Lippincott NursingCenter Pocket Card - February 2023

Fundoscopic Exam

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The Fundoscopic Exam

A fundoscopic exam, also known as ophthalmoscopic or retinal examination, is a test used to screen for eye disorders, injuries, and diseases. It can be one of the more challenging procedures performed during both routine physical examinations and emergency care evaluations.

Anatomy Review

The retina is the layer of cells lining the back wall inside the eye (fundus) that senses light and sends signals to the brain (American Academy of Ophthalmology, n.d.). The retina is the only part of the central nervous system that can be viewed from outside of the body and the fundus is the singular part of the body where vessels can be directly visualized (Stanford Medicine, n.d.). Health care providers use fundoscopy to screen for eye conditions such as (Healthline, 2016):
  • Damage to the optic nerve
  • Retinal tear or detachment
  • Glaucoma
  • Macular degeneration
  • Cytomegalovirus (CMV) retinitis (infection of the retina)
  • Ocular melanoma or melanoma that spreads to the eye
  • Hypertension
  • Diabetes

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Equipment Review

To perform fundoscopy, you’ll need an ophthalmoscope. Direct ophthalmoscopes are small, hand-held instruments equipped with a concave mirror, light source, eye piece, and handle. The light reflects off the retina and back through a hole in the opthalmoscope, providing the clinician with a magnified image of the anatomy at the back of the eye. Indirect ophthalmoscopes include monocular and binocular scopes. These are more sophisticated instruments typically used by ophthalmic specialists. Direct ophthalmoscopes include the following parts.

  • Lens (focusing) wheel:
    • Increasing the green (positive) numbers on the dial will focus close objects.
    • Increasing the red (negative) numbers on the dial will focus far objects.
  • Light source: ophthalmoscopes have 2 or 3 sizes of light that are selected based on the size of the pupil and amount of light in the room.
    • Small light for a very constricted pupil in a well-lit room
    • Medium light for a non-dilated pupil in a dark room
    • Large light used if pupils are dilated with mydriatic drops
  • Half light setting: used when the pupil is partly obscured by cataracts of the lens; allows light to pass through the clear part of the pupil.
  • Aperture/filter dial
    • Red free setting: helps view vessels and hemorrhages by enhancing contrast; the image will appear black and white.
    • Slit beam: used to inspect contour abnormalities of the cornea, lens, and retina.
    • Blue Light: used to inspect corneal abrasions and ulcers after fluorescein staining.
  • Grid: used to approximate space between retinal lesions.

Performing Fundoscopy (Stanford Medicine, n.d.;  Schneiderman, 1990)

Developing a consistant approach to fundoscopic examinations will improve the speed and efficiency with which you are able to perform this procedure.
 
  1. Ask the patient to remove their eyeglasses. Contact lenses may remain in place.
  2. Dim the lights, however the room shouldn’t be completely dark.
  3. Explain the procedure to the patient.
  4. Patient should be in an upright sitting position.
  5. Ask the patient to focus on a specific point about 3 feet away, looking slightly away from you.
  6. Hold the scope in your right hand, up to your right eye and press it against your right cheek. Rest your other hand on the patient’s head with your thumb on the patient’s right eyebrow.
  7. Look through the ophthalmoscope into the patient’s right eye. Keep your other eye open.
  8. Begin at arm’s length and shine the scope into the patient’s pupil. Move the scope 15 degrees away (laterally) from the center and look for the red reflex. Then follow the red reflex medially (toward the nose) until you see the retina.
  9. Slowly move toward the patient until the instrument is about 1-2 inches away from the patient’s eye. You may rest your head on your left thumb.
  10. You should see the optic disc. If out of focus, adjust the lens dial up or down until you achieve focus.
  11. Move the light around the retina until you have visualized all areas. Ask the patient to look directly into the light to view the macula last.
  12. Repeat procedure with the left eye.
Mydriatic (pupil dilating) drops may be used to facilitate the procedure, typically in specialized ophthamology settings. If dilating drops will be used, inform that patients that they’ll need someone to drive them home. Ask the patient to report an inability to regain accommodation (focus) within two hours after the procedure. They should also report any eye pain or unusual headache that day.
 

Normal Anatomical Landmarks

Once you master the ability to view the retina, work on observing these normal anatomical landmarks.
  • Optic disc – yellow-pink in color and stands out from the red/orange backgNormal-Retina-w-labels.jpeground; this is the optic nerve head.
  • Optic cup – pale-white, central area of the optic disc, normally less than one-third the diameter of the optic disc.
  • Macula – dark spot on the retinal surface free from arteries or veins. It is responsible for central vision and is comprised of the fovea and perifovea areas.
  • Fovea – central area of the macula; better seen with a red-free filter and is typically 2 disc diameters away from the optic disc. It is responsible for high-acuity vision.
  • Vessels
    • Start at the disc and follow the vessels out inspecting for hypertensive and arteriosclerotic changes.
    • Central retinal artery branches off the optic nerve. Arteries are smaller, narrower, and lighter in color than veins.
    • Central retinal vein branches off the optic nerve and appears pulsating.

PEARLS

  • An increased size in the optic cup may indicate glaucoma.
  • An obscured red reflex may be caused by corneal scars, cataracts, or vitreous hemorrhage.
  • Neovascularization (new vessels)on the optic disc are a sign of proliferative diabetic retinopathy.
  • Retinal detachment is best viewed with pupils dilated under indirect fundoscopy.

References
American Academy of Ophthalmology. (n.d.). Retina. American Academy of Ophthalmology. https://www.aao.org/eye-health/anatomy/retina-103
 
Healthline. (2016, December 18). Opthalmoscopy: Purpuse, Procedure & Risks. What is ophthalmoscopy? Healthline. https://www.healthline.com/health/ophthalmoscopy
 
Schneiderman, H. (1990). The Funduscopic Examination. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd Edition. National Institute of Health, National Library of Medicine, National Center for Biotechnology Information.
https://www.ncbi.nlm.nih.gov/books/NBK221/
 
Stanford Medicine. (n.d.) Introduction to the Fundoscopic/Ophthalmoscopic Exam. Stanford Medicine 25. https://stanfordmedicine25.stanford.edu/the25/fundoscopic.html