Roldan-Pallares ea 2016 ‘MIRAgel: the immunohistochemical expression of CD3, CD34, and CD68 in the surrounding capsule', Eye (2016) 30, 1381–1388

Leek lange tijd het beleid te zijn om Miragel alleen te verwijderen ingeval van symptomatische klachten. Het advies van Roldan-Pallares ea 2016 is om alsnog alle Miragel plombes te verwijderen omdat gefragmenteerde Miragel door het menselijk immuunsysteem wordt gezien als vreemd lichaam, hetgeen lokaal ziektes veroorzaakt en bestendigt:

Abstract conclusions The immunohistochemical analysis revealed that the immune system is able to identify the fragments of MIRAgel (after its hydrolytic degradation) as a foreign body during a delayed T cell-mediated immune response. The phagocytosis by macrophages likely triggers and perpetuates local disease. Removal of MIRAgel explants before hydrolysis should be considered.

Discussion – (p.1386-1387)
(...) We can assume that swelling is something that probably is already ongoing in all cases at some point after 5 years of time. The mean implantation duration of our patients was 18.5 years (range, 16–24 years) and all the patients showed clinical pseudotumor caused by MIRAgel swelling because of hydrolytic degradation. Anyway, at the moment all the implanted patients must have MIRAgel for 16 years or more (MIRA Inc. discontinued MIRAgel in 1995 in USA,³⁹ but MIRAgel continued to be distributed outside the United States and we used it until the year 2000 ¹⁰). Then, removal of MIRAgel explants before hydrolysis and probably removal of all MIRAgel explants should be considered in order to avoid complications. A significant determination coefficient (r2= 0.1933, P=0.0105) was found in our series between CD3 number (higher risk) and longer duration of MIRAgel. The immunohistochemical analysis revealed that the immune system is able to identify the fragments of MIRAgel (after its hydrolytic degradation) as a foreign body during a T cell-mediated immune response.
 

Summary
What was known before

• MIRAgel is a scleral buckling material used in retinal reattachment surgery. Swelling and fragmentation 7 to 10 years after implantation with orbital discomfort and diplopia led to the discontinuation of its use in 1995.
  Prompt removal of the MIRAgel explants was recommended when discomfort and/or fragmentation begins.

What this study adds

• The immunohistochemical analysis revealed the immune system is able to identify the MIRAgel fragments as a foreign body during a delayed T cell-mediated immune response. The phagocytosis by macrophages likely triggers and perpetuates local disease. Thus, MIRAgel material should be removed before hydrolysis and fragmentation in all cases.