scholarly journals Ultraviolet crosslinking of corneal collagen in patients with thin cornea. Literature review

2021 ◽  
Vol 6 (6-1) ◽  
pp. 229-236
Author(s):  
A. V. Tereshchenko ◽  
I. G. Trifanenkova ◽  
Yu. Y. Golubeva ◽  
S. K. Demianchenko ◽  
E. N. Vishnyakova

For the treatment of progressive keratoconus in the early stages, corneal collagen crosslinking is currently actively used. This technique is based on the stabilization of the pathological process by increasing the biomechanical properties of the own cornea. The thickness of the cornea less than 400 microns significantly limits the possibility of a standard cross-linking procedure performing.The article analyzes the literature data on the use of various methods of corneal crosslinking with a corneal thickness of less than 400 microns, which signifi cantly limits the possibilities of the standard procedure.It is known, that during crosslinking, at the initial stage, de-epithelialization of the cornea is performed, which, in the postoperative period, leads to a pronounced corneal syndrome. This determined the direction of the fi rst modifi cations of the technique associated with the use of partial de-epithelialization or its complete absence. Later, during cross-linking of “thin” corneas, techniques with the use of additional covering materials were actively used in order to replenish the missing corneal tissue of the patient during the UV irradiation procedure. Among them are the use of a soft contact lens without an ultraviolet fi lter, the use of a corneal lenticule obtained after SMILE surgery, the use of a protective fl ap of the donor cornea obtained using a femtosecond laser from the residual stroma of the corneal disc after descemet membrane transplantation or posterior lamellar keratoplasty. The variety of the proposed modifications and the ongoing search for better options indicate the demand for this technology and the need for further research, taking into account the individual characteristics of the patient’s ectasia.

2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.


Author(s):  
Paraskevi G Zotta ◽  
Diamantis D Almaliotis ◽  
George D Kymionis ◽  
Vasilios F Diakonis ◽  
Kostas A Moschou ◽  
...  

ABSTRACT Purpose To determine the long-term alterations of corneal thickness, along with topographic outcomes, after corneal collagen cross-linking treatment (CXL) for keratoconus. Materials and methods In this retrospective case series, 46 patients (52 eyes), 32 males and 14 females, with progressive keratoconus were included. All eyes underwent CXL in accordance with the standard protocol (Dresden) for the treatment of their ectatic corneal disorder between January 2006 and June 2007. Pachymetric and topographic outcomes were evaluated preoperatively and at 1, 3, 6, 12, 24 and 36 months postoperatively. Results Mean follow-up was 28.08 ± 8.39 months (range, from 12 to 36 months). A statistically significant decline in corneal pachymetric values (at the thinnest location) when compared with preoperative values (467.65 ± 41.08 µm) was demonstrated at 1 (437.63 ± 50.57 µm), 3 (439.08 ± 52.27 µm), 6 (449.37 ± 52.73 µm), 12 (449.63 ± 83.53 µm) and 24 (459.97 ± 47.32 µm) months after CXL (p < 0.05, for all mentioned time intervals). Return to preoperative pachymetric values (469.52 ± 40.52 µm) was revealed 36 months post-CXL (p > 0.05). With respect to topographic (flat and steep keratometric values, keratoconus index), no statistically significant differences between preoperative and all postoperative intervals were found (p > 0.05, for all values for all time intervals). Conclusion Corneal pachymetric values reduce significantly up to 24 months after CXL treatment, while a return to preoperative values was revealed 36 months after the procedure. No significant changes’ concerning topographic outcomes was demonstrated after CXL, indicating stability of these parameters. How to cite this article Zotta PG, Almaliotis DD, Kymionis GD, Diakonis VF, Moschou KA, Karampatakis VE. Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):22-25.


