Effect of intracorneal ring segment implantation on high order aberrations comparing patients with eccentric versus central keratoconus

2021 ◽  
pp. 112067212110410
Author(s):  
Philipp Anders ◽  
Lisa-Marie Anders ◽  
Mohamed Elalfy ◽  
Samer Hamada ◽  
Berthold Seitz ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Significant Positive Correlation ◽  
Spherical Aberration ◽  
High Order ◽  
Visual Performance ◽  
Mean Square ◽  
Ring Segment ◽  
Intracorneal Ring Segment ◽  
High Order Aberrations

Purpose: To assess potential differences between central and eccentric cones in the aberrometric corneal profile and in visual and keratometric outcomes 6 months after intracorneal ring segment (ICRS) implantation for keratoconus. Methods: This study compared two groups consisting of 12 patients each, with central or eccentric keratoconus who were treated with femtosecond laser-assisted Keraring implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, keratometric readings and higher order aberrations (HOAs) including high order aberrations root mean square (HOARMS), coma, spherical aberration and trefoil were measured preoperatively and 6 months after ICRS implantation. Results: Trefoil and spherical aberration were significantly reduced after ICRS implantation compared to preoperative values in eccentric keratoconus (Trefoil, p = 0.0049; Spherical aberration, p < 0.0001). In central keratoconus spherical aberration was reduced not significantly after ICRS implantation compared to preoperative values ( p = 0.087). Coma showed a significant reduction in central ( p = 0.0001) and in eccentric keratoconus ( p = 0.0001). The reduction of spherical aberration in central keratoconus was significantly positively correlated to improvement in UDVA (Pearson’s correlation coefficient, r = −0.66; p = 0.02). In eccentric keratoconus there was a significant positive correlation between reduction of trefoil and improvement in UDVA (Spearmans R, r = −0.69; p = 0.01). Conclusion: Patients both with central and eccentric keratoconus benefit from ICRS implantation. Specifically, our data provide a slightly higher gain in visual performance for eccentric cones 6 month after ICRS implantation, which is accentuated by a greater reduction in spherical aberration and trefoil. Improvements in UDVA are positively correlated with reductions in HOAs.

Intracorneal circular ring implant with femtosecond laser: Pocket versus tunnel

2021 ◽  
pp. 112067212199472
Author(s):  
Luis Izquierdo ◽  
Ana M Rodríguez ◽  
Ramón A Sarquis ◽  
Diego Altamirano ◽  
Maria A Henriquez
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Randomized Study ◽  
Circular Ring ◽  
Continuous Ring ◽  
Refractive Outcomes ◽  
Scheimpflug Imaging ◽  
Ring Segment ◽  
Intracorneal Ring Segment ◽  
Student’S T

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.

Unilateral Ectasia characterized by Advanced Diagnostic Tests

2016 ◽  
Vol 5 (1) ◽  
pp. 40-51 ◽  
Author(s):  
Bernardo Lopes ◽  
Marcella Q Salomão ◽  
Isaac C Ramos ◽  
Fernando Faria-Correia
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Diagnostic Tests ◽  
Diagnostic Methods ◽  
Distance Visual Acuity ◽  
Epithelial Thickness ◽  
Ring Segment ◽  
Intracorneal Ring Segment ◽  
The Right

ABSTRACT To describe a case of very asymmetric ectasia successfully treated by femtosecond laser-assisted intracorneal ring segment implantation, in which the diagnosis of unilateral ectasia in the right eye was based on the clinical findings including history, follow-up, and advanced diagnostic data. The patient's history was positive for ocular allergy with moderate- to-intense eye rubbing only in the right eye. The uncorrected distance visual acuity was 20/63 in the right eye and 20/32 in the left eye. The corrected distance visual acuity (CDVA) was 20/40 in the right eye (-1.75-4.00 × 35°) and 20/16 in the left eye (-0.50-0.25 × 115°). After femtosecond laser-assisted intracorneal ring segment implantation, the right eye improved CDVA to 20/20-1. Concerning ectasia/keratoconus diagnosis, the left eye remained stable over 1 year of follow-up with unremarkable topometric, tomographic, and biomechanical findings. Epithelial thickness mapping by spectral domain optical coherence tomography and very-high-frequency digital ultrasound demonstrated epithelial thickness within normal limits in the left eye. Advanced diagnostic methods along with clinical data enable the distinction from unilateral ectasia cases and subclinical (fruste) keratoconus. Literature review is also performed along with case presentation and discussion. How to cite this article Ramos IC, Reinstein DZ, Archer TJ, Gobbe M, Salomão MQ, Lopes B, Luz A, Faria-Correia F, Gatinel D, Belin MW, Ambrósio R Jr. Unilateral Ectasia characterized by Advanced Diagnostic Tests. Int J Kerat Ect Cor Dis 2016;5(1):40-51.

