0
selected
-
1.
A case of in vivo iontophoresis-assisted corneal collagen cross-linking for keratoconus: An immunohistochemical study.
Manetti, M, Favuzza, E, Sgambati, E, Mencucci, R, Marini, M
Acta histochemica. 2017;(3):343-347
Abstract
The standard corneal collagen cross-linking (CXL), that includes the removal of corneal epithelium to permit adequate penetration of riboflavin in the stroma, is an established procedure to halting keratoconus progression. However, as epithelial removal may cause postoperative pain and an increased risk of corneal infection, new therapeutic approaches have been proposed. Iontophoresis is a recently developed non-invasive technique which provides the use of electrical current during CXL to enhance transepithelial penetration of riboflavin into the corneal stroma. Here, we describe for the first time the morphological changes of the corneal stromal compartment in a patient with keratoconus who underwent in vivo iontophoresis-assisted CXL (ionto-CXL) before full-thickness corneal transplantation. Immunohistochemistry for type I collagen and CD34 was performed to investigate the stromal distribution of collagen fibers and keratocytes, respectively. The histology of ionto-CXL-treated keratoconic cornea, collected 6 months after the intervention, was compared with that of healthy corneas and either untreated or standard CXL-treated keratoconic corneas. An attempt to restore a normal stromal architecture was observed in the ionto-CXL-treated cornea compared with untreated keratoconic corneas. In particular, the ionto-CXL-treated cornea showed a parallel distribution of type I collagen fibers, although fiber interweaving appeared less organized than in healthy corneas and standard CXL-treated keratoconic corneas. Moreover, the distribution of CD34-positive keratocytes was improved in keratoconic corneas following ionto-CXL treatment, though a scattered CD34 immunoreactivity was still noticeable in the subepithelial stroma. This study provides histological evidence that ionto-CXL may represent a non-invasive alternative in the management of progressive keratoconus in adults.
-
2.
Additive effect of repeated corneal collagen cross-linking in keratoconus.
Hafezi, F, Tabibian, D, Richoz, O
Journal of refractive surgery (Thorofare, N.J. : 1995). 2014;(10):716-8
Abstract
PURPOSE To report the long-term clinical outcome in a patient diagnosed as having bilateral progressive keratoconus who received a single corneal collagen cross-linking (CXL) treatment in the right eye and repeated CXL in the left eye. METHODS Observational case report. Topographical changes were assessed by high-resolution Scheimpflug imaging. The right eye underwent a standard epithelium-off CXL procedure in February 2008, followed by the left eye 4 weeks later. In 2012, the left eye was treated with CXL for a second time. Irradiation was performed in all cases at a fluence of 5.4 J/cm². Energy settings were 30 minutes @ 3 mW/cm² for the CXL procedures performed in 2008, and 10 minutes @ 9 mW/cm² for the second CXL procedure of the left eye that was performed in 2012. RESULTS The right eye that underwent a single CXL procedure showed a flattening of keratometry values between 2008 and 2012, followed by stabilization. The left eye showed a similar flattening effect between 2008 and 2012, followed by another flattening effect after the second CXL procedure and accompanied by a distinct increase in corrected distance visual acuity. CONCLUSIONS Following repeated CXL, the corneal stroma and endothelium remained inconspicuous, and postoperative haze and visibility of the stromal demarcation line was similar to what is usually observed after a single CXL procedure. Whether the additive flattening effect of the anterior surface observed in this single case goes along with an additive increase in biomechanical stiffness remains to be seen.
-
3.
Riboflavin-responsive multiple Acyl-CoA dehydrogenation deficiency in 13 cases, and a literature review in mainland Chinese patients.
Zhu, M, Zhu, X, Qi, X, Weijiang, D, Yu, Y, Wan, H, Hong, D
Journal of human genetics. 2014;(5):256-61
Abstract
Multiple Acyl-CoA dehydrogenation deficiency (MADD) is an autosomal recessive disorder of fatty acid oxidation and amino-acid metabolism. Most patients with late-onset MADD are well responsive to treatment with riboflavin, which is also termed as riboflavin-responsive MADD (RR-MADD). In this study, we summarized the clinical profiles and genetic features of 13 Chinese patients with RR-MADD and reanalyzed the existing data on RR-MADD patients in Mainland China. In a cohort comprising 13 patients, all were seen to present with severe muscular symptoms occasionally accompanied with mild involvements of extramuscular organs. A total of 18 mutations (13 reported and 5 novel) of the ETFDH gene were identified in this series of patients. Exon deletion/duplication was not found in all patients. ETF:QO expression from the muscle specimens was significantly decreased in all patients. At the time of this study the total number of RR-MADD cases had reached 148 in Mainland China since 2009. The muscle symptoms in Mainland China were similar to those in other regions. However, the common extramuscular symptoms were fatty liver and recurrent vomiting in mainland Chinese patients rather than encephalopathy found in Caucasian patients. A total of 68 mutations had been identified in 148 patients with RR-MADD. The c.250G>A had a high mutation frequency in Southern China, whereas c.770A>G and c.1227A>C were more geographically widespread hot spot mutations in Mainland China.
