Keratoconus in Children. Мodern Treatment Options

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

Preliminary Characterization of Predictive Factors of the Visual Change after Epi-On and Epi-Off Corneal Collagen Crosslinking Techniques

Purpose. To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. Methods. This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated. Results. The mean CDVA change at 3 months postoperatively was −0.04 ± 0.19 and −0.07 ± 0.25 in the epi-on and epi-off groups, respectively ( p = 0.809). In the epi-on group, this change was significantly correlated with the preoperative apical (r = −0.375, p = 0.045) and central corneal thickness (r = −0.402, p = 0.031). In the epi-off group, the CDVA change was significantly correlated with not only the preoperative apical (r = 0.402, p = 0.028) and central corneal thickness (r = 0.367, p = 0.046) but also with some topometric and aberrometric indices (r ≤ −0.374, p ≤ 0.042). Furthermore, the change in CDVA in the epi-on group could be predicted from age, preoperative refractive astigmatism J45 component, anterior corneal asphericity, and posterior corneal high order aberration root mean square ( p = 0.002, R2 = 0.503). In the epi-off group, the CDVA change could be predicted from the preoperative minimum corneal thickness and magnitude of the vertical anterior corneal primary coma component ( p = 0.001, R2 = 0.446). Conclusions. Clearly, different predictive factors of the visual change induced with the accelerated epi-on and epi-off CXL techniques are present, suggesting a different mechanism of action for stiffening the cornea and inducing changes in this structure.

Corneal Epithelial Remodeling After Femtosecond Laser-Assisted in Situ Keratomileusis Combined with Intraoperative Accelerated Corneal Collagen Crosslinking for Myopia: A Retrospective Study

Background This study analyzed regional corneal thickness remodeling, biomechanical properties, and visual outcomes after femtosecond laser-assisted in situ keratomileusis combined with intraoperative accelerated corneal collagen crosslinking (LASIK Xtra) for myopia. Methods This retrospective study comprised 21 consecutive patients (18 women and 3 men; 42 eyes) who were treated with LASIK Xtra. All treatments were performed with ultraviolet-A (energy, 2.7 J/cm2; irradiance, 30 mW/cm2), using continuous (90 s) illumination. Postoperative values of corneal biometrics and visual outcomes were compared with preoperative values. Corneal thickness changes were evaluated using anterior segment optical coherence tomography. All patients were followed up for 12 months postoperatively. Preoperative and postoperative data were compared statistically using the paired t-test for normally distributed parameters and the Wilcoxon rank-sum test and Friedman analysis of variance with Bonferroni correction for non-normally distributed data. Results Uncorrected distance visual acuity (UDVA) significantly improved at 6 months after surgery (P < 0.001). The central and inner regional corneal epithelial thickness significantly increased after LASIK Xtra (P < 0.05 for all), while peripheral corneal epithelial thickness remained stable at 12 months after surgery. There was also a statistically significant decreased in the stromal thickness at most locations (P < 0.05 for all), except in the outer superior and outer superior-temporal regions. Conclusion LASIK Xtra provided predictable postoperative UDVA, corneal curvature, and corneal biomechanical stability. Since the retrospective study results depended on the cohort members’ past information, it is inferred and confirmed that regular corneal thickness remodeling occurred after treatment.

The short term visual, refractive and Topographic outcome of Corneal Collagen Crosslinking in Keratoconus

Background: Keratoconus is a condition characterized by biomechanical instability of cornea presenting in a progressive asymmetry and bilateral way. Corneal collagen cross-linking with riboflavin and UVA is a technique that has influenced the treatment of Keratoconus by arresting the progression. Aims and Objectives: The aim of the study was to assess the short-term efficacy and safety of collagen cross-linking in Keratoconus. Materials and Methods: This prospective, nonrandomized, interventional case study was conducted at Aravind Eye hospital and PGI, Puducherry from June 2012 to April 2013. Statistical analysis was done using repeated measures ANOVA and Bonferonn’s using IBM SPSS Inc. 20.Version. Results: A total of 30 patients were enrolled in this study and standard cross linking procedure was done. It was found that UCVA, BSCVA both improved about 40%. Spherical Equivalent reduced by 0.7 D, cylinder reduced by 0.8 D and total astigmatism decreased by about 0.4 D. Steepest K value reduced by 2 D, Irregularity and astigmatism at 3 and 5 mm also changed significantly (P<0.05). Conclusion: Collagen cross-linking arrests the progression of Keratoconus. It seems to improve the UCVA and BCVA and it is a safe and effective procedure.

