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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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Méndez EA, Roys N, Mejía ME, Plata MC, Rosenstiehl SM. Results of Follow-up in Pediatric Keratoconus Treated With Intracorneal Ring Segments Implantation Alone or in Combination With Corneal Cross-linking. J Pediatr Ophthalmol Strabismus 2022; 59:118-127. [PMID: 34592870 DOI: 10.3928/01913913-20210719-02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To report visual and topographic outcomes of pediatric keratoconus with intracorneal ring segments (ICRS) implantation alone or in combination with accelerated corneal cross-linking (A-CXL). METHODS A descriptive, retrospective observational study was performed. Medical records of patients younger than 18 years at Fundación Oftalmológica Nacional in Bogotá, Colombia, were reviewed. Demographic data, follow-up time, preoperative and postoperative uncorrected (UCVA) and best corrected (BCVA) visual acuity, manifest refraction, and tomography were evaluated. SPSS software (version 22.0; SPSS, Inc) was used for analysis. RESULTS Twenty-six eyes of 19 patients with a mean age of 16.5 ± 1.8 years were analyzed, and 16 were boys (84.2%). Median follow-up time was 39.6 months (inter-quartile range [IQR] = 30). Fifteen patients (78.9%) had a history of allergic conjunctivitis. Sixteen eyes (61.5%) received ICRS implantation with A-CXL and 10 eyes (38.4%) received ICRS implantation only. Global results (including ICRS implantation with A-CXL and ICRS implantation only) were: (1) median UCVA of 0.90 logarithm of the minimum angle of resolution (logMAR) (IQR = 0.85) preoperatively improved to 0.54 logMAR (IQR = 0.70) postoperatively; (2) median BCVA of 0.43 logMAR (IQR = 0.39) preoperatively improved to 0.30 logMAR (IQR = 0.26) postoperatively; and (3) median spherical equivalent of -5.37 diopters (D) (IQR = -5.28) preoperatively improved to -4.12 D (IQR = -3.57) postoperatively. There was a reduction in half of the sphere and cylinder. The median maximum keratometry was 54.40 D (IQR = 7.4) preoperatively and 49.80 D (IQR = 5.3) postoperatively. The median asphericity was -1.18 (IQR = 0.70) preoperatively and changed to -0.75 (IQR = 0.68) postoperatively. No patient presented with complications before or after surgery. CONCLUSIONS ICRS implantation only or in combination with A-CXL induced visual and topographic improvement in patients with keratoconus, which was maintained throughout the follow-up time. It seems to be a safe procedure to delay or avoid corneal transplantation in the pediatric population. [J Pediatr Ophthalmol Strabismus. 2022;59(2):118-127.].
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David C, Reinstein DZ, Archer TJ, Kallel S, Vida RS, Goemaere I, Cuyaubère R, Borderie M, Laroche L, Borderie V, Bouheraoua N. Postoperative Corneal Epithelial Remodeling After Intracorneal Ring Segment Procedures for Keratoconus: An Optical Coherence Tomography Study. J Refract Surg 2021; 37:404-413. [PMID: 34170769 DOI: 10.3928/1081597x-20210225-02] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess epithelial corneal remodeling by anterior segment optical coherence tomography (AS-OCT) after intracorneal ring segments (ICRS) implantation in keratoconic eyes. METHODS This prospective observational study included patients with keratoconus receiving ICRS of different arc lengths according to their tomographic pattern. AS-OCT and corneal topography (Scheimpflug camera) were performed before and 1, 3, and 6 months after surgery. Corneal pachymetry mapping was performed and total corneal and epithelial thicknesses (3-mm central and 16 points on 6-mm zone) were measured over the pupil center using AS-OCT. Topographic parameters were also assessed. RESULTS A total of 68 keratoconic eyes were analyzed (Amsler-Krumeich stages 1 to 4) in four groups of 17 eyes: 210° ICRS, 320° ICRS, double 160° ICRS, and single 160° ICRS. Corneal pachymetry mapping revealed that epithelial thickness increased significantly in the internal zones juxtaposed to the ICRS without smoothing during the postoperative period (P < .05). Mean maximum epithelial thickness increased from 67 ± 6 to 79 ± 7 µm for 210° ICRS, 66 ± 9 to 82 ± 4 µm for 320° ICRS, 63 ± 6 to 78 ± 7 µm for double 160° ICRS, and 62 ± 5 to 77 ± 5 µm for single 160° ICRS (P < .0001). Significant epithelial thickening at the apex of the cone was observed in all groups (P < .05). CONCLUSIONS Significant epithelial thickening occurs after ICRS implantation adjacent to the ICRS to compensate for the ridge created with a thickening of epithelium over the cone due to regularization of the stromal surface. [J Refract Surg. 2021;37(6):404-413.].
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Iqbal M, Mounir A, Abd-Elaziz K, Said OM. Long-Term Visual, Refractive and Topographic Outcomes of KeraRings Combined with Accelerated Transepithelial Crosslinking for Management of Different Grades of Progressive Keratoconus: A Retrospective Cohort Study. Open Ophthalmol J 2021. [DOI: 10.2174/1874364102115010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Purpose:
To evaluate long-term visual, refractive, and topographic outcomes of KeraRings intrastromal implantation combined with accelerated transepithelial cross-linking for management of different stages of progressive keratoconus.
