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I read with great interest the article by Koranyi and coworkers, who evaluated a new technique for pterygium surgery using a fibrin tissue adhesive (Tisseel Duo Quick).1 In their randomised trial the authors concluded that using the glue instead of sutures caused less postoperative pain and shortened the surgical time. Nevertheless, the timing of the randomisation is not clearly stated in their report.
Whether or not the surgeon knew the patient’s group (sutures or fibrin glue) at the time of pterygium removal and conjunctival graft harvesting may have influenced the extent of the removal and the size of the graft. Therefore, the differences in postoperative pain and/or recurrence could be related to those initial steps and not only to the final step, as the authors suggest. Ideally, the surgeon should be informed if the conjunctival graft should be sutured or glued after harvesting it.
Additionally, in their discussion the authors did not mention the risk of infection when using fibrin glue. Some viruses, such as parvovirus B19 (HPV B19) are particularly difficult to remove or inactivate, and human infection has been reported after the use of fibrin glue.2 In thoracic surgery, epidemiological evidence suggests that more than 20% of uninfected people were subsequently infected with HPV B19 by use of fibrin during the procedure.3 Prions are also of concern. The direct application of any of the apparently effective methods of prion decontamination to plasma products is inappropriate because they are harsh and denaturing.4 Although the risks for both diseases are minimal, the authors should have addressed this issue in their discussion.
We thank Dr Alvarenga for his comment on our article about using fibrin glue for pterygium surgery.
We write in the “Material and methods” section that only the thickened and keratinised portion of the conjunctiva was excised and the graft was prepared to have the same size as the nasal conjunctival defect, regardless of which group the patient was randomised to. Thus, the knowledge of the surgery method did not influence the results or conclusions of the study. It is also impossible to randomise the patients without the surgeon’s knowledge, because the grafts were handled somewhat differently in the different methods described.
The fibrin adhesives in the references mentioned by Alvarenga are clearly not Tisseel Duo Quick (Baxter). In the article by Hino et al, the specific trade name of the fibrin sealant is not given, but the text states that the sealant in question is treated by dry heat to inactivate viruses—Tisseel is vapour heated, so it cannot be Tisseel. In the article by Kawamura et al the product is Beriplast (Aventis Behring). Nevertheless, we will pay attention to this matter in the future. We have not been able to find any report of HPV B19 infection when fibrin glue was used in minor surgery. To date we have used the fibrin glue in more than 700 eye procedures since 1999. Any clinical infection with HPV B19 has not yet been detected in our patients.