Hypertension and Changes of the Fundus Oculi

The light streak characteristics on retinal vessels were studied by microdensitometry on fundus photographs. We compared the width and the intensity of the reflex in a young group (mean: 19.7-year-old; n = 40) and in an older group (mean: 45.3-years-old; n = 22) of normal subjects. By subgrouping according to age and blood pressure levels, we studied possible effects of these parameters on the light streak. We found higher intensity of reflection from both arteries and veins in the older group (P less than 0.01). This effect seemed mostly related to the age of the subjects. We also registered a relation between systolic blood pressure and intensity of reflection from veins in the young group (P less than 0.03). Optical changes in the vessel walls in the ageing process and intravascular pressure effects on the indices of refraction in the erythrocytes/plasma may account for these findings. The width of the reflex was not found to be related to either the age or the blood pressure level of the subjects.

Section: Width (W/wo) and Blood Pressuresupporting

confidence: 85%

Section: Width (Wr/wo) and Agementioning

confidence: 99%

The light reflex in retinal vessels and its relation to age and systemic blood pressure

Brinchmann‐Hansen¹,

Myhre

Sandvik³

1987

“…Studies, which have solely evaluated the width of the reflex, found, however, that it did not correlate to the level of systemic blood pressure (Van Buchem et al 1964;Aurell & Tibblin 1965;Svardsudd et al 1978). The present study and previous reports (Brinchmann-Hansen et al 1987; Brinchmann-Hansen 8c Myhre 1989a) are in accordance with these observations: the width of the reflex seems not related to the systemic blood pressure level.…”

Section: Intensity Of the Light Reflex (Ir)mentioning

confidence: 99%

The response of the light reflex of retinal vessels to reduced blood pressure in hypertensive patients

Brinchmann‐Hansen

Christensen²,

Myhre³

1990

The response of retinal arteries and veins to 3 months of antihypertensive medication was studied in 10 patients (39-56 years old) with essential hypertension. We used computerized microdensitometry on fundus photographs, a technique allowing for objective and simultaneous measures of the caliber of blood columns and the width and intensity of their central 'light reflex'. A moderate lowering of diastolic and systolic blood pressures (P less than 0.001) resulted in a significant reduction in the intensity of reflection from retinal arteries (38.6%; P less than 0.005). An increase in the width of the blood column (2.8%; n.s.) and the reflex (8.6%; n.s.) was indicated. Traditionally, changes in light reflectivity has been associated with arteriosclerosis of the vessel wall. The study shows, however, that the vascular reflex is most sensitive to changes in the systemic blood pressure. This signals a need for critical reviewal of interpretation and usefulness of classical grading systems of ophthalmoscopic signs of hypertensive retinopathy.

“…Since age and abnormal systemic blood pressure levels might affect both the diameter of the blood column and its light reflex (van Buchem et al 1964;Aurell & Tibblin 1965;Svardsudd et al 1978), we chose a homogeneous group of normal subjects for our experiments. Since age and abnormal systemic blood pressure levels might affect both the diameter of the blood column and its light reflex (van Buchem et al 1964;Aurell & Tibblin 1965;Svardsudd et al 1978), we chose a homogeneous group of normal subjects for our experiments.…”

Section: ) Focusingmentioning

confidence: 99%

“…Material. Since age and abnormal systemic blood pressure levels might affect both the diameter of the blood column and its light reflex (van Buchem et al 1964;Aurell & Tibblin 1965;Svardsudd et al 1978), we chose a homogeneous group of normal subjects for our experiments. One hundred male applicants for pilot training in the Royal Norwegian Air force were used in the study (age 18-23 years old).…”

Section: ) Focusingmentioning

confidence: 99%

Fundus photography of width and intensity profiles of the blood column and the light reflex in retinal vessels

Brinchmann‐Hansen

Heier²,

Myhre³

1986

Various optical properties of the fundus camera may have important implications regarding the use of photographs for image size measurements. By scanning across retinal vessels with a microdensitometer the width and the intensity characteristics of both the central light reflex and the streaming blood column may be measured. To establish a reliable basis for future measurements, we analysed the retina-to-film magnification, possible aberrations and the resolving power of our Zeiss camera. Furthermore, fundus photography was performed in 100 young men, and the necessary level of accuracy in focusing the camera was established. We also investigated the effects of various amounts of defocusing on width and intensity readings from densitometric scans across retinal vessels.