Photodynamic therapy of subretinal neovascularization in radiation retinopathy

Radiation retinopathy intricacies and advances in management

Background: Radiation retinopathy is a chronic, progressive, vision-threatening complication from exposure to various radiation sources. While several treatment modalities are available, proper management for this disease is a continuing challenge with no consensus on the most efficacious.Objective: The aim of this article is to provide an updated review of the published literature on the course of the disease, available treatments and their efficacies, frequency of regimen, core issues in patient management, and additional newer treatment modalities, including possible prophylactic approaches.Value: We also highlighted the challenges encountered with managing chronically treated patients through an analysis of a clinical case report on a patient who was treated for several years with different modalities after a diagnosis of radiation retinopathy.

Supportive care for toxicities in children undergoing radiation therapy

Radiation therapy (RT) is an integral part of the management of many pediatric tumors; however, it is associated with both acute and permanent adverse events that can significantly impact a child's quality of life, lead to treatment delays, and potentially affect outcomes of cancer therapy. Prevention, early detection, and optimal management of these adverse effects will help reduce their impact on the patients' quality of life and overall well-being. Unfortunately, there has not been a coordinated effort to study the etiology, evaluate risk factors, and explore novel treatments for these conditions. Studies of supportive care for children undergoing RT are often small and uncontrolled. This review will focus on the impact of irradiation on the different organ systems and their current management. Further studies are required to improve our understanding of the contributing factors and explore novel treatment options for these adverse effects and to enable children and their families to better cope with some of the unavoidable toxicities following multimodality therapy.

Anti-Vascular Endothelial Growth Factor Therapy for Radiation Retinopathy

BACKGROUND AND OBJECTIVE

The purpose of this article is to review the role of anti-vascular endothelial growth factor (VEGF) therapy in treating patients with radiation retinopathy (RR).

PATIENTS AND METHODS

RR can be associated with a significant decrease in visual acuity (VA) related to the development of cystoid macular edema, macular ischemia, and proliferative retinopathy leading to neovascular glaucoma.

RESULTS

Anti-VEGF therapy is effective at stabilizing VA in around 80% of patients and achieving reductions in central macular thickness when it is administered using a constant algorithm. Furthermore, consistent prophylactic anti-VEGF therapy reduces the risk of development of RR, neovascularization of the iris, and neovascularization glaucoma.

CONCLUSION

Future studies are needed to determine the optimal regimen for anti-VEGF therapy according to patient risk factors and likelihood of developing RR. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S44-S49.].

Effect of intravitreal dexamethasone implant on the contralateral eye in recalcitrant radiation maculopathy

Radiation maculopathy, a subset of significant radiation retinopathy, is one of the most common causes of visual loss following localized, regional, or whole-brain radiotherapy. Ozurdex (Allergan Inc., Irvine, CA, USA), a sustained-release intravitreal implant of 0.7 mg dexamethasone, has been used as an off-label treatment for treating recalcitrant radiation maculopathy. However, to the best of our knowledge, the beneficial effect of intravitreal dexamethasone in the contralateral eye in a patient with radiation maculopathy has not been described in the literature so far. In this case report, we report the efficacy of dexamethasone 0.7 mg intravitreal implant in recalcitrant radiation maculopathy which was refractory to intravitreal bevacizumab therapy. The patient showed good anatomical and functional outcomes in both the eyes after unilateral injection of intravitreal dexamethasone as evident by optical coherence tomography scans and fundus fluorescein angiography. It is noteworthy that the contralateral was not treated for 4 years. The case reveals systemic exposure of dexamethasone after intravitreal injection by demonstrating the bilateral effect after unilateral injection of intravitreal dexamethasone

Current treatments for radiation retinopathy

BACKGROUND

to review the currently available therapeutic modalities for radiation retinopathy (RR), including newer investigational interventions directed towards specific aspects of the pathophysiology of this refractory complication.

METHODS

a review of the literature encompassing the pathogenesis of RR and the current therapeutic modalities available was performed.

RESULTS

RR is a chronic and progressive condition that results from exposure to any source of radiation. It might be secondary to radiation treatment of intraocular tumors such as choroidal melanomas, retinoblastomas, and choroidal metastasis, or from unavoidable exposure to excessive radiation from the treatment of extraocular tumors like cephalic, nasopharyngeal, orbital, and paranasal malignancies. After the results of the Collaborative Ocular Melanoma Study, most of the choroidal melanomas are being treated with plaque brachytherapy increasing by that the incidence of this radiation complication. RR has been reported to occur in as many as 60% of eyes treated with plaque radiation, with higher rates associated with larger tumors. Initially, the condition manifests as a radiation vasculopathy clinically seen as microaneurysms and telangiectases, with posterior development of retinal hard exudates and hemorrhages, macular edema, neovascularization and tractional retinal detachment. Regrettably, the management of these eyes remains limited. Photodynamic therapy, laser photocoagulation, oral pentoxyphylline and hyperbaric oxygen have been attempted as treatment modalities with inconclusive results. Intravitreal injections of anti-vascular endothelial growth factor such as bevacizumab, ranibizumab and pegaptanib sodium have been recently used, also with variable results.

DISCUSSION

RR is a common vision threatening complication following radiation therapy. The available therapeutic options are limited and show unsatisfactory results. Further large investigative studies are required for developing better therapeutic as well as preventive treatment strategies.

Photodynamic therapy for subretinal new vessels

Photodynamic therapy (PDT) involves the induction of endothelial cell death or occlusion of blood vessels. On the basis of this mechanism of action, PDT is used in the treatment of predominant classic choroidal neovascularization (CNV), if the classic component is over 50%, and in myopic CNV. This study describes 2 cases of distinctive, abnormal, large, subretinal new vessels that are thought to have originated from the choroids. Diminishment of the new vessels was observed following treatment with PDT.