Evisceración con doble cobertura escleral / Evisceration with doble scleral coverage

Se incluyeron en el estudio 35 pacientes con una edad comprendida entre 13 y 78 años. La pérdida del globo ocular es traumatizante para el paciente y constituye un fracaso para el oftalmólogo. Tras la evisceración, el implante de hidroxiapatita con la colocación de una prótesis ocular, aporta beneficios estéticos para el paciente. En todos ellos, se practicó la cuadrisección con doble cobertura escleral, que es una de las técnicas quirúrgicas de mayor difusión en la actualidad, con un tiempo de seguimiento de 2 a 30 meses, permitiendo colocar implantes independientemente del tamaño de la cavidad y disminuyendo el riesgo de exposición de estos.

35 patients aged 13-78 were included in the study. The loss of the eye globe is traumatizing for the patient and it is considered a failure for the ophthalmologist. After evisceration, the hydroxyapatite implant with the placement of an ocular prosthesis reports aesthetic benefits for the patient. All of them underwent cuadrisection with doble scleral visceration, one of the most spread surgical techniques at present, with a follow-up from 2 to 30 months. It allows to place implants independently of the size of the cavity and to reduce their exposure risk.

Management of Exposed Hydroxyapatite Implant with Acellular Dermal Allograft

PURPOSE: To evaluate the clinical effect of AlloDerm(R) graft on the management of exposed hydroxyapatite orbital implants. METHODS: Seven eyes of 7 patients with large exposure of hydroxyapatite orbital implants were included. After the spicules of hydroxyapatite implants were smoothened with a drill, AlloDerm(R) was applied to the exposed site and sutured with 8-0 Vicryl. One or two layers of amniotic membrane were transplanted on the AlloDerm(R) graft. RESULTS: All patients underwent the drilling, and the mean intervals from drilling to exposure was 73.4 +/- 46.6 months. The mean follow-up period was 11.17 +/- 2.0 months (range, 9-14 months). Complete conjunctival epithelization occurred in 3 eyes, and partial conjunctival epithelization in 3, including one eye which underwent reoperation with AlloDerm(R). In one eye which had been associated with previous infection, hydroxyapatite was removed due to progressive exposure and inflammation of the implant. CONCLUSIONS: AlloDerm(R) graft is useful in the management of exposed hydroxyapatite implant.

MRI Findings of Orbital Hydroxyapatite Implants in Postoperative 5 months

Fibrovascular ingrowth of 55 cases of intraorbital hydroxyapatite sphere was evaluated by magnetic resonance imaging about 5 months postoperatively at the Department of Ophthalmology, Yeungnam University College of Medicine from April 1993 through May 1998. Of them, evisceration was performed in 35 cases; enucleation in 14 cases, and secondary implantation in 6 cases. Fibrovascularization was classified into 4 groups by width and strength of enhancement, Grade 3-4 and 5 cases showed delayed fibrovascularization, Grade 1. Driling for peg could be performed within 1 month in the cases with Grade 3 fibrovasculariztion. In cases of delayed fibrovascularizated Grade 1 or Grade 2, driling should be performed after confirmation of complete fibrovascular ingrowth by repeated magnetic resonance imaging.

Infected Hydorx yapatite Implant by Pseudomonas Aeroginosa

The hydroxyapatite orbital implant has been known to be a biocompatible and nontoxic implant with good fibrovascular ingrowth, few postoperative complications, and excellent prosthesis motility. The complications after implantation of hydroxyapatite were included peg extrusion, implant exposure, conjunctival dehiscene, granulation tissue overgrowth, and infection of implant. Infected hydroxyapatite implants are, to date, rare. When they occur, implant removal has been the only successful treatment modality. Infection of hydroxyapatite implant occurred in 37months after surgery on conjuctival culture. Pseudomonas aeruginosa was identified as a causative microorganism. To our knowledge, this is the first report of complications with the latest infected hydroxyapatite after implantation of hydroxyapatite. The case also unique because causative microorganism is Pseudomonas aeroginosa instead of Staphylococcus aureus. Persistent conjunctival inflammation postoperatively despite using systemic and topical antimicrobial drops, persist orbital discomfort, discharge, conjunctival dehiscence and the development of a pyogenic grauloma after hydroxyapatite implant should be suspected possibility of hydroxyapatite implant infection.

