Cross-linking For Progressive Keratoconus Research Articles

Clinical, Anatomical, and Densitometric Changes following Dresden vs. Accelerated Corneal Cross-Linking in Progressive Keratoconus.

To compare clinical, anatomical, and densitometric changes following Dresden (DCXL) vs. accelerated (ACXL) corneal UVA cross-linking (CXL; Avedro KXL, Geuder, Heidelberg, Germany) in progressive keratoconus (KC). In this retrospective study, we analyzed 20 patients following DCXL (3 mW/cm², 30 min, 5.4 J/cm²) and 44 patients following ACXL (9 mW/cm², 10 min, 5.4 J/cm²) between January 2016 and February 2020. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), steepest keratometry (Kmax), keratoconus index (KI), thinnest pachymetry (Pthin), and corneal densitometry (CD) were measured before and 3, 6, 12, and 24 months after CXL. During the follow-up period, no changes in UCVA, BSCVA, Kmax, KI, or Pthin occurred. CCT significantly decreased 3 months after DCXL (p = 0.032) and ACXL (p = 0.006). At the 12- and 24-month follow-up, CCT remained decreased in the DCXL (p = 0.035, 0.036, respectively) but not in the ACXL group. At the 12-month follow-up, the reduction in CCT was significantly greater in DCXL compared to ACXL (p = 0.012). At the 3-, 6-, 12-, and 24-month follow-ups, we found a significant increase in the anterior stroma CD following DCXL (p = 0.019, 0.026, 0.049, 0.047, respectively) but not ACXL. The CD changes were localized in the central concentric zones (0.0 to 6.0 mm). No intra- or postoperative complications occurred. ACXL and DCXL effectively halted KC progression. ACXL proved to be a safe time-saving alternative to conventional DCXL. DCXL led to a reduction in CCT and an increment in the CD of the central anterior stroma during 24 months of follow-up.

Study Of Macular Function and Morphology After Transepithelial Accelerated Corneal Collagen Cross-linking in Progressive Keratoconus

Objective The aim of this work is to evaluate the effect of transepithelial accelerated cross-linking (Epi-on CXL) on the macular function and morphology in progressive keratoconus. Patients and Methods The study included 25 patients with progressive keratoconus with age ranged between 18 and 32 years. Epi-On Accelerated CXL was done for all cases. Evaluation was performed 2 and 6 weeks postoperatively after transepithelial (Epi-on) accelerated CXL by Optical coherence tomography (OCT) and multifocal electroretinography (mf-ERG). Results The central foveal thickness (CFT) decreased from 165.1 ± 21.5 µm to 163.4 ± 24.2 µm 2 weeks postoperatively to 164.8 ± 23.9 µm 6 weeks postoperatively, with no statistically significant difference. The preoperative retinal response density (RRD) decreased in macular ring 1 (foveal area of 2.8 degrees) from 179.5 ± 52.1 nV/deg2 preoperatively to 134.7 ± 43.2 nV/deg2 and 146.7 ± 41.6 nV/deg2 in 2 and 6 weeks, respectively postoperatively with statistically significant difference (p = 0.012), while the other 4 rings showed statistically insignificant difference (p >0.05) .On the other hand, implicit time latency (Pl) showed statistically insignificant difference between preoperative and postoperative values (p >0.05) in all macular rings. Conclusion There is a minimal change in macular morphology after Epi-on accelerated CXL in progressive keratoconus, however, no significant change in macular function without any structural changes in progressive keratoconus 6 weeks postoperatively. A longer follow-up period studies are recommended to provide more information.

Efficacy, Safety, and Outcomes following Accelerated and Iontophoresis Corneal Crosslinking in Progressive Keratoconus.

