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Mounir A, Mohamed Mostafa E, Amer I, Abdelgbar AA, Osman HO, Ahmed MA, Ziada H, Ali El Gabbar AG, Hassan MA, Mahmoud A. Corneal densitometry changes after femtosecond laser-assisted intracorneal ring segments implantation in keratoconus. MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2024; 13:27-34. [PMID: 38978823 PMCID: PMC11227663 DOI: 10.51329/mehdiophthal1491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Accepted: 05/23/2024] [Indexed: 07/10/2024]
Abstract
Background Intrastromal corneal ring segments are commonly implanted in the corneas of eyes with mild-to-moderate keratoconus; however, changes in corneal densitometry (CD) after implantation are a matter of debate in the current literature. We evaluated the changes in CD 1 and 3 months after femtosecond laser-assisted Keraring implantation. Methods This retrospective, non-comparative, multicenter, case series study included patients with keratoconus who underwent femtosecond laser-assisted implantation of double segments with 90° and 160° arc lengths or two 160° arc length Keraring segments. Demographic and baseline clinical ophthalmic data were recorded. Corneal topography and tomography data acquired using a Pentacam HR Scheimpflug tomography system (Pentacam High Resolution; Oculus, Wetzlar, Germany) with a best-fit sphere were used as a reference surface. Using the Pentacam HR, CD measurements were acquired over a corneal area of 12 mm in total and at four concentric zones (0-2, 2-6, 6-10, and 10-12 mm) of three corneal stromal depths: 120 μm of the anterior corneal stromal layer, 60 μm of the posterior corneal stromal layer, and the central layer of stroma lying between these two layers. Results We included 40 eyes of 40 patients, including 8 (20%) male and 32 (80%) female individuals, with a mean (standard deviation) age of 21.0 (6.4) years. We observed a significant improvement in the topographic values of steep keratometry (K), flat K, maximum K, and corneal astigmatism (all P < 0.05), but not in the mean K, thinnest corneal pachymetry, corneal thickness at the apex, back elevation, or front elevation (all P > 0.05). The mean total anterior, central, and posterior CD differed significantly among the time points, with a significant increase from the preoperative to the 1-month and 3-month postoperative visits (all P < 0.05) and no difference between those of the 1-month and 3-month postoperative visits (all P > 0.05). The mean CD for the anterior layer in the central, paracentral, and mid-peripheral zones, and the central layer in all four zones, differed significantly among time points, with a significant increase from the preoperative to the 1-month and 3-month postoperative visits (all P < 0.05), which remained unchanged from the 1-month to the 3-month postoperative visit (all P < 0.05), except for the central 2-6-mm zone, which decreased significantly from the 1-month to the 3-month postoperative visit (P < 0.001). The CD of the central 10-12-mm zone did not differ significantly in each pairwise comparison (all P > 0.05). In contrast, CD for the posterior layer in the paracentral zone decreased significantly from the preoperative to the 1-month and 3-month postoperative visits but increased, to a lesser extent, from the 1-month to the 3-month postoperative visit (all P < 0.05). Conclusions Femtosecond laser-assisted Keraring implantation significantly changes CD, with improvement in most topography parameters. Further longitudinal studies with larger sample sizes are required to verify these preliminary findings.
