IN-VITRO COMPARATIVE-STUDY OF A LOCALLY PREPARED CORNEAL STORAGE MEDIUM AND OPTISOL

Objective: To compare the in-vitro safety and efficacy of two corneal storage media, Optisol and H-Sol, a chondroitin-sulfate-based medium c ontaining hydrocortisone prepared at the Eye Bank of Canada (Ontario D ivision). Design: Twenty paired corneas from human donors (mean age 67 .9 years) were randomly assigned for storage in corneal viewing chambe rs at 4 degrees C in Optisol (10 corneas) or H-Sol (10 corneas). The s torage media were masked, and all measurements were done in a blinded fashion. Outcome measures: Corneal clarity and thickness (measured at 0, 2, 4, 8 and 12 days), endothelial cell density and morphology (anal ysed at days 0 and 12). At day 12 cell viability was determined by sta ining with trypan blue and alizarin red S, and three randomly selected corneas from either medium were examined by scanning electron microsc opy and transmission electron microscopy. Results: Corneal thickness i ncreased significantly from day 0 to day 12 in both Optisol and H-Sol, and corneal clarity decreased significantly in both media over this p eriod (p < 0.05). At days 2, 4, 8 and 12 the corneas stored in Optisol were significantly thinner than those stored in H-Sol (p < 0.05). The re were no significant differences between the media in any of the oth er indices studied. Endothelial cell density decreased significantly i n both Optisol and H-Sol (p < 0.05). There were no within-group differ ences in percentage of cell loss, coefficient of variation of cell are a, figure coefficient or percentage of hexagonal cells. Conclusions: T he difference in corneal thickness between Optisol and H-Sol may have been due to the higher concentration of chondroitin sulfate in the for mer (2.5%, compared with 2% in H-Sol) or perhaps to the addition of ot her components to Optisol that are not present in H-Sol. Efforts conti nue to improve the formulation of H-Sol. Further studies are necessary to assess its safety and efficacy in vivo.