Treatment and prophylaxis of radiation optic neuropathy: A systematic review and meta-analysis

Abstract

Purpose Radiation optic neuropathy (RON) generally follows radiation therapy that exceed 50 Gy to the visual axis and occurs within three years of therapy. Currently, there are no universally accepted treatments or prophylaxis for RON. The review aimed to examine the efficacy of all treatments and prophylaxis for RON. Methods MEDLINE, Embase, the Cochrane Library, and gray literature were searched to December 2020. Studies on treatment(s) and/or prophylaxis of RON were included. Results were meta-analyzed using a random-effects model. Primary outcomes included the proportions of patients who experienced improvement, no change, or worsening of visual acuity (VA) for each treatment. Secondary outcome was the incidence of RON for studies on prophylaxis. Results Overall, 50 studies (n = 5397) were included. Meta-analysis (n = 1752) showed significantly lower incidence of RON in patients who underwent intravitreal anti-VEGF prophylaxis compared to control (RR 0.64, 95%CI [0.48, 0.86]) for uveal melanoma. Intravitreal anti-VEGF injections (n = 68), hyperbaric oxygen therapy alone (n = 14), and pentoxifylline (n = 5) resulted in improved or stable vision ≤1 logMAR in 54.5%, 42.9%, and 40.0% of patients, respectively. Systemic corticosteroids (n = 82), anticoagulants (n = 12), and systemic bevacizumab (n = 7) showed improved or stable vision ≤1 logMAR in 17.1%, 33.3%, and 14.3% of patients, respectively. Overall risk of bias was low, but evidence was limited to retrospective studies. Conclusion Intravitreal anti-VEGF injections reduced incidence of RON in irradiated uveal melanoma patients. Systemic corticosteroids, systemic bevacizumab, and warfarin alone are likely ineffective treatments. Early hyperbaric oxygen therapy and intravitreal anti-VEGF injections were most effective among those investigated and require further investigation.

Case Report: Vision Loss in a Child Caused by Streptococcus constellatus

“…It can also exert an α-adrenergic effect, causing vasoconstriction, reducing local blood volume, and alleviating edema. Hyperbaric oxygen therapy has demonstrated efficacy in the management of various optic nerve disorders, including traumatic and radiation optic neuropathy 14,15 . The primary cause of vision loss is an elevated orbital pressure, which leads to ischemia and hypoxia in the optic nerve; hyperbaric oxygen therapy can help to improve this condition.…”

“…Hyperbaric oxygen therapy has demonstrated efficacy in the management of various optic nerve disorders, including traumatic and radiation optic neuropathy. 14,15 The primary cause of vision loss is an elevated orbital pressure, which leads to ischemia and hypoxia in the optic nerve; hyperbaric oxygen therapy can help to improve this condition. In our patient, vision improved to 20/200 after 1 month of surgical and medical treatment.…”