Investigation of a 3D printed nylon corneal limbus shield for use during corneal cross-linking

Session Details

Session Title: Moderated Poster Session: What News from Cornea?
Session Date/Time: Saturday 22/02/2020 | 14:00-15:00
Paper Time: 14:16
Venue: Poster Area


First Author: B.Lemanski USA
Co Author(s): N. Lemanski                 

Abstract Details

Purpose:

To determine if an inexpensive, single use corneal limbal shield can be designed with intent for single use, 3D printed in Nylon 680 on a fused filament deposition (FFD) printer with minimal dimensional changes after autoclaving.

Setting:

Private 2 provider ophthalmology practice located in Upstate New York, USA.

Methods:

A plastic ocular shield (reference) was dimensionally recorded into Autodesk Fusion (San Rafael, CA, USA). An eleven millimeter diameter hole (slightly less than the literature reported average white to white size in a population) was made on the model’s apex and a lip peripherally added for forceps manipulation. Design was sliced in Cura 3.6.20 (Aleph Objects, Loveland, CO, USA) and printed on a Single Extruder (2.1) LulzBot TAZ 6 in dried Nylon 680 (FDA Grade, 2.85mm) with varying settings to layer height and print speed to maximize surface quality. Parts were dimensionally checked, autoclaved, and rechecked.

Results:

Final designed dimensions were 20.1mm, by 18.2mm, by 3.5mm. Six shields a piece were printed at 160μm, 90μm, 60μm and 40μm layer heights. All parts were within 0.1mm tolerance of design. A suitable smooth, semi-opaque finish was observed at 60μm printed at 100% infill at reduced speed (40mm/s); 160μm and 90μm had insufficient surface finish and 40μm could not be reliably printed. Average print time was 10 minutes using 0.03m of filament (0.06 USD). Dimensional tolerances did not exceed 0.2mm after steam autoclaving. There was no appreciable difference on microscopic examination of filaments before or after autoclaving.

Conclusions:

A simple and inexpensive shield can be designed, quickly printed on a low-cost (<2500 USD) FFD printer. To our knowledge this is the first FFD printed and autoclavable corneal shield. While we did not conduct sterility testing on these printed parts, our group has previously demonstrated single use sterility on larger Nylon 680 parts created using the same printer setup abovementioned. The ability to design this type of shield affords additional applications in targeted crosslinking for bacterial keratitis. Future directions will incorporate elevation data from corneal topographers for better fitment.

Financial Disclosure:

None