Materials and Methods:
This retrospective cohort study included 70 eyes of 70 patients with Amsler-Krumeich grades 1 to 4 keratoconus. They were divided into two groups: group-A included 37 eyes with grades 1-2 keratoconus, and group-B included 33 eyes with grades 3-4 keratoconus. Both groups underwent combined Keraring implantation with TCXL treatment. The main outcome measures included the preoperative and postoperative visual acuity, refraction, keratometry readings, and pachymetry.
Results:
At postoperative month 60, group-B exhibited significantly higher values of all mean uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), sphere/cylinder/spherical equivalent/defocus equivalent (DEQ), and K1/K2/Kaverages/Kmax parameters compared to that of group A. However, group-A exhibited better stability of postoperative improvements. Keratoconus progression (KCP) was greater in group-B (45.5%) than group-A (10.8%). Two eyes revealed segments' migration while one eye showed tunnel vascularization and opacification with segments' migration.
Conclusion:
The diagnostic criteria of preoperative-KCP are not adequate for the diagnosis of postoperative-KCP following ICRS implantation. UDVA and K average posterior seemed to be more sensitive parameters than K max in documenting early postoperative-KCP. We suggest that deterioration of UDVA≥0.10 log MAR and/or K average posterior ≥0.25 D are highly suspicious of post-ring implantation keratoconus progression (PR-KCP). The occurrence of two of the following parameters: Kmax≥0.50 D, Kaverageanterior≥0.50 D, K average posterior ≥0.25 D, or pachymetry≥1.5% thinning, is diagnostic of PR-KCP. The occurrence of two or more of the following parameters: Kmax≥0.50 D, Kaverageanterior≥0.50 D, Kaverageposterior ≥0.25 D, pachymetry≥ 1.5% thinning or UDVA≥0.10 logMAR, is diagnostic of PR-KCP. We also suggest that Kmax≥0.75 D alone is diagnostic of PR-KCP.
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Tabatabaei SA, Soleimani M, Mirghorbani M, Tafti ZF, Rahimi F. Microbial keratitis following intracorneal ring implantation. Clin Exp Optom 2021; 102:35-42. [DOI: 10.1111/cxo.12810] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 04/12/2018] [Accepted: 06/17/2018] [Indexed: 11/26/2022] Open
Affiliation(s)
- Seyed Ali Tabatabaei
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | - Mohammad Soleimani
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | - Masoud Mirghorbani
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
| | | | - Firoozeh Rahimi
- Ocular Trauma and Emergency Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran,
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Arbelaez JG, Arbelaez MC. Efficacy of progressive thickness intrastromal corneal ring segments in the treatment of duck phenotype keratoconus. Eur J Ophthalmol 2021; 31:2191-2199. [PMID: 33726533 DOI: 10.1177/11206721211001722] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate clinical outcomes in patients with asymmetric duck phenotype keratoconus implanted with asymmetric progressive thickness intrastromal corneal ring segments (PT-ICRS, Keraring AS, Mediphacos, Belo Horizonte, Brazil), and to demonstrate improved visual acuity and symmetry in corneal flattening. METHODS This single-center, retrospective, observational study evaluated the clinical outcomes at 1, 3, and 6 months after implantation of PT-ICRS in patients with duck phenotype keratoconus. After creating the intrastromal tunnel with a femtosecond laser, one 160-degree arc length PT-ICRS, either 150/250 µm or 200/300 µm, was implanted. Changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction (MR), manifest refraction spherical equivalent (MRSE), mean keratometry (Kmean), maximum keratometry (Kmax), Coma@5mm, and manifest and topographical astigmatism were documented. RESULTS The study cohort included 23 eyes of 17 patients with a mean age of 24.6 years. From baseline to 6 months following implantation, mean UDVA improved from 0.70 logarithm of the minimum angle of resolution (logMAR) (20/100 Snellen) to 0.22 logMAR (20/33 Snellen), CDVA improved from 0.33 logMAR (20/42 Snellen) to 0.14 logMAR (20/27 Snellen), the mean sphere and MRSE decreased from -1.05 diopters (D) and -2.70 D to -0.25 D and -0.80 D, respectively, and the Kmean and Kmax improved from 46.5 D and 53.7 D to 44.6 D and 48.7 D, respectively. CONCLUSIONS The Keraring AS ICRS offers a safe, effective means of improving visual acuity while reducing refractive error, mean and max keratometry, and aberrations in patients with duck phenotype keratoconus.
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Affiliation(s)
- Juan G Arbelaez
- Muscat Eye Laser Center, Muscat, Shatti Al Qurum, Sultanate of Oman
| | - Maria C Arbelaez
- Muscat Eye Laser Center, Muscat, Shatti Al Qurum, Sultanate of Oman
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D'Oria F, Abdelghany AA, Ledo N, Barraquer RI, Alio JL. Incidence and Reasons for Intrastromal Corneal Ring Segment Explantation. Am J Ophthalmol 2021; 222:351-358. [PMID: 33011155 DOI: 10.1016/j.ajo.2020.09.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE To determine the main causes of intrastromal corneal ring segment (ICRS) explantation and define the incidence rate. DESIGN Multicenter, observational consecutive case series. METHODS Consecutive cases of ICRSs explanted in the last 10 years were reviewed. Clinical data included age of the patients at explantation, reasons for implantation and explantation, date of implantation and explantation, tunnel creation technique, and ICRS type. Main outcomes measures were the reasons for ICRS removal and the incidence rate. RESULTS During the study period, 121 ICRSs (119 patients) were explanted, with an explantation rate of 5.60%. Functional failure (74 eyes, 61.16%) represents the main cause for ICRS removal: of them, 48 (39.67%) ICRSs were removed for refractive failure and 26 (21.49%) in the setting of a keratoplasty related to poor visual performance of the implanted eye. In addition, 47 eyes (38.84%) had ICRS removal for anatomic failure: among them, 36 (29.75%) were explanted for spontaneous extrusion (overall extrusion rate: 1.58%), 7 (5.79%) for suspected infectious keratitis, 3 (2.48%) for corneal melting, and 1 (0.83%) for corneal perforation. Mild cases of keratoconus were more prone to be explanted because of a loss of the initial improved visual acuity, whereas spontaneous extrusion happened often in advanced cases of keratoconus. CONCLUSIONS We report the largest series of ICRS explantation as of this writing. The main cause of explantation was functional refractive failure followed by spontaneous extrusion of the ICRS, that is, correlated to an anatomic failure at the site of implantation in an advanced disease.