To investigate the outcomes of accelerated (A-CXL) and iontophoresis (I-CXL) corneal crosslinking in a large retrospective cohort with progressive keratoconus. This retrospective observational cohort study included consecutive patients treated by A-CXL (9 mW/5.4 J/cm2) or I-CXL with a minimal follow-up of 12 months. Visual acuity, manifest refraction, topography, specular microscopy, and corneal optical coherence tomography (OCT) were evaluated at baseline and at the last visit. Progression was defined as an increase in the maximum topographic keratometry (Kmax) of 1D. 302 eyes of 241 patients with a mean age of 25.2 ± 7.5 years were included from 2012 to 2019: 231 and 71 eyes in the A-CXL and I-CXL groups, respectively. The mean follow-up was 27.2 ± 13.2 months (maximum: 85.7 months). Preoperatively, the mean Kmax was 51.8 ± 4.0D, with no differences between groups. Mean topographic measurements and spherical equivalent remained stable during the follow-up. At the last visit, CXL failure was reported in 60 eyes (19.9%): 40 (14.7%) versus 20 (28.2%) in A-CXL versus I-CXL, respectively, p = 0.005. The likelihood of progression after CXL was significantly higher following I-CXL: RR = 1.62, CI95 = [1.02 to 2.59], p = 0.04. Demarcation line presence at 1 month was positively correlated with higher efficacy of CXL, p = 0.03. No endothelial damage was reported, especially in 51 thin corneas (range = 342-399 µm). A-CXL seems more effective than I-CXL in stabilizing keratoconus; this is to be taken into account when a therapeutic indication is posed according to the aggressiveness of the keratoconus.

Evaluation of Biomechanical Changes After Accelerated Cross-Linking in Progressive Keratoconus: A Prospective Follow-Up Study.

The aim of this study was to analyze the biomechanical effect of accelerated corneal cross-linking (9*10) in progressive keratoconus (KC) in comparison to untreated fellow eyes using Scheimpflug-based tonometry (Corvis ST, CVS). Forty-three eyes of 43 patients with KC showed progressive KC and were treated using accelerated corneal cross-linking. Twenty-five untreated fellow eyes were used as the control group. All eyes were examined biomechanically (CVS) and tomographically (Pentacam) at baseline, after 1-month, 6-month, and 12-month follow-up. Statistical analysis was performed using a linear mixed model. A logistic regression was performed to attribute the effects of changes in each parameter to treatment status (treated or untreated). Maximum keratometry values decreased statistically significantly at 12 months by -1.1 D (95 confidence interval: -2.0 to -0.1, P = 0.025) compared with baseline. Thinnest corneal thickness decreased significantly after 1 month ( P < 0.001) and recovered to baseline after 12 months ( P = 0.752). In the corneal cross-linking (CXL) group, biomechanical changes were observed by an increased bIOP, a shorter A2 time, and a lower integrated radius after 1 month (all P < 0.05). No biomechanical and tomographical changes were observed in the control group (all P > 0.05). Logistic regression pointed out that treated eyes can be separated from untreated eyes by differences in bIOP, corneal thickness, A1 velocity, integrated radius, and Kc mean at 1, 6, and 12 months. The alterations in biomechanical parameters indicated a corneal stiffening effect after CXL treatment, which was mostly detectable 1 month after treatment, although corneal thickness was reduced. The logistic regression model showed an adequate separation between CXL-treated and untreated eyes.

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.

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.

Safety and Efficacy of Repeated Corneal Collagen Crosslinking in Progressive Keratoconus.

Keratoconus is a progressive visually impairing disorder. Despite the beneficial effects of epithelial off-crosslinking (CXL) on the stabilization of keratoconus, progression may still occur. We report the efficacy and safety of a repeated CXL for significant progression of keratoconus after a single CXL procedure. This retrospective study includes patients diagnosed with progressive keratoconus who were previously treated with CXL and underwent repeated CXL. Demographic, clinical, and surgical data were retrieved and analyzed. Ten consecutive eyes of nine patients who developed progressive keratoconus after CXL were identified. The mean age at diagnosis of keratoconus was 20.2 ± 6.0 years. The post-repeated CXL follow-up period was 2.1 ± 1.3 years. The mean best corrected visual acuity (BCVA) remained stable throughout the follow-up period. The mean Kmax at baseline was 60.4 ± 3.6 D. Before the repeated CXL, Kmax progressed significantly ( P = 0.018) and was 62.2 ± 6.3 D, and at the last follow-up, the value decreased significantly ( P = 0.037) and was 60.3 ± 6.4 D. The mean minimal pachymetry was 464.0 ± 27.0 µ at base line. Before the repeated CXL, minimal pachymetry was significantly lower ( P = 0.018), and after the repeated CXL, the minimal pachymetry was stable ( P = 0.2). No intra- or postoperative complications were noted. Repeated CXL is a safe and effective treatment option when failure of the initial CXL is diagnosed, even in young patients. This procedure may prevent visual deterioration and a potential need for keratoplasty.

