Results Of Corneal Collagen Cross-linking Research Articles

Прогнозирование клинико-морфофункциональных результатов кросслинкинга роговичного коллагена у детей

Purpose. To develop methods of predicting corrected distance visual acuity (CDVA) and minimum corneal thickness (СT) 12 months after crosslinking in children using preoperative data. Material and methods. This study was conducted on 30 eyes in 30 patients (21 (68%) boys, 9 (32%) girls) with a median age of 16 [15; 17] years (from 12 to 17 years) who underwent the procedure of accelerated «epi-off» crosslinking. All patients underwent standard and special examination, including high-tech methods (Sheimpflug camera). Multiple regression was used to develop models for predicting CDVA and the minimum thickness of the cornea. The follow-up period was 12 months. Results. A model was developed for predicting CDVA 12 months after crosslinking, depending on the CDVA data and keratometry K2 before surgery, described by the formula: CDVA12 months after = –0,833 + 0,907 × CDVA before + 0,020 ×K2 (Adj R² =0.739, p<0.000). A model has been developed for predicting the minimum СT 12 months after crosslinking in children, depending on the data of the minimum СT and CDVA before surgery, described by the formula СT12 months after = 49,868 + 0,866 ×TRbefore + 14.551 × CDVAbefore (Adj R² =0,950 (p<0,001). Conclusion. The developed methods for assessing the clinical and morphofunctional results of corneal collagen crosslinking in children can significantly help in choosing the optimal tactics after the treatment of keratoconus in children using crosslinking. Key words: keratoconus, keratoconus in children, corneal collagen crosslinking, artificial intelligence, multiple regression

Corneal Collagen Cross-Linking for Progressive Keratoconus in Pediatric Patients: Up to 14 Years of Follow-up

To assess the long-term outcomes of corneal collagen cross-linking according to the Dresden protocol (S-CXL) in progressive pediatric keratoconus (KC). Retrospective, single-center noncomparative interventional study. Patients aged <18 years who underwent S-CXL from June 2007 to January 2011 in Humanitas Clinical and Research Center, Rozzano, Milan, Italy, and completed at least 10 years of follow-up were included. Corrected distance visual acuity (CDVA), refraction, and tomography were evaluated at baseline and ≥10 years after S-CXL. Meeting 2 of the following 3 criteria indicated reprogression: progression above 95% CI for post-CXL population of A or B values or a decrease in minimal thickness C evaluated with the ABCD display. Thirty-eight eyes of 24 patients fulfilled inclusion criteria. At a mean of 11.6 years postoperation (maximum 14 years), the CDVA improved significantly (from 0.703 ± 0.33 decimal fraction to 0.887 ± 0.2, P < .001). Similarly, the A value significantly improved from 2.550 ± 1.7 to 1.627 ± 1.68 (P=.019). Thirteen eyes (34%) showed significant postoperative progression in 2 of the 3 parameters A, B, and C. Of these, only 3 eyes (7.9%) of 3 patients showed a statistically significant change in the A value. S-CXL proved to be a safe treatment for progressive KC in pediatric patients with an anterior curvature progression rate of up to 7.9% at ≥10 years of follow-up.

Results of corneal collagen cross-linking with riboflavin and ultraviolet-A light for patients with keratoconus in Ramadi City

Results of corneal collagen cross-linking with riboflavin and ultraviolet-A light for patients with keratoconus in Ramadi City

Results of corneal collagen cross-linking in patients with corneal ectasia after laser refractive surgery—A prospective study

