Figures 1-2. These are the right and left corneas of a 30 year old man. He denies any pain. The corneas SHOW peripheral corneal thinning OU with an intact epithelium. There is yellowish lipid deposition central to the area of thinning.
Questions and Answers
1. What is your diagnosis? Answer: Terrien's marginal corneal degeneration. This condition is characterized by bilateral and symmetric corneal thinning with an intact epithelium. A yellow-white zone of lipid may be seen central to the area of thinning.
2. What is the epidemiology of this disorder? Answer: This condition is rare. There is a 3:1 male to female predominance. The condition may be seen at any age, but is most common in patients between the ages of 20 and 40.
3. What is the natural history of this disorder? Answer: The disease usually begins superonasally with fine punctate opacities in the anterior stroma with a lucent interval separating the opacities FROM the limbus. Over time the lesions may extend circumferentially or centrally. Progression occurs slowly over the course of years.
4. What are the potentially sight threatening complications in this disorder? Answer: The typical superior corneal thinning produces against the rule astigmatism. Thinning may become severe enough to produce corneal perforation. Spontaneous perforation or perforation due to minor trauma occurs in approximately 15% of patients.
5. How would you manage this condition? Answer: If not very severe, against the rule astigmatism may be treated with glasses or contact lenses. Severe astigmatism, impending perforation, or perforation may be treated with lamellar or eccentric penetrating corneal grafts.