Efficacy Of Corneal Collagen Cross-linking Research Articles

Corneal collagen cross-linking in patients with keratoconus associated with dry eye

Purpose The aim of this study was to assess the safety and efficacy of corneal collagen cross-linking in keratoconus associated with dry eye.Patients and methods This study included 35 eyes of 29 patients diagnosed as having keratoconus associated with moderate dry eye manifestations (as measured by Schirmer 1 test result of 8-4 mm after 5 min). Moreover, 12 keratoconic eyes were also included in this study without any manifestations of dry eye as a control group (as measured by Schirmer 1 test result of ≥15 mm after 5 min). All eyes were subjected to preoperative and postoperative assessments including uncorrected visual acuity, best-corrected visual acuity, pachymetry, simulated keratometry, and corneal topography. The thinnest corneal thickness was at least 400 μm in all eyes. As mentioned before, the degree of preoperative dry eye was assessed using Schirmer 1 test. Epithelium-on cross-linking technique was used. All data were analyzed and recorded.Results The results of ‘epithelium-on’ collagen cross-linking are variable, but its noninvasive nature makes it potentially useful in cases when epithelium debridement is better to be avoided, such as in patients with dry eyes.In our study, there was a remarkable improvement regarding postoperative uncorrected visual acuity and best-corrected visual acuity (one line or more). There was no statistical significant difference between the results among dry eyes and nondry eyes. Average K readings showed a marked reduction reaching more than 2 D. The mean astigmatism showed unremarkable changes. The main central corneal thickness showed marked corneal thinning with reduction in the corneal thickness of ∼50 μm or more in many eyes.Conclusion This study showed no significant difference in efficacy and safety of corneal collagen cross-linking among eyes with keratoconus either associated with dry eye or not.

Efficacy of Corneal Collagen Cross-Linking for the Treatment of Keratoconus: A Systematic Review and Meta-Analysis.

To examine the efficacy of corneal collagen cross-linking (CXL) for the treatment of keratoconus (KCN). A systemic literature review and meta-analysis of ocular functional and structural parameters of patients with KCN undergoing cross-linking procedures were performed using PubMed and the web of science. A literature search was performed for relevant peer-reviewed publications on population-based studies. Data were analyzed with R software (Meta library), and heterogeneity was assessed with the Cochran Q and I. A random-effects model was used for high heterogeneity; otherwise a fixed model was used. Sensitivity analysis of particular tested groups was used to explain high heterogeneity. The main outcome measures extracted from the articles were corrected distance visual acuity, uncorrected distance visual acuity, and maximum K. An improvement in visual acuity of 1 to 2 Snellen lines was found 3 months or more after undergoing CXL. Changes were more pronounced in uncorrected visual acuity. Some topography parameters were found to be improved (0.6-1 diopters) 12 to 24 months after CXL. The refractive cylinder improved by 0.4 to 0.7 diopters. Endothelial cell density decreased by 225 cells per square millimeter in the first 3 months and thereafter returned to normal. Corneal thickness was reduced by 10 to 20 μm in the year following CXL but not after 24 months. No changes in intraocular pressure were noted. CXL is a safe and effective method for halting the deterioration of KCN, while slightly improving visual function.

Corneal collagen cross-linking for progressive keratoconus in patients aged 9 to 14

Purpose: To determine the safety and efficacy of corneal collagen cross-linking (CXL) for progressive keratoconus in patients aged between 9 and 14 years old. Methods: Sixteen eyes of 11 patients (8 male and 3 female) with progressive keratoconus underwent epithelium-off CXL according to the standard Dresden protocol. Mean follow-up was 26 months (range, 12 to 60 months). Pre- and postoperative examinations included: uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, tonometry, refraction, corneal pachymetry, and endothelium cell count. Results: At the last follow-up visit, BSCVA improved by at least one Snellen line in six eyes (37.5%) and remained stable in nine eyes (56.25%). Two eyes (12.5%) in habitual eye rubbers required a re-treatment due to keratoconus progression, at 15 and 28 months after first CXL. Manifest refraction and endothelium cell count remained stable. Topographic results showed statistically significant improvement in maximum K readings up to two years after CXL. However, this lost significance over time. No intraoperative complications were observed. Two eyes (12.5%) presented grade one haze, which regressed after a month of topical steroid therapy. Conclusion: In this study of selected patients aged 9 to 14, CXL was a safe and effective option for the treatment of progressive keratoconus. However, the effect in stemming the disease may not be long lasting and may require retreatment. A larger sample size and longer follow-up time are needed to verify this trend.