PurposeTo evaluate the safety and efficacy of epithelium-off (epi‑off) corneal cross-linking (CXL) in patients with post-LASIK corneal ectasia (PLE) SettingPrivate clinical practice DesignProspective clinical trial Methods82 eyes of adult patients post-LASIK, ages 21–67, with a topography pattern consistent with corneal ectasia, corrected distance visual acuity (CDVA) worse than 20/20, and minimum corneal pachymetry > 400 µm underwent epi‑off CXL. Exclusion criteria were patients with corneas that were thinner than 400 μm or demonstrated central corneal scarring, history of herpetic eye disease, pregnancy or nursing. Follow up examinations of spherical equivalent, uncorrected distance visual acuity (UDVA), CDVA, steep keratometry (KSteep) and minimum pachymetry occurred on different but highly overlapping subsets of the operated eyes yearly until 5 years post-CXL. ResultsOver the 5 years of follow up, spherical equivalent did not significantly change while UCVA and CDVA stabilized or improved to a non-significant degree. KSteep and minimum pachymetry continued to be decreased to a statistically significant degree (p < 0.05 at 5 years). ConclusionsCXL in PLE patients is safe and efficacious: it halts progression of PLE and may improve visual function. KSteep and minimum pachymetry decrease post-CXL. Patients with PLE should be encouraged to stop progression of the disease by undergoing epi‑off CXL once progression is established.

The outcome of corneal collagen cross-linking in progressive keratoconus: A 24-month follow-up

Purpose: The purpose of this study is to evaluate the effect of corneal collagen cross-linking on visual acuity and corneal parameters like keratometry and pachymetry. Methods: It was a retrospective, noncomparative, open-label study conducted at a tertiary eye care center. The eyes that underwent epithelium-off CXL (corneal collagen cross-linking) for progressive keratoconus between 2018 January and 2019 December, and who completed 24 months' post-CXL follow-up, were included in the study. Data regarding uncorrected and best spectacle-corrected visual acuity (UCVA and BSCVA) and corneal topography parameters, that is, K max, K min, and pachymetry at thinnest point, were collected prior to the procedure and 2 years after the procedure. Results: A total of 92 eyes of 65 patients were included in the study. There was a significant improvement of logMAR BCVA from preoperative 0.40 ± 0.24 to 0.28 ± 0.19 at 24 months after CXL (P &lt; 0.001). UCVA also increased from preoperative value of logMAR 0.70 ± 0.28 to 0.61 ± 0.26 2 years postoperatively (P &lt; 0.001). The number of eyes achieving BCVA of 0.3 logMAR or better significantly increased from 54 (58.7%) preoperatively to 72 (78.26%) at 2 years and it was found to be statistically significant (P &lt; 0.001). There was a significant improvement in K max 49.38 ± 3.70 to 49.07 ± 3.45 (P = 0.0005) and K min 45.65 ± 2.69 to 45.19 ± 2.46 (P &lt; 0.001) following CXL. Conclusion: Corneal collagen cross-linking is a treatment modality to stabilize and even improve UCVA in patients with mild-to-moderate keratoconus.

Short- and long-term safety and efficacy of corneal collagen cross-linking in progressive keratoconus: A systematic review and meta-analysis of randomized controlled trials.

The purpose of the study is to evaluate the safety and outcomes of corneal collagen cross-linking (CXL) and different CXL protocols in progressive keratoconus (PK) population at short and long-term. A systematic review and meta-analysis was conducted. A total of eight literature databases were searched (up to February 15, 2022). Randomized controlled trials (RCTs) comparing CXL versus placebo/control or comparing different CXL protocols in the PK population were included. The primary objective was assessment of outcomes of CXL versus placebo and comparison of different CXL protocols in terms of maximum keratometry (Kmax) or Kmax change from baseline (Δ), spherical equivalent, best corrected visual acuity (BCVA), and central corneal thickness (CCT) in both at short term (6 months) and long term (1st, 2nd, and 3rd year or more). The secondary objective was comparative evaluation of safety. For the meta-analysis, the RevMan5.3 software was used. A total of 48 RCTs were included. Compared to control, CXL was associated with improvement in Δ Kmax at 1 year (4 RCTs, mean difference [MD], -1.78 [-2.71, -0.86], P = 0.0002) and 2 and 3 years (1 RCT); ΔBCVA at 1 year (7 RCTs, -0.10 [-0.14, -0.06], P < 0.00001); and Δ CCT at 1 year (2 RCTs) and 3 years (1 RCT). Compared to conventional CXL (C-CXL), deterioration in Δ Kmax, ΔBCVA and endothelial cell density was seen at long term in the transepithelial CXL (TE-CXL, chemical enhancer). Up to 2 years, there was no difference between TE-CXL using iontophoresis (T-ionto) and C-CXL. At 2 and 4 years, C-CXL performed better compared to accelerated CXL (A-CXL) in terms of improving Kmax. Although CCT was higher in the A-CXL arm at 2 years, there was no difference at 4 years. While exploring heterogeneity among studies, selection of control eye (fellow eye of the same patient vs. eye of different patient) and baseline difference in Kmax were important sources of heterogeneity. CXL outperforms placebo/control in terms of enhancing Kmax and CCT, as well as slowing disease progression over time (till 3 years). T-ionto protocol, on the other hand, performed similarly to C-CXL protocol up to 2 years.

