any type/length. We described uniform-thickness CAIRS previously. We now describe a new technique of customized CAIRS to personalize the flattening effect as per individual topography. A prospective interventional case series of patients with pericentral/ paracentral decentered cones and gradation of keratometry with one side steeper than the other was conducted. Individually customized tapered CAIRS with variable volume, arc length, taper length, and gradient of taper were implanted. In total, 32 eyes of 29 patients with at least 1-year follow-up were included. Special double-bladed trephines and a CAIRS customizer template allowed the creation of individually customized CAIRS. Mean uncorrected distance visual acuity (UDVA) and spectacle-corrected distance visual acuity improved from 0.22 to 0.47 (P = 0.000) and from 0.76 to 0.89 (P = 0.001), respectively. Significant improvement was seen in K1, K2, Km, Kmax, topographic astigmatism, Q-value, sphere, cylinder, spherical equivalent, Root Mean Square (RMS), Higher Order Aberrations (HOA), and vertical coma (P < 0.01, 0.05). There was no significant change in the width or height of CAIRS between 1 month and last visit on anterior-segment optical coherence tomography. Five eyes continued to remain at the same UDVA, 27 eyes had at least 2 lines, and 13 eyes had at least 3 or more lines improvement in UDVA. The maximum improvement in UDVA was 7 lines. A significant difference in flattening was obtained at different zones across the tapered CAIRS. Thus, differential flattening was achieved across the cone based on the customization plan. Personalized customization was possible for each cornea, unlike limited models of progressive-thickness synthetic segments. Allogenic nature, greater customizability, efficacy, and absent need for large inventories are advantages compared to synthetic segments.
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Affiliation(s)
- Soosan Jacob
- Department of Cornea, Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, Tamil Nadu, India
- Department of Cornea, Dr. Agarwal's Refractive and Cornea Foundation, Chennai, Tamil Nadu, India
| | - Amar Agarwal
- Department of Cornea, Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, Tamil Nadu, India
| | - Shady T Awwad
- Department of Ophthalmology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Cosimo Mazzotta
- Departmental Ophthalmology Unit, Alta Val D'elsa Hospital, USL Toscana Sudest, Italy
- Siena Crosslinking Center, Italy
| | - Parnika Parashar
- Department of Cornea, Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, Tamil Nadu, India
- Department of Cornea, Dr. Agarwal's Refractive and Cornea Foundation, Chennai, Tamil Nadu, India
| | - Sambath Jambulingam
- Department of Cornea, Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, Tamil Nadu, India
- Department of Cornea, Dr. Agarwal's Refractive and Cornea Foundation, Chennai, Tamil Nadu, India
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Bteich Y, Assaf JF, Gendy JE, Müller F, Jacob S, Hafezi F, Awwad ST. Asymmetric All-Femtosecond Laser-Cut Corneal Allogenic Intrastromal Ring Segments. J Refract Surg 2023; 39:856-862. [PMID: 38063823 DOI: 10.3928/1081597x-20231018-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
PURPOSE To describe a novel technique for cutting asymmetric allogenic segments using the femtosecond laser for the management of cases of keratoconus with non-coinciding astigmatism and coma axes. METHODS Four eyes of 2 patients with irregular keratoconus and asymmetric allogenic segments were included. Visual, refractive, tomographic, and aberrometric outcomes, and optical coherence tomography (OCT) sections were measured preoperatively and 6 months postoperatively. Evaluations included slit-lamp examination, manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuity, and simulated and maximum anterior keratometry (Kmax) using anterior segment OCT. RESULTS Spherical and cylindrical refractive errors decreased from -2.38 ± 2.96 and -2.94 ± 2.16 to -1.81 ± 2.77 (P = .04) and -1.75 ± 2.07 (P = .01) diopters (D), respectively, 6 months postoperatively. There was an average gain of three lines of CDVA. Kmax decreased from 50.02 ± 1.99 to 47.89 ± 3.05 D (P= .03) and coma from 1.05 ± 0.21 to 0.21 ± 0.19 D (P = .01). CONCLUSIONS Asymmetric femtosecond laser-cut allogenic segments allow a higher level of customization based on size, shape, and arc length, in contrast to the limited range of available synthetic asymmetrical segments. [J Refract Surg. 2023;39(12):856-862.].
