Corneal stromal depth of the demarcation line in ‘accelerated corneal cross-linking’ with different concentrations of riboflavin solutions (original) (raw)
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Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution
Arquivos Brasileiros de Oftalmologia, 2016
INTRODUCTION Keratoconus is a bilateral, asymmetric, non-inflammatory, and slowly progressive corneal disease with an approximate incidence of 1 in 2000 individuals. This condition is characterized by corneal thinning and protrusion, progressive myopia, and irregular astigmatism (1) and has conventionally been treated using modalities, such as rigid contact lenses, intrastromal corneal ring segment implantation, and keratoplasty. However, current treatment objectives include not only improved visual acuity but also the prevention of disease progression (2). Accordingly, corneal cross-linking (CXL) is a relatively new treatment method designed to increase the mechanical and biochemical strength of the stromal tissue via exposure of the ectatic cornea to riboflavin and ultraviolet-A (UVA) light (3). This procedure is the only currently available semisurgical therapeutic approach for patients with progressing keratoconus and has been shown to delay ABSTRACT Purpose: To analyze the short-term clinical and topographic outcomes in patients with keratoconus after corneal collagen cross-linking treatment (CXL) with dextran-free isotonic riboflavin solution. Methods: In this retrospective case series, 26 eyes from 26 patients with keratoconus were studied. The best corrected visual acuity (BCVA) and refractive and topographic findings were analyzed at a 6-month follow-up. Results: The mean BCVA (Snellen lines) values before and 1, 3, and 6 months after CXL were 0.51 ± 0.2, 0.48 ± 0.2, 0.57 ± 0.2, and 0.64 ± 0.2, respectively, and the difference between the preoperative and 6-month values was statistically significant (p=0.006). The mean spherical equivalent refraction decreased from-5.6 ± 2.4 diopters (D) preoperatively to-5.0 ± 2.1 D, and mean simulated ke ratometry decreased from 48.5 ± 2.5 D to 47.8 ± 2.6 D at 6 months. (p=0.145 and p=0.001, respectively). In addition, the maximum keratometry decreased progressively and significantly from the preoperative value during follow-up (p=0.003). The central and minimal corneal thicknesses, including those of the epithelium, also decreased from 442.8 ± 25.6 μm and 430.5 ± 23.9 μm preoperatively to 420.7 ± 31.8 μm and 409.3 ± 28.7 μm at the most recent follow-up (p<0.001), respectively. No intraoperative or postoperative complications were observed. Conclusions: CXL with dextran-free isotonic riboflavin solution appears to be a safe treatment alternative for keratoconus and yields sustained short-term improvements in visual acuity, keratometric readings, and corneal thickness. However, long-term results are needed to confirm these outcomes.
Journal of Ophthalmic and Vision Research, 2021
Purpose: To report structural changes observable in in vivo confocal microscopy (IVCM) in keratoconic corneas <400 μm treated with hypotonic riboflavin and collagen crosslinking (CXL). Method: Ten eyes of ten patients with progressive keratoconus and corneal thickness between 350 and 399 μm underwent CXL with hypotonic riboflavin. IVCM was performed preoperatively and at one month, three months, and six months after the procedure. Results: IVCM analysis one month postoperatively showed complete absence of the subepithelial nerve plexus with gradual regeneration over six months in 8 of the 10 eyes, and poor regeneration in the remaining 2 eyes. The anterior stroma showed extracellular lacunae and hyper-reflective cytoplasm in a honeycomb appearance signifying edema at one month which gradually decreased over six months post CXL. Stromal keratocyte apoptosis was evident in the anterior stroma in all cases and extended to the posterior stroma in four eyes with gradual regeneration e...