Long-Term Outcome of Corneal Collagen Crosslinking with Riboflavin and UV-A Irradiation for Keratoconus*

Purpose To evaluate long-term outcomes of corneal collagen crosslinking (CXL) using riboflavin and UV-A irradiation and to determine when to repeat CXL. Methods In this retrospective consecutive interventional case series 131 eyes of 131 patients (95 male, 36 female, mean age 29.7 ± 11.4 years) between 2006 and 2016 received standard CXL (Dresden protocol, epithelium-off) for progressive keratoconus. Corrected distance visual acuity (CDVA) and corneal tomography (K1, K2, K max) were repeatedly recorded 1 year (n = 103 eyes) to 10 years (n = 44) postoperatively. Only one eye per patient was included. Paired t-test or Wilcoxon matched-pairs signed rank test was used for parametric and nonparametric data, respectively. Results 1–3 years preoperatively, median K2 significantly increased by 1.1 D (p < 0.001). Postoperatively, median K2 increased by 0.1 D after 1 year, then decreased over the remaining postoperative period by 0.85 D (p = 0.021). K max fluctuated without significant change. Median apical corneal thickness decreased by 16 µm (p = 0.012) after 5 years and then returned to preoperative values. Mean CDVA showed a significant improvement (decrease in logMAR 0.08 after 10 years, p = 0.010). CXL non-responders, defined by a postoperative increase in K max>2 D, increased from 16% after 5 to 33% after 10 years. Risk factors for non-response were young age, high astigmatism (>4.3 D), thin cornea (<480 µm), poor initial visual acuity (CDVA ≥0.3 D), and atopic dermatitis. 4 eyes were re-treated 3–4 years after first CXL without complications and keratoconus stabilized thereafter. Conclusions CXL can slow or stop keratoconus progression. However, as the number of responders declines after 5 years, especially patients with risk factors may require re-treatment.

Comparative Study of Corneal Collagen Crosslinking (CXL) in Conjunction with Antimicrobial Agents to Antimicrobial Agents Alone in the Treatment of Infectious Keratitis

Purpose: To compare the outcome of corneal collagen crosslinking (CXL) in conjunction with antimicrobial agents (AMA) to antimicrobial agents alone in the treatment of infectious keratitis. Design: Prospective comparative clinical trial in a tertiary hospital in India. Participants: 40 patients with infectious keratitis randomised into two groups of 20 patients each- Group 1 and 2. Methods: Group 1 patients underwent CXL in addition to antimicrobial therapy. The patients in Group 2 received only antimicrobial therapy. The slit-lamp characteristics of the corneal ulceration, visual acuity, time taken for healing, and complications were documented in each group. The t-test was used for statistical analysis. P values less than 0.05 were considered statistically significant. Results: The mean time taken for healing in Group 1 was 44.5±11.2 days and in Group 2 was 27.65±7.79 days. Analysis of various parameters revealed that patients undergoing CXL showed slower healing duration (p=0.00). Conclusions: Use of CXL in conjunction with AMA lowers the risk of complications, but also slows the rate of healing of ulcers.

Accelerated versus conventional corneal collagen crosslinking: Short-term clinical outcomes in stabilizing keratoconus.

