LIMBAL STEMCELL DEFICIENCY(LSCD)
The limbal stem cells reside in a region between the cornea and conjunctiva, known as ‘Limbus’. These cells are responsible to prevent the outgrowth of the conjunctiva and simultaneously regenerate corneal epithelial cells. If this region is damaged then the conjunctiva grows over the cornea, which can lead to pain and vision loss. The front of the eye may also appear milky and blood vessels may be visible over the cornea. In addition to vision loss, patients may experience pain, photophobia and weeping of the eye. LSCD may also have a psychological impact on patients due to the appearance of the eye and the potential of a sudden deterioration in vision.
Symptoms
LSCD can cause discomfort and pain. The signs and symptoms may change over time.
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Short term (acute) signs and symptoms
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Soreness and inflammation of the eye
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Sensitivity to light (photophobia)
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Muscle spasms around the eye (blepharospasm)
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Watery eyes
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Blurry sight where the degree of blurriness depends on the level of damage to the cornea.
​Long term (chronic) signs and symptoms​
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As inflammation lessens over time, pain levels and sensitivity to light are likely to reduce
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As LSCD progresses, vision may be affected as the conjunctiva grows over the cornea
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The cornea scars and shows milky appearance (opaque)
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Blood vessels may be visible in the conjunctiva (neovascularization)
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Foreign-body sensation may develop which is caused by the growth of the conjunctiva, which does not have a smooth surface.
Causes
Number of causes can lead to LSCD. Some causes of LSCD can be inherited or LSCD can be acquired through infections, reactions or injury to the eye.
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Inherited causes of LSCD
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Aniridia
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Keratitis
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Epidermal dysplasia
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Dyskeratosis congenital
Acquired causes of LSCD
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Thermal or chemical burn.
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Stevens-johnson syndrome or chronic limbitits.
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Long-term contact lens wear.
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Radiotherapy, cryotherapy or surgery in the limbal area.
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Mitomycin C and 5-fluorouracil.
Treatment
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One of the most common treatment options is auto or allograft where a small biopsy is either taken from the healthy eye of the patient or from a suitable donor and sent to a good manufacturing practices lab. The lab then grows these cells either on an amniotic membrane or a fibrin glue and re-sends it for transplantation
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The other recent technique allows placing small pieces of biopsies straight on the affected eye and grow the cells with the help of nourishments from amniotic membrane which is patched on the eye as a bandage.
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Although there are known complications of these techniques, rescue options have already been studied to reduce these complication rates.