2013 ◽  
Vol 76 (3) ◽  
pp. 155-158 ◽  
Author(s):  
Belquiz Amaral Nassaralla ◽  
Diogo Mafia Vieira ◽  
Márcia Leite Machado ◽  
Marisa Novaes Faleiro Chaves de Figueiredo ◽  
João Jorge Nassaralla Jr

Author(s):  
E. Pateras ◽  
Ch. Koufala

Aims: To compare results of OrbscanIIz and Pentacam and Ultrasound pachymetry at different stages of keratoconus on corneal thickness. Sample and Study Design: 94 keratoconic patients participated in the study, of which 52 were men and 42 women. Keratoconus patients were measured with OrbscanIIz, Pentacam and Ultrasound pachymetry in pre-operation examinations for corneal collagen cross-linking. The patients belong to different keratoconus stages. Place and Duration of Study: University of West Attica Dept Biomedical Sciensce Course Optics & Optometry in collaboration with Athens “Ophthalmologico” Clinic during the period between October 2017 to January 2019. Methodology: Corneal Pachymetry maps correlation of three types of corneal pachymeters OrbscanIIz, Pentacam and Ultrasound pachymetry (Tomey SP-100 Pachymeter). The measurements of the thinnest point of the cornea from each patient were collected at different stages of keratoconus and compared. Results: A sample of 188 eyes were measured at different stages of keratoconus and compared for the thinnest corneal thickness with three different measurement systems, OrbscanIIz ,Pentacam and Ultrasound pachymetry. At sublinical stage Orbscan-Pentacam had Correlation coefficient r=0,7971, Orbscan-Ultrasound r=0,7483 and Pentacam-Ultrasound r=0,9442. At 1st stage Orbscan-Pentacam had Correlation coefficient r=0,8913, Orbscan-Ultrasound r=0,8151 and Pentacam-Ultrasound r=0,8151. At 2nd stage Orbscan-Pentacam had Correlation coefficient r=0,9339, Orbscan-Ultrasound r=0,8819 and Pentacam-Ultrasound r=0,9633. For 3rd stage Orbscan-Pentacam had Correlation coefficient r=0,8317, Orbscan-Ultrasound r=0,8457 and Pentacam-Ultrasound r=0,9633. For 4th stage Orbscan-Pentacam had Correlation coefficient r=-0,4655, Orbscan-Ultrasound r=0,3089 and Pentacam-Ultrasound r=0,9633. In Iatrogenic keratoectasiaafter refractive surgery Orbscan-Pentacam had Correlation coefficient r=0,9327, Orbscan-Ultrasound r=0,3089 and Pentacam-Ultrasound r=0,9859. Conclusion: Statistical differences between OrbscanIIz, Pentacam and Ultrasound pachymetry were found for corneal thickness in all stages of keratoconus for the thinnest point measured. Orbscan-Pentacam have statistical significant differences but weak to moderate correlation. Orbscan-Ultasound have also statistical significant differences their correlation is very weak, while Pentacam-Ultrasound have statistical significant differences smaller as the previous but their correlation is very strong at all stages of keratoconus.


Cornea ◽  
2014 ◽  
Vol 33 (11) ◽  
pp. 1164-1167 ◽  
Author(s):  
Refik Oltulu ◽  
Günhal Şatirtav ◽  
Meryem Donbaloğlu ◽  
Hürkan Kerimoğlu ◽  
Ahmet Özkağnici ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Kepa Balparda ◽  
Juan Carlos Mejia-Turizo ◽  
Tatiana Herrera-Chalarca

The purpose of this article is to describe the use of simultaneous noncentered photoactivated chromophore for keratitis-corneal collagen cross-linking (PACK-CXL) combined with penetrating keratoplasty in the treatment of a severe marginal Fusarium spp. keratitis case with imminent corneal perforation. It is a retrospective case report study; it was performed by collecting clinical data, images, video, and postoperative evaluations. The clinical control of the infection was accomplished, despite difficulties in obtaining antifungal medications due to the patient’s extremely poor socioeconomic status and essentially nonexistent health insurance. We can conclude that combining simultaneous decentered PACK-CXL with centered penetrating keratoplasty appears to be a safe and effective way of treating patients with fungal marginal keratitis with corneal perforation, in which regular penetrating keratoplasty alone would leave fungal elements in the receptor corneal tissue, which would predispose to infection of the graft.


