Abstract
Purpose: :
To evaluate decafluoro-di-n-pentyl ether (DFPE) as a temporary vitreous tamponade by examining ocular tolerance in rabbits’ eyes
Methods: :
Thirteen rabbits divided into four groups after vitrectomy. Group 1-DFPE(1.0ml) was injected in one eye of four rabbits, followed for six months; Group 2-DFPE(0.8 to 1.5ml) was injected in one eye of four rabbits, followed for twelve months; Group 3-DFPE(1.0 ml) and silicone oil (SiO)(0.2 ml) 5000 centistokes was injected in one eye of three rabbits, followed for six months, Group 4-balanced salt solution was kept in one eye of two rabbits, served as control. Postoperative clinical evaluation included tonometry, indirect binocular ophthalmoscopy and scotopic electroretinogram test (ERG). Following 1 month of liquid removal, another ERG test was performed in each group before the eyes were enucleated and processed for histological evaluation
Results: :
On group 1, 2 and 3, the liquid occupied the inferior portion of the vitreous cavity. Smaller droplets were gradually observed. Dispersion of the fluid appeared 2 weeks postoperatively and for the remainder of follow-up, globule size remained stable. Posterior subcapsular cataracts appeared in eyes with large fills of DFPE (> 50%). Cellular debris was observed at the interface between DFPE and physiological fluid in 6 of 8 DFPE-injected eyes and this remained unchanged until the end of study. Histological findings on group 1 and 2 showed no detectable change in outer nuclear layer thickness, but occasional dropout of photoreceptor cell nuclei occurred in inferior retina. Thickening of the inner retina was also noted inferiorly. Foam cells were observed in the vitreous and on the surface of the retina. Except for some vacuolations, the inner retina was well preserved in all injected eyes. Penetration of the liquid into the inner retina was not seen. On the ERG of all injected eyes, there was no effect on the a-wave amplitude and b-wave implicit time, but the b-wave amplitude was elevated with statistical significance (<0.001) at 1, 3 and 6 months postoperatively, on the other hand, there was no statistical significance (p>0.05) at 12 months of follow up and 1 month after DFPE removal.
Conclusions: :
DFPE demonstrated minimum adverse effects in retinal rabbits, further studies are needed before clinical use as short term tamponade
Keywords: vitreous substitutes • retinal detachment • proliferative vitreoretinopathy