Science-Driven Innovation:
Rethinking Corneal Preservation

The Evolution of Corneal Storage

For three decades, hypothermic storage has been the gold standard in corneal preservation. While traditional media have served the field well, they were developed with the limitations of 1990s technology and understanding.
Modern corneal surgery has evolved dramatically—ultrathin DSAEK grafts, delicate DMEK procedures, and international tissue distribution demand more from preservation media. The question is no longer just “Can we keep tissue viable?” but “Can we preserve tissue in a way that optimizes every aspect of the corneal journey?“a

What Makes XTRA4 Different

Dextran-Free Formulation Traditional storage media rely on dextran as a deswelling agent, but research has raised concerns about its uptake by corneal tissue. XTRA4 eliminates dextran entirely, using a carefully optimized alternative that maintains corneal thickness without potential tissue interaction.

Comprehensive Nutritional Support

XTRA4 provides corneal tissue with everything needed for extended preservation:

  • Vitamins and amino acids for cellular metabolism
  • Sodium pyruvate as an ATP precursor for energy production
  • Optimized buffering system (MEM and sodium bicarbonate) maintaining physiological pH
  • Broad-spectrum antimicrobial protection (gentamicin and streptomycin sulfate)

Osmotic Balance

The formulation maintains iso-osmolarity (255-345 mOsm/kg), preventing excessive fluid shifts that lead to stromal swelling and endothelial stress.

The R&D Process: Hundreds of Prototypes, One Solution

Dr. Jana D. Tóthová, from Moria’s R&D team, describes the development process: “We developed hundreds of prototypes and tested several alternatives for essential components. XTRA4 is a rich, carefully optimized formulation that was only finalized after extensive experimentation to identify the most effective ingredient of the highest quality”.  This iterative approach included:

  • Accelerated aging studies confirming 2-year shelf-life stability
  • Comprehensive biocompatibility testing (cytotoxicity, skin sensitization, ocular irritation)
  • Independent validation at three leading eye banks across two continents

Independent Validation

XTRA4‘s performance has been rigorously evaluated by:

  • VisionGift (Portland, Oregon) Supported by a High Impact Grant from the Eye Bank Association of America, researchers evaluated XTRA4‘s potential for extended storage, with findings presented at major international conferences.
  • Eversight (Cleveland, Ohio) Conducted comparative studies focusing on DSAEK graft preparation, demonstrating consistent thickness profiles and superior tissue handling characteristics.
  • Fondazione Banca degli Occhi del Veneto (Venice, Italy) Evaluated XTRA4 performance in European eye banking contexts, confirming results across different operational protocols and tissue preparation methods.

Key Innovation Outcomes

Stable Thickness Profile: unlike traditional media where corneas progressively thicken during storage, XTRA4-preserved tissue maintains near-baseline thickness. Average central corneal thickness increases by just 2.4% over 14 days, compared to 10% with Optisol-GS®.
Epithelium-Independent Preservation: Even when the epithelium is compromised—a common challenge in eye banking—XTRA4-stored corneas resist stromal swelling and maintain clarity. This resilience provides practical advantages in tissue assessment and handling.

Setting New Standards

XTRA4 represents more than incremental improvement—it’s a fundamental rethinking of what corneal storage media should achieve. By addressing the real-world challenges faced by eye banks and surgeons, it establishes a new benchmark for tissue preservation in the modern era of corneal transplantation