Evaluation of changes in corneal biomechanics in eyes with keratectasia

Purpose. To make a comparative analysis of topographic, tomographic and biomechanical values, measured by Pentacam HR and Corvis ST, in healthy multirefractive cohort versus patients with keratectasia of various severity. Material and methods. The prospective study comprised 237 patients aged from 18 to 47 years, subdivided into three groups. The first group included 174 healthy persons with various refraction (174 eyes). The second and the third group embraced 63 patients with keratoconus: 36 patients (36 eyes) with keratoconus of the I degree and 27 eyes with keratoconus of the II and III degrees. Besides the conventional comprehensive ocular examination the following studies were performed in all the patients: evaluation of topographic, tomographic and biomechanical corneal properties with application of Pentacam HR and Corvis ST (OCULUS Optikgerate GmbH; Wetzlar, Germany). Results. It was revealed that the following biomechanical values, assessed by means of Pentacam HR and Corvis ST, exhibited statistically significant changes (p<0,001) in all degrees of ketatoconus: a relative corneal thickness by Ambrosio, inverted radius of applanation curvature (IntRadius), DA Ratio Coefficient, values of corneal rigidity – SP-A 1 and SSI. Conclusion. The detected parameters may be applied as indicators, allowing to evaluate corneal biomechanics, to define early features of ectatic process, to assess effectiveness of the performed corneal collagen crosslinking and intralamellar keratoplasty with implantation of corneal segments. Key words: keratoconus, corneal biomechanics, pachymetry, index of pachymetric progression, corneal viscoelasticity.

Corneal collagen crosslinking in a child with keratoconus

This clinical case describes medical history of the patient who came to the clinic with complaints of progressive decrease in visual acuity and intolerance of spectacle correction. In the following article all methods of diagnostic are fully described. We are also mentioning and discuss aspects of modern methods of diagnostic and treatment of keratoconus in children such as corneal collagen crosslinking. Key words: keratoconus, keratoconus in children, corneal collagen crosslinking.

Corneal Densitometry Changes after Epithelium-Off Corneal Collagen Crosslinking

Background Keratoconus is a progressive non-inflammatory, degenerative disease that affects the integrity of the collagen matrix within the corneal stroma. Corneal cross-linking (CXL) has been described as the only modality in halting the disease progression over the past decade. Aim of the Work To compare the change in corneal densitometry before and 6 months after CXL using our unique protocol. Patients and Methods A prospective observational study was conducted on 30 eyes of 30 patients with progressive keratoconus. Epitheliumoff CXL was done with application of Riboflavin (VibeX RapidTM) for 6 minutes at a rate of 1 drop/ minute. UVA was delivered using the Avedro KXL machine (Avedro, Waltham, MA, USA) using the following parameters: 7.2 joules, 12 milli watt/ minute and 10 minutes of accelerated continuous UV delivery. Results Within the anterior (120 um) stromal layer, the concentric zones (0 to 2 mm) and (2 to 6 mm) showed a significant elevation of mean densitometry 6 months post-surgery (P = 0.020) and (P = 0.023) respectively compared to the baseline, However the concentric zones (6 to 10 mm) and (10 to 12 mm) showed a non-significant elevation of mean densitometry 6 months post-surgery (P = 0.167) and (P = 0.234) respectively compared to the baseline. Conclusion There is a significant increase in corneal densitometry 6 months postsurgery of the anterior stromal layer within the central 6 mm zone.

Treating protracted corneal ulcers with UVA corneal collagen crosslinking: clinical cases

It has recently been proposed to use ultraviolet (UVA) corneal collagen crosslinking as an alternative method of treating bacterial ulcerative lesions of the cornea. Ambivalent results regarding the efficacy and safety of this method of treatment limit its implementation in clinical practice so far.The purpose of this work is to analyze three clinical cases involving the use of a new device for local UVA crosslinking in the complex treatment of bacterial corneal protracted-course ulcers with the suspected development of mixed fungal infection.Material and methods. For a dynamic follow-up of patients, we used biomicroscopy with a fluorescein test, photo registration and optical coherence tomography of the anterior part of the eye. Inflammatory changes were assessed using a point scale.Results. 3–5 procedures of local UVA exposure (with instillations of 0.1% riboflavin solution) lasting 3–5 minutes each and given with an interval of 2–4 days ensured stable and fast epithelialization of the cornea and a significant increase in visual acuity in the inflammatory process outcome.Conclusion. The first results of treating bacterial corneal ulcers using a new portable device for local UVA crosslinking have shown its high therapeutic efficiency and good prospects for further use in clinical practice.