3D Printing in Ophthalmology – From Optical Coherence Tomography to Bioprinting a Human Cornea
3D printing, or additive manufacturing, has penetrated virtually every industry in existence today. Despite its very mechanical and industrial roots, the technology is also rampant in almost all aspects of the medical sector. Ophthalmology, which relates to the treatment of eye disorders, is no exception to this. We’ve seen everything from 3D printed corrective lenses to additively manufactured optics for ophthalmic imaging devices. On the surgical side of things, we’ve even been witness to 3D printed implants and transplantable corneas.
Additive manufacturing of ophthalmic apparatus
Earlier this year, the Medical University of Vienna announced that it was leading a five-year European project to develop a partly 3D printed mobile ophthalmic imaging device. The engineers and scientists working on the handheld eye scanner hope that by the end of the five years, Optical Coherence Tomography (OCT) will no longer be limited to a stationary clinical setting, but will instead be capable of fitting into a breast pocket.
For reference, OCT is a well-established medical method of diagnosing several common eye problems that can often lead to blindness if left untreated. The list, which is not exhaustive, includes diabetic retinopathy, glaucoma, and age-related macular degeneration. By reducing the size and overall manufacturing costs of OCT devices, accessibility to the technology will be increased, and eye care as a whole can be improved.
The device is currently being developed by seven partners across four European countries and has already received €6M in funding via the Horizon 2020 EU innovation program. As miniaturization is key here, nano-printing specialist Nanoscribe will use its two-photon polymerization technology to 3D print the freeform imaging optics of the chip powering the eye scanner.
Corrective lenses are the other major ophthalmic apparatus application of 3D printing. The leader in this space is no doubt Luxexcel, which announced plans to grow further into the market of smart glasses following a revamping of its leadership team back in September. Just last month, the company announced that it had fabricated its 50,000th prescription lens – a major milestone.
The company’s proprietary 3D printing technology is capable of integrating smart features into eyewear lenses, producing what you might call ‘fashionable smart glasses’. The idea is that its customers, which are mainly technology companies, can manufacture their smart eyewear products while also providing vision correction functionality for the users that may need it. This solves the problem of doubling up glasses and consolidates all of the functionality into just one pair.
Digging deeper, the technology works by jetting an acrylic-based resin in the shape of a lens and curing it under UV light. As this is done on a layer-by-layer basis, users can embed smart devices such as holographic films and LCDs directly in the lens between the layers, with the corrective prescription printed on top of the ‘smart layer’ – very clever.
3D printing and eye surgery
When it comes to surgical applications, doctors at the Israeli Galilee Medical Center recently came up with a novel technique utilizing 3D printing to treat a very nasty eye socket fracture. Specifically, the surgeons additively manufactured a titanium implant to replace a piece of bone in the face of a patient and used special AR glasses to precisely place it in the correct section of the skull.
The key here is that 3D printing meshes quite well with 3D scanning and X-ray technology, meaning the doctors were able to model the implant to fit perfectly into the fracture zone after taking a CT scan. The surgery was done promptly, and since the eye socket implant was a perfect fit, post-surgery recovery was encouraged and improved.
Finally – and this is probably the freakiest of the applications – pharmaceutics professor Mandip Sachdeva from Florida A&M University has previously led a research project to 3D bioprint a human cornea for transplantation. The project replicated the collagen matrix of the real cornea by bio-printing with stromal cells and keratocytes from a volunteer. Once transplanted, the printed cornea developed and maintained a normal corneal structure, helping to repair the area and integrate with the rest of the eye like it was always there. It’s amazing what modern tissue engineering can achieve.
The applications we’ve covered thus far are by no means the full list, but it just goes to show the power of 3D printing in a field as niche as ophthalmology. Seeing as the advanced manufacturing technology is so adaptable, it has great potential for intricate devices, prescriptions, and surgical purposes alike. With an ever-increasing volume of research and development in the field, we’ll likely see more work with equipment miniaturization, as well as further biological applications like ophthalmic medical models for drug development.