Corneal Collagen Cross-Linking for Infectious Keratitis: A Systematic Review and Meta-Analysis.

To assess the efficacy of corneal collagen cross-linking (CXL) in the management of infectious keratitis. Comprehensive literature search was performed in MEDLINE/PubMed and Cochrane Central Register of Controlled Trials using combinations of the following search terms: "corneal collagen cross linking" or "photoactivated riboflavin" or "UVA light and riboflavin" and "infectious keratitis" or "corneal ulcer." Last search was on March 19, 2015. Extracted data from individual studies were summarized and summary proportions of eyes healed and complications for different subgroups were estimated. Twenty-five studies were included (2 randomized controlled trials, 13 case series, and 10 case reports) with a total of 210 eyes of 209 patients, of which 175 eyes underwent CXL. Causative microorganisms were bacteria, fungi, acanthamoeba, and Herpes simplex virus in 96, 32, 11, and 2 cases, respectively. Coinfections were present in 13 and cause was inconclusive in 21 cases. Sixteen of 175 eyes received no additional antibiotics, whereas 159 underwent CXL as an adjunct to antimicrobial treatment. Proportion of eyes healed with CXL was 87.2% (95% confidence interval (CI), 81.9%, 91.8%). For bacterial keratitis, the proportion of eyes healed was 85.7% (95% CI, 78.5%, 91.7%), whereas 10/11 and 25/32 eyes with acanthamoeba and fungal keratitis, respectively, were healed (available data not sufficient to provide a valid proportion analysis). Treatment resulted in corneal melting and tectonic keratoplasty in both Herpes simplex virus cases. CXL seems promising in the management of infectious keratitis, excluding viral infections. However, more randomized controlled trials are required to assess its efficacy.

This issue of ACTA, printed and electronic

The cover illustration is a schematic drawing showing surgical technique for retinal vein cannulation and tissue plasminogen injection. This is reported by van Overdam et al. in this issue of Acta. Chan et al. in China review conflicting reports on the efficacy of corneal collagen cross-linking in infectious keratitis. Klefter et al. in Denmark measure increased retinal oxygen extraction in hyperglycaemia in patients with diabetes. van den Akken-van Marle et al. in Leiden recommend a risk factor guided screening programme for retinopathy of prematurity. Lin et al. in Taiwan correlate diabetic polyneuropathy and retinopathy in a nationwide study. vRezar et al. in Vienna report long-term benefits from anti-VEGF treatment for macular oedema in BRVO. Early treatment gives better visual outcome. Hautamäki et al. in Helsinki suggest that interleukin-8 may play a role in neovascularization in AMD. Fauser et al. in Köln measured elevated local inflammatory cytokines in neovascular AMD eyes. van Overdam et al. in Rotterdam show a surgical technique for retinal vein cannulation and tissue plasminogen injection in CRVO. Peters et al. in Sweden associate visual field index under 50% and/or mean defect worse than 18 dB with poor quality of life. Matlach et al. in Germany find trabeculectomy to reduce IOP more than canaloplasty, but with more complications. Rönnback et al. in Copenhagen and Singapore find genotype–phenotype heterogeneity in autosomal dominant optic atrophy. Mathew et al. in Houston and Uppsala find lamellar splitting in histological examination of keratoconus. Ekström and Taube in Uppsala suggest that pseudoexfoliation is a risk factor for cataract formation. Aclimandos et al. in UK, Belgium, France and Switzerland inform us about EBO's subspeciality examinations. Pérez-Cambrodí et al. in Spain and Poland review cataract aspiration with hollow needle in antiquity. The following articles are published in the electronic issue of ACTA and are accessible on www.actaophtalmologica.com, where you can also access the printed articles. Anitua et al. in Spain and USA examine the use of blood derived formulations used for the treatment of ocular surface disorders. Aptel et al. in France find great variation in progression visual field damage in POAG. Pillunat et al. in Germany stress nocturnal blood pressure dips in patients with glaucoma and relate this to daytime blood pressure measurements. Hussnain et al. in USA found more decline in corneal hysteresis in patients with glaucoma, but diabetes had no impact. Sheu et al. in Taiwan examined the effect of anti-VEGF drugs on retinal pigment epithelial cells and found variable effects on mitochondrial bioenergetics. Murakami et al. in Japan found reduced blood flow in macula to be associated with visual deterioration. Achiron et al. in Israel quantify metamorphopsia in DME and other macular diseases. Petrovic et al. in Slovenia and Czeck Republic relate a gene for reactive oxygen species modulation to the progression of diabetic retinopathy. García et al. in Spain and USA confirm the role of complement factor H gene in AMD and found variable effects of different haplotypes. Vagge et al. in Italy used near-infrared reflectance to image choroidal lesions in neurofibromatosis. Stemplewitz et al. in Germany found reduce macular volume and retinal nerve fibre thickness in patients with Parkinson's disease. Hoskin et al. in Australia emphasize the risk of fishing accidents and the need for eye protection. Vestergaard et al. in Odense find penetrating eye injuries to be most common in young men. Kuiper et al. in Utrecht discuss aqueous humour versus vitreal measurements of interleukins in diagnosis of ocular lymphoma. Tachibana et al. in Japan find improvement in horizontal but not vertical metamorphopsia following epiretinal membrane peeling. Suh et al. in Korea connect a connective tissue growth factor gene with pseudoexfoliation. Tode et al. in Germany use anti-interleukin-6 treatment for necrotizing scleritis. Örnek et al. in Turkey report transient thinning of choroid with bevacizumab injections for DME. Fonollosa et al. in Spain used a kinase inhibitor, vemurafenib to treat macular oedema in uveitis. Schäffer et al. in Austria relate anterior vitreous attachment and pseudophakic retinal detachments. I wish you a Merry Christmas, happy holidays and a prosperous New Year!

