Visual outcomes of sight threatening radiation-induced meningiomas after low-dose head irradiation: tinea capitis as a paradigm.

PURPOSE: To investigate the visual characteristics and prognosis of vision-threatening meningiomas following low dose head radiation and compare them to those of primary unexposed meningiomas.

METHODS

A retrospective cohort of adults with meningiomas adjacent to the optic nerves or intracranial visual pathways was categorized into radiation-exposed and unexposed meningiomas. Data collected included demographics, visual biomarkers at presentation and at final follow-up, including Visual Acuity (VA), color vision (CV), Visual Field (VF) and peripapillary Retinal Nerve Fiber Layer (RNFL) thickness via Optical coherence tomography (OCT). Comparative analyses were performed between radiation-exposed and unexposed cohorts.

RESULTS

289 eligible patients seen between 2004 and 2023 were included, out of which 31 (10.7%) had undergone tinea capitis radiation. At presentation, patients exhibited a median BCVA of 0.1 LogMAR [IQR 0.1-0.6], median CV of 100% [IQR 64.5%-100%], and 9 (29%) had normal visual fields. Notably, 16 (51.61%) experienced visual loss. Their BCVA decreased at final follow-up, to median 0.23 [IQR 0.1-1.46]. Comparative analysis with 114 radiation-naïve patients with meningioma-induced visual loss revealed no statistically significant disparities in visual characteristics at presentation or at follow-up.

CONCLUSIONS

No statistically significant differences in clinical presentation or visual prognosis were detected between patients with visual pathway meningiomas exposed to low-dose childhood radiation and radiation-naïve patients. Since low-dose cranial irradiation continues to be widely used for conditions such as thyroid eye disease, our findings are relevant beyond the specific context of tinea capitis.