Safety and Efficacy of Silicone Oil Tamponade for Surgical Attenuation of Radiation Damage in Choroidal Melanoma

A prospective, experimental, case series of 20 patients, with choroidal melanoma, in which pars plana vitrectomy and Silicone oil as vitreous substitute will be used as intraocular shielding for attenuating the deleterious effects of radiation dose delivered to healthy ocular tissue during Iodine-125 plaque brachytherapy treatment and assess if the treatment can reduce the incidence and severity of radiation-induced adverse effects like radiation retinopathy and permanent loss of vision.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* All treatment-naïve patients with clinical diagnosis of primary choroidal melanoma, amenable to treatment with plaque brachytherapy, aged 18 or older regardless gender, race/ethnicity or existing medical condition unless they are specifically mentioned as exclusion criteria.
* Patients with best corrected visual acuity of 20/400 or better in the study eye.
* Patients in whom the calculated dose of radiation to the optic nerve or macula is \> 25 Gray (Gy).

Tumor inclusion criteria:

* Unilateral choroidal melanoma, medium size as defined by COMS classification:

  1. At least 2.5 mm in height, but no more than 10 mm in height (no more than 8.0 mm whenever the tumor was near the optic disc), and
  2. No more than 16.0 mm In diameter, regardless the shape by ultrasound.

Exclusion Criteria:

* History of previous treatment for the choroidal melanoma.
* Pregnancy.
* Patients with any impairment which prevent attending follow-up appointments.
* The presence of concomitant significant life-treating medical conditions that significantly reduces the life expectancy to less than three years.
* The presence of other vision-treating ophthalmic condition, not directly related with choroidal melanoma which is likely to going to require intraocular surgery in the next three years.
* Clinical or radiological evidence of the presence of metastatic disease.
* The presence of significant media opacity (e.g. cataract) that precludes the investigator's ability to grade the tumor, performs retina surgery, or performs follow-up assessments.
* Patients that do not accept the informed consent

Tumor exclusion criteria:

* Inability to successfully grade, stage and delineate the tumor by ultrasound.
* Tumor location that will prevent the correct placement of the plaque or have significant risk of optic nerve damage during plaque placement.
* Tumors that involved the anterior chamber angle, the iris or have detectable extrascleral extension.
* Tumor margin location \< 1000 µm from the fovea.

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