Daru : journal of Faculty of Pharmacy, Tehran University of Medical Sciences, 2015
BackgroundComparison of long-term clinical results of two different pharmaceutical formulations used in corneal cross-linking (CXL) in keratoconus patients.MethodsSixty eyes of 60 keratoconus patients underwent CXL in two groups. We used riboflavin preparations from Sina Darou, Iran in group A, and Streuli Pharma, Switzerland in group B. Here we made inter-group comparison of changes in vision, refraction, Pentacam indices, corneal biomechanical indices, and endothelial cell count (ECC) 18 months after CXL.ResultsSince four patients were lost to follow-up, 56 eyes (28 eyes in each group) were compared. Mean improvement in uncorrected visual acuity (UCVA) was 0.31¿±¿0.65 LogMAR (P¿=¿0.014) in group A and 0.24¿±¿0.62 LogMAR (P¿=¿0.082) in group B. Best corrected visual acuity (BCVA) remained quite unchanged in both groups (P¿=¿0.774). Mean spherical refractive error reduced by 0.45¿±¿1.15 diopter (D) (P¿=¿0.041) in group A and 0.27¿±¿1.73 D (P¿=¿0.458) in group B (P¿=¿0.655). Cylinder...
Accelerated Corneal Cross-Linking With a Hypoosmolar Riboflavin Solution in Keratoconic Thin Corneas
Cornea, 2016
The aim of this study was to evaluate the early term topographic and aberration results of accelerated (9 mW/cm 2) corneal cross-linking (CXL) treatment in keratoconic thin corneas. Methods: Forty-nine eyes from 43 patients (mean age of 21.2 6 7.1) with progressive keratoconic thin corneas (,400 mm without epithelium) who had accelerated corneal CXL with hypoosmolar riboflavin solution throughout the procedure were enrolled. We measured the uncorrected and corrected distance visual acuity, refraction, slit-lamp examination, topographic values, and corneal higher-order aberrations (Pentacam HR, Oculus Optikgeräte GmbH) preoperatively and 1, 3, and 6 months after surgery. Results: Before surgery, the corneal thickness was 404 6 18 mm, and the thickness was reduced to 360 6 24 mm after removing the epithelium. After the application of hypoosmolar riboflavin solution, the thickness increased to 432 6 44 mm. At month 6, there was a significant increase in uncorrected distance visual acuity (P = 0.043) and corrected distance visual acuity (P = 0.024), a decrease in spherical refraction (P = 0.041), maximum keratometry (K max , P = 0.003), anterior elevation values (P = 0.008), corneal thickness (P , 0.001), coma (P = 0.022), spherical aberration (P = 0.001), higher-order root mean square (P = 0.004), and total root mean square (P , 0.001), whereas the cylindrical refraction (P = 0.627), anterior (P = 0.665) and posterior astigmatism (P = 0.165) of the cornea, posterior elevation (P = 0.198), and trefoil (P = 0.141) remained unchanged. No patients showed any complications or scar formation during follow-up. Conclusions: Accelerated corneal CXL with hypoosmolar riboflavin solution throughout the procedure is effective in thin corneas.
Medical Archives, 2015
Aim To determine the possible relation between intraocular pressure (IOP), central corneal thickness (CCT) and corneal resistance (CR) in kerotoconic eyes before, 3,6 and 12 months after collagen crosslinking procedure (CXL) with aim to find out does the thicker cornea means already more resistance cornea followed with higher IOP. Methods: Thirty eyes (30 patients) with central keratoconus (KC)were evaluated in retrospective cross sectional study. The corneal biomechanical parameters were taken with Wave Light Allegro Oculyzer produced by Alcon before the CXL, 3, 6 and 12 months after the procedure. IOP were checked by Goldmann applanation tonometry (GAT) before, 3, 6 and 12 months after CXL. Results The value of IOP before the CXL was 12,0 mmHg (10,62-15,25 mmHg), 3 months later 13,5 mmHg (11,0-16,0 mmHg), 6 months 14,0 mmHg (11,0-16,0 mmHg) and 12 months later 15,0 mmHg (10,37-17,25 mmHg) and was statistically significant higher (p=0,015) comparing to the value of IOP 3 months after the CXL, IOP 12 months after CXL procedure was statistically significant higher comparing to preoperative values (p=0,010). There were no statistically significant difference between the values 3 and 6 months after CXL. The CCT before the CXL procedure was 449 (433-505,75 microns), 3 months after CXL was 420 (383-473microns, p < 0,005), 6 months later 437 (401,25-480,25, p=0,001), 12 months after CXL 437 (401-503 microns, p=0,001). However there is statistically significant difference in CCT 12 months after CXL 437 (401-503microns p=0,032) and the value of CCT 3 months later the procedure (p=0,004) and the CCT 12 months after CXL and the value of CXL 6 months after CXL (p=0,036). The value of CCT did not show any statistically significant difference 3 and 6 months postoperatively. Conclusion After riboflavin-UVA CXL in eyes with KC there was significant decrease in central corneal thickness 3 and 6 months after the procedure and the thickness is almost the same 12 months later. However IOP is low before CXL , raising up 3 and 6 months after CXL but significant increase is seen 12 months later. It means the regular measurement of IOP could be the serious and confident indicator of increasing of corneal resistance which is the main goal of CXL treatment.