Efficacy of Primary Collagen Cross-Linking with Photoactivated Chromophore (PACK-CXL) for the Treatment of Staphylococcus aureus-Induced Corneal Ulcers.

To evaluate the efficacy of corneal collagen cross-linking (CXL) with photoactivated riboflavin (PACK-CXL) as primary therapy for Staphylococcus aureus-induced corneal ulcers in a rabbit model. The right eye of 40 rabbits was inoculated with S. aureus to induce formation of central corneal ulcers (day 1). The ulcer was examined on day 5, and rabbits were randomly assigned to 4 groups-group A: no treatment (control); group B: topical antibiotic treatment (cefazolin 50 mg/mL, garamycin 14 mg/mL drops, chloramphenicol 5% ointment every 2 hours); group C: PACK-CXL; group D: PACK-CXL + topical antibiotics. Follow-up by biomicroscopy was performed on day 5 and then every week for 1 month. The main outcome measures included infiltrates or the scar diameter, time to healing, time to full epithelialization, and a change in corneal thickness. After 1 month of treatment, group C ulcers had the smallest mean scar diameter (8.8 mm), followed by groups D (11.2 mm), B (13.0 mm), and A (24.5 mm) (P = 0.011). Group C had the shortest mean healing time (15.5 days), followed by groups D (17.2 days), B (19.7 days), and A (21.8 days). Analysis of relative reduction in the infiltrate size from day 5 yielded better results for groups C (P = 0.039) and D (P = 0.034) than those of group B. We demonstrate a beneficial effect of PACK-CXL as primary treatment, either as stand-alone or as an adjuvant to antimicrobial therapy.

Efficacy of corneal collagen cross-linking for treatment of keratoconus: a meta-analysis of randomized controlled trials.

ObjectiveTo evaluate the efficacy of corneal collagen cross-linking (CXL) for the treatment of keratoconus.MethodsWe performed a literature search for randomized controlled trials that assessed the effect of CXL in slowing progression of keratoconus. The primary outcome measures included changes of topographic parameters, visual acuity, and refraction. Efficacy estimates were evaluated by weighted mean difference (WMD) and 95% confidence interval (CI) for absolute changes of the interested outcomes.ResultsSignificant decrease in mean keratometry value, maximum keratometry value and minimum keratometry value were demonstrated in the CXL group compared with the control group (WMD = -1.65; 95% CI: -2.51 to -0.80; P < 0.00001; WMD = -2.05; 95% CI: -3.10 to -1.00; P < 0.00001; WMD = -1.94; 95% CI: -2.63 to -1.26; P < 0.00001; respectively). Best spectacle-corrected visual acuity improved significantly in CXL group (WMD = -0.10; 95% CI: -0.15 to -0.05; P < 0.00001), whereas uncorrected visual acuity did not differ statistically. Manifest cylinder error decreased significantly in patients undergoing CXL procedure compared with control patients in sensitivity analysis (WMD = -0.388; 95% CI: -0.757 to -0. 019; P = 0.04). The changes in central corneal thickness and intraocular pressure were not statistically significant.ConclusionCXL may be an effective option in stabilizing keratoconus. Further long-term follow-up studies will be necessary to assess the persistence of CXL.

