Stem cell therapy for corneal scarring

The transparent outer layer of the eye deceives all with its clear and smooth structure. What is generally not known, is the ability of the Cornea to protect the rest of the eye from the dust and debris of the outer world, and also refine vision.

Structure of the Cornea:

A cornea is formed of an amalgamation of 5 layers:

Corneal epithelium: It is the outermost layer of the cornea and keeps it moist.

Bowman’s layer: It is a dense layer that prevents abrasions from affecting the stroma.

Corneal stroma: It is the middle layer of the cornea and contributes to its cleanliness.

Descemet’s membrane: It separates stroma from the underlying endothelium. It gradually thickens throughout life.

Endothelium: It lies to the extreme interior.

Although, the cornea is immune to minor abrasions, vehement damage from lacerations, burns and deep abrasions may result in Corneal scarring.

Symptoms of Corneal scarring:

●       Blurred vision

●       Inflammation in the eye

●       Sensitivity to light

●       Swelling

●       Excessively teary-eyed

After a major injury, the corneal tissue may be replaced by scar tissue, or become obstructed by blood vessels. Mostly, this situation is overcome by replacing the damaged scar tissue and introducing a new cornea through Cornea Transplantation. But, Keratoplasty, has the risk of backlashing with graft rejection, which prevents corneal transplant to be universally accepted. Thus, numerous people facing corneal problems have been deadlocked, as transplant is not an option for their plight.

In the event, where the surface epithelial cells are damaged by certain diseases, the precursor stem cells to these epithelial cells die and cease these cells to regenerate. These stem cells find their place in the limbus- a region where the cornea meets with Sclera. It rarely happens that the limbus stem cells too are damaged beyond use and need to be replaced.

Over the last decade, researchers have been rummaging the prospect of corneal repair using limbal stem cell therapy, and the results are far from disappointing.

● Under normal conditions, human keratinocytes generate Holoclones amongst other types of cells. These types of cells are the stem cells of human epithelium. In humans, holoclones are absent in cornea, but found in the Limbus. This revolutionary realization led to the first use of these cultures in the regeneration of the corneal epithelium.

●  Patients suffering from partial to absolute limbal stem cell deficiency were enlisted in the study.

●  Analogous functional stem cells were derived from a biopsy specimen from the other eye, that was unscathed.

● The obtained Holoclone cells are cultured on Fibrin, that acts as a natural substrate for growing these cells.

● Clinically certified 3T3-J2 cells are used as feeder cells.

● The cells in the culture medium are cultivated till a stipulated time and their behaviour noted.

●Then the grown holoclone stem cells are placed onto the damaged eye and the outcome is assessed yearly as a corneal epithelium takes approximately a year to regrow.

●The new stem cells take over the limbus of the damaged eye to produce epithelial cells in abundance.

Stem cell therapy has proven its importance in curing a number of diseases and ailments, including corneal scarring. It has proven its worth, in the most complex of situations like stem cells for diabetes and even stem cells for newborns. It holds a lot of potential in the near future, and a very promising one.