Lack of photophobia associated with bilateral ventral occipital lesion

Abstract

Keywords Photophobia Bilateral ventral occipitalcortex Brightness Cerebral achromatopsiaBackgroundPhotophobia is a negative reaction to light, a ‘dazzling’ thatcauses temporary discomfort and/or decline in visualfunction. In healthy individuals, transient photophobiaoccurs in response to either bright light or glare and mayserve as a protective function. In patients, chronic orpathological photophobia may occur, persisting in even avery dim light. Many factors are known to cause patho-logical photophobia, but the neural mechanisms areunknown. Here, we report a pathology of the opposite type:three patients with total lack of photophobia resulting frombilateral lesions in the ventral occipital lobe. These caseshighlight the important role the ventral occipital cortexplays in photophobia.Case reportsThree patients had large lesions in the bilateral ventraloccipital lobe with cerebral infarction (Fig. 1a–c). Fundu-scopic examination, which elicits a photophobic reaction inhealthy individuals, did not produce any reaction in thesepatients. Hence, we asked the patients whether any brightlight, including the sun, caused an aversive reaction. Thepatients said that after their brain infarction they couldview the sun directly without any photophobia (thoughthey avoided doing so because they knew it was harmful).We used a simple qualitative observation to evaluatephotophobia [1]. After exposing each patient’s eyesvia indirect ophthalmoscopy with bright-intensity light(1,592 cd/m