Dataset Information

Evaluation of a Tangential Map-Based Nomogram for Intrastromal Corneal Ring Segments' Implantation in Keratoconus: One Year Results.

ABSTRACT: Purpose:To evaluate a new tangential map-based nomogram versus the axial map-based nomogram for ICRS in keratoconus. Methods:A prospective case series study including 64 eyes of 64 patients who underwent ICRS implantation. Cone location was determined for each eye with two maps: the axial and the tangential. Appropriate ring selection was determined using two surgical nomograms: axial map-based and tangential map-based. Visual, refractive, and topographic outcomes were assessed before, as well as at 3, 6, and 12 months after ICRS implantation. Results:The cone location, and consequently the ring selection, was significantly different in the two nomograms with a "centralization tendency" in the tangential map. In the axial group, UDVA and CDVA improved from 0.12?±?0.04 and 0.24?±?0.08 to 0.28?±?0.08 and 0.4?±?0.1, respectively. Similarly, MRSE substantially decreased from -6.7?±?3.3 to -1.2?±?1.1D at 12 months after the procedure. In the tangential group, UDVA and CDVA improved from 0.09?±?0.06 and 0.2?±?0.1 to 0.5?±?0.2 and 0.7?±?0.2, respectively. MRSE substantially decreased from -4.9?±?1D at 12 months after the procedure. In the tangential group, UDVA and CDVA improved from 0.09?±?0.06 and 0.2?±?0.1 to 0.5?±?0.2 and 0.7?±?0.2, respectively. MRSE substantially decreased from -4.9?±?1D at 12 months after the procedure. In the tangential group, UDVA and CDVA improved from 0.09?±?0.06 and 0.2?±?0.1 to 0.5?±?0.2 and 0.7?±?0.2, respectively. MRSE substantially decreased from -4.9?±?1P=0.01 ? . Similarly, the gain in the CDVA was 0.4 and 0.15 in the tangential and axial groups, respectively, at 12 months, P=0.01 ? . Similarly, the gain in the CDVA was 0.4 and 0.15 in the tangential and axial groups, respectively, at 12 months. Conclusion:The tangential map-based nomogram attained better visual and refractive outcomes at 1 year. In addition, the cone location was significantly different between both maps with a centralization tendency in the tangential one.

SUBMITTER: Zaky AG

PROVIDER: S-EPMC7049859 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Evaluation of a Tangential Map-Based Nomogram for Intrastromal Corneal Ring Segments' Implantation in Keratoconus: One Year Results.

Zaky Adel Galal AG KhalafAllah Mahmoud Tawfik MT Sarhan Abdelrahman Elsebaey AE Elsawy Moataz Faiz MF

Journal of ophthalmology 20200219

<h4>Purpose</h4>To evaluate a new tangential map-based nomogram versus the axial map-based nomogram for ICRS in keratoconus.<h4>Methods</h4>A prospective case series study including 64 eyes of 64 patients who underwent ICRS implantation. Cone location was determined for each eye with two maps: the axial and the tangential. Appropriate ring selection was determined using two surgical nomograms: axial map-based and tangential map-based. Visual, refractive, and topographic outcomes were assessed be ...[more]

PMID: 32148940

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Project description:Purpose:To evaluate the outcomes of femtosecond laser-assisted implantation of a 355-degree intracorneal ring (ICR) (Keraring) in patients with keratoconus in the three-year follow-up. Setting:Future Femtolaser Center, Sohag, Egypt. Design:Prospective interventional case series. Patients and Methods:A prospective case series of 38 eyes of 26 patients with keratoconus had implantation of the 355-degree ICR keraring after tunnel creation with a femtosecond laser. The uncorrected visual acuities (UCVA) and best-corrected visual acuities (BCVA), sphere, cylinder, and manifest refraction spherical equivalent (SE), and mean keratometry (K), K max, and K min were evaluated preoperatively and 3, 6, 12, 24, and 36 months postoperatively, and all complications were reported. Results:38 eyes of 26 patients with mean age 25.92?±?5.44 years were enrolled in the study, 11 were males (42.3%). The mean UCVA improved from 0.93?±?0.21 to 0.63?±?0.21 logMAR (P ? 0.001) and the mean BCVA from 0.67?±?0.22 to 0.43?±?0.26 logMAR (P < 0.001). The mean sphere, cylinder, and spherical equivalent have been changed dramatically from preoperative to 3 month postoperative, which is statistically significant (P ? 0.001), and the changes between 1 and 2 years and 2 and 3 years are also considerable and statistically significant; the K max and K min and K mean improved and the changes were statistically significant (P ? 0.001), and the changes between one, two, and three years were also statistically significant. The safety and efficacy indices were changed through the three-year follow-up. The complications were corneal neovascularization (36.84%), corneal melting (26.3%), and ring extrusion (31.5%) at the end of the study. Conclusions:Implantation of a 355-degree intracorneal keraring using femtosecond laser improved the visual, refractive, and topographic parameters in keratoconus patients, with a high rate of ICR extrusion and instability. The study has been registered for the Pan African Clinical Trial Registry (http://www.pactr.org) database within No: PACTR201810796878908 on 29 October 2018.

