3D Printable, Modified Trephine Designs for Consistent Anterior Lamellar Keratectomy Wounds in Rabbits

ABSTRACT

Purpose

Our goal is to develop a low-cost tool that can be used to create consistent, partial-thickness defects in rabbit and other large animals with minimal surgical training and that can facilitate pre-clinical testing of lamellar and in situ-forming biosynthetic matrix materials for corneal repair.

Materials & Methods

In this study, three modified trephines were designed to create deep corneal wound defects with consistent depth in large animals. The modified trephines incorporated either 3D-printed parts made from photopolymerizable resins, or custom-cut commercially available Teflon sheets. Wound defects were imaged with optical coherence tomography (OCT), and the depth was analyzed based on the OCT images.

Results

The results revealed that an inner-stopper guard trephine had the best performance in creating consistent and precise wound defect depth compared to modified vacuum trephine and custom guard vacuum trephine. A 75% ± 10% cut of the cornea was achieved with the inner-stopper guard trephine. The wound defect depth by created by the inner-stopper guard trephine was independent of the corneal thickness or size of the globes. Although the cut depth of the inner-stopper guard trephine differed by the experience-level of its users, the consistency (standard deviation) of the depth was independent of experience.

Conclusions

Our studies provided three cost-efficient animal trephines that can create corneal wounds of consistent depth by lab researchers without extensive training in keratectomy.

KEYWORDS:

• Anterior lamellar keratectomy
• anterior lamellar keratoplasty (ALK)
• rabbit corneal defect wound model
• animal vacuum trephine
• guarded trephine

Acknowledgments

The authors would like to acknowledge the support from the National Institutes of Health (National Eye Institute K08EY028176, T32 EY027816, and a Departmental P30EY026877 core grant), the Stanford SPARK Translational Research Grant and Maternal & Child Health Research Institute (MCHRI) (D.M.), the core grant and Career Development Award from Research to Prevent Blindness (RPB), the Matilda Ziegler Foundation, the VA Rehabilitation Research and Development Small Projects in Rehabilitation Effectiveness (SPiRE) program (I21 RX003179), and the Byers Eye Institute at Stanford. The authors also acknowledge Dr. Fernandes-Cunha, Gabriella M., Kristina Russano, Dr. Yang Hu, Dr. Liang Li, Dr. Fang Fang, and Haoliang Huang from the Department of Ophthalmology at Stanford.

Declaration of interest

The authors report no conflicts of interest

Data availability

All CAD drawings will be published and downloadable from the journal and our lab website.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by the National Eye Institute [K08EY028176, T32 EY027816, and P30EY026877]; The Maternal & Child Health Research Institute at Stanford; the Byers Eye Institute at Stanford; the Matilda Ziegler Foundation; the VA Rehabilitation Research and Development Small Projects in Rehabilitation Effectiveness (SPiRE) program [I21 RX003179]; a Career Development Award and departmental core grant from Research to Prevent Blindness (RPB); and the Stanford SPARK Translational Research program.