How to use a direct ophthalmoscope

The direct ophthalmoscope is a useful tool but often under utilized by
non-ophthalmologists. The following steps will help the doctors to obtain
a good fundal view provided the patient has clear media ie. without
corneal, lens or vitreous opacities.

1. To examine the right eye, sit or stand at the patient's right side.

2. Select "0" on the lens disc of the ophthalmoscope and start with
    the small aperture.

3. Hold the ophthalmoscope vertically in the right hand and placed it in
    front of your right eye with the light beam directed toward the patient .
    Place your right index finger on the edge of the lens dial so that you may
    change lenses easily if necessary.

4. Dim room lights. Instruct the patient to look straight ahead at a distant
    object. (If the patient looks at the light or focus on near object, the pupil
    will constrict due to accommodation making examination difficult.)

5. Position the ophthalmoscope about 6 inches (15 cm) in front and slight to
    the right (250) of the patient and direct the light beam into the pupil.
    A red reflex should appear as you look through the pupil. (Absence of red
    reflex occurs in dense cataract or scarred cornea)

6. While the patient is fixating on the specified object, keep the reflex in view
     and slowly toward the patient. The optic disc should come into view
     when you are about 11/2 to 2 inches (3-5cm) from the patient. If it is not
     focused clearly, rotate lenses with your index finger until the optic disc is
     as clearly visible as possible. The hypermetropic eye requires more plus
     lenses for clear focus of the fundus; the myopic eye require minus lenses
     for clear focus.

7. Now examine the disc for clarity of outline, colour, elevation and condition
    of the vessels. Follow each vessel as far to the periphery as you can.
    To locate the macula, focus on the disc, then move the light approximately
    2 disc diameters temporally. You may also have the patient look at the light
    of the ophthalmoscope, which will automatically place the macula in full view.
    Look for abnormalities in the macula area. The red-free filter facilitates
    viewing of the centre of the macula.

(If the patient presents with visual loss:

a. examine the disc for swelling: seen in anterior ischaemic optic neuropathy;
                                                                     central retinal vein occlusion
b. examine the vessels for:

c. examine the retina for:
8. to examine the extreme periphery, instruct the patient to:
a. look up for examination of the superior retina
b. look down for examination of the inferior retina
c. look temporally for examination fo the temporal retina
d. look nasally for examination fo the nasal retina.

Steps 7 and 8 will reveal almost any abnormality that occur in the fundus.

(Note: in patients who complain of sudden onset floaters, direct ophthalmoscope may not
give enough periphery view to locate peripheral tear or hole and referral is recommended
especially if you notice any retinal haemorrhages.)

Tips for better fundal view

1. Corneal reflection can interferes with fundal view.
    If this is troublesome, this can be overcome with:

2. Small pupil especially in the elderly. Use of short acting dilating drops can
    increase  the area of the fundus examined. The most effective combination
    is tropicamide 1% and phenylepherine 2.5% as they acts on different iris
    muscle. If you can only use one dilating drop instil tropamide which dilate
    the pupil more efficiently than phenylepherine.
Back to eye examination