The impact of routine storage in the human donor corneal endothelium.

Abstract

Purpose : Specular microscopy (SM) is commonly used in eye banks as complementary information of the donor corneal endothelium after processing and preservation. The purpose of this study is to analyze impact of routine storage in the donor corneal endothelium.

Methods : Sixteen corneas of 12 donors (48.7 ± 16.8 years old) from our local eye bank (Salvador Arena Human Tissue Bank- Santa Casa de São Paulo) were selected for the study. All corneas were preserved in situ and placed in Eusol-C® at 4°C as routine basis. For routine quality evaluation, donor cornea was incubated at 27°C for about 60 minutes on the day of the arrival of the cornea into the eye bank (T1). After T1, the corneas were finally stored at 4°C for routine storage. At the day of the distribution of the graft, the cornea was incubated again at 27° C for about 60 minutes for SM analysis (T2). For each SM analysis, 4 endothelial images of each donor cornea were obtained by non-contact Cornea Specular Microscope (NC-CSMe) (Kerato Analyzer EKA-10, KONAN©) and then the manufacturer’s software (KONAN KSS-EB10) produced a multi-sample average (figure 1): cell density (CD), average cell area (AVE), coefficient of variation (CV), percentage of hexagonal cells (HEX) and number of counted cells (NUM). Endothelial cell loss was estimated by the following equation: storage factor = [1-(CD T2/CD T1)] x100. Statistical analysis was performed by the IBM SPSS Statistics 22.0 program using the paired T-test and considering a significance level of 5%.

Results : The average corneal storage interval was 2.12 ± 1.45 days. The data obtained is shown in table 1. Statistically significant differences were observed for CD (p = 0.013), AVE (p = 0.023), CV (p = 0.006) and HEX (p = 0.035). There were no significant differences for NUM (p = 0.14). Estimated mean endothelial cell loss was 7.7 ± 11.8%; however, four corneas (C2, C7, C9, and C15) showed increase of endothelial cell density after storage time.

Conclusions : CD and HEX have decreased after storage period. CV has increased after storage period. Negative values of endothelial cell loss may indicate that CSMe technology has flaws and may not be appropriate for clinical use.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.