aka Ophthalmology Befuddler 029
A 71 year-old man tripped at home and bumped his forehead on the wall as he went to ground. He did not lose consciousness and apart from a minor bruise on his forehead and a major bruise on his ego, his only complaint is markedly blurred vision in his right eye. He has had previous cataract surgery on both eyes.
This is what you see on close inspection of his eye:
Q1. What is the diagnosis?
Anterior dislocation of an intraocular lens
There are two types of traumatic lens displacement (aka ectopia lentis):
- Dislocation — anterior or posterior displacement of the lens resulting from complete disruption of the lens zonule fibers.
- Subluxation — results from incomplete disruption of the lens zonule fibers.
The following questions relate to lens displacement in general (not just implanted intra-ocular lenses).
Q2. What are the risk factors for this condition?
Risk factors for lens displacement in the context of minimal trauma include:
- Marfan’s syndrome (upwards)
- Homocystinuria (downwards)
- Tertiary syphilis
- Previous intra-ocular lens insertion (e.g. cataract surgery)
- Pseudo-exfoliation syndrome (see this video at RootAtlas.com)
Q3. What features should be sought on history and examination?
- Symptoms —
monocular diplopia or visual distortion with subluxation
marked visual blurring with dislocation.
- Presence of risk factors (see Q2)
- Any associated injuries (ocular or otherwise)?
- Visual acuity — decreased
- Slit lamp exam —
edge of a subluxated lens can be seen when the pupil is dilated.
Iridodonesis — trembling or shimmering of the iris after rapid eye movements in lens dislocation.
- Look for associated ocular and other injuries. Look for evidence of risk factors (e.g. Marfanoid appearance)
Q4. What is the management of this condition?
Management of lens displacement involves:
- immediate ophthalmology consultation
- treatment options vary from observation to surgical removal and replacement depending on the location of the dislocated lens and associated eye injury.
- Ehlers JP, Shah CP, Fenton GL, and Hoskins EN. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease (5th edition). Lippincott Williams & Wilkins, 2008.
- Marx JA, Hockberger R, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice, 7th edition (2009) Mosby, Inc. [mdconsult.com]
- NSW Statewide Opthalmology Service. Eye Emergency Manual — An illustrated Guide, 2007. [link to free pdf]