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Small-Incision Femtosecond Laser–Assisted Intracorneal Concave Lenticule Implantation in Patients With Keratoconus
摘要： To evaluate the feasibility and efficacy of small-incision femtosecond laser–assisted intracorneal concave lenticule implantation (SFII) and penetrating keratoplasty (PKP) in patients with progressive keratoconus.
关键词： penetrating keratoplasty,femtosecond laser,keratoconus,intracorneal implantation,small incision
更新于2025-09-11 14:15:04
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Corneal stromal demarcation line after 4 protocols of corneal crosslinking in keratoconus determined with anterior segment optical coherence tomography
摘要： We read with great interest the recent publication by Spadea et al. about the depth of corneal stromal demarcation lines after the following 4 corneal crosslinking (CXL) protocols: epi-off Dresden (C-CXL), epi-off accelerated (TE-CXL), enhancers-assisted transepithelial (A-CXL), and iontophoresis-assisted CXL (I-CXL). The authors conclude that the difference in CXL efficiency estimated by the demarcation line would only be secondary to the stromal penetration of riboflavin and ultraviolet-A light. They suggest that because I-CXL had better stromal penetration, it would also have greater CXL efficacy.
关键词： anterior segment optical coherence tomography,Corneal stromal demarcation line,keratoconus,corneal crosslinking
更新于2025-09-10 09:29:36
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The Effect of In-Vivo Collagen Cross-Linking Procedure on the Material of Intracorneal Ring Segments
摘要： The material of Intracorneal Rings Segments (ICRS) has seemed to be polymerized after the absorption of Riboflavin and UV illumination in laboratory settings. This study aimed to assess the potential impact of in-vivo corneal crosslinking (CXL) on the chemical composition of ICRS. Within this contex, three ICRS samples (S1, S2 and S3) were extracted from patients' cornea, which formerly had undergone CXL treatment. Alterations on the chemical structure of PMMA rings were studied using Ultraviolet-Visible (UV-Vis) spectroscopy and Fourier Transform-Infrared (FT-IR) spectroscopy. An extracted ICRS from a patient who didn’t underwent CXL treatment, was also used as reference (S0). UV-Vis spectroscopy didn't identify any change in the specimens S1, S2 and S3. Nevertheless, FT-IR spectroscopic analysis showed alterations in the spectra of ICRS material of samples S1, S2 and S3, mainly at the 2800 to 3200 cm-1 spectral region [modification in band intensities of CH2 (2850 cm-1 and 2925 cm-1) and CH3 (2950cm-1)]. In conclusion, our results suggest crosslinking reaction in ICRS material after in-vivo CXL treatment. This should be taken into consideration prior to any CXL treatment of post ICRS implanted cornea.
关键词： FT-IR spectroscopy,Corneal crosslinking,INTACS,UV-Vis spectroscopy,Keratoconus
更新于2025-09-10 09:29:36
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Study and characterization of morphogeometric parameters to assist diagnosis of keratoconus
摘要： Background: In case of significant imperfections on the cornea, data acquisition is difficult and a significant level of missing data could require the interpolation of important areas of the cornea, resulting in a very ambiguous model. The development of methods to define in vivo customised geometric properties of the cornea based only on real raw data is extremely useful to diagnose and assess the progression of diseases directly related to the corneal architecture. The present work tries to improve the prognostic of corneal ectasia creating a 3D customised model of the cornea and analysing different geometric variables from this model to determine which variables or combination of them could be defined as an indicator of susceptibility to develop keratoconus. Methods: A corneal geometric reconstruction was performed using zonal functions and retrospective Scheimpflug tomography data from 187 eyes of 187 patients. Morphology of healthy and keratoconic corneas was characterized by means of geometric variables. The performance of these variables as predictors of a new geometric marker was assessed and their correlations were analysed. Results: The more representative variable to classify the corneal anomalies related to keratoconus was posterior apex deviation (area under receiver operating characteristic curve > 0.899; p < 0.0001). However, the strongest correlations in both healthy and pathological corneas were provided by the metrics directly related to the thickness, as deviations of the anterior/posterior minimum thickness points. Conclusions: The presented morphogeometric approach based on the analysis and custom geometric modelling of the cornea demonstrates to be useful for the characterization and diagnosis of keratoconus disease, stating that geometrical deformation is an effective marker of the ectatic disease’s progression.
关键词： Scheimpflug,Keratoconus,Virtual model,CAD,Surface reconstruction
更新于2025-09-10 09:29:36
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Appropriate Sequence of Combined Intracorneal Ring Implantation and Corneal Collagen Cross-Linking in Keratoconus
摘要： To compare surgical sequences of combined intracorneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in keratoconus and corneal ectasia in terms of visual, refractive, and keratometric outcomes.