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Sinjab MM. Keratoconus: A historical and prospective review. Oman J Ophthalmol 2023; 16:401-414. [PMID: 38059102 PMCID: PMC10697266 DOI: 10.4103/ojo.ojo_70_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 04/20/2023] [Accepted: 04/28/2023] [Indexed: 12/08/2023] Open
Abstract
This article is a historical and prospective review of keratoconus and ectatic corneal diseases. It covers definitions and terminology, the prevalence of keratoconus, predisposing factors, diagnosis, differential diagnosis, management, classifications, and progression criteria. It highlights other aspects of the disease that are usually over-missed, including the psychological, social, and economic impact. This review presents the information chronically in terms of the first author. It concludes by possessing the challenges and difficulties that are still to be overcome and suggests a plan.
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Affiliation(s)
- Mazen M. Sinjab
- Ophthalmology Department in Dr. Sulaiman Al Habib Hospital, DHCC, Dubai, UAE
- Sinjab Academy, International Keratoconus Society, Muscat, Oman
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Deshmukh R, Ong ZZ, Rampat R, Alió del Barrio JL, Barua A, Ang M, Mehta JS, Said DG, Dua HS, Ambrósio R, Ting DSJ. Management of keratoconus: an updated review. Front Med (Lausanne) 2023; 10:1212314. [PMID: 37409272 PMCID: PMC10318194 DOI: 10.3389/fmed.2023.1212314] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023] Open
Abstract
Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman's layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.
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Affiliation(s)
- Rashmi Deshmukh
- Department of Cornea and Refractive Surgery, LV Prasad Eye Institute, Hyderabad, India
| | - Zun Zheng Ong
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Radhika Rampat
- Department of Ophthalmology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Jorge L. Alió del Barrio
- Cornea, Cataract and Refractive Surgery Unit, Vissum (Miranza Group), Alicante, Spain
- Division of Ophthalmology, School of Medicine, Universidad Miguel Hernández, Alicante, Spain
| | - Ankur Barua
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Jodhbir S. Mehta
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Dalia G. Said
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Harminder S. Dua
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Renato Ambrósio
- Department of Cornea and Refractive Surgery, Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Darren Shu Jeng Ting
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Coskunseven E, Kayhan B. Asymmetric intracorneal ring segments in the treatment of snowman phenotype keratoconus. J Fr Ophtalmol 2023; 46:510-517. [PMID: 36890076 DOI: 10.1016/j.jfo.2022.11.012] [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: 09/04/2022] [Revised: 10/13/2022] [Accepted: 11/11/2022] [Indexed: 03/08/2023]
Abstract
OBJECTIVE To evaluate refractive, aberrometric, topographic, and topometric outcomes of asymmetric intracorneal ring segment (ICRS) implantation in snowman phenotype (asymmetric bow-tie) keratoconus. METHODS This retrospective, interventional study included eyes with snowman phenotype keratoconus. Two asymmetric ICRSs (Keraring AS) were implanted after femtosecond laser-assisted tunnel formation. Visual, refractive, aberrometric, topographic, and topometric changes after asymmetric ICRS implantation were evaluated with a mean follow-up of 11 months (6-24 months). MAIN RESULTS Seventy-one eyes were analyzed in the study. Keraring AS implantation corrected refractive errors significantly. The mean spherical error decreased from -5.06±4.23 D to -1.62±3.45 D (P=0.001), and the mean cylindrical error decreased from -5.43±2.48 D to -2.44±1.49 D (P=0.001). Uncorrected distance visual acuity improved from 0.98±0.80 to 0.46±0.46 Log MAR (P=0.001), and corrected distance visual acuity improved from 0.58±0.56 to 0.17±0.39 Log MAR (P=0.001). Keratometry (K) maximum, K1, K2, K mean, astigmatism, and corneal asphericity (Q-value) showed a significant decrease (P=0.001). Vertical coma aberration decreased significantly from -3.31±2.12μm to -2.56±1.94μm (P=0.001). All topometric indices of corneal irregularities were significantly reduced postoperatively (P=0.001). CONCLUSIONS Keraring AS implantation in snowman phenotype keratoconus demonstrated good efficacy and safety. Clinical, topographic, topometric, and aberrometric parameters improved significantly after Keraring AS implantation.
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Affiliation(s)
- E Coskunseven
- Département de chirurgie réfractive, hôpital Dunyagoz Etiler, Istanbul, Turkey; Faculté des sciences de la santé, université Rumeli d'Istanbul, Istanbul, Turkey
| | - B Kayhan
- Département de chirurgie réfractive, hôpital Dunyagoz Etiler, Istanbul, Turkey; Département d'ophtalmologie, Sultan II, hôpital de formation et de recherche Abdulhamid Han, université des sciences de la santé, Istanbul, Turkey.
