Visual problems

H53.0-H53.6/H53.8-9/H54.0-H54.7/H54.9

DESCRIPTION

Visual problems may be due to refractive errors, damage to the eye or optic nerve. This may be an indication of underlying disease such as diabetes or hypertension.

Assessment

Look for abnormalities of the eye.

Determine visual acuity accurately in both eyes by using the Snellen chart.

If vision is diminished (less than 6/12) perform the following tests:

  • Pin hole test
    • Make a hole of about 1 mm wide in a piece of dark/black paper– you can push a hole in paper or card with a pen tip.
    • Ask the patient to look through this hole at the Snellen chart.
    • If vision improves, this means that the patient has a refractive error.
  • Red reflex test
    The patient looks past the examiner’s head focussing on a distant target.
    • With the ophthalmoscope at 0 (zero) the examiner keeps it close to his eye and then focuses the beam of light so that it falls on the pupillary area of the cornea.
    • The examiner stands about 60 cm away from the patient.
    • In normal individuals, the examiner should be able to see a red or pink colour (reflex) through the pupil which comes from the retina.

Significance of an absent red reflex.
If there is a history of trauma or diabetes the absence of a red reflex is probably due to:

  • retinal detachment
  • a vitreous or internal haemorrhage
  • mature cataract

If there are cataracts one usually sees:

  • black shadows against the red reflex in immature cataracts, or
  • absence of red reflex in mature cataracts.

In a patient > 50 years of age with no history of trauma, diabetes or previous eye disease, an absent red reflex is often due to cataract formation, especially with decreased visual acuity.

Note: Associated diabetes or hypertension should be adequately managed with referral, as surgery can only be considered with appropriately managed disease.

REFERRAL

Urgent: within 12–24 hours

  • Sudden visual loss in one or both eyes.
  • Pain or redness in one eye only especially with visual and pupil abnormalities.
  • Recent proptosis of one or both eyes or enlargement of the eye (buphthalmos/glaucoma) in children.
  • Hazy cornea in children.
  • Unilateral watery eye

Within days

  • Squint of recent onset.
  • Suspected or previously diagnosed glaucoma.
  • Double vision following recent injury might indicate orbital fracture.
  • Leucokoria (white reflex from the pupil).
  • Squint at any age if not previously investigated by ophthalmologist.
  • Visual loss in patients with systemic disease such as diabetes.

Non-urgent referral

  • Cataracts.
  • Refractive errors.
  • Long-standing blindness – first visit to health facility.