Overview of Short-Term and Intermediate-Term Corneal Storage Solution: Comparison of Clinical Outcomes and Need For Future Research

The expanding roles of eye banks in India: Past, present, and future

This review highlights the evolution in the scope of eye banking activities in India. The roles and responsibilities of the eye banks have expanded to match the requirements and necessities that arose because of advancements in keratoplasty techniques and the need for corneal surgeons. Adoption of different types of corneal preservation solutions and methods of donor cornea preservation was a consequence of the changing and unprecedented times. The growth of eye banking in India has been a commendable journey and has placed the country in an "almost sufficient" category in eye banking and corneal transplantation. There exists a potential to reach the status of cornea surplus country in the future. The rules and laws governing eye banking operations need dynamic amendments based on the trends in keratoplasty, surgical practice patterns, and status of self-sufficiency. Newer technological advances and quality measures must be adopted in donor cornea evaluation and tissue preparation. Research should be integrated as an important component of eye banking, especially in developing novel methods of donor preservation, and evaluating and validating the existing and changing practices of eye banking.

Assessment of performance and safety of Corneal Chamber hypothermic storage medium and PSS-L corneal rinsing solution in human and porcine corneas

PURPOSE

To prove the safety and performance of the hypothermic corneal storage medium "Corneal Chamber" and the rinsing solution "PSS-L" in support of the new Conformité Européenne (CE) certification process in accordance with the Medical Device Regulation.

METHODS

Fifteen (n=15) human donor corneas and 11 (n=11) porcine corneas were evaluated for the following parameters: endothelial cell density (ECD) and mortality, percentage of hexagonal cells (HEX%), coefficient of cellular area variation (CV%) and corneal transparency at Day 0 and after 14±1 days of storage in Corneal Chamber medium at 2-8°C. Then, the same parameters were assessed after rinsing of corneas in PSS-L for 1 min at room temperature. Evaluation of gentamicin sulfate carryover after corneal storage and PSS-L rinsing was performed by ultra-high performance liquid chromatography analysis on human corneas homogenates.

RESULTS

Human and porcine corneas stored in Corneal Chamber medium showed a good overall quality of the tissue according to the quality parameters evaluated. In particular, mean ECD, HEX% and CV% did not show statistically significant changes at the end of storage and endothelial mortality increased to 3.1±3.3 and 7.8±3.5% in human and porcine corneas, respectively. Tissue rinsing with PSS-L did not affect the quality parameters evaluated before and gentamicin sulfate residues were absent in human corneas.

CONCLUSIONS

Corneal preservation in Corneal Chamber medium at 2-8°C for 14 days and the corneal rinse with PSS-L are safe and effective procedures allowing the preservation of the corneal quality parameters as well as the complete elimination of gentamicin sulfate from the tissues before transplantation.Cite Now.

Comparison of corneal endothelial cell density and morphology with Optisol GS and Life4C storage media in the eye bank: a 5-year retrospective analysis

Purpose

Optisol GS and Life4C are corneal storage media used by eye banks worldwide. We sought to determine if either solution was associated with superior corneal endothelial cell density (ECD) or morphology in a large cohort of donor corneas.

Methods

From January 2016 through December 2020, 10,316 corneas from 5,624 unique donors were acquired and analyzed at Rocky Mountain Lions Eye Bank. In April 2019, Life4C replaced Optisol GS as the sole storage medium. We compared ECD and morphology before and after April 2019, and excluded corneas processed within the transition period. Univariable and multivariable regression analyses accounted for age, sex, tobacco use, heavy alcohol use, and diabetes. Only right corneas were analyzed to account for the correlation between eyes.

Results

Of 5042 right corneas analyzed, 3486 were stored in Optisol GS and 1556 in Life4C. There was no significant difference in ECD across groups (2794 vs. 2793 cells/mm2 in Optisol GS and Life4C, p=0.88). In multivariate analyses, there was no significant difference in corneal ECD (0.6 cells/mm2 higher with Life4C, p=0.96) or hexagonality (0.22% higher with Life4C, p=0.31). However, the coefficient of variation was significantly lower in the Life4C group (-0.0039, p=0.03). After adjustment for above factors, corneas in Life4C demonstrated a 3.1% decreased likelihood of exhibiting CV values greater than 0.40 (p=0.009).

Conclusions

This study demonstrates comparable and favorable outcomes using both storage media and confirms their overall efficacy. The decreased CV in Life4C is not of clinically significant magnitude, but merits further research in clinical and long-term settings.

Role of Oxidative Stress in the Disruption of the Endothelial Apical Junctional Complex During Corneal Cold Storage

Purpose: To characterize the impact of corneal cold storage (CS) on the endothelial apical junctional complex (AJC). Methods: Porcine corneas were held in CS (4°C; 1-7 days) with Cornisol™ preservation medium supplemented with epothilone B (EpoB; microtubule stabilizer; 100 nM), SB-203580 (p38 mitogen-activated protein [MAP] kinase inhibitor; 20 μM), or antioxidants (quercetin, 100 μM; vitamin E, 1 mM; deferoxamine, an iron chelator, 10 mM). After CS termination, the damage to endothelial AJC was characterized by imaging perijunctional actomyosin ring (PAMR) and zonula occludens (ZO-1). The effects of EpoB and SB-203580 were characterized by imaging microtubules. The loss in the barrier function was assessed in cultured cells grown on biotin-coated gelatin by permeability to fluorescein isothiocyanate (FITC)-avidin. The accumulation of reactive oxygen species (ROS), altered mitochondrial membrane potential (MMP), lipid peroxidation, and lactate dehydrogenase (LDH) release were also determined in response to CS. Results: CS led to the loss of microtubules, destruction of PAMR, and breakdown of ZO-1 in the endothelium. The severity of damage increased when CS was prolonged. Although rewarming of the tissue increased the damage, the effect was marginal. CS also induced accumulation of ROS, alteration in MMP, lipid peroxidation, enhanced LDH release, and increased permeability to FITC-avidin. These changes were opposed by EpoB, SB-203580, and antioxidants. Conclusion: Corneal CS destroys AJC of the endothelium, leading to loss of its barrier function. The effects were surmounted by microtubule stabilization, p38 MAP kinase inhibition, and antioxidants. Thus, there is potential for reformulation of the preservation medium to maintain the health of the donor corneal endothelium before transplantation.