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Affiliation(s)
- Amr Mounir
- Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Engy Mohamed Mostafa
- Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Ibrahim Amer
- Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt
| | | | - Hamdy Osman Osman
- Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt
| | | | - Hossam Ziada
- Ophthalmology Department, Faculty of Medicine, Cairo branch, Al-Azhar University, Cairo, Egypt
| | | | - Mohamed Alsadawy Hassan
- Ophthalmology Department, Faculty of Medicine, Cairo branch, Al-Azhar University, Cairo, Egypt
| | - Alaa Mahmoud
- Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
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Mohammadpour M, Heirani M, Khoshtinat N, Khorrami-Nejad M. Comparison of two different 360-degree intrastromal corneal rings combined with simultaneous accelerated-corneal cross-linking. Eur J Ophthalmol 2024; 34:126-139. [PMID: 37139606 DOI: 10.1177/11206721231171420] [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] [Indexed: 05/05/2023]
Abstract
PURPOSE to compare five-year outcomes of two complete intracorneal implants (MyoRing versus annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive KCN. METHODS In this historical cohort study, preoperative and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters of 27 eyes of 27 patients who underwent implantation of two complete rings (13 AICI and 14 MyoRing) combined with A-CXL were recorded. RESULTS The mean age of patients in "AICI plus A-CXL" and "MyoRing plus A-CXL" groups were 28.1 ± 4.6 and 26.3 ± 3.8 years, respectively. All pre- and postoperative visual and refractive parameters between the two groups were not significantly different (p > 0.05). Comparing pre- and postoperative tomographic measurements showed that anterior corneal surface (ACS) flat-K and corneal thickness at pachymetric apex significantly improved for MyoRing plus A-CXL group after five years (p < 0.05). On the other hand, ACS K-max and mean-K values were significantly improved for AICI plus A-CXL group after five years (p < 0.05). Both groups revealed significant improvements in ACS steep-K and corneal astigmatism (p < 0.05). Five years after surgery, the high order aberration in the AICI group (2.60 ± 0.83) was significantly better than the MyoRing group (1.70 ± 0.43) (p = 0.007). CONCLUSIONS Both complete intrastromal rings (MyoRing or AICI) combined with A-CXL significantly Improved visual, refractive, and corneal aberrometric, biomechanical, and tomographic parameters and halt the progression of KCN with comparable long-term outcomes.
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Affiliation(s)
- Mehrdad Mohammadpour
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohsen Heirani
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Narges Khoshtinat
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Khorrami-Nejad
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran
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Faramarzi A, Hassanpour K, Mazouchi M, Einollahi B, Feizi S, Esfandiari H, Sadoughi MM, Moshirfar M. Clinical Outcomes of Femtosecond Laser-assisted Implantation of 325-Degree Versus 340-Degree Arc Length Intracorneal Ring Segments in Naive Keratoconic Eyes. J Ophthalmic Vis Res 2023; 18:369-378. [PMID: 38250234 PMCID: PMC10794807 DOI: 10.18502/jovr.v18i4.14545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/04/2023] [Indexed: 01/23/2024] Open
Abstract
Purpose To evaluate and compare clinical outcomes after femtosecond laser-assisted implantation of 325-degree versus 340-degree arc length intracorneal ring segments (ICRS) in eyes with keratoconus (KCN). Methods In this prospective non-randomized interventional case series, 23 eyes of 21 patients diagnosed with KCN, underwent femtosecond laser-assisted implantation of two types of ICRS, which included a 325-degree ICRS (Group 325) and a 340-degree ICRS (Group 340). The primary outcome measures were uncorrected distance visual acuity (UDVA), and the secondary outcome measures included corrected distance visual acuity (CDVA), sphere, cylinder, mean refractive spherical equivalent (MRSE), keratometry, vectorial change in corneal astigmatism, and the location of maximum keratometry relative to the corneal apex. The study groups were compared using the primary and secondary outcome measures obtained at postoperative months six and 12. Results Groups 325 and 340 consisted of 10 and 13 eyes, respectively. The two groups were comparable in terms of parameters measured preoperatively. On comparison to the baseline values, both study groups exhibited a significant increase in UDVA and CDVA measured at postoperative month six (Ps < 0.05) and a significant decrease in the sphere, cylinder, spherical equivalent refraction, and keratometry readings measured at postoperative months six and 12 (Ps < 0.05). No significant differences were observed between the two groups in terms of visual, refractive, and keratometric outcomes at any time point. No intraoperative or postoperative complications were observed in any of the study groups. Conclusion Both the 325-degree ICRS and the 340-degree ICRS effectively and equally improved visual, refractive, and keratometric outcomes in keratoconic eyes.
