The Stanford 25

An Initiative to Revive the Culture of Bedside Medicine

Fundoscopic Exam

Introduction: The retina is the only portion of the central nervous system visible from the exterior. Likewise the fundus is the only location where vasculature can be visualized. So much of what we see in internal medicine is vascular related and so viewing the fundus is a great way to get a sense for the patient’s overall vasculature.  But the fundoscopic exam can discover pathological process otherwise invisible—examples are plentiful, but include recognizing endocarditis, disseminated candidemia, CMV in an HIV infected patient, and being able to stage both diabetes and hypertension.

GOALS:

  • Recognize common findings of diabetes (micro-aneurysms, exudates, hemorrhages and new vessel formation).
  • Recognize findings in hypertension (ranging from vessel changes to papilledema).
  • Identify papilledema and optic atrophy.

TECHNIQUE

Traditional Direct Ophthalmoscope

  1. Wedge scope against your cheek with hand and then head/hand/scope should move as one unit.
  2. Use right hand right eye for patient’s right eye.
  3. Accommodate for distant vision (hard to do but this lets the most light into your pupil) and if you wear glasses for distant vision keep them on, otherwise take them off.
  4. When learning, stand at a distance in a darkened room, find the ‘cat’s eye’ or red reflex and then follow that in till you see a vessel. If you loose it, then step back and start again.

Panoptic Scope:

This is found in most of the outpatient clinics and the view once you learn to use it is spectacular. Use of the Panoptic is very similar to a traditional ophthalmoscope with a very few exceptions:

  1. Use the scope to view an object approximately 15 feet away and adjust the focus until clear (unless you’re wearing glasses and are taking them off, you’ll likely be in perfect focus at a setting of zero).
  2. You will NOT need to use your right eye, patient’s right eye and your right hand as usually instructed with the traditional ophthalmoscope. You can hold the Panoptic however you are most comfortable.
  3. To see other regions around the retina, rather than angling the ophthalmoscope, you simply ask the patient to look up to see the upper retina, down to see the lower retina, medial to see the medial retina, lateral to see the lateral retina and to look towards the light to see the macula.

Stanford second year residents now all carry the lightweight lens free scope (Optyse)!


Dilating the Pupil

Mydriatic drops (first look at the patient’s eye from the side and if the profile is shallow, and the anterior chamber seems shallow, don’t use).  Dilate one eye when you start your H&P and by the time you are done you will have a good look.

  • Parasympathetic agonists: paralyze circular muscle of iris (mydrasis) and the ciliary muscle (loss of accommodation).
    • Tropicamide: 1-2 drops (0.5%) 15-20 minutes before exam; may repeat every 30 minutes PRN. Individuals with heavily pigmented eyes may require larger doses.
    • Cyclopentolate:1 drop of 1% followed by another drop in 5 min; 2% solution in heavily pigmented iris.
    • Atropine: (1% solution): Instill 1-2 drops 1 hour before the procedure.
    • Homatropine:1 drop of 2% solution immediately before the procedure; repeat at 10 min intervals PRN.
  • Sympathetic agonists:
    • Phenylephrine: 1 drop of 2.5% or 10% solution, may repeat in 10-60 min PRN.
  • Contraindications: 1) head injury requiring monitoring

Want more information on the use of  mydriatic agents for the internist? Please look up this great article that reviews data on the risk of precipitating acute glaucoma:

Pandit, RJ and Taylor R. Mydriasis and glaucoma: exploding the myth. A systematic review. Diabet Med. 2000 Oct;17(10):693-9.

 

Findings

(Pictures below linked to via the  U Mich vision page. Please visit the Retinal Signs Module for detailed about the signs below and more.)

Normal fundus: vessels emerge from nasal side of disc. Arteries are narrower than veins.

Click for image source: U. Mich Kellog Eye Center

Pathological Optic Cupping: Note cup-to-disc ratio of ~0.8 (physiologic limit of 0.5).

Click for image source: U. Mich Kellog Eye Center

Optic Disk Edema: The optic disc is elevated and its surface is covered by cotton wool spots (damaged axons) and flame hemorrhages (damaged vessels). Four I’s: increased intracranial pressure (papilledema), infarction, inflammation, infiltration (by cancer).

Click for image source: U. Mich Kellog Eye Center

AV Nicking: Chronic hypertension stiffens and thickens arteries. At AV crossing points (arrow) arteries indent and displace veins.

Click for image source: U. Mich Kellog Eye Center

Cotton Wool Spots: Caused by microinfarcts. Exploded  ganglion cell axons extrude their axoplasm into retina. Long ddx: hypertension, diabetes, HIV, severe anemia or thrombocytopenia, hypercoagulable states, connective tissue disorders, viruses, and others.

Click for image source: U. Mich Kellog Eye Center

Emboli and Infarcts: Small fleck (arrow) a ‘Hollenhorst’ plaque caused from platelet/fibrin/cholestorol embolus. Resulting in an infarct (gray area above and right of the plaque).

Roth Spot: pale-centered hemorrhage. Caused by several conditions, not only bacterial endocarditis.

Click for image source: U. Mich Kellog Eye Center

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Written by stanford25admin

June 7, 2010 at 3:21 pm

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