Which of the following is NOT true regarding exposure keratopathy?

• A. It is typically worse at night
• B. It is typically caused by a CN 7 or Orbicularis Oculi issue
• C. Floppy eyelid syndrome can cause this
• D. Inferior SPK is a common presenting sign

Answer: (A)

Exposure keratopathy happens when the eyelids don’t close fully, so the cornea becomes exposed to the air, dries out, and develops surface damage. This drying and irritation are most evident after a period of sleep or lid opening, because the eye isn’t protected by blinking during that time. Because gravity tends to pull tear film away from the lower part of the cornea, you often see superficial staining or erosions in the inferior corneal area.

Causes include weakness or paralysis of the muscles that close the eyelids, especially CN VII palsy affecting the orbicularis oculi, which prevents proper lid closure. Floppy eyelid syndrome—where the lids are overly lax—also predisposes to exposure because the lids don’t seal reliably. These conditions allow the cornea to dry more, increasing the risk of surface loss.

A common presenting sign is inferior superficial keratopathy (SPK) due to the exposed inferior cornea and gravity helping tear film not to cover that area adequately. Clinically, patients report irritation or a gritting sensation, often worse after waking.

The statement that it is typically worse at night isn’t quite accurate. In practice, symptoms and corneal surface damage are most evident after overnight exposure and upon waking, rather than being worse throughout the night itself.