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Affiliation(s)
- Amir Faramarzi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kiana Hassanpour
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marjan Mazouchi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahram Einollahi
- Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sepehr Feizi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Esfandiari
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Mohammad-Mehdi Sadoughi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Majid Moshirfar
- John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, Salt Lake City, UT, USA
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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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Jabbarvand M, Khodaparast M, Jamali A, Ahmadzadeh H, Bordbar S. Changes in the Optical Corneal Densitometry, Visual Acuity, and Refractive Error after the Annular Intracorneal Inlay Implantation. J Curr Ophthalmol 2021; 33:23-30. [PMID: 34084953 PMCID: PMC8102947 DOI: 10.4103/joco.joco_154_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/04/2020] [Accepted: 09/29/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose: To investigate the changes in the optical corneal densitometry as an objective method in assessing the corneal light back-scattering before and 1 year after the annular intracorneal inlay (AICI) implantation into the keratoconic corneas. Methods: Changes in the optical corneal densitometry, visual acuity, refractive, and tomographical status were assessed before and 1 year after the AICI implantation into the corneas with different stages of keratoconus. Optical corneal densitometry was evaluated using the Pentacam-HR in 0–2, 2–6, 6–10, and 10–12 mm rings in the anterior 120 μ, central layers, posterior 60 μ and also the total value were measured for cornea in the Grey Scale Unit criterion. Results: Totally, 34 patients with keratoconus were studied; the uncorrected and best corrected visual acuity were increased after the surgery (0.98 ± 0.25 to 0.53 ± 0.30 logMAR, P < 0.001 and 0.26 ± 0.18 to 0.19 ± 0.14, P = 0.007 logMAR, respectively); the spherical equivalent was decreased from −4.45 ± 2.25 to − 2.06 ± 2.01 D (P = 0.004). AICI implantation led to an increase in the amount of optical corneal densitometry in 0–2 mm central, 2–6 mm central, 6–10 mm central, total central, 2–6 mm posterior, and 2–6 mm total rings (all, P < 0.05); however, a decrease was observed in 0–2 mm anterior ring (P = 0.049). Results of statistical analysis showed that the total optical corneal densitometry, anterior total, and posterior total back-scattering did not change after the AICI implantation (all, P > 0.05). Conclusions: Our results revealed a significant improvement in the visual function, including refractive error and visual acuity following the AICI implantation. Changes in the optical corneal densitometry were different in distinct regions and layers however, the total amount did not change after the AICI implantation.
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Affiliation(s)
- Mahmoud Jabbarvand
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Khodaparast
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Jamali
- Rehabilitation Research Center, Department of Optometry, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Hooman Ahmadzadeh
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Soodeh Bordbar
- English Department, Iran University of Medical Sciences, Tehran, Iran
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Izquierdo L, Rodríguez AM, Sarquis RA, Altamirano D, Henriquez MA. Intracorneal circular ring implant with femtosecond laser: Pocket versus tunnel. Eur J Ophthalmol 2021; 32:176-182. [PMID: 33579160 DOI: 10.1177/1120672121994729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate and compare visual and refractive outcomes after implantation of the intracorneal continuous ring 360° arc (ICCR) versus the intracorneal ring segment 340° arc (ICRS) using femtosecond laser for central keratoconus. SETTING Research Department, Oftalmosalud, Instituto de Ojos, Lima, Peru. METHODS Randomized study that included 40 eyes of 32 patients diagnosed with central keratoconus between November 2014 and March 2015. Twenty eyes had an implantation of ICCR (MyoRing, Dioptex GmbH, Austria) through an intrastromal pocket and 20 eyes had an implantation of ICRS (Keraring, Mediphacos, Brazil) through an intrastromal tunnel. Both procedures were performed with a femtosecond laser (LDV Z6 model, Ziemer Ophthalmic Systems AG). Visual acuity (VA), refraction, and Scheimpflug imaging analysis were performed pre- and postoperatively at 1 month and 1 year. Comparisons of means were performed using the Student's t-test. RESULTS At 1 year, uncorrected VA improved 0.77 LogMAR (p < 0.001) in the ICCR group and 0.79 LogMAR (p = 0.01) in the ICRS group; mean sphere improvement was 5.13 Diopters (D) in the ICCR group and 6.27 D in the ICRS group (p < 0.001 both); mean Steeper Keratometry improvement was 4.24 D in the ICCR group and 5.53 D in the ICRS group (p < 0.001 both). In the ICCR group, mean decrease in the pachymetry at the thinnest point of the cornea was 32.16 µm (p = 0.01), and in the ICRS group, mean increase was 4.2 µm at 1 year (p = 0.61). CONCLUSION Intracorneal continuous ring 360° arc (ICCR) and intracorneal ring segment 340° (ICRS) are effective treatments for central keratoconus. No significant differences between rings were found on visual acuity, refraction, and keratometry improvement.
