Introduction –  During our CME curricula, I have the good fortune of meeting with many of you and having the opportunity to discuss the various nuances facing our practices.  The questions are diverse, dealing with everything from ideas for different CME venues, apecific patient cases and practice management. At our meeting this May, Joseph Santry, O.D., from Brattleboro, Vt . offered a suggestion that I am excited about – utilizing real-life case reports which have been referred  from local eye doctors to our practice. So, I think it is only appropriate that we start with one of Dr. Santry’s cases (if you are a low-profile type, do not worry, I don’t need to use your name if you prefer). And of course, the names of patient’s have been changed to satiate HIPAA guidelines!

The  Case of Decreased Best-Corrected Visual Acuity and Visual Fluctuation

Sue Brown is a 48 y.o.  banker who has noticed progressive difficulty with distance and near acuity, mostly involving her left eye over the course of the past 5 years. The patient’s past ocular history is notable for simple myopia (-3.50 D OU). She used to wear soft contact lenses, but discontinued them years ago due to progressive decrease in tolerance, and she finally discontinued them on her own as the had “become a hassle.”

The patient’s medical history is unremarkable, she takes no medications and has no relevant family history of eye disease.

Ms. Brown has become concerned because she is having progressive difficulty at work. She denies any pain, but does note that her vision fluctuates significantly from day-to-day, and even during the course of a day.

On examination, the patient’s  BCSA is 20/40 OD and 20/25+ OS. Pupils, confrontational fields and extraocular motions are al within normal limits. Corneal sensation is intact and full in all four quadrants bilateraallly. Intraocular pressures are 16mm Hg OU via applanation at 2:30 pm.

Slit lamp examination finds the adnexa and conjunctival surfaces to be benign. The corneal epithelium is intact, however, each cornea manifests amorphous, axial opalescent opacities at the level of Bowman’s membrane(see photo).  The remainder of the anterior segment examination is benign. Likewise, dilated fundus examination is benign.
What’s your diagnosis?

Well, I have to admit, Joe Santry gift-wrapped this one, as Ms. Brown presented with his correct diagnosis of Epithial Basement Membrane Dystrophy (EBMD).  EBMD is also known as Cogan’s Microcystic Dystrophy and Map-Dot-Fingerprint Dystrophy. EBMD is typically sporadic, although a dominant pattern of inheritance has been identified.

Ms. Brown presented us with a chief complaint of decreased vision, and this was from the irregular astigmatism caused by the subepithelial accumulation of abnormal basement membrane in the area of the visual axis. A more common symptom is caused by recurrent epithelial erosions due to dysfunctional or totally absent hemidesmosomes. This causes the epithelium to be poorly adherent to the basement membrane and the the lids may from time-to-time “sheer” the epithelium from the surface of the cornea. These events frequently happen nocturnally or first thing in the morning – patients will tell you their lid (s) is “stuck” to their eye.

Initial treatment is conservative, beginning with bland lubricants in the evening. In recalcictrant cases, (or in a case like this one where there were visual issues) reoval of the abnormal basement membrane complexes will allow the epithelium to re-establish a more functional relationship to Bowman’s Membrane.