Neuro-Ophthalmic Literature Review

Neuro-Ophthalmic Literature Review David Bellows, John Chen, Hui-Chen Cheng, Peter MacIntosh, Jenny Nij Bijvank, Michael Vaphiades, and Konrad Weber 10-year follow-up demonstrates the safety and efficacy of fractionated conformal radiotherapy in the treatment of optic nerve sheath meningioma Pandit R, Paris L, Rudich DS, Lesser R, Kuppersmith M, Miller N. Long-term efficacy of fractionated conformal radiotherapy for the management of primary optic nerve sheath meningioma. Br J Ophthalmol. 2019;103:1436–1440. The purpose of this retrospective study was to determine the efficacy and safety of fractionated conformal radiotherapy (FCRT) in the treatment of optic nerve sheath meningioma. The authors identified 16 patients who had more than 10 years of follow-up (mean 14.6 years) after FCRT. These patients were treated with a mean cumulative dose of 50.0 Gy over a mean of 26.9 sessions. As of the last follow-up visit, 31% of patients had an improvement in vision (two or more lines), 56% had no change in vision, and 13% (two patients) had worsened vision. Of the two patients with worsened vision, one was attributed to radiation retinopathy with macular oedema and the second to a progressive optic neuropathy. The cause of the optic neuropathy was not determined. Quantitative visual fields were available in 63% of patients. Their analysis revealed no significant change in a mean deviation between the pre-FCRT and post-FCRT studies. The authors also report “borderline” improvement in pain, proptosis or diplopia, and no improvement or worsening of colour perception. Three patients (19%) developed late toxicity including one patient who lost visual acuity from radiation retinopathy. Although as many as 30% of patients with untreated optic nerve sheath meningioma will show stable tumour size and vision, we know that the majority will progress. In this retrospective study the authors have shown that, in most patients, visual function and symptoms will stabilize or even improve following FCRT. The authors propose that this should be the first-line treatment for patients with optic nerve sheath meningioma in spite of the inevitable risks including dry eye, radiation retinopathy and radiation optic neuropathy.