Evaluation of macular function and morphology following accelerated collagen cross-linking in progressive keratoconus.

To assess any changes in macular function and morphology in patients with progressive keratoconus undergoing accelerated corneal cross-linking (CXL). This prospective case series included 9 eyes of 8 patients with progressive keratoconus undergoing CXL using a high intensity accelerated protocol (9 mW/cm2 for 14 min) with a total surface dose of 7.5 J/cm2. Visual acuity assessment, slit lamp biomicroscopy, dilated fundoscopy, corneal tomography, multifocal electroretinography (mfERG) and spectral domain optical coherence tomography scan were performed at baseline, 2 weeks and 6 weeks postoperatively. Uncorrected and corrected distance visual acuity did not change significantly at 2 weeks and 6 weeks following accelerated CXL compared to baseline. Retinal response density (RRD) of mfERG significantly decreased at 2 weeks postoperatively compared to baseline (p = 0.008) but did not differ from the baseline value at 6 weeks postoperatively in the fovea (ring 1) (p = 0.95). Similarly, P1 latency significantly decreased at 2 weeks (p = 0.04) but did not change at 6 weeks (p = 1.00) postoperatively compared to baseline in the fovea. No changes in RRD or P1 latency were observed in the retinal rings surrounding the fovea (rings 2 to 5). Central foveal thickness did not change at 2 weeks and 6 weeks postoperatively compared to baseline (p = 0.53 and p = 0.93, respectively). A short-term reversible decrease in macular electrical activity without any structural changes seems to occur after accelerated CXL in patients with progressive keratoconus. The return of macular response to the preoperative values shows the safety of the CXL protocol.

Transepithelial Iontophoresis-Assisted Cross Linking for Progressive Keratoconus: Up to 7 Years of Follow Up.

Purpose: To report long-term clinical results of transepithelial cross-linking with iontophoresis (I-CXL) for progressive keratoconus (KC). Methods: Nineteen eyes of 19 patients treated with I-CXL for progressive keratoconus were included in this prospective clinical study. Preoperatively and in all available follow ups (6, 12, 24, 36, 48, 60, 72 and 84 months), the following parameters were measured. Corrected distance visual acuity (CDVA), spherical equivalent and cylinder refraction, corneal topography and aberrometry (Costruzione Strumenti Oftalmici (C.S.O.), Florence, Italy), Scheimpflug tomography (OCULUS Optikgeräte GmbH; Wetzlar, Germany). Definition of progression after I-CXL was 2/3 of the following criteria: increase of “A” value, increase of “B” value, decrease of minimal thickness evaluated with the ABCD progression display above 95% confidence interval for post-CXL population when compared to the scan 12 months post-op. Results: The mean follow-up time of included patients was 63 months (range 12 to 84 months, 5 patients reached 84 months). The general linear model showed no significant change over time in CDVA, Maximum Keratometry, Thinnest point, and A, B, C values of the Belin Progression Display (p > 0.05). Conversely, comatic and high order aberrations decreased significantly over time (both p =< 0.001). Five cases (26.31%) showed significant progression after a mean of 55 months (range 36–72) of follow up. Conclusion: Our study shows the ability of I-CXL to slow down KC progression in the majority of included patients, improving high order and comatic aberrations. A 26% progression rate was reported.

Accelerated corneal collagen cross-linking in progressive keratoconus: Five-year results and predictors of visual and topographic outcomes.

