INTRAVITREAL DEXAMETHASONE (OZURDEX) IMPLANT FOR RADIATION MACULOPATHY SECONDARY TO STEREOTACTIC RADIOTHERAPY FOR POSTERIOR UVEAL MELANOMA.

PURPOSE: To evaluate the efficacy of 0.7 mg intravitreal dexamethasone implant in the treatment of radiation maculopathy after stereotactic radiotherapy for posterior uveal melanoma. METHODS: Retrospective chart review of seven eyes of seven consecutive patients was performed. Extracted data included age, sex, initial and follow-up visual acuities and central macular thickness values, intraocular pressure, follow-up time, number of implants, and time elapsed from radiotherapy to implantation. Main outcome measures were visual acuity and central macular thickness. Glaucoma, cataract formation, or systemic side effects, if any, were recorded. RESULTS: Female to male ratio was 4:3. Mean age was 49.9 ± 17.0 (range: 27-73). Initial mean visual acuity was 20.4 ± 12.5 Early Treatment Diabetic Retinopathy Study letters and initial central macular thickness measured 514.1 ± 135.1 µm on spectral domain optical coherence tomography. All patients except one showed improvement in visual acuity and a mean improvement of 7.4 ± 6.2 letters was observed in the whole group (range: 0-16). The mean reduction in central macular thickness was 226.7 ± 157.0 µm after a mean 9.1 ± 3.4 months of follow-up. On average, implantation of intravitreal dexamethasone was performed 35.2 ± 16.5 months after radiotherapy. Four patients were treatment naive and three had previous intravitreal bevacizumab injections with limited response. Ozurdex reimplantations were performed in four patients and the mean number of injections was 1.7 ± 0.8. Mean time to reimplantation was 5.0 ± 2.12 months. Only one patient developed posterior subcapsular cataract and all patients had intraocular pressures within normal limits. No systemic side effects were observed. CONCLUSION: In our experience, intravitreal implantation of 0.7 mg dexamethasone is an anatomically, and to a lesser extent functionally effective procedure for radiation maculopathy after stereotactic radiotherapy for posterior uveal melanoma.

Radiation therapy: posterior segment complications.

Therapeutic radiation to the posterior segment of the eye is a common option for posterior segment tumors. Such tumors are often malignant, but sometimes, benign neoplasms are treated with ionizing radiation. Also, non-neoplastic intraocular lesions like wet age-related macular degeneration may be treated with radiotherapy. Orbital disease, both neoplastic lesions like optic nerve sheath meningioma and non-neoplastic entities like Graves' ophthalmopathy may be treated with radiotherapy and this may include radiation of the optic nerve and posterior segment of the eye. Occasionally, radiotherapy of extraocular malignant disease, involving, e.g. the paranasal sinuses, may cause significant radiation damage to the eye. Complications after radiation to the posterior segment of the eye are largely related to the radiation dose to the posterior segment. The amount of irradiated volume of normal tissue and fractionation are also important for the development of radiation complications to the posterior segment. Radiation retinopathy is the most common complication of the posterior segment, but radiation optic neuropathy also occurs frequently. Radiation scleral necrosis is less frequent probably due to the radioresistance of the scleral collagen. These complications have the potential to cause blindness (radiation retinopathy and optic neuropathy) or enucleation of the eye (scleral necrosis). Although numerous treatments have been advocated, management of radiation-induced damage remains controversial. Efficacy for any treatment still needs to be proven and, if possible, the best option by far is to minimize radiation changes to normal tissue.