Conditions Associated With Congenital Nystagmus: The 4 A’s

There are many different eye conditions that are associated with congenital nystagmus; theoretically, any bilateral visually-significant pathology present at birth or in infancy during the critical period of visual development may interfere with the development of stable fixation.1  Eventually I’ll get around to discussing the finer points of nystagmus; but for now, I’m sticking to some basic study stuff.

Here’s a little mnemonic that I used to help me remember some of the conditions associated with congenital nystagmus, the 4 A’s:

  • Leber’s congenital Amaurosis
  • Aniridia
  • Achromatopsia
  • Albinism

References and Additional Reading

  1. Dell’Osso LF, Daroff RB.  Chapter 11:  Nystagmus and Saccadic Intrusions and Oscillations.  In:  Duane’s Ophthalmology on CD-ROM, 2006 Ed.  Lippincott Williams and Wilkins, 2006.  Available online.

Do you have other suggestions for how to remember conditions associated with congenital nystagmus?  Leave a comment, visit our forum, or e-mail me at!

Corneal Dystrophies Presenting As Recurrent Erosions

Lattice corneal dystrophy type 1. Image from Wikipedia.

Corneal dystrophies are clinically fairly rare (with notable exceptions) but have pretty easily identifiable appearances.  Because we have learned quite a bit about the genetics, inheritance, etc. about many of the dystrophies, this seemed to be a pretty popular topic on tests – though it seemed like in the past few years the number of questions on corneal dystrophies decreased quite a bit.  I don’t know the minds of the test-writers, so who knows if it was a random thing, or if there was more emphasis on clinically significant questions.

In any case, recurrent corneal erosions/abrasions are fairly common.  While we typically consider trauma as one of the common causes, epithelial/anterior basement membrane dystrophy (EBMD/ABMD, map-dot-fingerprint dystrophy) is also a common cause of recurrent corneal erosions.  To help me remember the various corneal dystrophies that cause recurrent erosions, I came up with a mnemonic:  “Grass Erodes My Little Red Truck”:

  • Granular (rarer)
  • EBMD (map-dot-fingerprint)
  • Meesmann / Macular (rare)
  • Lattice (common)
  • Reis-Bucklers
  • Thiel-Behnke

Do you have a different or better way to remember corneal dystrophies that cause recurrent erosions?  Leave a comment!

Causes of Leukocoria: CREAM PIGMENT

A child with esotropia and left leukocoria from retinoblastoma.  Image from Wikipedia.

There are TONS of causes of leukocoria (white pupil).  But this can be a very important differential, as it can be the presenting sign of some sight-threatening and life-threatening conditions (most obviously retinoblastoma).  Because of its clinical importance, it is essential to be able to not only recognize what it is, but to also have a decent differential diagnosis so that you don’t miss out on any key causes when conducting a history and physical.

Given the sizable list of causes (a very short list is listed on the AAPOS website), I created a mnemonic that I could at least use to recall at least 3-5 (or more) causes of leukocoria.  The mnemonic is “Leukocoria looks like CREAM PIGMENT“:

  • Coats / Coloboma / Cataract
  • Retinoblastoma / Retinal dysplasia / Retinoma / ROP / Retinal fold
  • Endophthalmitis
  • Astrocytic hamartoma / Anisometropia
  • Myelinated NFL
  • PFV
  • Incontinentia pigmenti / Inflammation (uveitis)
  • Granuloma
  • Melanoma / Myopia / Medulloepithelioma
  • FEVR
  • Norrie
  • Trauma / Toxocariasis

What do you think?  Do you have any other tips on how to remember the differential for leukocoria?  Leave a comment!