Keratoconus is a condition where the cornea thins and protrudes into a conical shape. It is characterized by progressive corneal steepening typically in the inferior cornea, causing induced myopia and irregular astigmatism. While the exact causes are unknown, it is thought to involve both genetic and environmental factors. A key feature is stromal thinning related to increased degradative enzymes and decreased inhibitors in the corneal epithelium. Eye rubbing is strongly associated with keratoconus development possibly through mechanical trauma triggering wound healing responses and keratocyte cell death. Most cases are sporadic but about 10% of cases show familial inheritance.

1. KERATOCONUS
Chairperson : Dr. Sundip Shenoy
Moderator : Dr. Spoorthy
Presenter : Dr. Madhuri P

2. Definition
• Keratoconus is a clinical term used to describe
a condition in which the cornea assumes a
conical shape because of thinning &
protrusion

3. Introduction
• characterized by progressive corneal
steepening, most typically inferior to the
center of the cornea
• eventual corneal thinning, induced myopia,
and both regular and irregular astigmatism.

4. • Approx 50% of normal fellow eyes will
progress to KC within 16 years.
• Both eyes are affected eventually, at least on
topographical imaging, in almost all cases.

5. Etiopathogenesis
• not fully understood
• both genetic and environmental processes are
likely to be involved.
• Keratoconus is probably not a single disorder,
but rather a phenotypic expression of several
possible causes.

6. • A hallmark of keratoconus is stromal thinning,
related to alterations in enzyme levels in the
cornea, causing stromal degradation.
• Increased levels of degradative lysosomal
enzymes and decreased levels of inhibitors of
proteolytic enzymes in corneal epithelium.
• consistent with the observation of increased
collagenolytic and gelatinolytic activity in
keratoconic cells.

7. • Loss of stromal keratocytes has also been
reported in keratoconus, as suggested by
confocal microscopy.
• investigators have suggested that
abnormalities in corneal collagen and its
cross-linking may be the cause of keratoconus.

8. • Eye rubbing is strongly associated with the
development of Keratoconus, may be related
to mechanical epithelial trauma, triggering a
wound-healing response that leads to
keratocyte apoptosis
• cytokine interleukin-1 has been suggested as a
mediator of eye rubbing and stromal
degradation.

9. • Most patients do not have a family history,
with only about 10% of offspring developing
KC
• Autosomal dominant transmission with
incomplete penetrance has been proposed.