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Asymmetric Intrastromal Corneal Ring Segments with Progressive Base Width and Thickness for Keratoconus: Evaluation of Efficacy and Analysis of Epithelial Remodeling. J Clin Med 2023; 12:jcm12041673. [PMID: 36836208 PMCID: PMC9962479 DOI: 10.3390/jcm12041673] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
Purpose: The aim of this study is to describe visual outcomes and epithelial remodeling following the implantation of asymmetric intracorneal ring segments (ICRSs) of variable thickness and base width for the management of duck-type keratoconus. Methods: A prospective observational study of patients with duck-type keratoconus was conducted. All patients received one ICRS AJL PRO + implant (AJL Ophthalmic). We analyzed demographic and clinical data, anterior segment optical coherence tomography (AS-OCT) data and Scheimpflug camera images obtained with a Placido disc MS-39 (CSO, Firenze, Italy) one and six months after surgery to determine keratometric and aberrometric outcomes and epithelial remodeling. Results: We studied 33 keratoconic eyes. ICRS implantation significantly improved both corrected distance visual acuity (CDVA) and uncorrected distance visual acuity at six months, as assessed with the logMAR (minimum angle of resolution) system, from 0.32 ± 0.19 to 0.12 ± 0.12 (p < 0.001) and from 0.75 ± 0.38 to 0.37 ± 0.24 (p < 0.001), respectively. Overall, 87% of implanted eyes gained ≥ 1 line of CDVA, and 3% of patients (n = 1) lost one line of CDVA; 55% of eyes attained a manifest refraction spherical equivalent between +1.50 and -1.50 D. Epithelial remodeling was greater at the wider and thicker end (+11.33 µm ± 12.95; p < 0.001 relative to the initial value) than at the narrower and thinner end (+2.24 µm ± 5.67; p = 0.01). Coma aberration was significantly reduced from 1.62 ± 0.81 µm to 0.99 ± 0.59 µm (p < 0.001). Conclusions: AJL-PRO + ICRS implantation for duck-type keratoconus improves refractive, topographic, aberrometric and visual parameters and induces progressive epithelial thickening along the segment.
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Coskunseven E, Kayhan B. Clinical, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment implantations in duck-type keratoconus. Indian J Ophthalmol 2022; 70:2939-2945. [PMID: 35918949 DOI: 10.4103/ijo.ijo_2770_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose To evaluate the visual, refractive, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment (PT-ICRS) implantation in duck-type keratoconus. Methods This retrospective study included eyes with oval (duck-type) keratoconus treated with PT-ICRS implantation. After the femtosecond laser tunnel creation, one PT-ICRS (Keraring AS 5 with 160° arc length) was implanted along the ectatic, inferior half of the cornea. Data of uncorrected and corrected distance visual acuity (UDVA and CDVA), refraction, asphericity (Q value), and keratometry (K) were compared pre- and postoperatively. Additionally, changes in the topometric indices of corneal irregularity were also evaluated after PT-ICRS implantation. Results Thirty-one eyes of 30 patients were included in the study with a mean follow-up time of 9.06 months (ranging between 6 and 18 months). UDVA improved from 0.85 ± 0.36 to 0.27 ± 0.14 logMAR (P = 0.001), and CDVA improved from 0.37 ± 0.22 to 0.13 ± 0.11 logMAR (P = 0.001). The mean spherical error decreased from -3.66 ± 2.60 to -1.60 ± 1.42 D (P = 0.001), and the mean cylindrical error decreased from -4.91 ± 2.65 to - 1.41 ± 1.31 D (P = 0.001). All topographic parameters measured from the anterior cornea demonstrated statistically significant improvements after PT-ICRS implantation (P = 0.001). K mean, K maximum, corneal astigmatism, and Q value showed a significant decrease. Besides the index of height asymmetry, all topometric indices were significantly reduced after PT-ICRS implantation. There were no loss of lines and no complications. Conclusion PT-ICRS implantation in duck-type keratoconus is an effective and safe treatment. This intervention improves the visual acuity, refractive error, topographical, and topometric parameters significantly by decreasing both eccentricity and steepness of the cone.
