Duration 5min, Q&A 3min
In Vivo and In Vitro Feasibility Studies of Intraocular Use of FocalSeal to CloseRetinal Break in Porcine and Rabbit Eyes
FocalSeal® is an absorbable polyethylene glycol-based synthetic hydrogel sealant. This liquid is polymerized under visible xenon illumination, and forms clear, flexible, and firmly adherent hydrogel. In this study, we evaluated the intraocular biocompatibility of the sealant and explored its efficacy for closing retinal breaks.
An in vitro study was conducted to assess the efficacy of FocalSeal® in enucleated porcine eyes, and an in vivo study was performed to evaluate its safety in Dutch pigmented rabbit eyes.
In the in vitro study, retinal detachment with a hole was created in porcine eyecups after the vitreous gel was removed. FocalSeal® was applied to cover the hole, and was polymerized with 60-second application of xenon light. The strength of the retinal adhesion was tested by forcefully pouring balanced slat solution (BSS) to the retinal hole. The pH of FocalSeal® soaked in the BSS, incubated at 37℃, was measured periodically for 72 hours. In the in vivo study, FocalSeal® was injected into the vitreous cavity of left eyes of the rabbits. Ophthalmologic examinations were performed and bilateral electroretinograms (ERGs) were recorded simultaneously before and 4 weeks after injection. Both eyes were enucleated for histological evaluation.
Results and Conclusion
Adhesion of FocalSeal® to the retina was relatively strong. The forceful application of BSS to the retinal hole covered with FocalSeal® did not detach the retina, while the retinal hole without FocalSeal® detached immediately after BSS application. The pH of BSS containing FocalSeal® was between 7.2 to 8.0. With slit lamp microscopy and funduscopy, no inflammatory reaction was observed in the eyes during the 4-week follow-up after treatment. ERGs recorded before and after injection showed typical patterns. There was no significant difference in the amplitude or implicit time of the a-waves, b-waves, and oscillatory potentials of the ERGs between the study and control groups. Histological examination with a light microscope did not reveal any abnormality or inflammation in either group at the end of the study. FocalSeal® appeared to effectively seal retinal breaks in our in vitro experiment, and the in vivo studies indicated that FocalSeal® was not toxic to the eye.
[ Keyword ]
sealant / retinal break
[ Conflict of Interest ]