scholarly journals Pre-Descemetic Placement of Intracorneal Ring Segments for Keratoconus after Mechanical Implantation

2021 ◽  
pp. 940-943
Author(s):  
Faady Yahya ◽  
Christian F. Prünte ◽  
Hendrik P.N. Scholl ◽  
Zisis Gatzioufas
Keyword(s):  
Visual Acuity ◽  
High Resolution ◽  
Femtosecond Laser ◽  
Anterior Segment ◽  
Slit Lamp ◽  
Anterior Segment Oct ◽  
Ring Segment ◽  
Intracorneal Ring Segment

We report the case of a 23-year-old male who was referred to our clinic for a routine follow-up examination. The patient was treated for keratoconus 3 years ago in Colombia, where intracorneal ring segments were implanted mechanically in both eyes to improve his visual acuity. Surprisingly, we discovered a pre-descemetic placement of intracorneal ring segments, which could lead to potential complications, under circumstances. We illustrate this impressive finding with slit-lamp photography and high-resolution anterior segment OCT and advocate for the use of femtosecond laser as the method of choice for intracorneal ring segment insertion in order to provide maximal precision and safety.

Comparison of clinical outcomes between manual and femtosecond laser techniques for intrastromal corneal ring segment implantation

2019 ◽  
Vol 30 (6) ◽  
pp. 1246-1255 ◽  
Author(s):  
Tiago Monteiro ◽  
José F Alfonso ◽  
Nuno Franqueira ◽  
Fernando Faria-Correira ◽  
Renato Ambrósio ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Mean Square ◽  
Spherical Equivalent ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Manual Group ◽  
Ring Segment

Purpose: The purpose was to compare the visual, refractive and aberrometric results of intrastromal corneal ring segments implantation with manual dissection and femtosecond laser–assisted surgery. Methods: This is a multicentre study, which included consecutive patients with paracentral keratoconus, in which the difference between the axes of the topographic flattest and the coma aberration was <60°, who had Ferrara-type intrastromal corneal ring segment implantation using manual dissection or femtosecond laser technique. LogMAR uncorrected (uncorrected distance visual acuity) and corrected (corrected distance visual acuity) distance visual acuity, refractive errors and the root mean square for corneal coma-like aberration were recorded before and at 6 months after surgery. Results: The study included 84 and 110 eyes in the manual group and in the femtosecond group, respectively. After surgery, there was a statistically significant improvement in uncorrected distance visual acuity and corrected distance visual acuity for both groups ( p < 0.0001), and there were no statistically significant differences between groups ( p > 0.3). For both groups, there was a reduction in spherical equivalent after intrastromal corneal ring segment implantation ( p < 0.0001). There were no statistically significant differences between groups in the magnitude of spherical equivalent reduction ( p = 0.34) The magnitude of the root mean square coma-like reduction was 0.93 ± 0.76 and 0.83 ± 0.80 μm in the manual and femtosecond group, respectively ( p = 0.2). While in the femtosecond laser group no complications were reported, in the manual group, the intraoperative or postoperative complications rate was 13.09%. Conclusion: Although both surgical techniques provide comparable visual, refractive and aberrometric outcomes, it should be noted that the femtosecond laser is a safer surgical procedure, with no complications reported.

scholarly journals Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus

2017 ◽  
Vol 6 (2) ◽  
pp. 73-77
Author(s):  
Guillermo Rocha ◽  
Victor Penner ◽  
Kylee Lewis
Keyword(s):  
Visual Acuity ◽  
Spherical Aberration ◽  
Corneal Thickness ◽  
Case Series ◽  
High Order ◽  
Photorefractive Keratectomy ◽  
Cross Linking ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
High Order Aberrations

