title: Comparison of different methods of glycerol preservation for deep anterior lamellar keratoplasty eligible corneas.
abstract: OBJECTIVE
  To compare different methods of glycerol-preserved corneas intended for deep anterior lamellar keratoplasty (DALK).
  
  
  METHODS
  We analyzed transparency, transmittance, thickness, biomechanics, morphology, and antigenicity of donor corneas preserved by four different glycerol-based methods (n = 6 per group) for 3 months, as follows: tissues in anhydrous glycerol without aluminosilicate molecular sieves at room temperature (GRT); tissues in anhydrous glycerol with aluminosilicate molecular sieves at room temperature (SRT); tissues in anhydrous glycerol without aluminosilicate molecular sieves at -78°C (G78); and tissues in anhydrous glycerol without aluminosilicate molecular sieves at -20°C (G20).
  
  
  RESULTS
  Slit lamp images and transmittance curves obtained by spectrophotometer show that the G78 cornea was the most transparent tissue. Stress-strain behavior indicated that corneas in the G78 group were the most pliable, and SRT corneas were the stiffest. Electron microscopy analysis indicated that corneal cytoarchitecture and keratocyte integrity was destroyed in all glycerol-preserved corneas. Disorganized stromal collagen fibers were evident in groups stored at RT. Especially in SRT corneas, parallelism was lost, fibrils were extremely tortuous and discontinuous, and widespread fibril degeneration could be found. Antigenicity of tissue, assessed via immunohistochemistry for CD45-positive cells, HLA-ABC and HLA-DR, was lowered after glycerol preservation relative to fresh cornea tissues, and immunoreactivity was located mainly on corneal epithelium and limbus rather than stroma.
  
  
  CONCLUSIONS
  Anhydrous glycerol preservation without molecular sieves in a -78°C freezer was the best method to obtain DALK-eligible tissues that were both transparent and pliable.
authors: School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, China.
authors: Jinyang
authors: J
authors: Li
authors: Shuai
authors: S
authors: Shi
authors: Xin
authors: X
authors: Zhang
authors: Shouxiang
authors: S
authors: Ni
authors: Yu
authors: Y
authors: Wang
authors: Christine A
authors: CA
authors: Curcio
authors: Wei
authors: W
authors: Chen
mesh_terms: D000538:Aluminum Silicates / Q000009:adverse effects; D001696:Biomechanical Phenomena; D003094:Collagen / Q000502:physiology; D003315:Cornea / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D060527:Corneal Keratocytes / Q000187:drug effects / Q000648:ultrastructure; D003319:Corneal Stroma / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D016039:Corneal Transplantation; D003451:Cryoprotective Agents / Q000009:adverse effects*; D019573:Epithelium, Corneal / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D005990:Glycerol / Q000009:adverse effects*; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D046529:Microscopy, Electron, Transmission; D012029:Refraction, Ocular / Q000187:drug effects; D013314:Stress, Mechanical; D013696:Temperature; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D000538:Aluminum Silicates; D003451:Cryoprotective Agents; C049037:aluminosilicate; D003094:Collagen; D005990:Glycerol