DEPARTMENT OF OPTOMETRY & VISUAL SCIENCE
Lecture notes to accompany 02 Lecture
Optometric Screening for Vascular Hypertension
Dr Simon Barnard PhD BSc FCOptom FAAO DCLP
Why screen for vascular hypertension ?
What is vascular hypertension ?
There is in fact no clear dividing line between, hypertension and normotension. The higher the blood pressure, whether it be diastolic or systolic, constant or labile, the worse the prognosis.
However, there have to be artificial guidelines to enable the physician to determine when to intervene with treatment, and for optometrists to determine when to refer to the physician. Classically, a blood pressure of 120/80 has been said to be "normal" but when should a patient be referred? This question will be addressed later in this lecture.
The optometristsí role
Patients present for regular optometric checks. In the over 40 age group this is often driven by the evolution of presbyopia. Patients do not tend to visit their GP routinely but generally wait until they have an obvious problem.
Optometrists undertake about 95% of all primary eye care examinations in the UK with the remainder being carried out by ophthalmologists. Unlike other primary health care practitioners, the optometrist and ophthalmologist are skilled in fundoscopy. This provides the opportunity of combining sphygmomanometry findings with fundus appearance.
Sphygmomanometry may also be useful for those patients with suspected normal tension or low tension glaucoma.
Why not solely rely on the appearance of the fundus?
Barnard, Allen & Field (1991) showed that optometric evaluation of the retinal arteriolar tree does not provide adequate sensitivity and specificity. It was concluded that blood presuure measurement should be combined with fundus examination.
Grading retinal vascular hypertension
Remember that chronic vascular hypertension will lead to arteriosclerosis. However, fundus signs of vascular hypertension are often graded using Keith, Wagener & Barkerís (1939) scheme.
Grade 1 Narrowing of the arterioles (general or focal) Grade 2 More marked than grade 1 Grade 3 Grade 2 + cotton wool spots + haemorrhages
(often superficial flame shaped)
Grade 4 Grade 3 + papilloedema
If there is a combined arteriosclerotic/hypertensive fundus appearance, a useful term used to describe this appearance "arteriopath" e.g., grade 1 arteriopath.
Remove tight clothing
Patient reclining at 45 deg.
Middle of forearm level with heart
Place stethoscope over brachial artery in the antecubital fossa
Allow mercury to fall at 2 mm Hg/sec
Phase 1 = systolic
Phase 5 (silence) = diastolic
Guidelines for upper levels of BP for optometrists
Age (years) BP (mm Hg)
(1) Measure BP of everyone over a certain age ?
(2) Measure BP of at risk groups
Symptoms ? !
Retinal signs ?
Combine BP with fundoscopy
Take minimum of 2 measurements before referring unless 1 x diastolic =/>110 mm Mg
take into account :-
Letter to GP should not presume to diagnose
Place fundus findings in apposition with BP results
Barnard N.A.S. (1989) Sphygmomanometry & Ophthalmodynamometry, Chapter 25 In " Optometry" Eds. Edwards K &
Llewellyn R., Butterworths, London
Barnard NAS, Allen R, Field A (1991) Referrals for vascular hypertension in a group of 45-64 year-old patients
Ophthal Physiol Opt, 11, 3, 201-205