Corneal collagen crosslinking for progressive keratoconus in Saudi Arabia: One-year controlled clinical trial analysis

AimsTo determine the short-term efficacy of corneal collagen crosslinking (CXL) treatment in patients with progressive Keratoconus (KCN) in comparison with no treatment. Settings and designThis controlled clinical trial study was carried out at a tertiary eye hospital, Eastern Province, Saudi Arabia. Methods and materialA prospective controlled clinical study of patients being treated for Keratoconus at a tertiary eye care hospital in the Eastern province of Saudi Arabia. 51 eyes of 43 patients with progressive KCN who received corneal collagen crosslinking (treatment group) and 50 eyes of 34 patients with KCN and no treatment (control group) were included in our study. A one year clinical data were collected preoperatively as well as at 1, 3, 6 and 12months postoperatively for the treatment group patients. A baseline and 1year clinical data were collected for the control group patients. The short-term efficacy of the treatment in preventing progression of KCN in comparison with no treatment was analysed at one year. ResultsAt one year after crosslinking there was significant flattening of the average keratometry by 0.61D (p=0.001) [95% CI: 0.25, 0.97] compared to 0.40D (p=0.210) steepening in the control group; difference between treatment and control was 1.01D (p=0.006) [95%CI: 0.29, 1.72]. Pachymetry in treatment group thinned by 20.21μm (p<0.0001) [95% CI: 12.77, 27.66] compared to 0.32μm (p=0.912) in the control group. Visual acuity remained stable at the preoperative level of 20/30 (p=0.397) in the treatment group and 20/40 (p=0.553) in the control group at one year. ConclusionsCorneal CXL is an effective treatment for halting the progression of KCN as shown by reduced keratometry and stability of vision.

Long-term efficacy of corneal collagen cross-linking in patients with progressive keratoconus

to study the efficacy of corneal collagen cross-linking in patients with progressive keratoconus over longer (up to 2 years) follow-up periods. A total of 52 patients (104 eyes) aged 23-34 years with stage I-III progressive keratoconus were enrolled. Besides routine examinations (automatic refractometry, uncorrected and best corrected visual acuity (UCVA and BCVA) evaluation, pneumatic tonometry), Pentacam keratotopography and pachymetry ("Oculus", Germany) were performed in all cases. Corneal biomechanical properties were assessed with an Ocular Response Analyzer ("Reichert", USA). In all patients cross-linking procedure was carried out in the eye with more advanced keratoconus, the fellow eye being used as the control. Judging from the results of UCVA and BCVA evaluation, keratotopography, and pachymetry obtained 2 years after the standard corneal cross-linking procedure, stabilization has been achieved in 97% of cases. In the remaining 3% of eyes corresponding parameters declined, although to a lesser extent than in the controls. Indices describing biomechanical properties of the cornea, such as corneal hysteresis, corneal resistance factor, as well as elastonometry results did not differ significantly throughout the whole observation period, which agrees with literature data. Corneal collagen cross-linking has been proved capable of stopping keratoconus progression in most of the patients (97%). Further studies with even longer follow-up periods are needed.

Corneal Collagen Cross-linking for Treatment of Non-healing Corneal Ulcers.

Purpose:To evaluate the efficacy of corneal collagen cross-linking (CXL) for treatment of corneal ulcers not responding to antimicrobial therapy.Methods:Eight patients with corneal ulcers associated with corneal melting, not responding to conventional antibiotic therapy, were treated with CXL. The procedure was performed according to the standardized protocol for keratoconus. Preoperative medications were continued after CXL in all cases. Microbiological exams revealed Pseudomonas aeruginosa in 3 cases. Follow up continued from 1 to 10 months.Results:In 6 of 8 eyes, progression of corneal melting was halted and complete epithelialization occurred. In one eye emergency keratoplasty was needed due to corneal perforation. A conjunctival flap was performed to treat severe localized corneal thinning in one of the patients a few days after CXL. Significant clinical improvement occurred in all cases of Pseudomonas aeruginosa keratitis.Conclusion:CXL can be considered as a promising new treatment in the management of refractory non-healing corneal ulcers, including Pseudomonas aeruginosa keratitis.