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Affiliation(s)
- Luis Izquierdo
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
| | - Ana M Rodríguez
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
| | - Ramón A Sarquis
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
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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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Anatomical and Visual Effects of the MyoRing Implantation Measured by the ABCD Keratoconus Grading System. Eye Contact Lens 2020; 46:52-56. [DOI: 10.1097/icl.0000000000000595] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Khorrami-Nejad M, Aghili O, Hashemian H, Aghazadeh-Amiri M, Karimi F. Changes in Corneal Asphericity after MyoRing Implantation in Moderate and Severe Keratoconus. J Ophthalmic Vis Res 2019; 14:428-435. [PMID: 31875097 PMCID: PMC6825702 DOI: 10.18502/jovr.v14i4.5443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 02/06/2019] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To evaluate the effect of MyoRing implantation on corneal asphericity in moderate and severe keratoconus (KCN). METHODS This cross-sectional observational study comprised 32 eyes of 28 patients with KCN, who had femtosecond-assisted MyoRing corneal implantation. The primary outcome measures were preoperative and six-month postoperative corneal asphericity in 6-, 7-, 8-, 9-, and 10-mm optical zones in the superior, inferior, nasal, temporal, and central areas. The secondary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, thinnest location value, and keratometry readings. RESULTS A significant improvement in the UDVA and CDVA was observed six months after the surgery (P < 0.001) with a significant reduction in the spherical (4.67 diopters (D)) and cylindrical (2.19 D) refractive errors. A significant reduction in the corneal asphericity in all the optical zones and in the superior, inferior, nasal, temporal, and central areas was noted (P < 0.001). The mean thickness at the thinnest location of the cornea decreased from 437.15 ± 30.69 to 422.81 ± 36.91 μm. A significant corneal flattening was seen. The K1, K2, and Km changes were 5.32 D, 7 D, and 6.17 D, respectively (P < 0.001). CONCLUSION MyoRing implantation is effective for improving corneal asphericity in patients with KCN. It allows successful corneal remodeling and provides a significant improvement in UDVA, CDVA, and refractive errors.
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Affiliation(s)
- Masoud Khorrami-Nejad
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ozra Aghili
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hesam Hashemian
- Eye Research center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohamad Aghazadeh-Amiri
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farshid Karimi
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Efficacy of complete rings (MyoRing) in treatment of Keratoconus: a systematic review and meta-analysis. Int Ophthalmol 2019; 39:2929-2946. [DOI: 10.1007/s10792-019-01121-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 05/22/2019] [Indexed: 10/26/2022]
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Abstract
BACKGROUND Keratoconus is a degenerative condition of the cornea that profoundly affects vision and vision-specific quality of life. The axial cornea thins and protrudes, resulting in irregularity and, eventually, scarring of the cornea. There are multiple options available for treating keratoconus. Intrastromal corneal ring segments are small, crescent-shaped plastic rings that are placed in the deep, peripheral corneal stroma in order to flatten the cornea. They are made of polymethylmethacrylate (PMMA). The procedure does not involve corneal tissue nor does it invade the central optical zone. Intrastromal corneal ring segments are approved for use when contact lenses or spectacles are no longer adequate. OBJECTIVES To evaluate the effectiveness and safety of intrastromal corneal ring segments as a treatment for keratoconus. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 1); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not implement any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 25 January 2018. SELECTION CRITERIA Two review authors independently assessed records from the electronic searches to identify randomized controlled trials (RCTs). Disagreements were resolved by discussion. DATA COLLECTION AND ANALYSIS We planned for two authors to independently review full-text reports, using standard methodological procedures expected by Cochrane. MAIN RESULTS We found no RCTs comparing intrastromal corneal ring segments with spectacles or contact lenses. AUTHORS' CONCLUSIONS In the absence of eligible RCTs to review, no conclusions can be drawn.
