Abstract
Purpose :
There are limited treatment options for aniridia. 3D-printing may provide cost-effective, cosmetically acceptable iris implants for individuals with aniridia. The purpose of this study was to develop a proof-of-concept workflow for the fabrication of prosthetic irises using slit lamp photography, computer aided design (CAD) and 3D-printing.
Methods :
High resolution external ocular slit lamp photographs taken from healthy volunteers who had primarily green, blue, or brown irises to be representative of the overall population. Images were transferred to Photoshop Software Suite where the irises were isolated for additional processing. The isolated image of the iris was then transferred to Computer Aided Design (Auto CAD) software where it underwent additional processing into a vector file, followed by subsequent extrusion of iris detail. This extruded design was then sliced and used for 3D-printing. To match the color of inks used in the 3D-printed design, photos of the eye were white balanced in Photoshop in order to derive Cyan-Magenta-Yellow-Black (CMYK) values. A matrix of pigment concentrations was created to develop silicone inks (OOMOO 30 Smooth ON silicone rubber) with CMYK values that matched those derived from high resolution photos. 3D-printing of iris prototypes was accomplished with Envisiontec 3D-Bioblotter, which is designed for high resolution and automated bio-fabrication. A disc with a diameter of 34mm and circular pupil opening diameter of 3.5mm was printed. After partial curing, the additional detail of the design for the prototype was printed onto this disc. For the prototype, a simplified human-derived iris design was printed in black (iris detail) and white (base disc) but moving forward color of the disc will be matched to the most common secondary color of the healthy volunteer’s iris image.
Results :
Using images of six volunteer irises (3 brown, 2 green, 1 blue) we identified 9 shades for brown in tandem with 3 different shades that are used to calibrate the color matrix. We have four brown variations (dark, light, yellow, and red) that are within this color matrix. Our workflow produced a prototype iris (currently in black and white) with abovementioned dimensions derived from an external ocular slit lamp photograph.
Conclusions :
Future work will focus on miniaturization, use of color-matched inks, expansion of human iris matching, and tests for biocompatibility and safety.
This is a 2021 ARVO Annual Meeting abstract.