Retinal Vascular Disorders
Notes to accompany lecture to 2nd year City University undergraduates

Dr Simon Barnard Phd BSc FCOptom FAAO DCLP



Most tissues are pervaded by blood vessels and lymphatic vessels. Nutrition, respiration and other metabolic activities rely on proper local vascular supply.

Interference with movement of blood, lymph and tissue fluid are frequently discussed under the following headings:-


Obstructive diseases of the arteries

Diminution of arterial blood supply leads to ischaemia ® necrosis ® atrophy ® degeneration ® replacement fibrosis.

Such diseases that may affect the retina include:

  1. primary (b) renal (c) endocrine

Local affects of arterial obstruction depend on the size of artery, importance of tissue supplied, speed of occlusion, and whether there is any collateral circulation.

The central retinal artery is an "end artery".



This is an abnormal dilatation of an artery. Aneurysms may produce

Venous obstruction

Venous obstruction may be the result of

The effects will depend on the degree and speed of obstruction. If the obstruction occurs gradually there may be time for collateral vessels to be established. If not, then congestion, oedema, and haemorrhages may result (e.g. CRV occlusion).


Effects of vascular disease on the retinal blood vessels

all can be observed by the clinician by ophthalmoscopy.

Such disease include



Arteriosclerosis may be divided into the following categories based upon aetiology:

Arteriosclerosis first effects the blood vessel walls and only in the late stages will produce the haemorrhages and exudates which is then termed a retinopathy.

Although purely hypertensive retinopathy can occur in chronic hypertension, the condition will be invariably be accompanied by arteriosclerosis.


Effects of arteriosclerosis/hypertension on the retina

There may be an observable change in "a/v" ratio from the "normal" 2:3.

Pathological changes include:

  1. copper wire
  2. silver wire… both (a) and (b) denote an increase in the relative width of the reflex associated with thickening and hyaline degeneration of the arterial media.
  3. Irregularities
  4. vessel sheathing
  1. deflection… depression/humping/ ‘U’ or ‘S’ shaped deflection
  2. apparent nipping
  3. ‘right angling’
  1. dot/blot haemorrhages (e.g., found in diabetes mellitus)
  2. flame-shaped (e.g., found in hypertensive retinopathy)
  3. thrombosis… usually veins (e.g., CRV occlusion)
  4. embolism (e.g., causing a CRA occlusion)

Apart from vascular hypertension and arteriosclerosis, other conditions/associations which may affect the retinal vascular tree include:


Further reading

Alexander L. (1995) Primary Care of the Posterior Segment. Appleton & Lang,


Further questions ?… contact e-mail