An Update on the Safety and Efficacy of Corneal Collagen Cross-Linking in Pediatric Keratoconus.

Keratoconus is a degenerative disease that affects adolescents and young adults and presents with variable thinning and conical deformation of the corneal apex. The resultant irregular astigmatism can progress to levels that can significantly affect everyday activities and overall quality of life. Therefore, stopping the progression of the disease is an essential part in managing patients with keratoconus. Corneal collagen cross-linking is a minimally invasive procedure that stiffens the anterior corneal stroma by creating strong covalent bonds between collagen fibrils. Over the past decade, many studies have proved its safety and efficacy in halting keratoconus progression in adults. This review of the literature highlights the growing trend towards using this treatment in pediatric keratoconic patients. In children, keratoconus tends to be more severe and fast progression is often encountered requiring closer follow-up intervals. Standard cross-linking shows comparable results in children with a good safety-efficacy profile during follow-up periods of up to three years. Further research is needed to standardize and evaluate transepithelial and accelerated cross-linking protocols as these could be of tremendous help in a population where cooperation and compliance are major issues.

Transepithelial corneal collagen crosslinking for keratoconus: Six-month results

To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) using a transepithelial technique to treat keratoconus. Cornea and refractive surgery subspecialty practice. Prospective clinical trial. Transepithelial CXL was performed in eyes with keratoconus using proparacaine with benzalkonium chloride (BAK) 0.01% to facilitate riboflavin absorption and riboflavin 0.10% without dextran. Eyes were randomized to receive ultraviolet-A treatment (365 nm, 3 mW/cm(2)) with concurrent administration of riboflavin randomized to every 1 minute or every 2 minutes for 30 minutes. The principal outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities and topography-derived maximum keratometry (K) values. Patients were followed for 6 months. Thirty eyes of 25 patients were treated. The mean maximum K value flattened by 0.9 diopter (D) (baseline 58.7 D; 6 months 57.8 D) (P=.01). The maximum K worsened by 2.0 D or more in 1 patient. The mean CDVA improved by 0.83 Snellen lines (P=.03). One patient lost 2 lines of CDVA. There were no differences in the UDVA, CDVA, or keratometry outcomes between the 1-minute instillation subgroup and the 2-minute instillation subgroup. Transepithelial CXL resulted in a statistically significant improvement in maximum K values and CDVA at the 6-month follow-up. Further follow-up is necessary to ascertain the ability of transepithelial CXL to achieve long-term stabilization of the cornea in eyes with keratoconus.

One-year clinical study on efficacy of corneal cross-linking in Indian children with progressive keratoconus.

The aim of this study was to assess the efficacy of corneal collagen cross-linking (CXL) with riboflavin using ultraviolet-A light in children with progressive keratoconus. Thirty-five eyes of 24 children with progressive keratoconus aged between 9 and 16 years were included in this retrospective study. Ocular examination included the best-corrected visual acuity (BCVA), dilated refraction, slit-lamp exam, and corneal topography (Orbscan II) at 6 and 12 months. All children were treated with riboflavin with ultraviolet-A light under topical anesthesia and all completed 1-year follow-up. The mean age of the children was 13.65 years (range, 9-16 years). Follow-up was for a period of 1 year. The mean of preoperative keratometry (Kmax) was 55.11 ± 5.34 diopters (D), whereas the mean of postoperative Kmax was reduced to 53.87 ± 4.99 D. The mean preoperative pachymetry was 412.31 ± 36.54 μm, which changed to 361.31 ± 58.04 μm postoperatively. At 1 year, improvement in the BCVA was noted in 18 (51.42%) eyes, stabilization in 12 (34.28%), and worsening in 5 (14.28%) eyes. Overall, the BCVA improved by 1 line, which was statistically significant (P = 0.0368) at the end of 1 year. There was a reduction in both cylindrical and spherical equivalent, of which, the latter was not statistically significant (P = 0.77), whereas the former was of weak statistical significance (P = 0.061). No complications were reported. CXL with riboflavin is an effective procedure for children with progressive keratoconus. The results show stabilization, improvement, or both in keratoconus in terms of BCVA and corneal curvature after CXL in most children.

