Purpose:
To demonstrate safety and efficacy of nanoparticles with superparamagnetic properties injected during vitrectomy as a tamponade to reattach the retina in a retinal detachment model.
Methods:
Right eyes of ten NZ rabitts were operated. An external magnet sutured on superior sclera was implanted in each right eye. Vitrectomy was performed in experimental eyes. A retinal tear was generated with a 23G cannula in a place correspondent to the external implant location, and saline solution was injected through the tear until the retina was detached at least one quadrant. Nanoparticles sized under 20 nm were obtained with a caracterization such that they behave as superparamagnetic ( magnetic behavior only under influence of a magnetic camp) . Superparamagnetic nanoparticles (SPMNP) 10% were mixed with 1% hyaluronic acid. SPMNP were injected around the lesion in 7 eyes. Three eyes remained without injection for control. Three additional rabbits were injected without surgery to evaluate inflammatory response to SPMNP. Images of the fundus and OCT were obtained at days 3, 7, 14 and 21 after surgery. The 13 rabitts were sacrified on day 21, and eyes were fixed for retinal histology with H-E to assess signs of inflammation, toxicity or damage.
Results:
Retina was attached in the 7 eyes with SPMNP. Retinas remained detached in three eyes without SPMNP. Neither signs of cataract, inflammation nor toxicity were recorded in the histology of the three groups. No SPMNP were detected beyond internal limiting membrane. No signs of structural damage were observed.
Conclusions:
Magnetic tamponade with SPMNP may be a safe and efficacious treatment for retinal detachment at a preliminar preclinical fase in animal model.
Keywords: retinal detachment • vitreous substitutes • vitreoretinal surgery