2019 ◽  
Vol 13 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Khalid Al Zubi ◽  
Yaser Albakar ◽  
Rana Nasser

Background: The progression of keratoconus is stabilized with the help of corneal collagen cross-linking (CXL) supported through photosynthesized riboflavin. Objective: This study aims to compare the effectiveness of the transepithelial procedure and epithelium off procedure of corneal collagen crosslinking among keratoconus patients in Jordan. Methods: The study recruited 80 patients suffering from progressive keratoconus, from a tertiary care setting in Jordan. These participants were randomly divided into two groups; group 1 with 40 participants subjected to transepithelial (Corneal collagen cross-linking) CXL; and 40 participants in group 2 received conventional epithelium off CXL. Results: Improvement was observed in the mean contact lens, which corrected distance visual acuity (CDVA) from logMAR 0.332 ± 0.09 (group 1), 0.35 ± 0.09 (group 2) to 0.241 ± 0.07 (group 1), 0.21 ± 0.07 (group 2), respectively at the end of follow-up (12 months). The mean pachymetry improved from 429.81 ± 18.96 μm (group 1), 430.08 ± 17.05 μm (group 2) to 436.5 ± 15.49 μm (group 1), 436.44 ± 12.53 μm (group 2), respectively, after twelve months. Additionally, the mean Sim K astigmatism declined from 7.0 ± 2.0 (group 1), 6.73 ± 1.98 (group 2) to 5.97 ± 1.88 (group 1), 5.53 ± 0.08 (group 2) respectively at twelve months post-treatment. Majority of the patients in group 2 experienced more pain as compared to group 1 participants. Conclusion: The effectiveness of a cross-linking procedure related to keratometry readings and corneal thickness showed that conventional (epithelium off) CXL method is more effective than transepithelial CXL.


2021 ◽  
Vol 18 (4) ◽  
pp. 840-844
Author(s):  
E. Yu. Markova ◽  
G. V. Avakyants ◽  
E. V. Kechin

Objective: to evaluate the results of corneal collagen crosslinking in children with keratoconus.Patients and methods. Since 2017, 125 children aged 4 to 17 years have been under observation, who have applied to the Eye Microsurgery named after Academician S.N. Fedorov with complaints of reduced visual acuity and, in some cases, the inability to select optical correction. All patients were examined, including using high-tech methods (Sheimpflug camera, OCT). Based on the anamnesis and the data obtained, the diagnosis of keratoconus stage I–III was made. Corneal collagen crosslinking was performed in 30 patients with stage II–III.Results. The study included 30 eyes of 30 patients (21 (68 %) boys, 9 (32 %) girls) with a median age — 16 (15; 17) years (12 to 17 years), who underwent accelerated “epi-off” crosslinking. No intra-and postoperative complications were observed. 12 months after CXL, there was a slowdown in the progression of keratoconus in children (minimum corneal thickness before surgery 460.00 (445.00; 477.00), after surgery 457.00 (441.00; 477.00), p = 0.112; K1 before surgery 44.60 (43.20; 46.90), after surgery 44.60 (42.90; 46.50), p = 0.481; K2 before surgery 48.30 (47.30; 51.25), after surgery 48.20 (47.21; 49.20), p = 0.779; elevation of the posterior surface before surgery 25.00 (18.00; 42.00), after surgery 26.00 (21.00; 42.00), p = 0.074, and increased visual acuity (NCOZ from 0.30 (0.05; 0.40) to 0.30 (0.20; 0.40) (p = 0.039) and MCOZ from 0.60 (0.40; 0.80) to 0.60 (0.50; 1.00) (p = 0.010)).Conclusion. 1. Keratoconus is also found in the child population. 2. Timely cross-linking of corneal collagen can slow the progression of keratoconus in children


2015 ◽  
Vol 2 (88) ◽  
pp. 6-11
Author(s):  
M. V. Khajtovych

Summary. Personalized medicine it is a model of health care based on a selection of diagnostic, therapeutic and preventive means taking into account the genetic, physiological, biochemical and other features of the patient. Personalized medicine new branch of modern medicine, in which developed and applied treatments, “tailored” specifically for the individual patient. Areas of application of personalized medicine in modern terms: the transition from traditional to personalized clinical diagnosis of the disease based on individual patient parameters, including using different molecular biomarkers nature, and save biomaterial throughout his life; predictions based on genomic data likelihood of a disease with the development of individual preventive scheme; identification of potential pharmacotherapeutic targets for selective exposure at the initial stage of the pathological process; choice of treatment strategy tailored to the individual patient parameters; monitoring of treatment using biomarkers. Strengthening the role of clinical pharmacology and create genetically informed personalized medicine algorithms increase the efficiency and safety of pharmacotherapy. New technologies make it possible to clarify the causes adverse side effects at the genetic level, prevent, reduce treatment costs and significantly enhance its security and therefore implementation of these approaches in the long run will contribute to significant savings.


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