MYELINATED NERVE FIBERS

 Ordinarily nerve fibers have insulation around them, just like electrical wires need insulation.  This insulation is called myelin.  But when the nerve fibers enter the eye they ordinarily become demyelinated.  Very occasionally, a patient will have myelination on some retinal nerve fibers.  This is harmless and non-progressive but interesting.  The photo below is probably the most myelinated retinal nerve fibers I've noticed in 23 years of practice.  So I thought I'd post it.

CORNEAL ULCER

A 19 year old female presented with the chief complaint of a painful, light sensitive right eye.  She normally wear a Biofinity toric contact lens in the right eye and a Biofinity spherical lens in the left eye about 16 hours per day.  A single, mid-peripheral corneal ulcer was responsible for her symptoms.  The cornea is the only structure in the body that gets it's oxygen from the air.  When you wear a contact lens, it reduces the oxygen getting to the corneal surface.  The cornea can tolerate it up to 12 hours per day in general, but beyond this the cornea becomes hypoxic, or oxygen deprived.  Bacteria love this hot, moist, anaerobic environment and the cornea suddenly becomes a petri dish for bacteria to grow and eat away at the cornea.  Sometimes these ulcers can occur in the very center of the vision and cause permanent scarring that can permanently affect the vision.  Some ulcers can be so bad as to cause a complete loss of the cornea and eye.  Symptoms begin suddenly, so it is extremely important that patients wear properly fitted contact lenses according to the regimen prescribed by their doctor.

Corneal ulcer with white blood cells underlying

Corneal ulcer with fluorescein stain