PURPOSE:The purpose of the study is to compare the short-term outcomes of corneal collagen crosslinking (CXL) using the conventional (Dresden) protocol and an accelerated CXL (ACXL) protocol to stop keratoconus (KC) progression.METHODS:A chart review was performed for all the patients with KC who underwent CXL in the last 7 years. Data were compared at baseline and at all follow-up examinations for uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BCVA), keratometry (K), central corneal thickness, and complications of CXL. Pre- and post-intervention values were compared for each group. P < 0.05 was statistically significant.RESULTS:After the treatment, there was a statistically greater improvement in UCVA in the conventional CXL (CCXL) group (49%) compared to the ACXL group (34%) (P = 0.028). The improvement in BCVA was similar between the groups (P = 0.060). Gain of two lines of UCVA and stability were comparable between groups (P = 0.078 and P = 0.060, respectively). The average flat K and steep K values fluctuated remarkably across different follow-up assessments in both the groups. At 3 months of follow-up, there was a statistically significantly faster return to baseline levels of flat and steep Ks in the CCXL group (P = 0.028 and P = 0.002, respectively).CONCLUSION:The findings of the current study confirm the efficacy and safety of accelerated high-fluence CXL compared to CCXL. Both protocols were effective in stabilizing KC at 9th-month and the last follow-up visit. Larger prospective randomized controlled trials and longer follow-up are required to confirm our findings.

Tomographic changes after corneal collagen cross-linking for progressive keratoconus - one-year follow-up study

Introduction/Objective. The aim of this study was to evaluate the outcome of corneal collagen crosslinking (CXL) in patients with progressive keratoconus. Methods. This retrospective single-centered interventional study included 52 eyes of 41 patients who underwent epithelium-off CXL procedure at the age &gt; 18 years. Corneal tomography data, uncorrected, and best spectacle-corrected distant visual acuity (UDVA and CDVA, respectively) were analyzed at baseline and postoperatively over the initial 12-month period. In addition, the natural course of corneal tomographic changes was demonstrated at one, three, six, nine, and 12 months after the CXL procedure. Results. At one year, mean UDVA improved significantly from 0.15 ? 0.22 (0.3 min ? logMAR ? 0 max logMAR) at baseline to 0.06 ? 0.09 logarithm of minimum angle resolution (logMAR) (0.1 min logMAR ? 0 max logMAR) (p = 0.024). Mean CDVA was 0.45 ? 0.39 0.45 ? 0.39 logMAR (0.8 min logMAR ? 0 max logMAR) at baseline and 0.06 ? 0.13 logMAR (1 min logMAR ? 0 max logMAR) at one year (p = 0.039). Maximum keratometry showed a significant flattening of 1.36 D ? 1.53 D (p = 0.0032) at one year after CXL. Minimum keratometry significantly decreased with a mean change of 1.15 ? 1.20 (p = 0.011). Mean anterior and posterior best fit sphere (ABFS and PBFS, respectively) remained stable during the entire follow-up period. Mean reduction of corneal thickness after CXL was 47 ? 61 ?m (p = 0.003). At one year, 29 (56%) eyes showed K max regression, 22 (53%) showed stabilization, and one (2%) showed progression. Spearman correlation coefficients were calculated to assess the correlation between difference in preoperative corneal thickness (CT), in posterior elevation corneal thickness (PECT), and minimum corneal thickness, ?CT (PECT ? minCT) and radius difference ?r (r1-r2). Spearman rs &gt; 0.3 proved statistical significance and correlation. Conclusion. In our study, CXL effectively prevented progression of keratoconus in 98% of eyes at one year, while improving visual acuity. The effect of CXL can be evaluated at the earliest after six months; at that time, the stability of the corneal shape was provided by following the CXL procedure. The main limitation of this study is the small number of patients included.

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

Long-term visual, refractive, tomographic and aberrometric outcomes of corneal collagen crosslinking (CXL) with or without hypoosmolar riboflavin solution in the treatment of progressive keratoconus patients with thin corneas.

