| ◄▬ | 2004 Metz ea | ▬► |
Metz e.a. beschrijven in een artikel van febr. 2004 een patiënt met een MIRAgel scleral buckle, waarvan de complicaties leidde tot blindheid.
A hydrophilic implant for scIeral buckling was developed in 1980. 1 Advantages include softness and elasticity, no dead spaces, ability to gradually absorb and release antibiotics, and stimulating production of a fibrous capsule around the implant. Short-term follow up studies in rabbits showed no clinical or histologic complications. 1-2 Long-term complications of the hydrogel scleral buckle have emerged in the last 10 years. 3-6 These included fragmentation, subconjunctival buIging, intraocular erosion, migration, and restriction of extraocular movement. We recently encountered a patient with progressive restrictive strabismus beginning 8 years after retinal detachment repair with a MIRAgel (hydrogel; MlRA, Uxbridge, MA) scleral buckle. W orsening complaints of diplopia and discomfort led to strabismus surgery. Untreatable retinal detachment resulted in enucleation.
De operatie liep slecht af. Er werd een Miragel plombe aangetroffen, die gezwollen was tot wel vier of vijf maal zo groot, die bij de geringste aanraking fragmenteerde. De sclera bleek verdund ‘with choroidal exposure and leaking liquid vitreous’ met een dag later fatale gevolgen!
During surgery, the forced-duction test showed marked restriction to downgaze of the right eye. Attempts to expose the muscles resulted in observation of a large encapsulated scleral exoplant. After opening the capsule, the MIRAgel buckle appeared translucent and swollen to four to five times normal size. Maneuvers to remove the buckle resulted in fragmentation to the slightest touch.
Continued dissection to remove the exoplant resulted in the appearance of a thinned area of sclera with choroidal exposure and leaking liquid vitreous. No retinal prolapse or detachment was noted. The overlying segment of buckle was replaced to act as a tamponade, and the overIying Tenon's capsule and conjunctival tissue were closed securely.
The following day. the patient was evaluated by his retina! surgeon who found a "kissing" choroïdal detachment in the right eye. Treatment, including reoperation to close the scleral perforation, was unsuccessful. Several months later, the right eye was enucleated.
De auteurs vermelden de complicaties van siliconen explants zoals extrusie en erodering door de sclera. De hydrogel ‘Refojo implant’ was ontwikkeld om deze complicaties tegen te gaan. Korte termijn testen bij konijnen waren positief. In 1992 rapporteerden Marin ea lange termijn complicaties, die door MIRA Inc. werden ontkend. Daarna verschenen meer rapporten over lange termijn complicaties (Hwang ea 1997, Braunstein ea 2002),
Discussion
Scleral buckling with cxoplant material, such as solid silicone and silicone sponge. has heen associated complications such as extrusion, pressure necrosis with erosion through the sclera, infection rates reporred from 2.7% to 18%,2 and restrictive strabismus with diplopia during a period several months after surgery. This can occur with any scleral huckling surgery. In an attempt to eliminate or minimize these problems, a hydrogel material was developed by Refojo et al. I Favorable qualities of the new material included softness, elasticity, nonabsorbability, absence of dead spaees, ability to be sterilized with heat, and ahility to ahsorh and gradually release antibiotics. Shortterm follow up studies in rabbits indicated no clinical or histologic signs of significant toxiciry or inflammation. 1-2
In 1992, Marin 3 reported seven patients in whom longterm complications developed from swelling of the hydrogel buckling implant (MIRAgel) 7 to 11 years after surgery. Hasslinger,7 the director of research and development at MIRA Inc, denied knowledge of any reported complications secondary to the placement of MIRAgel implants. Since then, there have been several reports of long-term problems in patients who have had hydrogel used for scleral buckling repair of their retinal detachments. 3-6-8 The implants were often removed because of excessive scleral indentation and subconjunctival intrusion or extrusion. On removal, the hydrogel appeared friable and swollen with dehiscence of the scleral bed (as in the case of implants), vitreous hemorrhage, and loss of vision in some cases.
A patient reported by Hwang and Lim 4 had limitation of adduction and infraduction with diplopia 8 years after scleral buckling with MIRAgel, and this condition worsened over time. After the scleral buckle was removed, the patient became orthophoric in primary gaze with mild remaining restriction of adduction and infraduction.
Braunstein and Winnick 6 reported a patient with complications 13 years after uneventful scleral buckling procedure using MIRAgel. Diplopia and orbital swelling were noted, and infraduction of the operated eye was limited. These findings mimicked a periorbital mass lesion. During surgery to remove the buckle, the hydrogel material was noted to be 4.5 times its norma[ size. Removal of the buckle resulted in elimination of diplopia.
De auteurs vermelden ook dat verwijdering van de hydrogel implants moeilijk is vanwege het fragmenteren van het materiaal en erosie en perforatie van de sclera.
Our case report patient did weIl for 8 years after retinal detachment repair. He then presented with incrcasing horizontal and vertical diplopia as well as increasing restrictions to ocular motility. We now know that hydrogel implants are often well tolerated for a number of years, but they have the potential to cause late problems. Special care must he taken in attempting to remove these implants because the surgery is difficuIt and tedious, the material fragments easily, and scleral erosion and perforation have been noted as in the case of our patient. In some cases, it may be best to leave the implant in place rather than put the eye at additional risk. This decision depends on the effect of the scleral buckle and the situation. If surgery becomes unavoidable, the strabismologist should consider obtaining the assistance of a retinal surgeon. It seems advisable to have banked sclera, tissue, glue, etc, available in these types of surgeries in case there is a need to close any sclera defects encountered.
| ◄▬ | 2004 Metz ea | ▬► |