Abstract
Purpose (i) To evaluate a new viewing chamber (NVC, AL.CHI.MI.A. Srl) under corneal hypothermic storage conditions. (ii) To compare NVC to other market viewing chambers (VCs) considering hermetic closure, integrity and cleanliness.
Methods Human corneas were preserved in NVC (n=4) or in a sterile glass vial (n=4) at 4°C for 14 days. Corneal qualitative parameters including ECD, EC morphology, CCT were measured at 0, 3, 7 and 14 days of storage, with specular microscope CellChek®D+ (Konan Medical Inc) and optical coherence tomography (Casia OCT, Tomey GmbH).
In comparative analysis NVC and 3 commercially available devices were included: the NVC Group (n=40) and Market Viewing Chamber groups 1 (MVC1, n=20), 2 (MVC2, n=20) and 3 (MVC3, n=20). The integrity and cleanliness of optical fundi were evaluated by stereoscopic inspection with a four-point score assignment. The capacity of VCs to accommodate the volume of commercially available hypothermic storage media (20 mL) was tested with a graduated pipette. A leakage stress test was developed to simulate corneal processing from procurement to shipment to the operating theatre using different combinations of time, temperature, chambers orientation and shaking conditions.
Results Both the NVC and GV were compatible with specular microscopy, but the Donor Enhance imaging system, integrated into the CellChek®D+, was exclusively accessible through NVC, allowing additional evaluation of corneal tissues and aiding in the assessment of potential anomalies. Differently from the glass vial, NVC was compatible with OCT without necessitating the transfer of tissue into new containers. All the corneal quality parameters remained stable during the storage in both containers with no statistical difference between the two groups at any time point.
During stereoscopic inspection, NVC and MVC2 had the best scores in cleanliness and integrity. NVC, MVC2, and MVC3 accommodated the entire volume of the commercially available storage media, while MVC1 did not. In the stress leakage test, NVC excelled with 97.5% of samples showing absence of leakage, followed by MVC1 (60%), MVC3 (30%), and MVC2 (0%).
Conclusions NVC shows promise as a reliable option for hypothermic storage, resulting safe for human cornea and compatible with EB instruments. In addition, NVC had best performance in all tested parameters, including hermetic closure and appropriate capacity of contained liquids and cleanliness and integrity of optical components.
