Limbal stem cell deficiency (LSCD) is a complex disease that shares some symptoms of chronic dry eye. LSCD may cause severe vision problems and impact quality of life. Understanding the signs and symptoms of LSCD can help you get the right diagnosis and treatment.
Anatomy of the eye
The surface of the eye is known as the ocular surface. The ocular surface includes the:1,2
- Cornea
- Conjunctiva
- Eyelid structures
- Tear glands (lacrimal glands)
- Meibomian glands
- Limbus
- Tear gland drainage structures.
Tear production and drainage occur at the ocular surface.1,2
Functions of the ocular surface and limbal stem cells
The corneal epithelium protects the ocular surface. The epithelium is a thin layer of cells responsible for maintaining the health and stability of the cornea. Its function is to help keep the moisture on the cornea and heal the cornea when needed.1,2
The corneal epithelial cells undergo constant shedding, renewal, and regeneration (regrowth). The stem cells responsible for regrowth are found within the basal epithelium (bottom layer of the epithelium) at the limbus. In this area, the cornea (the central clear part of the eye) meets the sclera (white part of the eye).1,2
Limbal stem cells maintain the health of the corneal surface. In LSCD, the corneal epithelium cannot be renewed. Instead, it is replaced by the conjunctival epithelial cells, which are not normally found on the cornea.1,2
Causes
There are several common causes of LSCD. The most common include:1-4
- Chemical and thermal burns
- Eye surgeries, including LASIK, glaucoma, and cataract surgery
- Contact lens wear, especially when worn for an extended period
- Stevens-Johnson syndrome, a rare disorder of the skin and mucous membranes
- Mucous membrane pemphigoid, a group of rare autoimmune conditions affecting the mucous membranes of the body
Signs and symptoms
LSCD symptoms depend on the severity of the condition and the length of time LSCD has been present. Some symptoms may include:5
- Blurred and decreased vision
- Photophobia, pain, and discomfort when seeing light
- Abnormal tearing
- Scratchy, gritty feeling in the eyes
- Sores, ulcers, and scarring of the cornea in severe cases
Complications
LSCD causes inflammation and irritation of the ocular surface. Depending on the severity and the length of time LSCD has occurred, scarring may be present. Scarring on the ocular surface leads to vision problems and often results in an overall decrease in the quality of life.5
New imaging techniques
Exciting new progress in both diagnosing and treating LSCD has occurred in recent years. These new techniques allow your eye doctor to view the surface of the eye non-invasively with great detail. Non-invasive means seeing the part of the body without having to perform surgery.3
Treatments
In the past, LSCD treatment was dependent on donor tissue for transplantation. Stem cells can now be taken from the mouth or eye surface of the affected person in a technique called autologous transplantation.5
The first step in managing LSCD is improving the health of the ocular surface. Depending on the cause of LSCD, treatment may be different. For chemical burns from Stevens-Johnson syndrome, steroid eye drops may help to control ocular surface inflammation. If LSCD is due to contact lens wear, the person may have to stop wearing contact lenses and use steroid eye drops to heal the surface of the eye.5
Severe injury or disease of the ocular surface may require the use of fluid-ventilated, gas-permeable scleral contact lenses. These contact lenses help to improve vision, decrease eye pain, and decrease light sensitivity.5
In total bilateral LSCD, limbal stem cell transplantation is necessary. These stem cells may come from a deceased donor or from a living, related donor.5
New technologies and treatments may help to improve the overall outcomes of LSCD.