Abstract
Purpose:
Complications have been reported with perfluorocarbon liquids (PFCLs), which can be attributed to the transparent nature of these compounds. The use of colored PFCLs would help in a more complete and safe removal of these substances. Our objectives were to test (1) stability, (2) residue formation inside the vial and (3) evaluation of residual pigment inside the eye of blue perfluoro-n-octane (PFnO) and blue perfluorodecaline (PFD).
Methods:
A total of 15 enucleated pig eyes, 10 vials of blue PFnO and 10 vials of blue PFD were used: (1) Stability: 2 groups (blue PFnO and blue PFD). 23G pars plana vitrectomy (PPV), colored PFCL introduction and endophotocoagulation during 15 minutes were performed. After the colored PFCL was aspirated to a syringe and MALDI-TOF EXPLORER 70107 analysis performed. (2) Residue formation inside the vial: 2 groups (blue PFnO and blue PFD). The vials were stored at 20C and at 4C for 7 and 14 days. Residue formation was evaluated at day 7 and day 14. Freshly prepared solutions served as control. (3) Evaluation of residual pigment inside the pig eye: 3 groups (blue PFnO, blue PFD and blue powder used to color the PFCL). 23G PPV, colored PFCL / powder introduction and air exchange were performed. After the eye was fixed in 10% formaldehyde solution and residual pigment analysis performed.
Results:
(1) Stability: MALDI-TOF EXPLORER 70107 analysis did not show alteration of both colored PFCLs analyzed when comparing previous composition of those substances to the composition of the same substance after laser stress test. (2) Residue formation inside the vial: (a) Blue PFD: no crystals were seen except when solutions were stored at 4C for 7 days. (b) Blue PFnO: crystals were seen in all situations. (3) Evaluation of residual pigment inside the pig eye: (a) Blue PFD: discrete amounts of vitreous residues were observed. (b) Blue PFnO: small blue particles homogeneously localized on whole retinal surface and also on the vitreous. (c) Blue powder: particles not homogenously distributed on the retinal surface and large blue particles/agglomerates detected in the vitreous samples.
Conclusions:
In a phakic enucleated pig eye extraction of all PFCL residues was not possible. Although blue PFnO was as stable as blue PFD, it showed more residue formation and residual pigment than PFD. Only blue PFD presents the correct characteristics to proceed to the phase 1 clinical trial on human subjects.
Keywords: 764 vitreous substitutes •
762 vitreoretinal surgery •
688 retina