To evaluate the long-term visual, refractive, tomographic, and aberrometric outcomes of corneal collagen crosslinking (CXL) with or without hypoosmolar riboflavin solution in the treatment of progressive keratoconus patients with thin corneas. Charts of consecutive progressive keratoconus patients with thinnest corneal thickness less than 470µm who underwent corneal collagen CXL with or without hypoosmolar riboflavin solution and using a standardized protocol for treatment and examinations were analyzed retrospectively. The indication for hypoosmolar riboflavin use was a central corneal thickness less than 400µm as measured by ultrasound pachymetry after epithelial debridement and before exposure to ultraviolet A (UVA) light. Uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, slit lamp biomicroscopy, corneal tomography, corneal aberrometry, and endothelial cell counts were evaluated at baseline and yearly at all postoperative follow-up examinations until month 36. The outcomes of corneal CXL procedure performed using hypoosmolar riboflavin were compared to those performed using the standard procedure. Twenty-three eyes (19 patients) were treated using hypoosmolar riboflavin application, and 30 eyes (28 patients) were treated using the standard procedure. Compared to baseline, the mean UDVA, CDVA, and keratometric readings improved statistically significantly in both groups at postoperative year 3, without any statistically significant between-group differences. Progression was not observed in any patient eye in either group. No significant endothelial cell loss and no sight threating complication were observed in any patient eye. At 3years follow-up, the safety and efficacy of CXL using hypoosmolar riboflavin solution seems to be similar to that of standard CXL in progressive keratoconic eyes with thin corneas. The visual, refractive, keratometric, tomographic and aberrometric outcomes of the two procedures were comparable, as well.

Outcomes of customized topographic guided epithelial debridement for corneal collagen cross-linking.

To evaluate the outcomes of corneal collagen cross-linking performed with customized epithelial debridement technique in progressive keratoconic corneas. Forty eyes of 40 patients were included in the study. We performed an ophthalmologic examination and recorded the uncorrected visual acuity, best corrected visual acuity (BCVA), central corneal thickness at the thinnest point (t-CCT), flat meridian keratometry (K1), steep meridian keratometry (K2), endothelial cell density (ECC), hexagonal cells (HEX), and coefficient of variation of cell areas (CV) measured preoperatively and at the 1st, 3rd, 6th and 12th months postoperatively. The mean UCVA and BCVA were increased (p < 0.05). The mean flattest and steepest K readings were decreased (p < 0.05). The mean t-CCT decreased in the first months after treatment and increased after 6months. The mean t-CCT was thicker at 12months compared to pretreatment status (p < 0.05). The mean ECC and CV were not significantly different between follow-up intervals (p > 0.05). The mean HEX was statistically increased (p > 0.05). Corneal collagen cross-linking performed with customized epithelial debridement technique is a successful alternative method for stopping the progression of keratoconus after 12months of 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&lt;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.

Long-term results of corneal collagen crosslinking for recurrent corneal erosion

BACKGROUND: Recurrent corneal erosion (RCE) is characterized by excacerbation and remission episodes, reduced patients quality of life affecting their daily and professional activities. In case of conservative therapy inefficacy surgical procedures are used (Bowmans membrane polishing with diamond drill, excimer laser phototherapeutic keratectomy, anterior stromal puncture, and amniotic membrane transplantation). All methods have their advantages and weak points, as well as a certain percent of recurrence. In this regard the use of corneal collagen cross-linking is of the interest as an alternative method of the RCE surgical treatment.&#x0D; MATERIALS AND METHODS: 18 patients (20 eyes) with RCE without central corneal stroma scars, aged from 30 to 66 (average 49,5 10,6, all women), after conservative treatment failure (more than 6 months) underwent cross-linking according to the Dresden protocol with the UVX device, version 1000, by IROC INNOCROSS (Switzerland).&#x0D; RESULTS: All patients were asymptomatic and had no recurrence during the observation period (from 1 to 6 years, in average 2,6 1,6). There was a slight but statistically significant BCVA improvement (from 0,93 0,09 at baseline to 0,97 0,07 after intervention).&#x0D; CONCLUSIONS: Crosslinking may be an additional and effective treatment in a number of RCE cases when there is no central corneal stromal scars present. To reduce stromal keratocytes alteration during the procedure modified protocols may be used.