-
4.
Histological findings in a failed corneal riboflavin-UVA collagen cross-linking performed for progressive keratoconus.
Pecorella, I, Appolloni, R, Tiezzi, A, Plateroti, P, Plateroti, R
Cornea. 2013;(2):191-5
Abstract
PURPOSE To report the histological and immunohistochemical findings in a cornea removed from a patient who had undergone collagen cross-linking (CXL) with riboflavin and ultraviolet-A for progressive keratoconus. CXL was performed following the Siena protocol. Two years post-CXL, a visual acuity impairment in the treated eye secondary to corneal stromal opacity had occurred, together with corneal thinning and flattening. METHODS The excised cornea was formalin-fixed, paraffin-embedded, and examined microscopically. Deparaffinized 4-μm sections were stained with hematoxylin-eosin and Masson trichrome. Further tissue sections were subjected to immunohistochemical evaluation of CD34 and Ki-67 antigens. RESULTS Histologically, there was no scar tissue in the failed cornea. The biomicroscopic stromal opacity corresponded microscopically to an acellular area, devoid of keratocytes, and to compaction of the lamellar collagen. Amorphous, weakly eosinophilic interlamellar deposits, extending from the anterior to the posterior two thirds of the stroma, were noted. CONCLUSIONS CXL is a promising procedure for the treatment of progressive keratoconus with minimal reported side effects. In the present case, we speculate that the short corneal soaking time (15 minutes according to the Siena protocol) may have resulted in inefficient ultraviolet-A blocking, thermal injury, and deeper keratocyte death. Inadequate keratocyte stem cells reservoir could also play a role in individual cases.
-
5.
Endothelial failure after collagen cross-linking with riboflavin and UV-A: case report with literature review.
Bagga, B, Pahuja, S, Murthy, S, Sangwan, VS
Cornea. 2012;(10):1197-200
Abstract
PURPOSE To report a case of endothelial decompensation after a collagen cross-linking (CXL) procedure for keratoconus. METHODS An 18-year-old boy had CXL for keratoconus in the right eye. He developed keratouveitis with generalized corneal edema seen 3 weeks after the procedure. Polymerase chain reaction for aqueous humor Herpes simplex virus was negative. The patient was treated with topical steroids. Specular microscopy revealed mildly reduced density of endothelial cells. On follow-up to 6 months, corneal edema increased with the formation of epithelial bullae. Penetrating keratoplasty was performed. Possible causes for this complication are discussed. RESULTS Clinical and histopathological analyses revealed generalized loss of endothelial cells along with signs of inflammation. CONCLUSIONS Although it is considered very safe, collagen CXL can cause severe keratouveitis and endothelial failure.
-
6.
Post-transplant headache: benefit from riboflavin.
Stracciari, A, D'Alessandro, R, Baldin, E, Guarino, M
European neurology. 2006;(4):201-3
Abstract
Post-transplant headache is a recognized complication of organ transplantation. Its treatment can sometimes be problematic given the status of the patient and the risk of drug interference. Six organ-transplanted patients (5 liver and 1 heart) experiencing post-transplant headache were successfully treated with riboflavin 200 mg daily. The drug proved safe and well tolerated and its properties are unlikely to produce clinically relevant drug interactions in the transplant recipient. Awaiting specific trials, riboflavin is proposed as an option for the preventive treatment of post-transplant headache.
-
7.
Therapeutic trial in the first three Asian cases of ethylmalonic encephalopathy: response to riboflavin.
Yoon, HR, Hahn, SH, Ahn, YM, Jang, SH, Shin, YJ, Lee, EH, Ryu, KH, Eun, BL, Rinaldo, P, Yamaguchi, S
Journal of inherited metabolic disease. 2001;(8):870-3
Abstract
Three Korean girls with ethylmalonic encephalopathy, the first Asian cases, were identified. In all three cases, we observed slight improvement in motor functions, cognitive behaviours and chronic mucoid diarrhoea after treatment with riboflavin and/or coenzyme Q10 treatment. The precise pathogenesis of ethylmalonic encephalopathy has not been fully elucidated, but riboflavin treatment may be helpful.