Crosslinking treatment of progressive keratoconus: new hope.
ABSTRACT A new method has been introduced for the treatment of progressive keratoconus using collagen crosslinking by the photosensitzer riboflavin and ultraviolet A-light. Biomechanical measurements have shown an impressive increase in corneal rigidity of 328.9% in human corneas after crosslinking.
The 3 and 5-year results of the Dresden clinical study have shown that in all treated 60 eyes the progression of keratoconus was at least stopped ('freezing'). In 31 eyes there also was a slight reversal and flattening of the keratoconus by up to 2.87 diopters. Best corrected visual acuity improved slightly by 1.4 lines. So far, over 150 keratoconus patients have received crosslinking treatment in Dresden. Laboratory studies have revealed that the maximum effect of the treatment is in the anterior 300 mum of the cornea. As for the corneal endothelium, a cytotoxic level for endothelium was found to be 0.36 mW/cm which would be reached in human corneas with a stromal thickness of less than 400 mum.
Collagen crosslinking by the photosensitzer riboflavin and ultraviolet A-light is an effective means for stabilizing the cornea in keratoconus. Collagen crosslinking might become the standard therapy for progressive keratoconus in the future diminishing significantly the need for corneal transplantation. Preoperative pachymetry and individual control of the ultraviolet A-irradiance before each treatment are mandatory. The treatment parameters must not be varied.
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ABSTRACT: Anterior segment optical coherence tomography (AS-OCT) was recently developed and has become a crucial tool in clinical practice. AS-OCT is a noncontact imaging device that provides the detailed structure of the anterior part of the eyes. In this review, the author will discuss the various clinical applications of AS-OCT, such as the normal findings, tear meniscus measurement, ocular surface disease (e.g., pterygium, pinguecula, and scleromalacia), architectural analysis after cataract surgery, post-LASIK keratectasia, Descemet’s membrane detachment, evaluation of corneal graft after keratoplasty, corneal deposits (corneal dystrophies and corneal verticillata), keratitis, anterior segment tumors, and glaucoma evaluation (angle assessment, morphological analysis of the filtering bleb after trabeculectomy, or glaucoma drainage device implantation surgery). The author also presents some interesting cases demonstrated via AS-OCT.Journal of Ophthalmology 02/2015; 2015. DOI:10.1155/2015/605729 · 1.94 Impact Factor
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ABSTRACT: To compare the 6-month results of accelerated and standard collagen crosslinking (CXL) treatment of progressive keratoconus. Noor Eye Hospital, Tehran, Iran. Prospective randomized clinical trial. Two groups of eyes (intervention and control) received corneal collagen crosslinking (CXL) treatment. The intervention group received accelerated CXL (18 mW/cm(2), 5 minutes), and the control group received standard CXL (3 mW/cm(2), 30 minutes). The eyes were evaluated for changes in the visual indices, refraction, and topography preoperatively and 1, 3, and 6 months postoperatively and regarding corneal rigidity indices and the endothelial cell count (ECC) preoperatively and at 6 months. The study evaluated 62 eyes (31 patient) in 2 groups. The mean changes in uncorrected (P = .733) and corrected (P = .646) distance visual acuities and manifest refraction spherical equivalent (P = .598) did not differ statistically significantly between the 2 groups. The central corneal thickness was higher in the standard group than the accelerated group (P = .025). The mean decrease in the maximum keratometry (K) (P = .865) and mean K (P = .974) and the mean changes in the asphericity (P = .272) were not statistically significantly different between the 2 groups. The mean changes in corneal hysteresis (CH) (P = .548) and the corneal resistance factor (CRF) (P = 1.000), CH-CRF (P = .282), and the area under the peak 2 (P = .260) were similar in both groups. The mean decrease in the ECC was not statistically significantly different between the 2 groups (P = .218). Based on 6-month results, accelerated and standard corneal CXL arrested the progression of keratoconus similarly. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015. Published by Elsevier Inc.Journal of Cataract and Refractive Surgery 03/2015; 41(3):533-40. DOI:10.1016/j.jcrs.2014.07.030 · 2.55 Impact Factor
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ABSTRACT: Corneal cross-linking (CXL) with riboflavin and ultra-violet A is less invasive in comparison with other procedures such as penetrating keratoplasty. Hence, we planned this study to evaluate the efficacy of CXL in disease progression and to compare keratoconus indices before and 1 year after cross-linking by Pentacam. In this prospective clinical trial, we enrolled 37 eyes of 37 patients suffering from keratoconus who were candidates for CXL. All eyes were examined before and one 1 year after surgery with a slit lamp and Pentacam for corneal topography. To compare the mean of each Pentacam parameter and index before and 1 year after the surgery, we used paired t-test. There were 23 males and 14 females. The mean age was 21.5 years 18-30 years). At the 12(th) month examination, the corneal thickness had decreased (P = 0.0068) and the Index of Height Decentration (IHD) had increased (P = 0.016). There were no statistically significant differences in other indices and parameters 1 year after CXL. Most of the parameters and indices had not changed during 1 year after CXL. The procedure seems to be effective in stopping the disease progression at least for 12 months after surgery.01/2015; 4(1). DOI:10.4103/2277-9175.151886