A corneal inlay (shown dyed in red) measuring just two millimeters in diameter, approximately 50 microns thick, and composed primarily of water.
The Challenge
The existing solution utilized a laser-cut titanium mesh housed within a specialized enclosure and stored inside a vial. While technically functional, the system was difficult to manufacture and even more difficult to use.
Deploying the inlay required:
- Multiple handling steps
- A trained assistant
- Removal of excess saline
- Careful separation of several components
- Secondary surgical instruments to complete placement
- Verification that the nearly transparent inlay remained properly oriented
The process was highly dependent on user technique and introduced unnecessary opportunities for error.
Beyond usability concerns, the delivery system carried a cost of goods exceeding $67 per unit while adding little value to the clinical outcome.
An old trick with a drinking straw led to an entirely different deployment architecture.
Looking Beyond the Existing Solution
Rather than optimizing the existing design, we stepped back and reconsidered the underlying problem.
What was the device actually required to do?
The answer was simple:
- Keep the inlay hydrated
- Survive sterilization
- Present the inlay in the correct orientation
- Allow a surgeon to place it accurately
- Minimize handling and training requirements
By stripping the challenge down to its fundamentals, the path forward became clear.
During early experimentation, we observed that the same fluid forces used in a drinking straw could be leveraged to manipulate the inlay. Preliminary proof-of-concept testing using simple components demonstrated that the inlay could be reliably captured, transported, and released using fluid mechanics already present within the system.
This insight became the foundation of an entirely new deployment platform.
The Marker has been designed from the ground up to provide an inlay deployment device with robust performance over a wide range of operator variables.
Engineering the Marker
The resulting device, internally known as the Marker, transformed a complex deployment procedure into a simple pen-like action.
The self-contained system housed the inlay in only 300 microliters of saline while maintaining hydration during storage and transport. A two-stage cap system protected the inlay until use, allowing the surgeon to prepare the device quickly and consistently.
Key innovations included:
- A specially engineered deployment tip that retained the inlay during handling while allowing controlled release onto the corneal bed
- A retaining cap geometry that protected the inlay regardless of cap removal speed
- A sealing system capable of maintaining hydration for extended storage
- A 45-degree deployment angle that improved visibility during placement
- A one-handed operating sequence that dramatically simplified the procedure
The result was a device designed around the workflow of the surgeon rather than the constraints of the previous packaging approach.
The Marker is extremely efficient using approximately 0.3ml of saline for a 3-year shelf life. Economical yet USP Class VI autoclavable thermoplastic allow for higher quality at less cost. And keys allow part indication for assembly automation and to help prevent assembly errors.
Design for Manufacturing
A successful medical device must work clinically, but it must also be manufacturable.
The original concept relied on expensive specialty materials and intricate components. Through careful engineering analysis, we eliminated unnecessary complexity and selected materials that could withstand sterilization requirements while significantly reducing cost.
The design was optimized for:
- Injection molding
- Assembly automation
- Packaging flexibility
- Sterilization compatibility
- Long-term shelf stability
The final architecture reduced the number of critical components while improving overall reliability.
Most importantly, the cost of goods fell from approximately $67 to nearly $3 per unit at production volumes.
The marker costs just a few dollars to make, but the critical cost the Marker aims to reduce is product returns due to failed deployments.
Placing the inlay is as easy as drawing a dot.
Time studies measured a rage of cap-removal times and validated both slow and quick removal.
Vibration testing was vital to ensure the inlay stayed in place and remained intact during shipping and handling
Prototypes were fabricated using in-house MMA-based 3D printing
Validation
Development extended well beyond product design.
Henning performed testing and documentation covering:
- Deployment repeatability
- Packaging approaches
- Transportation and vibration effects
- User variability
- Material performance
- Clinical handling procedures
This work ensured that the final solution was not merely a prototype, but a repeatable system ready for commercialization.
Feedback from ophthalmologists was immediate and positive.
One surgeon's reaction captured the success of the project:
"This is so easy. Now all I need to do is draw dots all day."
A custom tray pack with IFU documentation was designed for a complete solution.
Results
The final solution delivered meaningful improvements across every major metric:
- Reduced deployment complexity
- One-handed operation
- Improved placement consistency
- Better than 90% deployment success during testing
- Significant reduction in product replacement risk
- Cost reduction of more than 90%
- Simplified manufacturing and packaging
- Improved surgeon experience
What began as a packaging problem became a complete redesign of the product experience.