title: Intrascleral outflow after deep sclerectomy with absorbable and non-absorbable implants in the rabbit eye.
abstract: BACKGROUND
  The purpose of the study is an analysis of intrascleral drainage vessels formed in rabbits' eyes after non-penetrating deep sclerectomy (NPDS) with absorbable and non-absorbable implants, and comparison to eyes in which surgery was performed without implanted material.
  
  
  METHODS
  NPDS was carried out in 12 rabbits, with implantation of non-absorbable methacrylic hydrogel (N=10 eyes) or absorbable cross-linked sodium hyaluronate (N=6 eyes), or without any implant (N=8 eyes). All the animals were euthanized 1 year after surgery. Twenty-one eyeballs were prepared for light microscopy and 3 were prepared for transmission electron microscope (TEM) analysis. Aqueous humour pathways were stained with ferritin in 6 eyeballs.
  
  
  RESULTS
  By light microscopy, small vessels adjacent to the areas of scarring were the most common abnormality. Vessel density was significantly higher in operated sclera compared to normal, healthy tissue, regardless of the type of implant used. The average vessel densities were 2.18±1.48 vessels/mm2 in non-implanted sclera, 2.34±1.69 vessels/mm2 in eyes with absorbable implants, and 3.64±1.78 vessels/mm2 in eyes with non-absorbable implants. Analysis of iron distribution in ferritin-injected eyes showed a positive reaction inside new aqueous draining vessels in all groups. TEM analysis showed that the ultrastructure of new vessels matched the features of the small veins.
  
  
  CONCLUSIONS
  Aqueous outflow after NPDS can be achieved through the newly formed network of small intrascleral veins. Use of non-absorbable implants significantly increases vessel density in the sclera adjacent to implanted material compared to eyes in which absorbable implants or no implants were used.
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland. kubeye@poczta.onet.pl
authors.forename: Jakub J
authors.initials: JJ
authors.lastname: Kałużny
authors.forename: Dariusz
authors.initials: D
authors.lastname: Grzanka
authors.forename: Halina
authors.initials: H
authors.lastname: Wiśniewska
authors.forename: Alicja
authors.initials: A
authors.lastname: Niewińska
authors.forename: Bartłomiej J
authors.initials: BJ
authors.lastname: Kałużny
authors.forename: Alina
authors.initials: A
authors.lastname: Grzanka
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D003228:Conjunctiva / Q000473:pathology / Q000648:ultrastructure; D005293:Ferritins; D005451:Fluorescein Angiography; D005453:Fluorescence; D020007:Implants, Experimental; D011817:Rabbits; D011859:Radiography; D012590:Sclera / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000601:surgery* / Q000648:ultrastructure; D012599:Sclerostomy
chemical_list: D005293:Ferritins