To analyze the 5-year results of accelerated corneal collagen crosslinking (CXL) for progressive keratoconus and identify preoperative characteristics predictive of visual and topographic outcomes. A prospective interventional case series. Nineteen eyes of 19 patients receiving accelerated CXL with settings of 18 mW/cm2 for 5 min were included. Clinical and topographic parameters were assessed. Linear regression and logistic regression were used to compare the R2 and odds ratio (OR), respectively, between baseline characteristics and postoperative outcomes. Corrected distance visual acuity (CDVA) remained stable from 0.28 ± 0.21 to 0.25 ± 0.18 logMAR (P = 0.486). The mean cylindrical refraction was stable (P = 0.119). The maximal keratometry (Kmax) decreased from 61.99 ± 10.37 to 59.25 ± 7.75 D (P < 0.001), flattening in the flattest and steepest meridians and mean keratometry were also observed (P ≤ 0.040). The mean anterior elevation at the apex reduced from 21.42 ± 16.69 to 18.53 ± 12.74 μm (P = 0.013) and changes in posterior elevation were non-significant (P = 0.629). Preoperative Kmax best predicted the postoperative change in Kmax (R2 = 0.55, P < 0.001) compared to the other baseline characteristics (P ≤ 0.028), whereas preoperative CDVA was the only significant predictor of postoperative change in CDVA (R2 = 0.41, P = 0.003). Accelerated CXL is less likely to fail in eyes with a steeper preoperative Kmax (OR = 0.74, P = 0.040) or greater posterior elevation at the apex (OR = 0.91, P = 0.042). Kmax significantly decreased following accelerated CXL. Eyes with worse preoperative CDVA and higher Kmax were more likely to have an improvement in visual acuity and corneal flattening.

Accelerated versus Standard Corneal Cross-linking for Progressive Keratoconus in Syria.

PurposeTo compare the outcomes of accelerated versus standard corneal cross-linking for the treatment of progressive keratoconus.Methods In this retrospective comparative study, 63 eyes of 40 patients with progressive keratoconus were divided into two groups; 27 eyes in group one were treated with an accelerated protocol (10 mW/cm, 9 min) and 36 eyes in group two were treated with the standard method (3 mW/cm, 30 min). Visual acuity, refraction, corneal topography, corneal tomography, and anterior and posterior corneal higher-order aberrations (HOAs) were assessed preoperatively and 18–30 months postoperatively.ResultsThe LogMAR uncorrected and corrected distance visual acuity values were improved in both groups postoperatively. However, the improvement was significantly higher in group one (P 0.05, all). The flattening in the anterior keratometry readings, flat K, steep K, and average K were significantly higher in group two (P 0.001, all). The maximum anterior keratometry (AKf) values significantly decreased in both groups, whereas the maximum posterior keratometry (AKb) values increased. The reduction in the minimum corneal thickness (ThKmin) was significantly greater (36.49um) in group two, compared to 10.85um in group one. There was a significant increase in the posterior average keratometry, and a significant decrease in the posterior astigmatism, along 3 mm meridian in S-CXL (P = 0.03, P = 0.008, respectively), while the corresponding values showed no statistical significance in group one (P 0.05). The anterior corneal trefoil was significantly reduced in group one (P = 0.002), whereas anterior total HOAs and coma were significantly improved in group two (P 0.0014, all). The posterior corneal spherical aberration decreased significantly in group one (P = 0.02), while group two revealed significant reduction in the posterior trefoil values (P = 0.011). The change in the anterior maximum keratometry was significantly and positively correlated to the preoperative maximum keratometry in group two (P = 0.53, P = 0.003).ConclusionAn accelerated cross-linking protocol using 10 mW/cm for 9 min showed more visual improvement and less pachymetric reduction when compared to the standard protocol, however, anterior corneal flattening, posterior corneal steepening, and the change in the posterior astigmatism were significantly higher in the standard protocol; while corneal HOAs were improved in both protocols.