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Affiliation(s)
- Francesco D'Oria
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain; Section of Ophthalmology, Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari, Bari, Italy
| | - Ahmed A Abdelghany
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain; Ophthalmology department, Faculty of Medicine, Minia University, Minia, Egypt
| | - Natalia Ledo
- Instituto Universitario Barraquer, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rafael I Barraquer
- Instituto Universitario Barraquer, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jorge L Alio
- Vissum Innovation, Alicante, Spain; Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.
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Larco P, Larco P, Torres D, Piñero DP. Intracorneal Ring Segment Implantation for the Management of Keratoconus in Children. Vision (Basel) 2020; 5:1. [PMID: 33374847 PMCID: PMC7838879 DOI: 10.3390/vision5010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/10/2020] [Accepted: 12/22/2020] [Indexed: 11/17/2022] Open
Abstract
The short-term safety and efficacy of intracorneal ring segment (ICRS) implantation in keratoconus eyes of children are investigated in this study. A retrospective interventional case series study including a total of 33 keratoconus eyes (age 8 to 17 years) that had undergone ICRS (Keraring segments, Mediphacos) implantation was conducted. Information about visual, refractive, pachymetric, corneal topographic and aberrometric, and corneal endothelial changes during a 3-month follow-up were extracted and analysed. A significant improvement was observed in logMAR corrected distance visual acuity (p = 0.005), combined with a statistically significant reduction in keratometric readings (p < 0.001). A reduction in the magnitude of corneal astigmatism of ≥1 D was observed in 52.8% of eyes. No significant changes were observed in corneal endothelial density (p = 0.317). Significant changes were found in the anterior vertical coma component (p = 0.002) as well as in the spherical aberration of the posterior corneal surface (p = 0.004). Only two relevant complications were described: one corneal microperforation with penetration of the ring segment into the anterior chamber (1 eye, 2.8%), and a case of ring extrusion (1 eye, 2.8%). ICRS implantation in children keratoconus eyes allows a reduction of corneal astigmatism, irregularity, and aberrations, leading to a significant visual improvement.
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Affiliation(s)
- Pablo Larco
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - Pablo Larco
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - Daniel Torres
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - David P. Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
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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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Intracorneal Stromal Ring Can Affect the Biomechanics of Ectatic Cornea. J Ophthalmol 2020; 2020:4274037. [PMID: 33083047 PMCID: PMC7563082 DOI: 10.1155/2020/4274037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 07/27/2020] [Accepted: 08/04/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose The biomechanical properties of ecstatic cornea undergo changes. This study evaluates the biomechanical changes of ecstatic cornea after implantation of two types of intracorneal stromal ring (ICR). Methods For doing this prospective cross-sectional study, 32 patients with keratoconus (KCN) were randomly divided into two 16-member groups (group I: MyoRing, group II: KeraRing). The main inclusion criteria were transparent cornea with no scar in the central part, corneal thickness >450 µ in the incision region, keratometry within 48–52 diopters, and progressive course of corneal thinning. Biomechanics of the cornea was evaluated by “ORA” and “Corvis” devices. All of the data were recorded and analyzed before implantation of the rings and 6 months thereafter. Results The mean ages of patients of groups I and II were 26 ± 6.55 and 33.86 ± 8.5, respectively. The postoperative change of sphere refraction was significant in both groups. However, reduction in the astigmatism was significant only in group I. In addition, the change of flat meridian keratometry (Kf) was significant before and after ring implantation in group I, unlike group II. The changes in CH and CRF parameters (ORA) were not significant in either group before and after the operation. Besides, only HRC parameter (Corvis) decreased significantly in both groups before and after the operation. Conclusion Both MyoRing and KeraRings have positive effects on the biomechanics of cornea at least during the first year after implantation. Comparison of these two types of ICR did not show significant differences in Corvis and ORA parameters.
