What are limbal stem cell deficiencies?
Limbal stem cell deficiency is the loss of stem cells in the limbus which can stem from a variety of causes. These causes include long-term contact lens wear, congenital conditions such as aniridia, and acquired causes such as trauma or injury. It can also result from various systemic conditions.
In eyes with limbal stem cell deficiency, the ability to re-populate the corneal epithelium is severely hindered, such that the corneal epithelium becomes unable to repair and renew itself.
How to diagnose limbal stem cell deficiency:
Patients with limbal stem cell deficiencies often present with blurred vision, accompanying tearing, pain, and/or foreign body sensation.
On clinical examination, there is oftentimes a “whorled” epithelium appearance with a loss of limbal Palisades of Vogt. The conjunctival epithelium may also appear to have encroached upon the corneal surface with the help of fluorescein staining.
These patients can suffer from and exhibit persistent epithelial defects which can lead to corneal ulceration. It is not uncommon to observe pannus, corneal scarring, and neovascularization in these patients.
When it comes to specific diagnostic testing, corneal impression cytology is largely beneficial. On histological analysis, the presence of goblet cells are usually indicative of limbal stem cell deficiency.
One of the biggest issues when it comes to patients with limbal stem cell deficiencies is oftentimes there is a lack of awareness around limbal stem cell transplants, and as such, they are not aware that there are treatment options available to them.
Limbal stem cell transplants and therapies have really changed the visual prognosis in and for these patients.
What is the process of limbal stem cell transplants?
Limbal stem cell transplants involve taking two cadaver eyes, and specifically utilizing the corneo-scleral rims. Once you have your corneo-scleral rims, you must trephinate the middle, slice those in half, and then utilizing those segments to completely encircle the eye post conjunctival resection, and then allow that area to grow back in.
Post operatively, these patients will then need to complete an intense, and often expensive immunosuppression regimen for a period of years before undergoing a slow taper off meds to ensure the success of the procedure.
One of the largest indicators of success in limbal stem cell transplantation is the post-operative care given, so this should be carefully analyzed and executed to ensure success.