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Affiliation(s)
- Efekan Coskunseven
- Department of Refractive Surgery, Dunyagoz Etiler Hospital; Faculty of Health Sciences, Istanbul Rumeli University, Istanbul, Turkey
| | - Belma Kayhan
- Department of Refractive Surgery, Dunyagoz Etiler Hospital; Department of Ophthalmology, Sultan II. Abdulhamid Han Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
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Hamon L, Schlötzer-Schrehardt U, Flockerzi FA, Seitz B, Daas L. Morphological characterization and clinical effects of stromal alterations after intracorneal ring segment implantation in keratoconus. Graefes Arch Clin Exp Ophthalmol 2022; 260:2299-2308. [PMID: 35106630 PMCID: PMC9203383 DOI: 10.1007/s00417-022-05572-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/16/2022] [Accepted: 01/20/2022] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To analyze the histological and (ultra)structural stromal tissue changes after femtosecond (Fs) laser-assisted intracorneal ring segment (ICRS) implantation and their refractive and topographic effects in patients with keratoconus. METHODS This monocentric retrospective case series included 15 consecutive patients with clinical peri-segmental lamellar channel deposits after treatment with Fs-ICRS implantation for keratoconus. The stromal changes were investigated using in vivo confocal microscopy. Two patients underwent a penetrating keratoplasty after the Fs-ICRS implantation; the explanted corneas were processed for histopathology and transmission electron microscopy (TEM). Refractive and topographic effects were investigated comparing the uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent (SE), flat (K1), steep (K2), and steepest (Kmax) keratometry before and after detection of lamellar channel deposits. RESULTS In vivo confocal microscopy revealed diffuse linear and focal granular hyperreflective structures. Histologically, there was mild proliferation of fibroblasts and fibrosis. TEM demonstrated focal accumulations of degenerated keratocytes with cytoplasmic lipid inclusions. There were no significant changes for UDVA (Δ = 0.0 ± 0.2 logMAR; p = 0.67), CDVA (Δ = 0.0 ± 0.1 logMAR; p = 0.32), SE (Δ 0.1 ± 0.9 D; p = 0.22), K1 (Δ = 0.3 ± 1.0 D; p = 0.28), K2 (Δ = 0.1 ± 0.9 D; p = 0.51), and Kmax (Δ = 0.3 ± 1.5 D; p = 0.17). CONCLUSIONS Two types of structural stromal changes were identified: (1) diffuse peri-segmental fibrosis and (2) lamellar channel deposits. These structural changes showed no evidence of a relevant refractive or topographic effect.
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Affiliation(s)
- Loïc Hamon
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Fidelis A. Flockerzi
- Department of Pathology, Saarland University Medical Center (UKS), Homburg, Saar Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
| | - Loay Daas
- Department of Ophthalmology, Saarland University Medical Center (UKS), Kirrberger Straße 100, Bld. 22, 66421 Homburg, Saar Germany
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Clinical Outcomes of a New Type of Continuous Intrastromal Corneal Ring for Treatment of Keratoconus. Cornea 2021; 41:435-442. [PMID: 34267059 DOI: 10.1097/ico.0000000000002807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/03/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the efficacy and safety of implantation of a new continuous corneal ring in keratoconic corneas of an Iranian population. METHODS This study was conducted on 95 contact lens-intolerant keratoconic eyes with clear central corneas. A continuous corneal ring, annular intrastromal corneal inlay (AICI), was inserted using femtosecond laser in all cases. Patients were followed up for 1, 3, and 12 months postsurgery. Visual and subjective refractive outcomes were evaluated in each examination. Besides, keratometry and aberrometric values were recorded before and 12 months after surgery. Finally, vector analysis of refractive astigmatism was performed using the Alpins method. RESULTS The uncorrected and corrected distance visual acuities improved significantly 12 months after surgery from 0.91 ± 0.39 to 0.38 ± 0.22 (P < 0 0.001) and 0.33 ± 0.21 to 0.13 ± 0.11 logMAR (P < 0.001), respectively. Moreover, spherical and cylindrical refractive components reduced from -2.52 ± 2.62 to -0.76 ± 1.78 D (P < 0.001) and -4.14 ± 1.64 to -1.91 ± 1.18 D (P < 0.001), respectively. The mean anterior keratometry had a significant reduction 12 months after AICI insertion (P< 0.001). Primary coma and spherical aberration values showed a significant increase (both, P < 0.05). Our results showed 100% safety (safety index: 1.8) and 45% efficacy (efficacy index: 1). CONCLUSIONS AICI implantation seemed to be a safe and effective procedure for improving visual acuity and refractive outcomes in subjects with keratoconus.
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