Long-term results of corneal collagen crosslinking with ectatic forms of corneal dystrophy

Corneal collagen crosslinking is one of the most effective methods of prophylactics and treatment of progressive corneal ectasias. In the literature, there are occasional data related to remote results concerning only the most common form of ectasias keratoconus. In published studies, no remote results are met concerning the efficacy of corneal collagen crosslinking in other forms of corneal ectasias, which are now on the rise, including secondary ectasias that became more frequent with refractive surgery. The number of diagnosed cases of pellucid marginal degeneration increased as well. The literature shows no data on comparative analysis of remote results concerning the efficacy of this method in treatment of various forms of corneal ectasias.&#x0D; The aim of the investigation was to evaluate the efficacy of corneal collagen crosslinking based on the analysis of long-term results of this treatment method for various forms of corneal ectasias.&#x0D; Materials and methods. The results of corneal collagen crosslinking in patients with various forms of corneal ectasia 6 years after surgery were analyzed. The nosological structure of the study included patients with keratoconus, pellucid marginal degeneration, and secondary ectasia. The group of patients with keratoconus included 30 patients (30 eyes), that with pellucid marginal degeneration 30 patients (30 eyes), and that with secondary ectasia 30 patients (30 eyes). Corneal collagen crosslinking was performed by the same specialist, during the first or the second year of follow-up. Then changes in the state of the cornea and visual functions were monitored for 6 years. To assess the efficacy, preoperative examination results and interim data were used.&#x0D; Results. In all groups, there was an increase in the best corrected visual acuity, a decrease in the index of asymmetry of the corneal surface and its refractive power in the center of ectasia. However, best corneal collagen crosslinking results were obtained in groups of patients with keratoconus and secondary corneal ectasia.

Outcome of Corneal Collagen Cross-Linking in Keratoconus: Introducing the Predictive Factors.

Purpose:To evaluate the multiple pretreatment characteristics and topographic factors of keratoconus (KC) patients and their relationship to clinical outcomes of corneal collagen cross-linking (CXL).Methods:In this prospective study, 61 patients (106 eyes) with KC as candidates for CXL were included. Demographic data including age, sex, place of birth and residence, atopic constitution, family history, rubbing history, sleep apnea, and blood group were collected via a structured checklist. Complete ophthalmologic examination and tear collection to assess tear interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) level were performed. Topometric parameters were evaluated using a rotating Scheimpflug topography device. Changes in best corrected visual acuity (BCVA) and maximum keratometry (K-max) were considered the main predicted variables. Predictive variables were analyzed by univariate and multivariate regression.Results:The use of multivariate analysis changes in K-max was significantly associated with rubbing frequency (coefficient = 0.94, P = 0.02), blood group (coefficient = 4.52, P = 0.005), pretreatment corneal asphericity (coefficient = −3.99, P ≤ 0.001), and pretreatment central keratoconus index (CKI) (coefficient = −55.38, P = 0.001). Regarding the changes in BCVA, the multivariate analysis showed a significant association with place of birth (coefficient = −0.08, P = 0.03), pretreatment BCVA (coefficient = −0.67, P < 0.001), pretreatment central corneal thickness (CCT) (coefficient = −0.005, P = 0.04), and pretreatment keratoconus index (KI) (coefficient = 0.53, P = 0.04). Other parameters assessed in the multivariable analysis did not appear to have an individual effect on treatment outcomes.Conclusion:Our results demonstrated that blood group, rubbing of eye, place of birth, corneal asphericity, pretreatment BCVA, CKI, KI, and CCT were statistically associated with the outcome of KC following CXL.