Long-term study of topographic changes following pulsed accelerated corneal collagen cross-linking in progressive keratoconus

Purpose To evaluate long-term stability following pulsed accelerated cross-linking (CXL) in patients with progressive keratoconus by studying the changes in corneal topography.Patients and methods A retrospective study was conducted on patients with progressive grades 1–3 keratoconus who underwent epithelium-off pulsed-light accelerated corneal CXL (30 mW/cm2 for 8 min) using the KXL system (Avedro Inc.). Follow-up period was 12–36 months. Topographic changes including maximum keratometry (Kmax), minimum keratometry (Kmin), topographic cylinder, central corneal thickness, and thinnest point (TP) were recorded and analyzed.Results A total of 72 eyes of 38 patients were included. The 12-month results showed significant reduction in Kmin (P=0.038), central corneal thickness (P˂0.001), and TP (P˂0.001). At 24 and 36 months, there were no significant changes in corneal topography, except for reduction in TP (P=0.024 and 0.002, respectively).Conclusion Pulsed accelerated CXL is an effective long-term method of arresting keratoconus progression.

Visual and topographical outcomes following accelerated corneal crosslinking in progressive keratoconus

Visual and topographical outcomes following accelerated corneal crosslinking in progressive keratoconus

Epithelium-Off vs. transepithelial corneal collagen crosslinking in progressive keratoconus: 3 years of follow-up

PurposeTo compare the efficacy of epithelium-off corneal collagen crosslinking (CXL) with transepithelial CXL in patients with progressive keratoconus with a follow-up of 3 years, taking into account the patients’ age and the location of the corneal ectasia. MethodsIn this prospective study participated 64 eyes with progressive keratoconus were included in this long-term study, of which 31 eyes were treated by epithelium-off CXL and 33 by transepithelial CXL. All of the patients with a follow-up of 36 months were evaluated for visual variables (corrected distance visual acuity (CDVA), corneal aberrations, and corneal densitometry), structure variables (astigmatism, keratometry, corneal asphericity, maximum posterior elevation, corneal thickness, and corneal volume), and keratoconus index variables. ResultsAfter corneal CXL, CDVA improved significantly in both central and paracentral keratoconus, with greater improvement in the centrals (p = 0.001), asphericity at 6 mm improved in central keratoconus (p = 0.047). In the epi-off group, there was a significant improvement in coma-like (p = 0.038), higher-order aberrations (p = 0.036), asphericity at 8 mm (p = 0.049), asphericity at 10 mm (p = 0.049), and index of surface variance (p = 0.049). ConclusionAlthough both techniques halted and stabilized the progression of keratoconus, epithelium-off CXL was more effective. In addition, after the corneal CXL, there was a greater degree of regularization of the corneal surface and, therefore, a greater improvement in the CDVA with central keratoconus than with paracentral keratoconus.

Comparative 2-year outcomes of conventional and accelerated corneal collagen crosslinking in progressive keratoconus.

To compare the safety and efficacy of conventional versus accelerated (9 mW/cm2) corneal collagen crosslinking (CXL) in progressive keratoconus at the 2-year follow-up. In this prospective study, consecutive progressive keratoconus patients were randomized to receive either conventional CXL (CCXL) or accelerated CXL (ACXL; using hydroxypropyl methylcellulose-assisted riboflavin imbibition for 10min at 9 mW/cm2). Visual, refractive, keratometric, topographic, and aberrometric outcomes and stromal demarcation line depth (DLD) measurements were compared at the end of a 2-year follow-up. Thirty-two eyes from 32 patients in the CCXL and 27 eyes from 27 patients in the ACXL groups completed 2-year follow-up. At 2y post-CXL, both uncorrected and corrected visual acuities improved significantly in both groups. The improvements in keratometric readings, flattening rate (flattening of the maximum keratometry more than 1 D), 3 topographic indices, and vertical coma were significantly better in the CCXL group compared to the ACXL group (P<0.05). The DLD as measured by anterior segment optical coherence tomography or in vivo confocal microscopy was better detectable and significantly deeper in the CCXL group compared to the ACXL group. The deeper DLD was found to be significantly correlated with improvements in the mean keratometry measurements. Progression was noted in 11.1% of eyes in the ACXL group, whereas progression was not observed in any patient eye in the CCXL group. In this prospective randomized study, ACXL is less effective in halting the progression of keratoconus at a 2-year follow-up compared to CCXL.