Project description:Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) was used to characterize three-dimensionally (3-D) corneal topography in keratoconus before and after implantation of intracorneal ring segments (ICRS). Previously described acquisition protocols were followed to minimize the impact of the motions of the eye. The collected set of images was corrected from distortions: fan (scanning) and optical (refraction). Custom algorithms were developed for automatic detection and classification of volumes in the anterior segment of the eye, in particular for the detection and classification of the implanted ICRS. Surfaces were automatically detected for quantitative analysis of the corneal elevation maps (fitted by biconicoids and Zernike polynomials) and pachymetry. Automatic tools were developed for the estimation of the 3-D positioning of the ICRS. The pupil center reference was estimated from the segmented iris volume. The developed algorithms are illustrated in a keratoconic eye (grade III) pre- and 30 days post-operatively after implantation of two triangular-section, 0.3-mm thick Ferrara ring segments. Quantitative corneal topographies reveal that the ICRS produced a flattening of the anterior surface, a steepening of the posterior surface, meridional differences in the changes in curvature and asphericity, and increased symmetry of the anterior topography. Optical distortion correction through the ICRS (of a different refractive index from the cornea) allowed accurate pachymetric estimates, which showed increased thickness in the ectatic area as well as in peripheral corneal areas. Automatic tools allowed estimation of the depth of the implanted ICRS ring, as well as its rotation with respect to the pupil plane. Anterior segment sOCT provided with fan and optical distortion correction and analysis tools is an excellent instrument for evaluating and monitoring keratoconic eyes and for the quantification of the changes produced by ICRS treatment.

Project description:Background:To analyze the clinical results of an artificial neural network (ANN) that has been processed in order to improve the predictability of intracorneal ring segments (ICRS) implantation in keratoconus. Methods:This retrospective, comparative, nonrandomized, pilot, clinical study included a cohort of 20 keratoconic eyes implanted with intracorneal ring segments KeraRing (Mediphacos, Belo Horizonte, Brazil) using the ANN (ANN group) and 20 keratoconic eyes implanted with KeraRing using the manufacturer's nomograms (nomogram group). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) (visual acuity is expressed in decimal value and in LogMAR value in brackets), manifest refraction, corneal topography, tomography, aberrometry, pachymetry and volume analysis (Sirius System. CSO, Firenze, Italy) were performed during the preoperative visit; and the two groups, ANN group and nomogram group, did not differ significantly preoperatively in all of the parameters evaluated. These preoperative values were compared with the results obtained at the third-month visit. Mann-Whitney test and Wilcoxon test were used for the statistical analyses. Results:The spherical equivalent and the keratometric values decreased significantly in both groups. The CDVA improved from 0.60?±?0.23 (0.22 LogMAR) pre-operatively to 0.73?±?0.21 (0.14 LogMAR) post-operatively in the ANN group (p?<?0.005), and from 0.54?±?0.19 (0.27 LogMAR) pre-operatively to 0.62?±?0.19 (0.21 LogMAR) post-operatively in the nomogram group (p?<?0.01), with statistically significant difference between the two groups (p?<?0.05), being better in the ANN group. Coma-like aberrations decreased significantly in the ANN group, while in the nomogram group they did not change significantly, but no statistically significant difference was found between the two groups. Conclusions:ANN to guide ICRS provides an increase in the visual acuity, reduction in the spherical equivalent and improvement in the optical quality of keratoconus patients. ANN gives better results when compared with the manufacturer's nomograms in terms of better corrected vision and reduction of the coma-like aberrations. The constant inclusion of new cases will make the predictability of ANN increasingly better as the software finetunes its learning.

Project description:PurposeKeratoconus (KC) is a corneal ectasia characterized by structural changes, resulting in progressive thinning and biomechanical weakening that can lead to worsening visual acuity due to irregular astigmatism. Corneal collagen Crosslinking (CXL) and Intracorneal Ring Segment (ICRS) are widely used treatments in KC disease, but the alterations they cause in biomechanical mediators are still poorly understood. The aim of this study was to analyze the tear proteome profile before and after treatments to identify biomarkers altered by surgery.Materials and methodsAn observational, prospective, case-control pilot study was conducted, analyzing tear samples from KC patients by nano-liquid chromatography-mass spectrometry (nLC-MS/MS). Data are available via ProteomeXchange with identifier PXD035655. Patients with KC who underwent ICRS surgery (n = 4), CXL (n = 4), and healthy subjects (Ctrl, n = 4) were included in this study. Clinical parameters were measured and tear samples were collected before and 18 months after surgery. Proteins with ≥2 expression change and p-value < 0.05 between groups and times were selected to study their role in post-operative corneal changes.ResultsThese analyses led to the identification of 447 tear proteins, some of which were dysregulated in KC patients. In comparisons between the two surgical groups and Ctrls, the biological processes that were altered in KC patients at baseline were those that were dysregulated as a consequence of the disease and not of the surgical intervention. Among the biological processes seen to be altered were: immune responses, cytoskeleton components, protein synthesis and metabolic reactions. When comparing the two treatment groups (ICRS and CXL), the process related to cytoskeleton components was the most altered, probably due to corneal thinning which was more pronounced in patients undergoing CXL.ConclusionThe changes observed in tears after 18 months post-operatively could be due to the treatments performed and the pathology. Among the deregulated proteins detected, A-kinase anchor protein 13 (AKAP-13) deserves special attention for its involvement in corneal thinning, and for its strong overexpression in the tears of patients with more active KC and faster disease progression. However, it should be kept in mind that this is a pilot study conducted in a small number of patients.

Dataset Information

Evaluation of a Tangential Map-Based Nomogram for Intrastromal Corneal Ring Segments' Implantation in Keratoconus: One Year Results.

Publications

Evaluation of a Tangential Map-Based Nomogram for Intrastromal Corneal Ring Segments' Implantation in Keratoconus: One Year Results.

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