Comparison of Optisol‐GS and neomycin‐polymyxin B‐gramicidin ophthalmic solution for corneal storage in the dog

Abstract

The objective of the research was to compare the efficacy of Optisol-GS (OGS, Bausch & Lomb Surgical, Irvine, CA, USA) with triple antibiotic ophthalmic solution (neomycin-polymyxin B-gramicidin, NPG; Bausch & Lomb, Tampa, FL, USA) in preserving the viability of corneal endothelial cells. The study subjects were thirty young to middle-aged dogs with no gross corneal pathology that had been euthanized by pentobarbital overdose for reasons unrelated to this project. Corneal tissues were harvested, analyzed, and randomly assigned to treatment groups: one of two media (OGS or NPG), and one of five storage times (1, 7, 14, 21, or 35 days). Six corneas were stored in each medium for each time period. Corneal endothelial cell viability was evaluated pre- and poststorage by vital staining (trypan blue and alizarin red S), and endothelial cell morphology was evaluated with scanning electron microscopy. Storage in NPG caused significant loss (100%) of endothelial cells after all storage times. OGS storage maintained a high level of endothelial cell viability up to 21 days (98.9% +/- 1.3% viability). A significant decrease in percentage viability was also found for OGS-stored corneas between 21 and 35 days, when endothelial cell viability decreased to 61.4% +/- 45.9%. The conclusions are that NPG storage at -20 degrees C is a very poor choice of media for corneal tissue banking if graft clarity is the goal. Storage in Optisol-GS at 4 degrees C for up to 21 days resulted in significantly higher percentages of viable endothelial cells. Optisol-GS storage should facilitate corneal preservation for canine keratoplasty patients.

Preservation of canine and feline corneoscleral tissue in Optisol® GS

“…(1991) in humans 12 and Andrew et al . (1999) in dogs 31 . After 5 days of storage, there was no evidence of cell loss in the endothelial cell layer, as assessed by light and scanning electron microscopy, although normal hexagonal shape had been lost in some cells.…”

“…(1999) in dogs. 31 After 5 days of storage, there was no evidence of cell loss in the endothelial cell layer, as assessed by light and scanning electron microscopy, although normal hexagonal shape had been lost in some cells. In addition, a decrease in cell density, accompanied by cell hypertrophy was observed, which indicated that individual cells had died and been eliminated.…”

“…The effects of storage of corneoscleral tissue of dogs and cats were assessed in a similar manner to that described by Kaufman et al . (1991) in humans 12 and Andrew et al . (1999) in dogs.…”

“…These changes were reflected in cell density, which decreased to 2311 and 2194 cells/mm 2 in dogs and cats, respectively, just slightly higher than the proposed critical cell density for human corneas. 29 In a recently published study, 31 the viability of canine corneas stored in two different solutions, namely Optisol ® GS and a triple antibiotic ophthalmological solution (neomycinpolymyxin B-gramicidin ( NPG) ), was evaluated and compared after days 1, 7, 14, 21 and 35 of storage. Corneal viability was assessed before and after storage by vital stain of the cells using trypan blue and alizarin red and by evaluating cellular morphology by scanning electron microscopy.…”

Morphology of endothelial cells from different regions of the cornea of dogs

“…Analysis of healthy canine corneal endothelium using 0.2% alizarin red allowed clear identification of cell borders and was possible to identify and to evaluate the number of sides of each endothelial cell. Previous experiments with the use of alizarin red in different concentrations and exposition times have been performed (ANDREW et al, 1999;PARK et al 2012;FAGANELLO et al, 2016). Dual staining of corneal endothelium with vital dyes, using 0.2% alizarin red and 0.25% trypan blue, is the most frequently used technique for determining nonviable and viable cells in areas where cells cannot be identified with specular microscopy.…”