RT dose main risk for radiation-induced optic neuropathy

(HealthDay)—The main risk factor for developing radiation-induced optic neuropathy (RION) is radiation dose, with no indication of other significant risk factors, according to a study published online Feb. 9 in Clinical & Experimental Ophthalmology.

Ian Ferguson, from Washington University in St. Louis, and colleagues conducted a retrospective case-control study at a university hospital tertiary care center. They identified 14 cases meeting criteria for a diagnosis of RION by neuro-ophthalmologic exam. Cases were matched with 31 controls without RION based upon maximum radiation dose to the optic apparatus. The authors examined patient characteristics and treatment parameters for attributes predisposing to RION in univariate analysis.

The researchers found that there were no significant associations for alternative risk factors after controlling for radiation dosage.

"These results support the literature suggesting that the primary risk factor for developing RION is radiation dosage and that additional, patient- and tumor-related risk factors may play only a minor role," the authors write.