Abstract
Purpose: :
To evaluate the staining affinity of new vital dyes to the lens anterior capsule (AC), retinal internal limiting membrane (ILM), epiretinal membrane (ERM), and vitreous in enucleated porcine eyes, human donor eyes, and freshly removed human ERMs.
Methods: :
Ninety-six freshly enucleated porcine eyes had anterior segment and vitreous removed, followed by injection of 0.05 ml of 0.5% methyl violet (MV), crystal violet (CV), eosin Y (EY), sudan black B (SB), methylene blue (MB), toluidine blue (ToB), light green (LG), indigo carmine (IC), fast green (FG), congo red (CR), evans blue (EB), brilliant blue (BriB), and bromophenol blue (BroB) onto the AC and ILM. The staining pattern was analyzed and retinas examined with light microscopy. Vitreous was stained with 2 ml of dye for 1 minute. In a further set-up, six safer and better vital dyes (IC, EB, FG, LG, BroB, BriB) were selected for experiments in human donor eyes in same technique as porcine-eyes. In addition, freshly removed human ERM were exposed to 1 ml of dyes at 0.5% and 0.05%. Intensity of membranes staining was graded as no (0), faint (+), moderate (++), or strong staining (+++).
Results: :
Experiments with pigs revealed no ILM-staining after EY exposure, whereas CR and LG promoted faint (+) ILM staining. ILM-staining with MB, ToB, IC, EB,BroB and FG revealed (++) coloring, and MV, CV, BriB or SB yielded (+++) ILM-staining. MV, CV, SB, ToB, and MB caused severe histologic retinal damage in porcine retinas. Vitreous examination revealed: (++) staining with CR, CV, FG, EY, MB, ToB, BriB, BroB and MV, a strong (+++) staining with LG and EB, and (+) staining with IC and SB. Human ERM examination revealed strong staining with 0.5% EB, moderate staining with 0.5% LG, FG, BriB, BroB, faint staining after exposure to 0.5% IC. Evaluation in human donor-eyes disclosed (+) ILM-staining with 0.5% IC, FG, (++) coloring with EB LG, and BroB, and (+++) with 0.5% BriB. Most dyes stained moderate or strongly the vitreous. Lens AC evaluation showed (+) staining with 0.5% IC, (++) staining with 0.5% EB, FG, and BriB, while 0.5% LG and BroB induced (+++) capsule staining.
Conclusions: :
BriB possesses great staining affinity to ILM, while BroB, EB and LG may also stain ILM very well. Most dyes bind appropriately to vitreous and ERMs. EB, FG, BriB, BroB and LG may represent good alternative dyes for lens AC-identification.