Aim To compare the choroidal thickness measurements obtained during the attack period and during the pain-free interval in migraine patients using enhanced depth imaging optical coherence tomography (OCT).

Methods 58 eyes of 29 subjects with a diagnosis of migraine with or without aura were enrolled in this observational, cross-sectional study. Two OCT scans were performed for each patient, one during the peak period of the migraine attack and the other during the headache-free interval, using the enhanced depth imaging mode. Choroidal thicknesses were measured at the fovea, at three locations nasal and at three locations temporal to the fovea at 500 μm intervals.

Results In patients with unilateral headaches, the choroidal thickness measurements obtained during the attack period were significantly increased only in the eyes on the headache side (p<0.001) compared to basal levels. At the fovea, the choroidal thickness measured in the pain-free interval was 373.45±76.47 μm (mean±SD), which increased to 408.80±77.70 μm during the attack period (p<0.001). When the choroidal thickness measurements of patients with bilateral headaches were compared to basal levels, a statistically significant increase was observed at five out of the seven measured points in the right eyes (p<0.05) and at all seven measured points in the left eyes (p<0.05).

Conclusions Choroidal thickness was found to be significantly increased in migraine patients during the attack period when compared to basal levels. The possible implications of this finding on the association between migraine and glaucoma are discussed.