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Monteiro T, Alfonso JF, Freitas R, Franqueira N, Faria-Correira F, Ambrósio R, Madrid-Costa D. Comparison of Complication Rates between Manual and Femtosecond Laser-Assisted Techniques for Intrastromal Corneal Ring Segments Implantation in Keratoconus. Curr Eye Res 2019; 44:1291-1298. [PMID: 31226888 DOI: 10.1080/02713683.2019.1635165] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Purpose: To compare the incidence of complications between manual and femtosecond-laser assisted surgery for intrastromal corneal ring segments (ICRS) implantation.Material and methods: This study included keratoconus patients who had ICRS implantation using manual dissection and using the femtosecond laser with a minimum follow-up of 12 months. Uncorrected (UDVA) corrected (CDVA) distance visual acuity (CDVA), refraction, corneal topography and aberrometry, pachymetry map and slit-lamp microscopy were assessed before and after surgery.Results: The study included 265 eyes in the manual group and 111 in the femtosecond laser group. In the manual group, there were complications in 48 eyes (18.11%); while in the femtosecond laser 4 eyes had a complication (3.6%). In the manual group, the most frequent complications were ICRS exchange/adjustment for visual and refractive enhancement (25 eyes; 9.43%) and late ICRS spontaneous extrusion (15 eyes; 5.66%). In the manual group, 81.25% of complications were observed during the first 3 years of surgeon's experience. Eyes who suffered a complication had preoperatively higher mean refractive (p = .002) and topographic cylinder (p = .003) and lower UDVA (p = .005) and CDVA (p = .002). After a second surgical procedure for complication management visual, refractive and topographic outcomes significantly improved.Conclusion: Manual mechanical ICRS surgery shows a higher rate of intra- and postoperative mechanical and refractive complications when compared to femtosecond laser assisted technique. The incidence is specially higher during the surgeon's first years of implementation of the technique.
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Affiliation(s)
- Tiago Monteiro
- Ophthalmology Department, Hospital de Braga, Braga, Portugal.,Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - José F Alfonso
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, Oviedo, Spain
| | - Rui Freitas
- Ophthalmology Department, Hospital de Braga, Braga, Portugal.,Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - Nuno Franqueira
- Ophthalmology Department, Hospital de Braga, Braga, Portugal.,Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - Fernando Faria-Correira
- Ophthalmology Department, Hospital de Braga, Braga, Portugal.,Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - Renato Ambrósio
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil.,Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - David Madrid-Costa
- Optometry and Vision Department, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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Benoist d'Azy C, Pereira B, Chiambaretta F, Dutheil F. Efficacy of Different Procedures of Intra-Corneal Ring Segment Implantation in Keratoconus: a Systematic Review and Meta-Analysis. Transl Vis Sci Technol 2019; 8:38. [PMID: 31211003 PMCID: PMC6561134 DOI: 10.1167/tvst.8.3.38] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/27/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the efficacy of the functional, keratometric, and refractive postoperative parameters of intracorneal ring segment (ICRS) implantation in keratoconus and its association with collagen cross-linking (CXL), photorefractive keratectomy (PRK), and intraocular lenses (IOLs). Methods We conducted a systematic review and meta-analysis on case series published between 2007 and 2017. Results We included 95 case series with a total of 4560 patients. We included 64 studies of the ICRS procedure, 20 studies of ICRS+CXL, 9 studies of ICRS+CXL+PRK, and 5 studies of ICRS+IOL. We demonstrated an overall improvement of all parameters in all procedures. Cylinder was decreased with an overall effect size (ES) of −1.15 (−1.36 to −0.95; I2 = 93.7%). Corrected distance visual acuity was improved with an overall ES of 0.89 (0.78 to 1.00; I2 = 81.9%). Maximal keratometry was decreased with an overall ES of 0.98 (0.85 to 1.11; I2 = 78.9%). ICRS+IOL is the best procedure to improve spherical equivalent and uncorrected distance visual acuity (P < 0.05) compared with other procedures. ICRSs versus ICRS+CXL are similar in all parameters except for corrected distance visual acuity. ICRS+CXL+PRK is better than ICRS alone in all parameters except for the correction of spherical equivalent. Conclusions Although the quality and strength of the data are questionable, ICRS implantation is an effective strategy to preserve visual function in keratoconic patients. Particularly, ICRS+CXL+PRK could be a low invasive procedure to propose to young keratoconic patients. Translational Relevance To propose an overview of postoperative parameters on each ICRS procedure on keratoconus.
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Affiliation(s)
- Cédric Benoist d'Azy
- University Hospital of Clermont-Ferrand, CHU Clermont-Ferrand, Ophthalmology, Preventive and Occupational Medicine, Clermont-Ferrand, France
| | - Bruno Pereira
- University Hospital of Clermont-Ferrand (CHU), Biostatistics Unit, Clinical Research and Innovation Direction, Clermont-Ferrand, France
| | - Frédéric Chiambaretta
- University Hospital of Clermont-Ferrand, CHU Clermont-Ferrand, Ophthalmology, Clermont-Ferrand, France
| | - Frédéric Dutheil
- Clermont Auvergne University, CNRS, LaPSCo, Physiological and Psychosocial Stress, University Hospital of Clermont-Ferrand, CHU Clermont-Ferrand, Preventive and Occupational Medicine, WittyFit, Clermont-Ferrand, France.,Australian Catholic University, Faculty of Health, School of Exercise Science, Melbourne, Victoria, Australia
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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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Garcia-Ferrer FJ, Akpek EK, Amescua G, Farid M, Lin A, Rhee MK, Varu DM, Musch DC, Mah FS, Dunn SP. Corneal Ectasia Preferred Practice Pattern®. Ophthalmology 2019; 126:P170-P215. [DOI: 10.1016/j.ophtha.2018.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 02/07/2023] Open
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Spontaneous breakage of intracorneal ring segments (ICRS) 8 years after implantation. Saudi J Ophthalmol 2018; 32:341-345. [PMID: 30581308 PMCID: PMC6300748 DOI: 10.1016/j.sjopt.2018.03.005] [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] [Received: 11/26/2016] [Revised: 03/06/2018] [Accepted: 03/13/2018] [Indexed: 11/23/2022] Open
Abstract
We present a case of spontaneous in situ breakage of intracorneal ring segments (ICRSs) 8 years after their implantation in a patient with keratoconus. The patient presented to our clinic with a red and painful right eye that had not improved despite topical steroids and antibiotics. The decision was made to explant the broken ICRSs from the cornea and send them for laboratory analyses, by which manufacturer defects were excluded. It is noteworthy that corneal curvature re-steepening was observed 4 months after ICRS removal despite the performance of crosslinking (CXL) 1 year prior to ICRS implantation.