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Affiliation(s)
- Karla Zadnik
- The Ohio State UniversityCollege of Optometry338 West Tenth AvenueColumbusOhioUSAOH 43210
| | | | - Kristina Lindsley
- IBM Watson HealthLife Sciences, Oncology, & GenomicsBaltimoreMarylandUSA
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Peris-Martínez C, Bueno-Gimeno I, Alvarez-Arana I, Piñero DP, Gené-Sampedro A. Characterization of the effect of intracorneal ring segment in corneal ectasia after laser refractive surgery. Eur J Ophthalmol 2018; 30:125-131. [PMID: 30384777 DOI: 10.1177/1120672118808968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate the visual, refractive, topographic, pachymetric, and biomechanical outcomes after intracorneal ring segment implantation in corneas with post-LASIK ectasia. METHODS Retrospective longitudinal study enrolling 26 eyes of 22 patients with post-LASIK ectasia and undergoing intracorneal ring segment implantation (KeraRing®, Mediphacos) using a 60-kHz femtosecond laser (IntraLase®, IntraLase Corp.) for corneal tunnelization. Visual, refractive, anterior, and posterior corneal topographic (Pentacam HR, Oculus), pachymetric, and corneal biomechanical changes (Ocular response Analyzer, Reichert) were evaluated during a 12-month follow-up. Vector analysis of astigmatic changes was performed. RESULTS A statistically significant reduction of sphere (p = 0.043) was observed at 1 month after surgery, with a significant improvement of uncorrected distance visual acuity associated (p = 0.019). Likewise, a significant reduction of anterior corneal power measurements (p ⩽ 0.014) and steepest posterior keratometric reading (p = 0.006) were observed at 1 month postoperatively, with no significant changes afterwards (p ⩾ 0.133). No significant changes were observed in manifest cylinder (p ⩾ 0.175), corrected distance visual acuity (p ⩾ 0.174), flattest posterior keratometric measurement (p ⩾ 0.282), volumetric measurements (p ⩾ 0.051), and corneal biomechanical parameters (p ⩾ 0.068). Vector analysis revealed an initial trend to overcorrection of astigmatism, with a trend to undercorrection at the end of follow-up and a significant variability in the outcome achieved in each patient. CONCLUSION The implantation of KeraRing segments in post-LASIK corneal ectasia generates a significant modification of spherical refraction and a visual improvement due to a central corneal flattening generated. More refined nomograms of implantation in these cases should be developed to achieve a more predictable correction of astigmatism.
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Affiliation(s)
- Cristina Peris-Martínez
- FISABIO Oftalmología Médica (FOM), Cornea and External Diseases Unit, Valencia, Spain.,Aviño&Peris Eye Clinic, Valencia, Spain
| | - Inmaculada Bueno-Gimeno
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain
| | - Izaskun Alvarez-Arana
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Andrés Gené-Sampedro
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain.,Research Institute on Traffic and Road Safety (INTRAS) University of Valencia, Valencia, Spain
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13
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Pashtaev NP, Pozdeeva NA, Zotov VV, Sinitsyn MV, Shcheglova MA. [Strength properties of rabbit cornea after femtosecond laser keratoplasty with and without different intracorneal implants]. Vestn Oftalmol 2018. [PMID: 29543194 DOI: 10.17116/oftalma2018134118-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM to conduct a comparative experimental study of the effect of the use of intracorneal implants during femtosecond laser-assisted intrastromal pocket (IP) and intrastromal tunnel (IT) formation on the strength properties of the cornea. MATERIAL AND METHODS The experimental study was performed on 24 corneas of 12 rabbit eyes enucleated 1 month after slaughtering. All eyes were divided into 6 groups according to the method of operation. IP and IT were created with IntraLase FS 60 kHz femtolaser. Group 1 (control group) consisted of rabbit eyes with intact corneas. In group 2 corneas, intrastromal tunnels were formed, in group 3 - intrastromal pockets, and in group 4 - intrastromal tunnels with 2 intracorneal segments (ICS). In groups 5 and 6, intrastromal pockets, each supplemented with an intrastromal ring, were created at the depth of 62-72% and 80% of pachymetry readings from the 5.0-mm optical zone, respectively. RESULTS Higher voltage had to be applied to stretch the samples from group 2 as compared to those from groups 3 and 6. Distribution of the Young's modulus of the test corneas agreed with voltage distribution in the study groups. CONCLUSION IP was associated with greater reduction in corneal biomechanical stability as compared with IT. Ring implantation into an IP yielded a more pronounced increase in the strength properties of the cornea than ICS implantation into an IT. The result was also more favorable at greater depths of intrastromal ring implantation.