Outcome of corneal collagen crosslinking for progressive keratoconus in paediatric patients.

Purpose. To evaluate the efficacy of corneal collagen crosslinking for progressive keratoconus in paediatric patients. Methods. This prospective study included 25 eyes of 18 patients (aged 18 years or younger) who underwent collagen crosslinking performed using riboflavin and ultraviolet-A irradiation (370 nm, 3 mW/cm2, 30 min). Results. The mean patient age was 14.3 ± 2.4 years (range 8–17) and mean followup duration was 20.1 ± 14.25 months (range 6–48). Crosslinked eyes demonstrated a significant reduction of keratometry values. The mean baseline simulated keratometry values were 46.34 dioptres (D) in the flattest meridian and 50.06 D in the steepest meridian. At 20 months after crosslinking, the values were 45.67 D (P = 0.03) and 49.34 D (P = 0.005), respectively. The best spectacle corrected visual acuity (BSCVA) and topometric astigmatism improved after crosslinking. Mean logarithm of the minimum angle of resolution (logMAR) BSCVA decreased from 0.24 to 0.21 (P = 0.89) and topometric astigmatism reduced from mean 3.50 D to 3.25 D (P = 0.51). Conclusions. Collagen crosslinking using riboflavin and ultraviolet-A is an effective treatment option for progressive keratoconus in paediatric patients. Crosslinking stabilises the condition and, thus, reduces the need for corneal grafting in these young patients.

Efficacy of Corneal Collagen Crosslinking with Riboflavin and Ultraviolet A in Progressive Keratoconus

Purpose: To analyze the efficacy of Corneal Collagen Crosslinking with Riboflavin and Ultraviolet- A in progressive Keratoconus.

Anatomical and functional changes in the cornea and retina after ultraviolet-A riboflavin cross-linking in patients with keratoconus

PurposeThe aim of this study was to evaluate the efficacy of corneal collagen cross-linking in stabilization of the keratoconus and the safety of the procedure in the cornea and retina.DesignThis study is a prospective interventional case series study.Patients and methodsThe study included 19 eyes of 19 patients with grade II-III keratoconus. All of them were treated with riboflavin ultraviolet-A collagen cross-linking. The patients were followed up monthly for 6 months. Examination of each patient included evaluation of the uncorrected visual acuity, best-corrected visual acuity, and spherical equivalent; endothelial cell counting; anterior segment optical coherence tomography using a corneal Scheimpflug camera; posterior segment assessment by fluorescein angiography; posterior segment optical coherence tomography; and multifocal electroretinography.ResultsUncorrected visual acuity and best-corrected visual acuity showed statistically significant improvement. The mean improvement in spherical equivalent was 1.5 (΁1.0) D. The K-value at the apex significantly decreased (the mean decrease was 1.40 D). There was a significant decrease in the corneal pachymetry at the thinnest location at the first month postoperatively; however, at 3 months postoperatively, the corneal pachymetry increased gradually, reaching stability at the end of the follow-up period. There was a significant increase in the mean intraocular pressure of the treated eyes. Of the treated eyes, 13 showed a demarcation line at a depth of 300 ΁ 10.5 mm. The preoperative mean endothelial cell count showed a statistically significant decrease. Retinal fluorescein angiography, optical coherence tomography, and multifocal electroretinography at the foveal ring showed no abnormalities in the riboflavin-treated eyes.ConclusionCorneal collagen cross-linking is an effective procedure in stopping the progress of keratoconus and is safe for both anterior and posterior segments.

Results of Corneal Collagen Cross-linking in Pediatric Patients

To evaluate the safety and efficacy of corneal collagen cross-linking (CXL) in the treatment of keratoconus in pediatric patients. Epithelium-off CXL using the standard protocol was performed in 15 eyes from 15 patients (age range: 10 to 15 years) with moderate keratoconus in 1 eye and advanced disease in the fellow eye. Principal outcomes included uncorrected and corrected distance visual acuity (CDVA), refraction, and topography-derived outcomes of maximum and average keratometry (K). Mean uncorrected distance visual acuity improved significantly from 1.00 ± 0.30 (20/200) to 0.72 ± 0.29 (20/100) logMAR (P=.035) and mean CDVA from 0.56 ± 0.21 (20/70) to 0.30 ± 0.15 (20/40) logMAR (P=.003) at the end of 12 months. Mean change in apical K (1.01 ± 2.40 diopters) was also significant (P=.004). No significant complications were noted. Corneal collagen CXL was found to be safe and effective in the first 12 months for keratoconus in children with similar initial efficacy as in adults in terms of improvement in visual and topographic outcomes.