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Sedaghat MR, Momeni-Moghaddam H, Belin MW, Zarei-Ghanavati S, Akbarzadeh R, Sabzi F, Yekta AA, Sadeghi Allahabadi J. Changes in the ABCD Keratoconus Grade After Intracorneal Ring Segment Implantation. Cornea 2018; 37:1431-1437. [PMID: 29863546 DOI: 10.1097/ico.0000000000001648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess the changes in the ABCD keratoconus staging system 6 months after intracorneal ring segment implantation. METHODS Fifty eyes of 50 patients with keratoconus who were implanted with the Keraring (Mediphacos, Belo Horizonte, Brazil) using the femtosecond laser were assessed. Preoperative and postoperative assessments included determination of distance uncorrected visual acuity and distance corrected visual acuity (DCVA), refraction, and Scheimpflug tomography with the Pentacam HR. In the ABCD keratoconus staging system, the elements A, B, C, and D stand for anterior and posterior radii of curvature in a 3.0-mm zone centered on the thinnest point (TP), corneal thickness at the TP, and DCVA, respectively. RESULTS Keraring implantation produced significant flattening changes (preoperatively vs. postoperatively) in the anterior (6.60 ± 0.48 vs. 7.22 ± 0.57 mm, P < 0.001) and posterior (4.99 ± 0.47 vs. 5.16 ± 0.53 mm, P = 0.002) radii of curvature of the 3-mm zone centered on the corneal TP associated with a statistically significant improvement in the DCVA (0.56 ± 0.24 vs. 0.70 ± 0.22 in the decimal notation, P = 0.001) with no significant change in the corneal thickness at the TP (P = 0.285). The most changes occurred in element A of the ABCD keratoconus classification. Also, a 1-stage change was observed for element B, whereas elements C and D did not show changes in their postoperative stages after ring implantation. ABCD keratoconus staging before ring implantation was A2B3C2D1 and changed to A1B2C2D1 6 months after surgery. CONCLUSIONS The ABCD staging system provides a more comprehensive guide that better illustrates the structural changes and visual acuity as one aspect of visual function after the implantation of the intrastromal corneal ring segments.
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Affiliation(s)
| | - Hamed Momeni-Moghaddam
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Michael W Belin
- Department of Ophthalmology and Vision Science, University of Arizona, Tucson, AZ
| | | | - Reyhaneh Akbarzadeh
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Sabzi
- Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Abbas-Ali Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
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Three-Year Outcomes of Cross-Linking PLUS (Combined Cross-Linking with Femtosecond Laser Intracorneal Ring Segments Implantation) for Management of Keratoconus. J Ophthalmol 2018; 2018:6907573. [PMID: 29576880 PMCID: PMC5822772 DOI: 10.1155/2018/6907573] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/11/2017] [Accepted: 11/12/2017] [Indexed: 11/17/2022] Open
Abstract
Purpose To analyze the results of three-year outcomes of combined epithelium-on cross-linking with femtosecond laser ICRS (cross-linking PLUS) for keratoconus management. Design A retrospective multicenter clinical study. Methods 43 eyes of 38 patients were subjected to preoperative and postoperative UCVA, BCVA, refraction, Pentacam pachymetry, and keratometry examinations at 3-, 6-, 12-, 24-, and 36-month follow-up period. Results The preoperative and postoperative mean UCVA was 1.30 ± 0.48 (logMAR ± SD) and 0.82 ± 0.22 respectively. The preoperative and postoperative mean BCVA was 0.90 ± 0.40 and 0.60 ± 0.30, respectively. The preoperative and postoperative mean K average was 50.63 ± 0.87 (D ± SD) and 45.56 ± 0.98, respectively. The preoperative and postoperative mean pachymetry was 471 ± 92.36 (μm ± SD) and 423 ± 39.58, respectively. The preoperative and postoperative mean astigmatism was 7.55 ± 1.75 and 3.39 ± 1.26, respectively. One eye showed ICRS edge exposure while 6 eyes showed progression of keratoconus. Conclusion CXL PLUS was proved to be a successful procedure to halt progression (mainly by CXL) and to correct the refractive status of the keratoconic eye (mainly by ICRS). CXL PLUS performed a synergistic action correcting and maintaining the correction of both myopic and astigmatic components of keratoconus.
