• autologous serum
• ocular surface disease
• dry eye
• keratoconjunctivitis sicca

The dry eye is often referred to as a condition, a syndrome, or a disease; and it is likewise known by a variety of terms. Keratoconjunctivitis sicca (KCS), or more commonly keratitis sicca, refers to any eye with some degree of dryness either by history or by objective clinical findings. The literature is confusing on this subject and often blurs the difference between the symptoms of dryness and clinical findings based on objective criteria.¹ In similar fashion, the term dry eye syndrome is sometimes used interchangeably with dry eye symptoms, a lapse in descriptive terminology that unfortunately clouds the issue. Other descriptive terms for ocular dryness include xerophthalmia, which is used almost exclusively to describe the eye findings associated with vitamin A deficiency in children, and xerosis, which connotes the extreme ocular dryness and keratinisation that sometimes occurs after Stevens-Johnson syndrome, trachoma, and other causes of severe conjunctival cicatrisation. And then there is Sjögren’s syndrome, a generalised inflammatory disease that stands alone in its own category. Patients with Sjögren’s syndrome usually have dry eyes or KCS but they also have or may not have an associated rheumatological disease depending on whether they have primary Sjögren’s syndrome (without associated rheumatological findings) or secondary Sjögren’s syndrome (with an associated rheumatological disease).² Having KCS does not necessarily imply that a patient has Sjögren’s syndrome, but the reverse with few exceptions is usually true.

The truth of the matter is that dry eyes, for which we can interchangeably use the term KCS, is a …