Headaches associated with refractive errors: myth or reality?
BACKGROUND
Headache and refractive errors are very common conditions in the general population, and those with headache often attribute their pain to a visual problem. The International Headache Society (IHS) criteria for the classification of headache includes an entity of headache associated with refractive errors (HARE), but indicates that its importance is widely overestimated.


OBJECTIVE
To compare overall headache frequency and HARE frequency in healthy subjects with uncorrected or miscorrected refractive errors and a control group.


METHODS
We interviewed 105 individuals with uncorrected refractive errors and a control group of 71 subjects (with properly corrected or without refractive errors) regarding their headache history. We compared the occurrence of headache and its diagnosis in both groups and assessed its relation to their habits of visual effort and type of refractive errors.


RESULTS
Headache frequency was similar in both subjects and controls. Headache associated with refractive errors was the only headache type significantly more common in subjects with refractive errors than in controls (6.7% versus 0%). It was associated with hyperopia and was unrelated to visual effort or to the severity of visual error. With adequate correction, 72.5% of the subjects with headache and refractive error reported improvement in their headaches, and 38% had complete remission of headache. Regardless of the type of headache present, headache frequency was significantly reduced in these subjects (t = 2.34, P =.02).


CONCLUSIONS
Headache associated with refractive errors was rarely identified in individuals with refractive errors. In those with chronic headache, proper correction of refractive errors significantly improved headache complaints and did so primarily by decreasing the frequency of headache episodes.
Gil-Gouveia
R
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Department of Neurology, Hospital Santa Maria, Lisboa, Portugal.
Martins
I P
IP
D000293:Adolescent; D000328:Adult; D005260:Female; D006261:Headache / Q000209:etiology*; D006801:Humans; D006956:Hyperopia / Q000150:complications; D008297:Male; D008875:Middle Aged; D012030:Refractive Errors / Q000150:complications* / Q000473:pathology; D012720:Severity of Illness Index; D013223:Statistics as Topic