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Coskunseven E, Sharma DP, Grentzelos MA, Sahin O, Kymionis GD, Pallikaris I. Four-Stage Procedure for Keratoconus: ICRS Implantation, Corneal Cross-linking, Toric Phakic Intraocular Lens Implantation, and Topography-Guided Photorefractive Keratectomy. J Refract Surg 2017; 33:683-689. [DOI: 10.3928/1081597x-20170807-01] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 07/28/2017] [Indexed: 11/20/2022]
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Long-Term Follow-Up of Intrastromal Corneal Ring Segments in Paracentral Keratoconus with Coincident Corneal Keratometric, Comatic, and Refractive Axes: Stability of the Procedure. J Ophthalmol 2017; 2017:4058026. [PMID: 28948045 PMCID: PMC5602624 DOI: 10.1155/2017/4058026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/03/2017] [Accepted: 07/27/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To assess the long-term outcomes of implanting intrastromal corneal ring segments (ICRS) in paracentral keratoconic eyes. Methods 58 eyes with paracentral keratoconus with coincident refractive, keratometric, and comatic axes were evaluated. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and refractive errors were recorded before and at all follow-up visits. The postoperative follow-up was 5 years. Patients were divided into two groups: group I (30 years old or younger) and group II (more than 30 years old). Results The mean UDVA (logMAR) rose from a preoperative 0.83 ± 0.31 to a five-year postoperative 0.42 ± 0.33 (P < 0.0001). The mean CDVA varied from 0.16 ± 0.17 to 0.11 ± 0.18 (P = 0.0003). Both the UDVA and CDVA were stable over the postoperative period in both groups (P > 0.05). The spherical equivalent and the refractive cylinder declined steeply after ICRS implantation in both groups (P < 0.001), and were stable over the postoperative period (P > 0.05). The keratometric values were also stable over the postoperative follow-up. Conclusion Ferrara-type ICRS implantation in keratoconus that meets the characteristics of the sample under study reduces the refractive error at the same time as it improves postoperative UDVA and CDVA six months after surgery and that these results remain stable over five years of follow-up.
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Abstract
SIGNIFICANCE Reliable intraocular pressure (IOP) measurement after intrastromal corneal ring segments (ICRS) implantation is a challenge because of altered corneal morphology. In this study, IOP is measured with four tonometers, compared with Goldmann applanation tonometry (GAT) values and the influence of corneal parameters is established. PURPOSE This study compares IOP measurements made using different tonometers in patients implanted with ICRS and assesses the effects of central corneal thickness (CCT), corneal curvature, and corneal astigmatism on the IOP measurements obtained. METHODS In this cross-sectional study, IOP was measured using three different tonometers in 91 eyes of 91 patients with corneal ectasia implanted at least 6 months previously with ICRS. The tonometers tested were the TonoPen XL, Pascal dynamic contour tonometer (DCT), and iCare Pro rebound tonometer. GAT measurements were used as reference. Agreement among the IOPs provided by the different tonometers and the influence of corneal variables on the IOP measurements obtained were assessed using the Bland-Altman method, intraclass correlation coefficients, and multiple linear regression analysis. RESULTS Mean IOP differences were GAT versus TonoPen XL -0.8 ± 3.07 mm Hg, GAT versus DCT -1.0 ± 3.26 mm Hg, and GAT versus iCare Pro 0.8 ± 2.92 mm Hg. Our multiple linear regression analysis identified CCT as a confounding factor affecting all the tonometer readings but DCT-IOP. CONCLUSIONS In patients fitted with ICRS, IOP measurements made using the iCare Pro and TonoPen XL showed most agreement with GAT. Intraocular pressure measurements made by DCT were unaffected by corneal topographic factors though this procedure slightly overestimated GAT readings.
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Long-Term Follow-up of Intrastromal Corneal Ring Segments (210-Degree Arc Length) in Central Keratoconus With High Corneal Asphericity. Cornea 2017; 36:1325-1330. [DOI: 10.1097/ico.0000000000001339] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
PURPOSE To describe a new technique of femtosecond laser-assisted intracorneal ring segment implantation. METHODS The study included 6 eyes of 5 patients. Software of the LDV Z6 femtosecond laser was modified to create a 110-degree reverse side cut between the corneal surface and incision instead of the conventional 90 degree angle (which changed the angle between the incision and tunnel from conventional 90-70 degrees) and 2 disjointed tunnels separated by 10 degrees arc length at the proximal and distal ends. RESULTS One-year postoperatively, there were no cases of segment extrusion or touch/overlap. Anterior segment optical coherence tomography showed appropriate position of the rings in all eyes postoperatively. Improvement was also found in visual, refractive, keratometric, and asphericity parameters. CONCLUSIONS The results of this pilot study are promising. A comparative prospective study with more eyes and longer follow-up may confirm whether this technique is better than the conventional femtosecond laser-assisted one.
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Heikal MA, Abdelshafy M, Soliman TT, Hamed AM. Refractive and visual outcomes after Keraring intrastromal corneal ring segment implantation for keratoconus assisted by femtosecond laser at 6 months follow-up. Clin Ophthalmol 2016; 11:81-86. [PMID: 28096650 PMCID: PMC5207472 DOI: 10.2147/opth.s120267] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose We attempted to evaluate the efficacy of femtosecond laser-assisted intrastromal corneal ring segment implantation in patients with keratoconus (KC). Patients and methods A retrospective interventional consecutive clinical study was conducted on patients with KC who were treated with femtosecond laser Keraring implantation. All procedures were performed at Ebsar Eye Center in the period from January 5, 2015, to February 28, 2016. Results Thirty eyes of 20 patients were included in this study. The mean age of patients was 27.43±3.57 years. Eleven patients (55%) were female and nine patients (45%) were male. Keraring segments were successfully implanted in all eyes. There were no complications or need for ring repositioning. The follow-up period was 6 months postoperatively. There was a significant improvement in the mean logarithm of the minimum angle of resolution (LogMAR) of uncorrected visual acuity (UCVA) after Keraring segment implantation from 1.5±0.23 preoperatively to 0.54±0.16 at 6 months postoperatively (P=0.001). The preoperative mean LogMAR of best-corrected visual acuity (BCVA) was 0.85±0.17. At 1 month postoperatively, it was 0.35±0.15; at 3 months postoperatively, it was 0.26±0.11, and at 6 months postoperatively, it was 0.14±0.07 (P=0.001). The mean preoperative maximum keratometric value for 3 mm pupil in diopters (K max) significantly decreased from 55.85±5.44 preoperatively (N=30) to 44.05±1.64 D at 6 months postoperatively (P=0.001). There was a statistically significant reduction in the mean preoperative spherical equivalent from −5.43±1.76 D preoperatively to −2.43±0.95 D at 6 months postoperatively. No statistically significant differences were detected between 1 and 3 months of follow-up regarding the visual and refractive outcomes. Conclusion Analysis of the outcomes after Keraring ICRS implantation showed a significant postoperative corneal flattening with a subsequent increase in UCVA and BCVA. Using the femtosecond laser for tunnel creation made the procedure easy and fast with an accurate precise depth of implantation and reduced the risk of operative and postoperative complications.