ABSTRACT Purpose To demonstrate clinical outcomes of epithelium-off corneal cross-linking (CXL) in combination with wavefront-guided photorefractive keratectomy (PRK) for the treatment of keratoconuns. Materials and methods Total, 28 keratoconic eyes of 21 patients were included. The Sirius Wavefront Analyzer (SCHWIND eye-tech-solutions GmbH and Co. KG) was used to evaluate the high-order aberrations (HOAs). The coupled Amaris 750S excimer laser then performed a PRK of no more than 40 μm using the measured HOA. The CXL was then carried out respecting the standard of 400 μm of corneal thickness. Results The average age was 32 (15—48) years. Uncorrected distance visual acuity (UDVA) improved from 0.58 to 0.31 logMAR (p < 0.001), with best corrected distance visual acuity (CDVA) improving from 0.03 to 0.02 logMAR (p = 0.7). On manifest refraction, the average spherical component decreased from –1.87 to –1.40 D (0.47 ± 2.12, p = 0.4). Cylinder decreased from 2.18 to 0.87 D (1.31 ± 1.14 D, p < 0.001). All HOAs decreased: total HO 0.94 to 0.58 (0.36 ± 0.42, p = 0.05); spherical aberration: 0.142 to –0.018 (0.160 ± 0.160, p < 0.001); secondary astigmatism: 0.21 to 0.11 (0.10 ± 0.11, p = 0.02); coma: 0.80 to 0.42 (0.38 ± 0.47, p = 0.03); trefoil: 0.33 to 0.29 (0.04 ± 0.17, p = 0.7). Conclusion Utilizing HOA to guide the laser treatment in combination with CXL resulted in a significant decrease of HOA at 6 months postprocedure. This is a small case series, but demonstrates a promising trend of improved HOA. Considering that keratoconic eyes have very irregular surfaces with significant HOA, reducing these aberrations should improve best corrected quality of vision. Having longer follow-up and greater numbers may demonstrate a clearer improvement. How to cite this article Penner V, Lewis K, Rocha G. Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):73-77.

New Technique of Femtosecond Laser-Assisted Intracorneal Ring Segment Implantation

Cornea ◽  
2017 ◽  
Vol 36 (7) ◽  
pp. 884-888
Author(s):  
Luis Izquierdo ◽  
Alejandra Orozco ◽  
Maria A. Henriquez
Keyword(s):  
Femtosecond Laser ◽  
New Technique ◽  
Ring Segment ◽  
Intracorneal Ring Segment

scholarly journals Long-term Stability of Ectasia in a Young Patient with Asymmetric Keratoconus

2015 ◽  
Vol 4 (2) ◽  
pp. 66-68
Author(s):  
Rosane de Oliveira Corrêa ◽  
Ana Laura Caiado Canedo ◽  
Rozalia Beildeck ◽  
Marcella Quaresma Salomão ◽  
Penelope Burle de Politis
Keyword(s):  
Visual Acuity ◽  
Young Patient ◽  
Distance Visual Acuity ◽  
Long Term Stability ◽  
Uncorrected Distance Visual Acuity ◽  
Manifest Refraction ◽  
Corrected Distance Visual Acuity ◽  
Ring Segment ◽  
Intracorneal Ring Segment ◽  
The Right

ABSTRACT Purpose To report the clinical course of a typical young patient presenting with asymmetric keratoconus (KC), that demonstrates that stabilization of the ectatic process is possible without cross-linking (CXL) procedure. Methods Case report and review of the literature. Results A 17-year-old male patient was referred due to the diagnosis of keratoconus. Patient complained of loss of vision in the left eye (OS). Uncorrected distance visual acuity (UDVA) was 20/25+ in the right eye (OD) and 20/80 in the left eye; wavefront-assisted manifest refraction gave best corrected distance visual acuity (CDVA) of 20/20 in OD and 20/40 in OS. The diagnosis of keratoconus was confirmed with Placido disk-based topography (Oculus Keratograph 4), and Pentacam HR corneal tomography (Oculus Optikgeräte GmbH, Wetzlar, Germany). Femtosecond laser-assisted intracorneal ring segment (ICRS) implantation was performed in the left eye and treatment for allergy was prescribed for both eyes, along with patient education and advice not to rub the eyes. After 3 months, significant improvement was observed on UDVA (20/30) and CDVA (20/20) in the left eye. Topometric and tomographic stability of ectasia was observed in the right eye in a 4-year follow-up. Conclusion Intracorneal ring segment caused significant regularization of the corneal shape and improvement on visual acuity. Ectasia stability was achieved with no need for CXL, despite the patient's young age. This case raises the point that the indication of CXL for every keratoconic patient should be reconsidered. How to cite this article de Oliveira Corrêa R, Canedo ALC, Beildeck R, Salomão MQ, de Politis PB, Ambrósio R Jr. Longterm Stability of Ectasia in a Young Patient with Asymmetric Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):66-68.

