BACKGROUND: Hypertensive patients with retinal arteriolar abnormalities are at increased risk for cardiovascular events. However, the extent of retinal microvascular changes in naïve, never-treated patients with hypertension of short duration has not been established. In addition to this, the lack of relevant data about other phenotypes of hypertension (masked and white-coat hypertension) determined by ambulatory blood-pressure measurement (ABPM) is notable, despite their relationship to increased cardiovascular risk mediated by underlying target-organ and vascular damage.METHODS: We conducted a study in which nonmydriatic retinal photography was used to assess central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) diameters and the retinal arteriovenus ratio (AVR) in a group of 103 individuals with never-treated hypertension of recent (< 1 year) appearance, 28 individuals with masked and 20 with white-coat hypertension, and 50 normotensive individuals, as appropriately classified by ABPM.RESULTS: Patients with sustained and masked hypertension had narrower values of CRAE than did normotensive individuals (86.7±10.1 and 87.6±9.2 vs. 94.8±10.6, P < 0.001 and P = 0.02, respectively). The AVR was lower in patients with sustained hypertension (0.736±0.102), masked hypertension (0.716±0.123), and white-coat hypertension (0.739±0.127) than in normotensive subjects (0.820±0.095), P < 0.001, P < 0.001, and P = 0.03, respectively. Both AVR and CRAE were negatively associated with mean systolic and diastolic daytime, nighttime, and 24-hour blood pressures, even after adjustment for other factors.CONCLUSIONS: Subtle retinal microvascular signs of pathology are observed in hypertensive patients at early stages of hypertension and in patients with both masked and white coat hypertension. These changes may be indicative or may mediate the differences in cardiovascular mortality in persons with masked and white-coat hypertension, and relevant information about this can be easily accessed with retinal photography.