Purpose: To explore the relationship between the refractive state of the eye and high blood pressure in a representative population.
Design: Case-control study.
Methods: Three hundred twenty-one patients with essential hypertension (mean age 53.9 +/- 15.5 years) and 188 age-matched and sex-matched healthy control subjects (mean age 50.9 +/- 7.3 years) from the same regional Health Maintenance Organization were consecutively included for the study (P > .05 for age and sex). The refractive state of the eyes was identified objectively by an autorefractometer and retinoscopic examination, recording the autorefractometer values. Spherical equivalents between -0.50 (included) and +0.50 (included) diopters were regarded as emmetropia. Values below or above this interval were regarded as either myopia or hypermetropia. Mean spherical equivalents of the groups were compared using independent samples t test; distributions of refraction were compared with chi(2) test.
Results: The mean spherical equivalent of the patients with essential hypertension was +0.88 +/- 1.34 diopters (range -3.75 to +6.38 diopters), whereas the mean spherical equivalent of the control subjects was -0.26 +/- 1.12 diopters (range -5.00 to +3.38 diopters) (P < .0001). Whereas 61.4% of hypertensive patients were hypermetropic, 18.1% of normotensive patients were hypermetropic (P < .0001).
Conclusions: There is a strong association of essential arterial hypertension with hypermetropia, which has not been previously reported. Given the findings of this study, we recommend that patients who have hypermetropia and have had no recent systemic examination should at least have their blood pressure checked.