Corneal collagen cross-linking in pediatric patients with keratoconus

Introduction/Objective. The aim of this study was to report visual, refractive, and tomographic outcomes of corneal collagen cross-linking (CXL) in pediatric keratoconus. Methods. This retrospective study included 17 eyes of 12 patients with progressive keratoconus who underwent epithelium-off CXL at the age ? 18 years. Following data were analyzed at baseline and postoperatively at one, three, six, nine, 12 months for all the patients, and annually where available: uncorrected distant visual acuity (UDVA) and best spectacle-corrected distant visual acuity (CDVA), refraction and corneal tomography. Results. Mean UDVA improved significantly from 0.52 ? 0.38 at baseline to 0.24 ? 0.29 logarithm of minimum angle resolution (log MAR) at one year (p = 0.011) and remained stable at two-year follow-up (0.21 ? 0.34 log MAR). Mean CDVA was 0.15 ? 0.21 at baseline and 0.06 ? 0.13 log MAR at one year (p = 0.248). Maximum keratometry showed a significant flattening of 1.30 ? 1.99 D (p = 0.011) after a year and remained stable two years after CXL. Minimum keratometry significantly decreased with a mean change of 1.34 ? 1.37 (p = 0.001). Mean reduction of corneal thickness after CXL was 55.35 ? 64.42 ?m (P=0.003). After a year, seven (42%) eyes showed Kmax regression, nine (53%) stabilization, and one (5%) progression. Conclusion. In our study CXL effectively prevented progression of keratoconus in 95% of pediatric patients after a year, while improving UDVA and keratometry values. One patient with eye rubbing behavior showed signs of keratoconus progression after CXL treatment.

Objective and Subjective Outcome of Corneal Collagen Crosslinking in Keratoconic Patients According to Keratoconus Grading

Abstract Background: Keratoconus is a progressive bilateral disease characterized by corneal thinning. Cross linking is one of the most effective treatments of keratoconus and here we studied its objective and subjective effects. Aim of Study: This study aims to investigate differences in objective and subjective outcome of collagen corneal crosslinking of different keratoconus grades. Patient and Method: Twenty-four eyes of twenty-four patients with keratoconus were enrolled in this prospective study arranged into 2 groups according to k reading (Group I: Less than 48, Group II: 48-52); 12 eyes of patients in each group all the eyes underwent full ophthalmological clinical evaluation (Best Spectacle Corrected Visual Acuity (BSCVA) by log MAR and wave light Pentacam assessment to investigate Keratometry readings, Central Corneal Thickness (CCT), and Aberrations scan by Zernike analysis. Evaluations were done at baseline and 3 months' post CXL. Results: The BCVA insignificantly deteriorated in group I & II after 3 months follow-up by (0.016±0.04) p=0.166 and (0.016±0.08) p=0.503 respectively. The mean average K insignificantly decreased in group I & II by (0.216±0.63) p=0.261 and (0.250±1.66) p=0.619 respectively. The mean central corneal thickness increased in group I by (11.00±31.97) p=0.258 while decreased in group II by (5.750±16.75) p=0.259. The mean of total aberration of group I decreased by (0.033± 0.09) p=0.219, while in group II increased by (0.666±0.49) p=0.503. Conclusion: We found insignificant decrease in (BCVA, Average K,) in the two groups the mean CCT increased in group I and decreased in group II. The mean of total aberration decreased in group I while increased in group II.

Early evaluation of corneal collagen crosslinking in ex-vivo human corneas using two-photon imaging

The clinical outcome of corneal collagen crosslinking (CXL) is typically evaluated several weeks after treatment. An earlier assessment of its outcome could lead to an optimization of the treatment, including an immediate re-intervention in case of failure, thereby, avoiding additional discomfort and pain to the patient. In this study, we propose two-photon imaging (TPI) as an earlier evaluation method. CXL was performed in human corneas by application of riboflavin followed by UVA irradiation. Autofluorescence (AF) intensity and lifetime images were acquired using a commercial clinically certified multiphoton tomograph prior to CXL and after 2h, 24h, 72h, and 144h storage in culture medium. The first monitoring point was determined as the minimum time required for riboflavin clearance from the cornea. As control, untreated samples and samples treated only with riboflavin (without UVA irradiation) were monitored at the same time points. Significant increases in the stroma AF intensity and lifetime were observed as soon as 2h after treatment. A depth-dependent TPI analysis showed higher AF lifetimes anteriorly corresponding to areas were CXL was most effective. No alterations were observed in the control groups. Using TPI, the outcome of CXL can be assessed non-invasively and label-free much sooner than with conventional clinical devices.