Ex Vivo Whole Eye Perfusion System

Introduction: Vision impairment remains a significant global health burden, with 43 million people blind and hundreds of millions more affected by mild to severe vision loss in 2020. By 2050, projections indicate that blindness will exceed 61 million cases, with substantial increases across all categories of visual impairment, underscoring the urgent need for improved prevention and treatment strategies. Whole eye transplantation (WET) has emerged as a promising breakthrough, demonstrating that key retinal and neural structures can survive transplantation and create new opportunities for future sight restoring interventions. In this study, we aim to develop and validate a portable whole‑eye perfusion system capable of maintaining physiological viability ex vivo through intact vascular pedicle perfusion, with the goal of extending preservation time and enabling future applications in ocular transplantation.
Methods: A portable and versatile perfusion platform was developed with an integrated eye cassette, inline oxygenation, pH and gas monitoring, and pulsatile flow control. Porcine eyes (n=8) were procured with the ophthalmic artery and associated vascular pedicle intact, cannulated, and perfused under controlled subnormothermic conditions (20°C). A proprietary perfusate consisting of AMES buffer supplemented with metabolites and nutrients was used for the preservation studies. Hemodynamics, perfusate biochemistry, tissue hydration, and oxygen delivery were continuously monitored. Functional assessments included electroretinography (ERG), retinal cup calcium imaging, Fundus imaging, and optical coherence tomography (OCT) Imaging to evaluate preservation of retinal signaling.

Results: The whole eye perfusion maintained stable pulsatile pressures ranging from 5-15mmHg (Figure 1A) in the ophthalmic artery and physiologic flow profile of 0.5mL/min (Figure 1B) for extended perfusion durations up to 6 hours. Vascular pedicle perfusion preserved intraocular hemodynamics with 0% edema and supported sustained oxygenation above 700mmHg throughout the globe (Figure 1C). The proprietary perfusate maintained physiologic pH and sodium levels with content ranging from 7.3-7.4 (Figure 1D) and 139-145 mmol/L, respectively. Glucose content was initially 93mg/dL, which decreased slightly over time, indicating metabolic consumption of glucose by the perfused tissue (Figure 1E & F). Functional assays demonstrated retained retinal activity, including measurable ERG responses, spontaneous calcium transients, and neuronal firing patterns during ex vivo perfusion.