Custom-made artificial eyes using 3D printing for dogs: A preliminary study
Authors: Ho-Hyun Kwak
Jeong-Hee An
Heung-Myong Woo
Kyung-Mee Park
Seo-Young Choi
Ka-Young Lim
Kamal Hany Hussein
So-Young Park
Hyun Kwon
Journal: PLoS ONE (2020)
Discipline: Multidisciplinary
Keywords: eye diseases; phthisis bulbi; evisceration method; silicone balls; impaired cornea
Affiliations: Department of Ophthalmology and Surgery, College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea., Department of Surgery, College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea., Department of Animal Surgery, College of Veterinary Medicine, Assiut University, Assiut, Egypt.

Abstract:  Various incurable eye diseases in companion animals often result in phthisis bulbi and eye removal surgery. Currently, the evisceration method using silicone balls is useful in animals; however, it is not available to those with impaired cornea or severe ocular atrophy. Moreover, ocular implant and prostheses are not widely used because of the diversity in animal size and eye shape, and high manufacturing cost. Here, we produced low-cost and customized artificial eyes, including implant and prosthesis, using computer-aided design and three-dimensional (3D) printing technique. For 3D modeling, the size of the artificial eyes was optimized using B-mode ultrasonography. The design was exported to STL files, and then printed using polycaprolactone (PCL) for prosthesis and mixture of PCL and hydroxyapatite (HA) for ocular implant. The 3D printed artificial eyes could be produced in less than one and half hour. The prosthesis was painted using oil colors and biocompatible resin. Two types of eye removal surgery, including evisceration and enucleation, were performed using two beagle dogs, as a preliminary study. After the surgery, the dogs were clinically evaluated for 6 months and then histopathological evaluation of the implant was done. Ocular implant was biocompatible and host tissue ingrowth was induced after in vivo application. The custom-made prosthesis was cosmetically excellent. Although long-term clinical follow-up might be required, the use of 3D printed-customized artificial eyes may be beneficial for animals that need personalized artificial eye surgery. 

Retracted: No

PubPeer comments:
 2021 expression of concern. https: journals.plos.org plosone article?id=10.1371 journal.pone.0245080 After this article [1] was published, concerns were raised about whether the study meets internationally accepted standards of animal research ethics, as is required per PLOS ONEu2019s Editorial Policy. Specifically, questions were raised as to whether the implants and prosthetics evaluated in the study would offer clinical benefits for dogs as compared to conventional eye removal procedures, so as to justify the reported research. Questions were also raised about the scientific and or clinical justification for using nau00efve dogs instead of clinical cases to achieve the studyu2019s objectives. The ethics statement in [1] reports that the animal experiments were approved by the Chungbuk National University Animal Care and Use Committees (Number: CBNUA-1155-18-01) of Laboratory Animal Research Center at Chungbuk National University (Cheongju, Korea). The article did not discuss the above issues which have implications for adherence of the study to PLOS ONEu2019s policies on animal research ethics. In addition, questions have been raised about aspects of the methods, results, and conclusions: Concerns were raised about the adequacy of the analgesic regimen used given the reported observations of post-operative pain. The methods used to assess animal pain were not clearly reported. Questions were raised as to whether the conclusions were well-supported in light of the small sample size and the results reported in Table 1. The PLOS ONE Editors are reassessing the article and following up on the above issues in accordance with Committee on Publication Ethics (COPE) guidance. In the meantime, we issue this Expression of Concern. Reference 1.Park S-Y, An J-H, Kwon H, Choi S-Y, Lim K-Y, Kwak H-H, et al. (2020) Custom-made artificial eyes using 3D printing for dogs: A preliminary study. PLoS ONE 15(11): e0242274. https: doi.org 10.1371 journal.pone.0242274 pmid:33216792 ,