The biocompatibility of silicone, fluorosilicone and perfluorocarbon liquids as vitreous tamponades. an ultrastructural and immunohistochemical study.
OBJECTIVE
To investigate the interactions occurring at the interface between some currently used vitreous tamponading substances and the ocular tissues, in an early follow-up after surgery.


METHODS
Adult albino rabbit eyes underwent vitrectomy and were injected intravitreally with silicone oils at 1,000 or 3,000 cSt, fluorosilicone oil and perfluorodecalin. Different morphological techniques (light microscopy, scanning and electron microscopy, immunohistochemistry) were applied.


RESULTS
All the tested materials, although non-toxic, penetrate the ocular tissues also at the anterior segment level, and in the long-term follow-up this can yield functional impairment. No massive inflammation has been detected in the zones in contact with the materials, but immunoglobulins and complement fractions are anyway present in the stroma of various tissues and around the droplets of emulsified materials, suggesting a local immune reaction.


CONCLUSIONS
Data from this study confirmed that a permanent vitreous substitute, showing a perfect biocompatibility, still does not exist. The indication to remove the tamponading substance within 2 months after the surgery emerges from this investigation, confirming previous studies. Despite some negative features, silicone oil still appears the most biocompatible material for vitreous replacement.
Versura
P
P
Centre of Biotechnological and Clinical Research in Ophthalmology, University of Bologna, Italy. versura@alma.unibo.it
Cellini
M
M
Torreggiani
A
A
Bernabini
B
B
Rossi
A
A
Moretti
M
M
Caramazza
R
R
D000818:Animals; D001672:Biocompatible Materials / Q000633:toxicity*; D015932:Complement C3c / Q000032:analysis; D019084:Fluorescent Antibody Technique, Indirect; D005466:Fluorocarbons / Q000633:toxicity*; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007267:Injections; D008855:Microscopy, Electron, Scanning; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000276:immunology / Q000648:ultrastructure; D012164:Retinal Diseases / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D012827:Silicone Oils / Q000633:toxicity*; D014821:Vitrectomy; D014822:Vitreous Body / Q000187:drug effects
D001672:Biocompatible Materials; D005466:Fluorocarbons; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012827:Silicone Oils; C008805:perfluorodecalin; C054077:fluorosilicone oil; D015932:Complement C3c