Progression of Keratoconus and Efficacy of Corneal Collagen Cross-linking in Children and Adolescents

To study the progression rate of keratoconus and assess the clinical outcome of corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A light in children and adolescent patients up to 3 years after treatment. Fifty-nine eyes from 42 children and adolescents (aged 9 to 19 years) with confirmed keratoconus were included in this retrospective interventional cohort study. Refraction, slit-lamp examination, Placido-based corneal topography, and Scheimpflug imaging were performed bilaterally in all patients preoperatively and at 6 and 12 months postoperatively. Maximal keratometry readings (Kmax), corrected distance visual acuity (CDVA), corneal thickness, and the keratoconus index (KI) were analyzed. Follow-up was up to 36 months (mean follow-up: 26.3 months [range: 12 to 36 months]). Fifty-two of the 59 eyes enrolled in this study showed progression, corresponding to a progression rate of 88%. Forty-six eyes were treated by CXL. Maximal keratometry, CDVA, and KI showed significant changes over the follow-up period. However, significant Kmax reduction observed up to 24 months after CXL lost significance at 36 months. Cross-linking seems to be safe in children and adolescents. Progression of keratoconus occurred in 88%. We propose that awaiting documentation of progression is not mandatory and CXL in children and adolescents should be performed as soon as the diagnosis has been made. However, the effect of arrest of disease progression might not be as long-lasting as in adults and longer follow-up is needed to verify this trend.

Collagen cross-linking for resistant corneal ulcer

Corneal ulcer is a devastating corneal disease which is potentially sight-threatening and conventionally is treated by topical antibiotics and in some cases with more invasive procedures such as keratoplasty. The aim of this study is to evaluate the efficacy of corneal collagen cross-linking in resistant corneal ulcers. Ten patients with resistant infectious corneal ulcers who had not responded properly to maximal treatment with topical and subconjunctival antibiotics were enrolled in the study and underwent classic corneal collagen cross-linking with riboflavin and UV-A under sterile conditions in the operating room and were followed up regularly. The result was healing and scar formation with improvement of vision in all patients except for two who underwent enucleation and tectonic penetrating keratoplasty. Corneal collagen cross-linking is a viable therapeutic option for treatment of corneal ulcers and can be used as an adjuvant for conventional treatment in resistant cases.

Safety and Efficacy of Simultaneous Corneal Collagen Cross-linking With Topography-guided PRK in Managing Low-grade Keratoconus: 1-year Follow-up

To evaluate 1-year visual and topographic outcomes and safety and efficacy of corneal collagen cross-linking (CXL) combined with topography-guided photorefractive keratectomy (TG-PRK) to achieve near emmetropia in eyes with low-grade keratoconus. Twenty-two eyes from 15 patients (11 women, 4 men) were included in a prospective, nonrandomized, noncontrolled clinical study. Mean patient age was 26.6±6.07 years (range: 19 to 40 years). Inclusion criteria were low-grade keratoconus with evidence of progression, transparent cornea, corrected distance visual acuity (CDVA) 0.8 (decimal) or better, corneal thickness >440 μm, and maximum keratometry readings (K-max) <51.00 diopters (D). All patients underwent simultaneous TG-PRK with CXL. Study parameters were uncorrected distance visual acuity, CDVA, manifest refractive error, manifest and topographic (corneal) astigmatism, patient satisfaction, and efficacy and safety of the treatment. Follow-up was 1 year. After 1 year, statistically significant improvement was noted in all study parameters (P<.01). The safety and efficacy indices were 1.6 and 0.4, respectively. Patient satisfaction questionnaire showed that 91% were satisfied, 9% were not completely satisfied but believed they improved, and none were dissatisfied. Corneal topography demonstrated significant improvement in 55%, improvement in 36%, and minor improvement in 9% of cases. No cases progressed as evidenced by keratometry readings. Simultaneous TG-PRK with CXL is an effective and safe treatment with remarkable visual and topographic outcomes in patients with low-grade keratoconus who meet the recommended inclusion criteria.