2009
Methods: 14 keratoconic patients enrolled for penetrating keratoplasty were selectioned as in vivo samples donors and 16 warm-stored ex vivo sclerocorneal rings unsuitable for transplant were used. In vivo samples were immediately exposed to sterile 0.1% riboflavin solution. 7 of the 14 specimens were debrided and the other 7 were left with the epithelium in situ. One of the latter and one of the debrided samples were not exposed with riboflavin (control groups). In 7 sclerocorneal rings epithelium was removed and in 9 was left in situ. Debrided and not debrided samples were soaked with 0.1% riboflavin solution, instilled every 2 minutes for 5 min, 15 min and 30 min in both in vivo and ex vivo groups. Riboflavin concentrations were determined by HPLC.
Corneal collagen cross-linking with hypoosmolar riboflavin solution in keratoconic corneas
BioMed research international, 2014
To report the 12-month outcomes of corneal collagen cross-linking (CXL) with a hypoosmolar riboflavin and ultraviolet-A (UVA) irradiation in thin corneas. Eight eyes underwent CXL using a hypoosmolar riboflavin solution after epithelial removal. The corrected distance visual acuity (CDVA), manifest refraction, the mean thinnest corneal thickness (MTCT), and the endothelial cell density (ECD) were evaluated before and 6 and 12 months after CXL. The MTCT was 413.9 ± 12.4 μm before treatment and reduced to 381.1 ± 7.3 μm after the removal of the epithelium. After CXL, the thickness decreased to 410.3 ± 14.5 μm at the last follow-up. Before treatment, the mean K-value of the apex of the keratoconus corneas was 58.7 ± 3.5 diopters and slightly decreased (57.7 ± 4.9 diopters) at 12 months. The mean CDVA was 0.54 ± 0.23 logarithm of the minimal angle of resolution before treatment and increased to 0.51 ± 0.21 logarithm at the last follow-up. The ECD was 2731.4 ± 191.8 cells/mm(2) before tr...
DARU Journal of Pharmaceutical Sciences, 2014
Background: To compare the 6-month results of two formulations of Riboflavin provided by Sina Darou, Iran, and Uznach, Switzerland, in corneal collagen cross-linking (CXL) for keratoconus patients. Findings: Considering the results of the previous study about the similarity of the formulations and the active ingredients of the two types of Riboflavin, they were used in the CXL procedure of 60 keratoconic eyes (30 eyes in each group). After 6 months, the mean improvement of UCVA (0.239), BCVA (0.707), and MRSE (0.513) did not differ significantly between the two groups. The mean decrease in max-K (0.731), mean-K (0.264), central corneal thickness (0.759), and Q-value (0.669) did not show any significant difference between the two groups. The two groups had no significant difference in endothelial cell count decrease (0.229). The Sina Darou formulation decreased corneal hysteresis more than the Swiss formulation (P = 0.057) but there were no significant differences in the mean decrease of corneal resistance factor between the two groups (P = 0.117).