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Affiliation(s)
- N P Pashtaev
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - N A Pozdeeva
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - V V Zotov
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - M V Sinitsyn
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - M A Shcheglova
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley prospekt, Cheboksary, Russian Federation, 428028
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Pashtaev NP, Pozdeeva NA, Sinitsyn MV. [Comparative analysis of corneal aberrations after intrastromal segments and MyoRing implantation using femtosecond laser in patients with keratoconus]. Vestn Oftalmol 2017; 133:3-8. [PMID: 28745650 DOI: 10.17116/oftalma201713334-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM to comparatively analyze corneal aberrations after intrastromal corneal segments (ICS) and MyoRing implantation using femtosecond laser in patients with stage II-III keratoconus (KC) by Pentacam examination. MATERIAL AND METHODS We have operated on 135 patients (145 eyes) with stage II or III KC. Depending on surgical technique, all patients were divided into two groups. Group I consisted of patients with KC, who received optimized femtosecond laser-assisted MyoRing implantation, group II - of those, who received femtosecond laser-assisted ICS implantation. Depending on the stage of the disease, each group was further divided into two subgroups, for stage II and stage III KC, respectively. Before and after surgery, all patients underwent visometry, biomicroscopy, corneal topography, and corneal aberrations measurement under photopic and mesopic conditions on Pentacam. The follow-up period averaged 30 months (from 6 to 34 months). RESULTS In both groups corneal aberrations significantly decreased after surgery, which was confirmed by an improvement in parameters of refraction and keratometry readings. CONCLUSION Implantation of intrastromal MyoRings leads to a greater reduction in the total corneal aberration, higher-order aberrations under photopic and mesopic conditions, and spherical aberration under photopic conditions as compared to ICS in patients with stage III KC; a comparable reduction in the total corneal, higher-order, and spherical aberrations under photopic conditions as compared to ICS in patients with stage II KC; a comparable increase in spherical aberration under mesopic conditions as compared to ICS in patients with stage III KC.
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Affiliation(s)
- N P Pashtaev
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley St., Cheboksary, Chuvash Republic, Russia, 428028; I.N. Ulyanov Chuvash State University, 15 Moskovskiy pr., Cheboksary, Russia, 428015
| | - N A Pozdeeva
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley St., Cheboksary, Chuvash Republic, Russia, 428028
| | - M V Sinitsyn
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley St., Cheboksary, Chuvash Republic, Russia, 428028
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Al-Tuwairqi WS, Osuagwu UL, Razzouk H, AlHarbi A, Ogbuehi KC. Clinical evaluation of two types of intracorneal ring segments (ICRS) for keratoconus. Int Ophthalmol 2016; 37:1185-1198. [DOI: 10.1007/s10792-016-0385-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/22/2016] [Indexed: 11/25/2022]
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16
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Callou TP, Garcia R, Mukai A, Giacomin NT, de Souza RG, Bechara SJ. Advances in femtosecond laser technology. Clin Ophthalmol 2016; 10:697-703. [PMID: 27143847 PMCID: PMC4844446 DOI: 10.2147/opth.s99741] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Femtosecond laser technology has become widely adopted by ophthalmic surgeons. The purpose of this study is to discuss applications and advantages of femtosecond lasers over traditional manual techniques, and related unique complications in cataract surgery and corneal refractive surgical procedures, including: LASIK flap creation, intracorneal ring segment implantation, presbyopic treatments, keratoplasty, astigmatic keratotomy, and intrastromal lenticule procedures.
