A journal has issued an expression of concern for a 2020 paper by researchers in Korea who have used 3-D printing to create artificial eyes for dogs.
The study triggered a slew of critical comments from readers, who were outraged by the ethics of the research and what they saw as inadequate protections for the animals against pain.
The paper is titled “Custom-made artificial eyes using 3D printing for dogs: A preliminary study,” and the senior author is Kyung-Mee Park, of Chungbuk National University. According to the abstract:
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.
The paper was published on November 20. On December 8, a comment from “gmusk” appeared, stating:
I find it disappointing that a preliminary study of only two dogs can be published when the ethical questions about the value of the technique are largely unanswered, certainly to my satisfaction. The anaesthetic and analgesic management of these two cases is also questionable and the authors acknowledge that post operative pain was observed. The performance of such procedures without a comprehensive preventive and multi-modal analgesia regime is not consistent with the standards to which I would expect such procedures to be performed, as a veterinary anaesthetist.
That was followed by a string of equally critical comments about the paper. One poster remarked:
I am aware of no evidence that a prosthetic eye would provide any benefit to the individual dog. If there is any evidence that the cosmetic aspect of unilateral or bilateral eye loss somehow impairs social interactions between dogs, or impacts their quality of life in any way, it should have been presented as a pre-requisite for approving the study, and a full discussion of ethical implications should have been included in the manuscript. There can be no justification for such studies if their sole motivation is to pander to the cosmetic desires of the owner for their pet.
Another, identified as PennyRSPCA, wrote:
Dog owners who cannot accept that their companion animals will look different following surgery need to be educated with respect to the intrinsic worth of animals, and encouraged to reflect on the appropriateness of their attitudes and beliefs. Subjecting laboratory animals to painful and distressing procedures, to evaluate unnecessary prosthetics, is not the solution. My organisation successfully rehomes many animals who do not look ‘perfect’ to people who do not have such superficial values, and we are opposed to cosmetic procedures on animals to satisfy human aesthetics.
The expression of concern reads:
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 ONE’s 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 naïve dogs instead of clinical cases to achieve the study’s 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 ONE’s 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.
Park did not respond to a request for comment.
David Knutson, the senior communications manager for PLOS ONE, told us:
We sincerely regret that the concerns noted in the Expression of Concern were not addressed prior to publication, during peer review. However, we cannot disclose information about the reviewers’ and Academic Editor’s comments to the authors, per PLOS policy regarding confidentiality of the peer review process.
Update, 2030 UTC, 3/11/22: PLOS has corrected the expression of concern, saying that a number of issues were resolved.
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I have required enucleation surgery and wear a very realistic prosthetic eye. I am extremely grateful for the skills, both medical and artistic, of the team involved in my treatment. However, these eyes are very expensive in their current hand crafted form and I’ve often wondered why we cannot use some means of digital reproduction. This could make such items considerably more available to the poorer members of our societies.
I had anticipated considerable pain following surgery, especially as I was advised to fulfill a prescription for an opioid pain medication before the surgery for later use. On the second day following surgery I’d forgotten I was advised to continue with non-prescription painkiller for a week. It was simply no problem. The initial pain was related to severing muscles during the surgery itself but was not debilitating.
There is a huge “yuck” factor for people thinking about eye surgery. People who have had it generally comment otherwise (not to denigrate those who have lots of other eye conditions including chronic pain).
While the immediate application of this paper may seem trivial, I see it as a start towards a major change in thinking about human prosthetic design and manufacture.
Would canines even be the appropriate human analogue?
Some obvious differences, but there would be the same requirement for precision, individualised shape and size plus the material used must be impervious and hard but resistant to scratching.
I’m not sure, but it looks to me that the dogs did not have an implant in the socket before the prosthesis is fitted. Mine looks rather like an oversized contact lens. I can remove it easily for cleaning. The implant fills the socket and covered with a layer of skin as well as being attached to muscles and hence some movement of the prosthesis on top.