Clinical Results of Repeated Corneal Collagen Cross-linking in Progressive Keratoconus.

To evaluate the effectiveness of repeated corneal collagen cross-linking (CXL) in eyes with progressive keratoconus after primary CXL. Twelve eyes of 10 patients who underwent repeated CXL were included in this study. All cases were treated with a second CXL when disease progression was noted. Uncorrected visual acuity, best-corrected distance visual acuity, and corneal tomography were performed before and after repeated CXL. Common risk factors for progression were recorded. The mean age of the patients was 23.4 ± 6.2 (14-34) years. Eye rubbing was detected in 6 patients. The preoperative maximum keratometry (Kmax) value was >58.0 diopters (D) in 11 eyes (62.2 ± 4.9 D). Repeated CXL was performed with a mean interval of 19.3 months after the first CXL procedure when a disease progression of 2.3 D on average in Kmax was determined. With a mean follow-up of 36 months, Kmax regressed in 8 eyes, remained stable in 2 eyes, and progressed in 2 eyes after repeated CXL. Uncorrected and corrected visual acuity remained unchanged. No complications were observed. Repeated CXL seems to be effective in stabilizing keratoconus progression after failure of primary CXL. Patients should be followed up at least for 2 years after primary CXL.

Corneal Crosslinking in Progressive Keratoconus: Comparison of Dextran-Based and Hydroxypropyl Methylcellulose-Based Riboflavin Solutions Differences in demarcation line depth and 1 yaear outcomes

Keratoconus is a progressive ectatic disorder characterised by irregular myopic astigmatism and loss of visual acuity due to corneal thinning. Corneal collagen crosslinking is the treatment recognised to stop the progression of keratoconus. Our study evaluates and compares visibility and depth of the stromal demarcation line after corneal collagen crosslinking using anterior segment optical coherence tomography between two groups:crosslinking with dextran-based and hydroxypropyl methylcellulose-based riboflavin solutions. Our work proved a better visibility and a deeper demarcation line when we used HPMC-based riboflavin. Also the study revealed that HPMC-based riboflavin is associated with better biomechanical outcomes than dextran-based riboflavin.

Investigation of the Outcomes of Corneal Cross-linking in Progressive Keratoconus

Investigation of the Outcomes of Corneal Cross-linking in Progressive Keratoconus

Late onset corneal haze after corneal collagen crosslinking for progressive keratoconus

Late onset corneal haze after corneal collagen crosslinking for progressive keratoconus

Time Course of Changes in Simulated Keratometry and Total Corneal Refractive Power after Corneal Collagen Cross-Linking for Progressive Keratoconus.

Purpose To assess the simulated keratometry (Sim K) and the total corneal refractive power (TCRP) in eyes undergoing conventional corneal cross-linking (CXL). Methods This study comprised 20 eyes of 20 keratoconic patients (14 men and 6 women; median age (25th and 75th percentile), 26.5 (21.8, 38.0) years) who underwent CXL. The Sim K and TCRP were measured with a rotating Scheimpflug system (Pentacam HR, Oculus), preoperatively and 1, 3, 6, and 12 months postoperatively. Results The values of Sim K were 52.65 (46.00, 55.70), 52.45 (45.85, 56.88), 51.70 (45.78, 55.83), 51.40 (45.68, 56.80), and 51.25 (46.08, 56.15) D preoperatively and 1, 3, 6, and 12 months postoperatively, respectively. The corresponding figures of TCRP were 52.10 (45.48, 55.08), 51.30 (45.18, 55.20), 50.95 (45.15, 54.50), 50.00 (45.18, 55.08), and 49.80 (45.48, 54.15) D, respectively. The variances of the Sim K and TCRP data were not statistically significant (p=0.994 and p=0.970, respectively, Kruskal–Wallis test). The Sim K was significantly larger than the TCRP before CXL and at 1, 3, 6, and 12 months after CXL (p<0.001, Wilcoxon signed-rank test). Conclusions Not only the Sim K but also TCRP was decreased by approximately 1 D after CXL. The Sim K readings may overestimate the TCRP, even after CXL for progressive keratoconus.