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Affiliation(s)
| | - Renato Garcia
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
| | - Adriana Mukai
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
| | | | | | - Samir J Bechara
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
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Al-Raddadi HS, Al-Barry MA, Al-Harbi E, Samman MI, Albalawi AM, Basit S. Sequence analysis of the VSX1 and SOD1 genes in families with Keratoconus and a review of the literature. J Taibah Univ Med Sci 2016. [DOI: 10.1016/j.jtumed.2015.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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Agreement Between Autorefraction and Subjective Refraction in Keraring-Implanted Keratoconic Eyes. Eye Contact Lens 2016; 43:116-122. [PMID: 26825280 DOI: 10.1097/icl.0000000000000244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess the agreement between subjective refraction and autorefraction and to explore the relationship between the magnitude of higher order aberration, and visual acuity and refraction, before and after keraring implantation. METHODS This prospective, randomized, interventional study enrolled 27 subjects (mean age 28.1±6.5 years) with keratoconus. Noncycloplegic refraction was performed subjectively by one clinician and with an autorefractor by another clinician, before and 6 months after surgery. The limit of agreement (LoA) between methods was assessed, and the relationships between the corrected distance visual acuity, logMAR on the one hand and refraction measurements and higher-order aberrations on the other, were examined. RESULTS The agreement in mean spherical equivalent refraction (MSER) between methods was good postoperatively but poor preoperatively. The autorefractor gave a more myopic refraction than subjective refraction preoperatively (-3.28±3.06 D; LoA -9.27 to +2.71 D, P<0.0001) and postoperatively (-0.63±1.64 D; LoA -3.85 to +2.58 D, P=0.055), and returned higher negative cylinders preoperatively (-1.10±1.17 D; LoA -3.40 to +1.19 D, P<0.0001) and postoperatively (-1.08±1.27 D; LoA -3.60 to +1.41 D, P<0.0001) in keratoconic eyes. The difference in MSER between methods was significantly related to the refractive error at both visits (P<0.05) and to the magnitude of higher-order aberrations in keratoconic eyes preoperatively (P<0.05). The logMAR visual acuity achieved subjectively worsened as the magnitude of higher-order aberrations increased preoperatively (P<0.001). CONCLUSIONS The autorefractor returns values that are significantly more myopic in MSER and higher negative cylinders than subjective refraction, preoperatively, but the MSER was similar between devices postoperatively. The autorefactor seems a valid starting point for subjective refraction in keratoconic eyes treated with keraring, but the cylinder should be corrected by about +1 D. The instruments agree more in less myopic than high myopic eyes.
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Nasrollahi K, Rezaei L, Ghoreishi M, Kashfi A, Mahboubi M. Clinical outcomes of MyoRing implantation in keratoconic eyes by using the Femtosecond laser technology. J Med Life 2015; 8:66-71. [PMID: 28316668 PMCID: PMC5348932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose: To assess the outcomes of the insertion of the MyoRing (DIOPTEX, GMBH, Linz, Austria) by applying the Femtosecond Laser Technology (FLT) method in eyes that have keratoconus problem. Methods: A prospective, nonrandomized, clinical examination was managed. 27 eyes of 15 subjects with stable keratoconus (6 females and 9 males), with lifetimes differing from 14 to 49 years were involved. All subjects have problems about decreased fine-accurate ocular awareness, lens intolerantness or trouble, and also the middle corneal height larger than 350 micrometers. MyoRing additions of about 320 micrometers into height and 2.5 mm into radius were inserted in each subject inside an Intrastromal Corneal Pocket using(ICP) formed with applying FLT. Ocular, refractive errors, corneal shape, and pachymetry changes were assessed throughout a 6-months follow-up period. Results: The average UDVA (uncorrected distance visual acuity) notably increased originating at 1.73 ± 0.53 LogMAR preoperationally to 0.54 ± 0.40 LogMAR post-operationally. The average CDVA (corrected distance ocular awareness) notably increased from 0.59 ± 0.47 LogMAR preoperationally to 0.27 ± 0.16 LogMAR post-operationally. The change in the average UDVA and CDVA was analytically meaningful (P< 0.000). The average reduction in the average keratometry from preoperational to 26 weeks post operational was -6.41 ± 3.62 D. This change was analytically meaningful (P< 0.000). The average lowest and highest keratometry amounts were similarly analytically notable at shorter than 26 weeks preoperatively. A notable increase in UDVA and CDVA was observed 26 weeks following the operation, that was compatible with the notable decrease in sphere and cylinder. Moreover, a notable corneal straightening with an average amount of -6.41 ± 3.62 diopters (D) was determined. Conclusion: MyoRing implantation employing FLT would be a harmless, effective, and predictable method to treat selected subjects of keratoconus, being a helpful choice for the therapy of keratoconus.
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Affiliation(s)
- K Nasrollahi
- Isfahan University of Medical Sciences, Isfahan, Iran
| | - L Rezaei
- Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - M Ghoreishi
- Isfahan University of Medical Sciences, Isfahan, Iran
| | - A Kashfi
- Isfahan University of Medical Sciences, Isfahan, Iran
| | - M Mahboubi
- Abadan School of Medical Sciences, Abadan, Iran
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