关键词： corneal ectasia,corneal collagen cross-linking,keratoconus,intracorneal ring
更新于2025-09-10 09:29:36
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Comparison of keratometric and pachymetric parameters with Scheimpflug imaging in normal and keratoconic Asian eyes
摘要： Purpose: To evaluate the keratometric and pachymetric parameters of keratoconic corneas of Asian eyes with the Scheimpflug imaging camera. Patients and methods: This is a cross-sectional study of 22 eyes with Amsler-Krumeich stage 1 keratoconus and 48 eyes from normal subjects conducted in a tertiary eye hospital. A rotating Scheimpflug imaging system, the Pentacam, was used to evaluate all eyes for tomographic parameters, as well as pachymetric progression indices (PPI) and Ambrósio relational thickness (ART). Results: All PPI and ART parameter values were significantly different between study and control groups. Cornea minimum radius of curvature, absolute distance from corneal apex to thinnest location, as well as the distance from corneal apex to thinnest location in Y-axis also demonstrated statistically significant differences. The mean ART values for keratoconus eyes were 241 μm (ART-maximum) and 352 μm (ART-average), falling within previously reported best cutoff values for detecting keratoconus. On receiver operating characteristics curve analysis, the area under the curve values were highest for PPI and ART parameters. Conclusion: There are significant differences in tomographic parameters between stage 1 keratoconic and normal Asian eyes. Pachymetric indices such as the PPI and the ART index can serve as additional tools in differentiating keratoconic from normal eyes. The findings validate the usefulness of the ART in identifying keratoconic eyes in Asians.
关键词： corneal tomography,keratoconus,pentacam,Ambrósio relational thickness
更新于2025-09-09 09:28:46
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Impact of corneal cross-linking combined with photorefractive keratectomy on blurring strength
摘要： The aim of this study was to evaluate the impact of corneal cross-linking combined with photorefractive keratectomy (PRK) on blurring strength. A total of 63 patients with keratoconus were recruited for this study, and two study groups were formed according to the therapeutic intervention: corneal collagen cross-linking (CxL) group (33 patients) received corneal cross-linking according to the Dresden protocol, while the rest additionally received topography-guided photorefractive keratectomy (tCxL). The impact of surgical procedure on blurring strength was assessed by power vector analysis. Potential association between blurring strength and vision-specific quality of life was assessed using the National Eye Institute Visual Function Questionnaire (NEI-VFQ) 25 instrument. Blurring strength presented excellent correlation with NEI-VFQ scores both preoperatively and postoperatively (all P,0.01). Both groups demonstrated nonsignificant changes in best-corrected visual acuity; however, only the tCxL group had significant reduction in blurring strength (13.48+10.86 [preoperative], 4.26+7.99 [postoperative], P=0.042). Only the combined treatment (tCxL) resulted in significant reduction in blurring strength. Moreover, the excellent correlation of blurring strength with NEI-VFQ scores indicates its reliability as an index of self-reported quality of life in keratoconus, since it seems to address the nonsignificant changes in best-corrected visual acuity following CxL treatments that are conceived as subjective improvement by the patient.
关键词： blurring strength,keratoconus,tCxL,cornea crosslinking
更新于2025-09-04 15:30:14
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Corneal changes after collagen crosslinking for keratoconus using dual scheimpflug imaging
摘要： Purpose: To evaluate corneal changes after collagen crosslinking (CXL) therapy for keratoconus (KCN) using the Galilei dual Scheimpflug analyzer. Methods: This prospective, nonrandomized clinical study included 35 eyes of 32 keratoconus patients who had undergone CXL. The eyes were saturated with riboflavin solution and were subjected for 30 minutes to ultraviolet-A (UV-A) light with irradiance of 3 mW/cm2. Effectiveness of the treatment was assessed by measuring uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest cylinder/sphere, keratometry, pachymetry, posterior and anterior elevations by the Galilei dual Scheimpflug analyzer. Prior to treatment and 8 months after therapy, Scheimpflug analysis was performed using the Galilei system. The four sets of data including keratometry values, pachymetry, elevation parameters and surface indices were statistically analyzed and compared. Results: Mean patient age was 22.3 ± 3.8 years and mean postoperative follow-up was 8.1 ± 3.2 months. There was a significant increase in UCVA (0.54 ± 0.35 Log MAR preoperatively to 0.49 ± 0.34 LogMAR postoperatively, P = 0.01) and BCVA (0.21 ± 0.19 Log MAR preoperatively to 0.16 ± 0.17 LogMAR postoperatively, P = 0.01). Mean cycloplegic spherical equivalent refractive error was ?4.13 ± 2.65 Diopter (D) preoperatively and ? 4.67 ± 2.96 D postoperatively (P < 0.001). During the follow-up period, no significant difference was observed in pachymetric and elevation data postoperatively. Conclusion: Corneal stabilization could be achieved by collagen crosslinking therapy for keratoconus in terms of corneal thickness, keratometry values, elevation parameters and surface indices.
关键词： Keratoconus,Galilei Dual Scheimpflug Analyzer,Collagen Crosslinking
更新于2025-09-04 15:30:14