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Abstract
To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus.
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Hafez M. Combined cross-linking with femtosecond laser Myoring implantation versus combined cross-linking with femtosecond laser Keraring implantation for treatment of keratoconus. DELTA JOURNAL OF OPHTHALMOLOGY 2016. [DOI: 10.4103/1110-9173.178760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Feasibility of custom-made hydrogel contact lenses in keratoconus with previous implantation of intracorneal ring segments. Cont Lens Anterior Eye 2015; 38:351-6. [DOI: 10.1016/j.clae.2015.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 02/11/2015] [Accepted: 03/31/2015] [Indexed: 11/21/2022]
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Reshaping procedures for the surgical management of corneal ectasia. J Cataract Refract Surg 2015; 41:842-72. [PMID: 25840308 DOI: 10.1016/j.jcrs.2015.03.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 12/31/2022]
Abstract
UNLABELLED Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography-guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Jafarinasab MR, Shirzadeh E, Feizi S, Karimian F, Akaberi A, Hasanpour H. Sensitivity and specificity of posterior and anterior corneal elevation measured by orbscan in diagnosis of clinical and subclinical keratoconus. J Ophthalmic Vis Res 2015; 10:10-5. [PMID: 26005546 PMCID: PMC4424711 DOI: 10.4103/2008-322x.156085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 06/22/2014] [Indexed: 11/04/2022] Open
Abstract
PURPOSE To determine the sensitivity and specificity of anterior and posterior corneal elevation parameters as determined by Orbscan II (Bausch and Lomb, Rochester, NY, USA) in discriminating between (sub) clinical keratoconus (KCN) and normal corneas. METHODS This prospective case-control study included 28 eyes with subclinical KCN, 65 with clinical KCN and 141 normal corneas. Anterior and posterior corneal elevation was measured and compared in the central 5-mm corneal zone using Orbscan II. RESULTS Receiver operating curves (ROC) curve analyses for posterior corneal elevation showed predictive accuracy in both KCN and subclinical KCN with an area under the curve (AUC) of 0.97 and 0.69, respectively while optimal cutoff points were 51 μm for KCN and 35 μm for subclinical KCN. These values were associated with sensitivity and specificity of 89.23% and 98.58%, respectively, for KCN; and 50.00% and 88.65% for subclinical KCN. ROC curve analyses for anterior corneal elevation showed predictive accuracy in both KCN and subclinical KCN with AUC of 0.97 and 0.69, respectively while optimal cutoff points were 19 μm for KCN and 16 μm for subclinical KCN. These values were associated with sensitivity and specificity of 93.85% and 97.16%, respectively, for KCN; and 60.71% and 87.94% for subclinical KCN. CONCLUSION Anterior and posterior corneal elevation data obtained by Orbscan II can well discriminate between KCN and normal corneas, however the reliability of their indices is lower in differentiating subclinical KCN from normal cases.
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Affiliation(s)
- Mohammad Reza Jafarinasab
- Ophthalmic Epidemiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ebrahim Shirzadeh
- Department of Ophthalmology, Sabzevar University of Medical Sciences, Sabzevar, Tehran, Iran ; Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sepehr Feizi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farid Karimian
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Arash Akaberi
- Iranian Applied Research Center for Public Health and Sustainable Development, North Khorasan University of Medical Sciences, Bojnurd, Iran
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Parker JS, van Dijk K, Melles GRJ. Treatment options for advanced keratoconus: A review. Surv Ophthalmol 2015; 60:459-80. [PMID: 26077628 DOI: 10.1016/j.survophthal.2015.02.004] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.
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Affiliation(s)
- Jack S Parker
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; UAB Callahan Eye Hospital, Birmingham, Alabama, USA
| | - Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Gerrit R J Melles
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; Amnitrans EyeBank, Rotterdam, The Netherlands.
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Valdés-Mas MA, Martín-Guerrero JD, Rupérez MJ, Pastor F, Dualde C, Monserrat C, Peris-Martínez C. A new approach based on Machine Learning for predicting corneal curvature (K1) and astigmatism in patients with keratoconus after intracorneal ring implantation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2014; 116:39-47. [PMID: 24857632 DOI: 10.1016/j.cmpb.2014.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 03/26/2014] [Accepted: 04/07/2014] [Indexed: 06/03/2023]
Abstract
Keratoconus (KC) is the most common type of corneal ectasia. A corneal transplantation was the treatment of choice until the last decade. However, intra-corneal ring implantation has become more and more common, and it is commonly used to treat KC thus avoiding a corneal transplantation. This work proposes a new approach based on Machine Learning to predict the vision gain of KC patients after ring implantation. That vision gain is assessed by means of the corneal curvature and the astigmatism. Different models were proposed; the best results were achieved by an artificial neural network based on the Multilayer Perceptron. The error provided by the best model was 0.97D of corneal curvature and 0.93D of astigmatism.