The Clinical Experience of Hydroxyapatite Implantation using Autologous Sclera and Vicryl Mesh

The hydroxyapatite implant, recetnly widely used new intraorbital implant, in light, highly biocompatible, characterized by easy fibrovascular proliferation. Thus, when inserted after evisceration, it has some beneficial effect cosmetically: it can cause less protrusion of implant or alteration of position and can have good artificial eye motion by linking to the implant. However, in case of hydroxyapatite implantation after evisceration with the cornea preserved, there is a risk of cornea melting by contact with the implant, and in case with the cornea preserved of the eyeball size being too small, hydroxyapatite implant is impossible after evisceration. Hydroxyapatite implantation is done after enucleation using donor sclera, which is not readily available in Korea. Thus we inserted hydroxyapatite implant covered with circular from of Vicryl mesh on endothelium after evisceration in 11 eyes, and inserted hydroxyapatite implant using autologous sclera with Vicryl mesh after enucleation in 3 eyes, in which 18 mm-sized implant could not be implanted after evisceration from August 195 to July 1996. Follow-up examination was done during 6 to 20 (mean 12.9) months postoperatively. Motion of extraocular muscle was very good. During follow-up examination, adverse effects such as conjunctival wound dehiscence and exposure or protrusion of hydroxyapatite implant through the conjunctiva didn`t occur. It should be considered an excellent operative method, because the hydroxyapatite implantation using autologous sclera with Vicryl mesh decreases the risk of exposure or protrusion of the implant and can be performed without the use of donor sclera.

Fibrovascular Ingrowth of the Orbital Hydroxyapatite Implant evaluated by Magnetic Resonance Imaging

The degree and completion of the fibrovascular ingrowth into the implant were evaluated by magnetic resonance imaging on twenty-one cases of intraorbital hydroxyapatite implant insertion following evisceration (16 cases), enucleation (3 cases), and secondary implantation (2 cases) operated at the Department of Ophthalmology, Yeungnam University Hospital during the period from April 1993 through June 1995. Six to seven microholes were made into the hydroxyapatite sphere. It was inserted into the orbital cavity without wrapping with the preserved sclera during the enucleation procedure and posterior scleral incision was performed for insertion of the implant in the evisceration procedure. The magnetic resonance imaging was first taken 2 months postoperatively and then a month interval by the time of complete fibrovascularization. The range of complete fibrovascularization time varied from 86 to 203 postoperative days. The mean time was 4.48 months which was significantly faster than that of the other authors reported in the literatures. The complete fibrovascularization time of the implant had no significant relation to the preoperative conditions, the age, the surgical procedures and the sizes of the implant.

Clinical Experiences of Hydroxyapatite Implantation

Hydroxyapatite which has been used as bone substitute in orthopedic and maxillofacial surgery is used as ocular implant recently. It has been shown to be completly biocompatable, nontoxic and nonallegic so less extrusion and migration develop. We performed 37 cases of hydroxyapatite implantation: 20 cases(51.4%) after evisceration, 8 cases(21.6%) after enucleation and 9 cases(24.3%) secondarily for the better prosthetic motility. Wound dehiscence developed in 6 cases(16.2%): 2 cases(10.0%) after evisceration, 2 cases(25.0%) after enucleation and 2 cases(22.2%) after secondary hydroxyapatitie implanation. Wound dehiscence was managed with dermis graft in 1 case and healed spontaneously in 1 case. Another 4 cases are under observation to expect the wound dehiscence to heal spontaneously. But no extrusion, migration and infection of implant were noted. We thought that wound dehiscence after hydroxyapatite implantation was related to conjunctival damage and atrophy by coarse surface of hydroxyapatite implant. Wound dehiscence can develop after hydroxyapatite implantation but careful patient selection and reducing tissue damage during surgery may alleviate the problems of wound dehiscence.