66 year-old female presents for routine exam to monitor for tumor recurrence 20 months after brachytherapy
Choroidal melanoma OS s/p plaque brachytherapy
Choroidal nevus OD
Tumor has been decreasing in size on ultrasound
Last liver CT four months ago without evidence of metastatic disease
Reports occasional flashes in both eyes and slow decrease in vision OS
Exam Findings
VA 20/25; 20/100
Pupils RR OU, no RAPD
IOP 18; 14
EOM full OU
SLE unremarkable OU
Figure 1: Minimally elevated superotemporal choroidal nevus with overlying drusen OD.Figure 2: Superior choroidal melanoma s/p plaque brachytherapy with surrounding chorioretinal atrophy OS.Figure 3: Fluorescein angiography with staining of the drusen overlying the choroidal nevus OS.Figure 4: Fluorescein angiography of the radiated left eye demonstrating peripheral vascular drop out, mild vascular attenuation, choroidal atrophy with window defects, a ‘hot’ optic nerve and leakage in the OS.Figure 5: OCT macula with cystoid macular edema OS.Figure 6: OCTA with normal foveal avascular zone area OD.Figure 7: OCTA with increased foveal avascular zone area OS.
Differential Diagnosis
Radiation retinopathy
Diabetic retinopathy
Central retinal vein occlusion
Branch retinal vein occlusion
Hypertensive retinopathy
Coats’ disease
Diagnosis
Radiation maculopathy/retinopathy
Pathophysiology
Exposure to radiation causes preferential loss of endothelial cells in the vasculature with sparing of pericytes. Irradiation causes direct endothelial cell damage as well as damage from free radicals created by radiation-related damage to red blood cells and iron.
Clinical findings:
Retinal microaneurysms (more prevalent in other vasculopathies, including diabetes mellitus)
Retinal hemorrhages
Retinal hard exudates
Macular edema
Cotton-wool spots
Retinal neovascularization
Vitreous hemorrhage
Tractional retinal detachment
Uveitis
Treatment
Intravitreal anti-VEGF
Intravitreal/periocular triamcinolone
Grid macular laser photocoagulation
Sector scatter and pan-retinal photocoagulation to areas of retinal non-perfusion
Photodynamic therapy, hyperbaric oxygen
Vitrectomy
Primary Prevention: Ways to decrease radiation dose or to treat before an issue is found
Shielding during external beam radiation
Hyperfractionationed external beam radiation
Collimating plaques
Prophylactic periocular triamcinolone
Prophylactic laser photocoagulation
Prophylactic anti-VEGF therapy
Prognosis and Future Directions
Radiation retinopathy and neuropathy is the leading cause of permanent and severe vision loss after radiation
Onset of symptoms start from six months to three years (reported from one month to 15 years)
Radiation maculopathy risk factors:
45 Gy dose for plaque brachytherapy, 15 Gy for external beam
Recent studies on OCT angiography as an new sensitive imaging modality for radiation retinopathy
Therapy is multimodal with anti-VEGF and intravitreal steroid injections. Some centers are using these modalities as prophylactic therapy with promising results.
References
Stallard HB. Radiotherapy for malignant melanoma of the choroid. Br J Ophthalmol. 1966 Mar;50(3):147-155.
Flick JJ. Ocular lesions following the atomic bombing of Hiroshima and Nagasaki. Am J Ophthalmol. 1948 Feb;31(2):137-154.
Puusaari I, et al. Ocular complications after iodine brachytherapy for large uveal melanomas. Ophthalmology. 2004 Sep;111(9):1768-1777.
Archer DB, et al. Radiation retinopathy–clinical, histopathological, ultrastructural and experimental correlations. Eye (Lond). 1991;5(Pt 2):239-251.
Shields CL, et al. Plaque radiotherapy for uveal melanoma: long-term visual outcome in 1106 consecutive patients. Arch Ophthalmol. 2000 Sep;118(9):1219-28.
Monroe AT, et al. Preventing radiation retinopathy with hyperfractionation. Int J Radiat Oncol Biol Phys. 2005 Mar 1;61(3):856-864.
Shields CL, et al. Optical Coherence Tomography Angiography of the Macula after Plaque Radiotherapy of Choroidal Melanoma: Comparison of Irradiated Vs Non Irradiated Eyes in 65 Patients. Retina. 2016 Aug;36(8):1493-505.
Horgan N, et al. Periocular triamcinolone for prevention of macular edema after plaque radiotherapy of uveal melanoma: a randomized controlled trial. Ophthalmology. 2009 Jul;116(7):1383-1390.
Shah SU, et al. Intravitreal bevacizumab at 4-month intervals for prevention of macular edema after plaque radiotherapy of uveal melanoma. Ophthalmology. 2014 Jan;121(1):269-75.
Contact
Jesse Berry, MD, Assistant Professor of Clinical Ophthalmology and Associate Director of Ocular Oncology, jesse.berry@med.usc.edu
