Application of 3-dimensional printing technology to construct an eye model for fundus viewing study.
OBJECTIVE
To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system.


METHODS
We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy.


RESULTS
In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value.


CONCLUSIONS
The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research.
Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China.
Ping
P
Xie
Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China.
Zizhong
Z
Hu
Department of Ophthalmology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing 210000, P.R. China.
Xiaojun
X
Zhang
School of Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China; Ophthalmic Technology of College, Jinling Institute of Technology, Nanjing, 210001, P.R. China.
Xinhua
X
Li
School of Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China.
Zhishan
Z
Gao
Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China.
Dongqing
D
Yuan
Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China.
Qinghuai
Q
Liu
D001251:Astigmatism / Q000503:physiopathology; D003198:Computer Simulation; D003315:Cornea / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000379:methods*; D005654:Fundus Oculi; D006801:Humans; D007910:Lenses, Intraocular; D008953:Models, Anatomic; D019904:Polymethyl Methacrylate; D066330:Printing, Three-Dimensional; D012030:Refractive Errors / Q000503:physiopathology
D019904:Polymethyl Methacrylate