scholarly journals Changes of corneal high-order aberrations after femtosecond laser-assisted in situ keratomileusis

Medicine ◽  
2018 ◽  
Vol 97 (18) ◽  
pp. e0618 ◽  
Author(s):  
Jing Wang ◽  
Yanlin Ren ◽  
Kun Liang ◽  
Zhengxuan Jiang ◽  
Liming Tao
Keyword(s):  
Femtosecond Laser ◽  
High Order ◽  
High Order Aberrations

scholarly journals Ocular wavefront aberrations in acute central serous chorioretinopathy

2021 ◽  
Vol 9 (1) ◽  
pp. 33-33
Author(s):  
Banafsheh Kharrazi Ghadim ◽  
Nazli Taheri ◽  
Mohammad Reza Niyousha
Keyword(s):  
Visual Acuity ◽  
Root Mean Square ◽  
Central Serous Chorioretinopathy ◽  
Spherical Aberration ◽  
Optical Parameters ◽  
Average Height ◽  
Mean Square ◽  
Pupillary Dilation ◽  
Foveal Thickness ◽  
Wavefront Aberrations

Background: Central serous chorioretinopathy (CSCR) is a condition of choroidal and retinal pathologies that may affect vision, so we assessed vision by the ocular wavefront in the acute form of CSCR. Methods: This cross-sectional study included 21 cases (16-male, 5-female) of acute onset CSCR was referred to the retina clinic of Nikookari Eye Hospital. Visual acuity and ocular examination with and without pupillary dilation record. Central macular thickness and sub-foveal fluid height of all patients measured by spectral-domain optical coherence tomography (SD-OCT). All of them fulfilled binocular visual function analyzer by Tracy Technology after complete pupillary dilation. The items such as spherical equivalent, total root mean square, total lower-order aberration, total higher-order aberration, defocus, astigmatism, secondary astigmatism, coma, spherical aberration, trefoil, Strehl ratio in point spread function, the average height in the modulation transfer function, and root mean square error registered. Generalized Estimation Equations (GEE) were used to compare two groups of affected CSCR and normal contralateral eyes. Results: The mean uncorrected distance visual acuity in the CSCR eyes is (Decimal Notation) 0.82±0.17 and in the contralateral eyes is 0.95±0.09 (P=0.002). Analysis of macular OCT data CSCR group represents: central foveal thickness 485.9±165.12 μm and mean fluid height 284.3±165.42 μm. The mentioned optical parameters of ocular wavefront aberrations do not have significantly different results in the two groups. Conclusion: Our study showed CSCR reduced uncorrected visual acuity but it did not detect significant ocular wavefront changes in acute CSCR

scholarly journals Intacs Intracorneal Ring Segments Complications in Patients Suffering from Keratoconus

2013 ◽  
Vol 2 (3) ◽  
pp. 121-128 ◽  
Author(s):  
Ramez Barbara ◽  
Adel Barbara
Keyword(s):  
Quality Of Life ◽  
Visual Acuity ◽  
Postoperative Complications ◽  
Retrospective Studies ◽  
Contact Lenses ◽  
Case Reports ◽  
High Order ◽  
Positive Results ◽  
High Order Aberrations

ABSTRACT Intacs, intrastromal corneal rings are widely used to reduce myopia, astigmatism, keratometry readings and high order aberrations in patients suffering from keratoconus, almost 15 years have passed from the first procedure which was performed in the eye of a patient with unsatisfactory visual acuity and contact lenses intolerance. Many publications including book chapters, retrospective studies, case reports and literatures reviews have been published on this issue. In this review, we are reporting on the complications of Intacs implanted in keratoconic eyes, we are reporting on intraoperative and postoperative complications. The review although focusing on complications of the does not contradict the positive results of the procedure on the quality of life of the patients suffering from keratoconus and the its safety. How to cite this article Barbara A, Barbara R. Intacs Intracorneal Ring Segments Complications in Patients Suffering from Keratoconus. J Kerat Ect Cor Dis 2013;2(3):121-128.

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