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Affiliation(s)
- M A Valdés-Mas
- LabHuman, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain(1)
| | - J D Martín-Guerrero
- Dpt. Enginyeria Electrònica, Universitat de València, Avgda. Universitat, s/n, 46100, Burjassot, Valencia, Spain(2)
| | - M J Rupérez
- LabHuman, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain(1).
| | - F Pastor
- Fundación Oftalmológica del Mediterráneo, Bifurcación Pío Baroja-General Avilés, s/n, 46015 Valencia, Spain(3)
| | - C Dualde
- Fundación Oftalmológica del Mediterráneo, Bifurcación Pío Baroja-General Avilés, s/n, 46015 Valencia, Spain(3)
| | - C Monserrat
- LabHuman, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain(1)
| | - C Peris-Martínez
- Fundación Oftalmológica del Mediterráneo, Bifurcación Pío Baroja-General Avilés, s/n, 46015 Valencia, Spain(3)
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Torquetti L, Ferrara G, Almeida F, Cunha L, Ferrara P, Merayo-Lloves J. Clinical outcomes after intrastromal corneal ring segments reoperation in keratoconus patients. Int J Ophthalmol 2014; 6:796-800. [PMID: 24392327 DOI: 10.3980/j.issn.2222-3959.2013.06.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 08/16/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments (ICRS) reoperation in patients with keratoconus. METHODS A total of 37 keratoconus eyes implanted with intrastromal corneal ring segments, which had an ICRS exchange, addition, reposition or removal were evaluated. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), keratometry (K), asphericity (Q) and pachymetry at the thinnest point (PTP) of the cornea were evaluated using a corneal tomography (Oculus Pentacam, USA). RESULTS The mean follow-up time after the reoperation was 30.5±9.7 months. The mean UCVA improved from 20/300 to 20/80 (P=0.005); the mean BCVA improved from 20/160 to 20/50 (P=0.0002), the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D (P=0.0001), the mean pachymetry at the thinnest point increased from 450±42.9μm to 469±40.8μm (P=0.0001). The asphericity increased from -0.84±0.74 to -0.35±0.81 (P=0.15) and the spherical equivalent reduced from -4.64±4.87D to -3.04±3.45D (P=0.137). The changes in the asphericity and spherical equivalent were not statistically significant. CONCLUSION Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus treatment. Good outcomes can be obtained even after removal, addition, reposition or exchange of ICRS.
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Affiliation(s)
| | - Guilherme Ferrara
- Paulo Ferrara Eye Clinic, Belo Horizonte 30110-031, Brazil ; Fernandez-Vega Eye Institute, Oviedo 33012, Spain
| | | | - Leandro Cunha
- Hilton Rocha Foundation, Belo Horizonte 30210-090, Brazil
| | - Paulo Ferrara
- Paulo Ferrara Eye Clinic, Belo Horizonte 30110-031, Brazil
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Jabbarvand M, SalamatRad A, Hashemian H, Mazloumi M, Khodaparast M. Continuous intracorneal ring implantation for keratoconus using a femtosecond laser. J Cataract Refract Surg 2013; 39:1081-7. [DOI: 10.1016/j.jcrs.2013.02.054] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 02/12/2013] [Accepted: 02/14/2013] [Indexed: 11/26/2022]
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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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Changes in visual function under mesopic and photopic conditions after intrastromal corneal ring segment implantation for different stages of keratoconus. J Cataract Refract Surg 2013; 39:393-402. [DOI: 10.1016/j.jcrs.2012.09.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/22/2012] [Accepted: 09/24/2012] [Indexed: 11/22/2022]
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Ameerh MAA, Hamad GI, Ababneh OH, Gharaibeh AM, Refai RMA, Bdour MDA. Ferrara ring segments implantation for treating keratoconus. Int J Ophthalmol 2012; 5:586-90. [PMID: 23166869 DOI: 10.3980/j.issn.2222-3959.2012.05.08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 09/12/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the efficacy of Ferrara rings (FR) implantation in the treatment of keratoconus. METHODS It was a retrospective case series descriptive study. The sample was comprised of 50 patients 79 eyes diagnosed with progressive keratoconus. This included 24 (48%) males and 26 (52%) females between the age of 13 and 44 years. All participants underwent surgical implantation of FR in the period between January 2009 and September 2010 at Jordan University Hospital. Thorough ophthalmologic examinations were applied to measure vital variables for each pathological condition before and after surgery. RESULTS Findings indicated an overall significant postoperative improvement in both uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA) throughout follow up visits. Moreover, results illustrated a significant decrease in spherical equivalent (SE) and keratometric readings (lower, higher and the average). CONCLUSION Surgical intervention strategies are being frequently developed to meet the needs of patients with keratoconus. The implantation of Ferrara rings has proven to be a safe and feasible alternative procedure for the treatment of mild-moderate keratoconus especially for patients with contact lenses intolerance. We have found that this procedure has improved visual outcomes in all eyes studied. Nevertheless, further research is needed to investigate long term outcomes.
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