title: New histopathologic and ultrastructural findings in Reis-Bücklers corneal dystrophy caused by the Arg124Leu mutation of TGFBI gene.
abstract: BACKGROUND
  Reis-Bücklers corneal dystrophy (RBCD) was consistently reported as a corneal dystrophy only affected Bowman's layer and superficial corneal stroma, and superficial keratectomy was a recommendation surgery for treatment in literatures. The study reported new histopathological and ultrastructural findings in RBCD caused by the Arg124Leu mutation of transforming growth factor induced (TGFBI) gene in a four-generation Chinese pedigree.
  
  
  METHODS
  Subjects including eight patients and seven unaffected family members received slit-lamp biomicroscopy and photography. DNA was obtained from all subjects, and exons 4 and 11 to 14 of TGFBI gene were analyzed by polymerase chain reaction and the products were sequenced. Anterior segment optical coherence tomography (AS OCT) and in vivo confocal microscopy were conducted for ten eyes of five patients. Based on the results of AS OCT and in vivo confocal microscopy, deep anterior lamellar keratoplasty (DLKP) using cryopreserved donor cornea was applied for four eyes of four patients. Four lamellar dystrophic corneal buttons were studied by light and transmission electron microscopy, and TGFBI immunohistochemistry.
  
  
  RESULTS
  Eight patients had typical clinical manifestations of RBCD presenting recurrent painful corneal erosion starting in their early first decades, along with age-dependent progressive geographic corneal opacities. TGFBI sequencing revealed a heterozygous mutation, Arg124Leu in all eight patients. Anterior segment optical coherence tomography and in vivo confocal microscopy showed the dystrophic deposits involved not only in subepithelial and superficial stroma, but also in mid- or posterior stroma in four examined advanced eyes. Light microscopy showed Bowman's layer was absent, replaced by abnormal deposits stain bright red with Masson's trichrome. In superficial cornea, the deposits stacked and produced three to five continuous bands parallel to the corneal collagen lamellae. In mid- to posterior stroma, numerous granular or dot- like aggregates were heavily scattered, and most of them presented around the nuclei of stromal keratocytes. Transmission electron microscopy revealed the multiple electron-dense rod-shaped deposits aggregated and formed a characteristic pattern of three to five continuous bands in superficial cornea, which were similar to those seen under light microscopy. In mid- to posterior stroma, clusters of rod-shaped bodies were scattered extracellular or intracellular of the stromal keratocytes between the stromal lamellae suggesting the close relationship between mutated proteins and keratocyte.
  
  
  CONCLUSIONS
  The study offer evidences indicating DLKP is a viable treatment option for advanced RBCD to avoid recurrence, and the mutated TGFBIp in dystrophic corneas are of keratocytes origin.
authors: Department of Ophthalmology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China.|Key laboratory of Biotherapy of Zhejiang Province, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China.
authors: Wen-Ya
authors: WY
authors: Qiu
authors: Department of Ophthalmology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China.|Key laboratory of Biotherapy of Zhejiang Province, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China.
authors: Li-Bin
authors: LB
authors: Zheng
authors: Department of Ophthalmology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China.
authors: Fei
authors: F
authors: Pan
authors: Core Facilities, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, 310058, Zhejiang, People's Republic of China.
authors: Bei-Bei
authors: BB
authors: Wang
authors: Department of Ophthalmology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China. yaoyuf@mail.hz.zj.cn.|Key laboratory of Biotherapy of Zhejiang Province, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East, Hangzhou, 310016, Zhejiang, People's Republic of China. yaoyuf@mail.hz.zj.cn.
authors: Yu-Feng
authors: YF
authors: Yao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D050541:Bowman Membrane / Q000473:pathology / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D003315:Cornea / Q000473:pathology / Q000648:ultrastructure; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D060527:Corneal Keratocytes / Q000473:pathology; D003319:Corneal Stroma / Q000473:pathology / Q000648:ultrastructure; D005091:Exons; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015948:Keratoplasty, Penetrating; D008297:Male; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D041623:Tomography, Optical Coherence; D016212:Transforming Growth Factor beta / Q000235:genetics*; D055815:Young Adult
chemical_list: D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta
keywords: Corneal Bowman’s layer; Deep anterior lamellar keratoplasty; Keratocyte; Reis-Bücklers corneal dystrophy; Transforming growth factor induced gene