Retinopathy

BASICS


DESCRIPTION


• Radiation retinopathy is a delayed onset, chronic, progressive, occlusive vasculopathy of the retinal circulation resulting from previous radiation treatment to the eye, orbit, head, or neck.


– It can be divided into nonproliferative and proliferative retinopathy.


EPIDEMIOLOGY


Incidence


• Varies by total radiation dose, mode of delivery (brachytherapy vs. external beam), fraction size, and isotope.


• Rare when dose is <40 Gy.


• Incidence peaks 2–3 years post radiation exposure.


Prevalence


Depends on the length of follow-up


RISK FACTORS


• Diabetes


• Chemotherapy


• High dose per fraction


PATHOPHYSIOLOGY


Loss of retinal capillary endothelial cells leading to vascular incompetence and eventually occlusion and nonperfusion.


ETIOLOGY


Radiation induced free radical formation causing direct damage to endothelial cells. Radiation induced damage to cellular chromosomal DNA.


DIAGNOSIS


HISTORY


Previous radiation treatment to the eye, orbit, head, or neck.


PHYSICAL EXAM


• Capillary dilation


• Telangiectasias


• Microaneurysm


• Cotton wool spots


• Macular edema


• Intraretinal hemorrhages


• Lipid exudates


• Vascular sheathing


• Neovascularization of the retina, disc, or iris


• Vitreous hemorrhage


• Retinal detachment


DIAGNOSTIC TESTS & INTERPRETATION


Lab


• Careful slit lamp examination for anterior segment neovascularization


• Tonometry and gonioscopy to monitor neovascular glaucoma


Diagnostic Procedures/Other


• Diagnosis is usually made clinically.


• Fluorescein angiography may show microaneurysms, telangiectasias, capillary nonperfusion, neovascularization, and cystoid macular edema.


• Optical coherence tomography may demonstrate cystoid macular edema.


DIFFERENTIAL DIAGNOSIS


Diabetic retinopathy, hypertensive retinopathy, arteriole obstruction, venous occlusions, ocular ischemia syndrome


TREATMENT


ADDITIONAL TREATMENT


General Measures


• Loss of visual function due to nonperfusion is irreversible and permanent.


• Focal or grid laser treatment may be beneficial for vision loss associated with macular edema. Panretinal photocoagulation is indicated for optic nerve, retinal, or anterior segment neovascularization.


Additional Therapies


Anti-VEGF (bevacizumab or ranibizumab) therapy for macular edema or neovascularization may provide short-term benefit.


COMPLEMENTARY & ALTERNATIVE THERAPIES


• Monocular precautions


• Polycarbonate lenses


SURGERY/OTHER PROCEDURES


Vitrectomy surgery for patients with vitreous hemorrhage or retinal detachment.


ONGOING CARE


FOLLOW-UP RECOMMENDATIONS


An ophthalmologist should be consulted every 3–6 months.


Patient Monitoring


Monitor visual acuity, IOP, slit lamp exam, and dilated fundus exam for neovascular complications.


PROGNOSIS


Radiation retinopathy is a slowly progressive condition that often leads to irreversible vision loss.


COMPLICATIONS


• Visual loss


• Neovascular glaucoma


ADDITIONAL READING


• Archer DB, Amoaku WM, Gardiner TA. Radiation retinopathy – clinical, histopathological, ultrastructural and experimental correlations. Eye 1991;5:239–251.


• Gunduz K, Shields CL, Shields JA, et al. Radiation retinopathy following plaque radiotherapy for posterior uveal melanoma. Arch Ophthalmol 1999;117:609–614.


• Monroe AT, Bhandare N, Morris CG, et al. Preventing radiation retinopathy with hyperfractionation. Int J Radiat Oncol Biol Phys 2005;61:856–864.


CODES


ICD9


362.10 Background retinopathy, unspecified


362.15 Retinal telangiectasia


362.29 Other nondiabetic proliferative retinopathy


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Nov 9, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Retinopathy

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