DEPARTMENT OF OPTOMETRY & VISUAL SCIENCE

CITY UNIVERSITY

Lecture notes to accompany 02 Lecture

Optometric Screening for Vascular Hypertension

Dr Simon Barnard PhD BSc FCOptom FAAO DCLP

Introduction

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 1Narrowing of the arterioles (general or focal)
Grade 2More marked than grade 1
Grade 3Grade 2 + cotton wool spots + haemorrhages
(often superficial flame shaped)
Grade 4Grade 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.

Sphygmomanometry

Mercury column

Aneroid

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

Korotkoff sounds

5 phases

Phase 1 = systolic

Phase 5 (silence) = diastolic

 

Guidelines for upper levels of BP for optometrists

Age (years) BP (mm Hg)

18-44 140/90

45-64 150/90

>64 160/95

Sphygomanometry protocols

(1) Measure BP of everyone over a certain age ?

(2) Measure BP of at risk groups

Family history

Obesity

Symptoms ? !

Retinal signs ?

Combine BP with fundoscopy

Take minimum of 2 measurements before referring unless 1 x diastolic =/>110 mm Mg

take into account :-

fundus appearance

obesity

family history

past history

Referral

Letter to GP should not presume to diagnose

Place fundus findings in apposition with BP results

Further reading

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