LSCD means limbal stem cell deficiency. It is characterized by a loss or deficiency of stem cells at the limbus. Corneal stem cells are located at the limbus. So, damage to the limbus results in varying degrees of limbal stem cell deficiency. LSCD is generally caused by the chemical injury or burn. But wearing contact lenses also can be a cause of LSCD. Around 2.4% of contact lens wearer is experienced with LSCD which is a significant number, because around 30 million people wear contact lenses worldwide (1). Another journal reported that approximately 15% of know LSCD is caused by poor contact lens fitting or misuse of contact lens (2). Soft and hard both types contact lenses wearer are experienced with LSCD. LSCD can lead corneal opacity, vascularization and mild to moderate visual impairment. Post LSCD leaves a stromal scar which is the causes visual impairment. One case reports presented by Florencia yeh, of a patient who wears soft contact lenses since 10 years. That was a history of a 22 years old female who wear bi-weekly contact lenses 14-15hrs/daily (3). On 2003 at iovs E.K. Jacobson et al, reported LSCD of six patients associated with contact lens wearer. They told that contact lens-related LSCD can develop with both soft and hard contact lenses. It appears to be associated with long-term contact lens wear, aqueous deficient dry eye, and corneal hypoesthesia (4).
Causes:-Primary causes:- 1. Aniridia 2. Dyskeratosis congenital 3. Congenital erythrokeratodermia 4. Epidermal dysplasia
Secondary causes (5):- 1. Excessive lens wearing means overtime lens wearing and overnight lens wear. Except Ortho-k lenses other lenses are not suitable for sleeping. So if you sleep with the lenses then there is a chance of increase LSCD. 2. Poor contact lens fitting is one if the cause of LSCD. Peripheral too much touch creates pressure on cornea and limbus which may be one of the causes of the following condition. 3. Hypoxia 4. According to Dr. Townsend chronic UV radiation also causes of LSCD (3) 5. Bullous keratopathy 6. Extensive limbal cryotherapy, radiation, or surgery 7. Stevens-Johnson syndrome & Toxic epidermal necrolysis 8.Chronic limits: Autoimmune disease, extensive microbiological infection, atopic conjunctivitis 9. Systemic chemotherapy (Hydroxyurea)Sign:-
1. Superficial Neovascularization 2. The earliest sign is punctuated fluorescein staining of the epithelium in the superior cornea near limbus. The staining pattern looks like whorl-like patternSymptoms:- Early stage is generally asymptomatic. Common symptoms are 1. Irritation 2. Redness 3. Photophobia 4. Mild to moderate decrease vision
Treatment:- Discontinue contact lenses for few days. So that eyes get more oxygen. It can be manage with preservative-free topical steroid and also topical cyclosporine may be needed. If in this primary treatment the condition not improved then may need debridement of epithelium layer. Along with this lubricant eye drop and anti-inflammatory eye drops may be required. Few ophthalmologists prefer only lubricating eye drops at initial stages. Also punctual occlusion and meibomian gland disease treatment required (If dysfunction present). A surgical invention like stem cell transplant may be required for severe cases and if the condition not improves after 6 months. For more information please contact with your Ophthalmologist. Complications are like stromal scarring, loss of vision and permanent loss of limbal stem cell seen.
My aim of writing this topic is to increase awareness of contact lens wearer. Those who wear contact lenses should be careful. We need a periodic eye check up and also need to consult with lens consultant periodically. Sometimes mild redness is seen which we generally avoid consulting with a specialist. The reason may be negligence or shortage of timing. So we should not overlook the minor problem with contact lenses. Mild redness associated with lens intolerance or blurred vision should be given priority for better eye health.
References:- 1.http://www.eyeworld.org/article-limbal-stem-cell-deficiency-associated-with-contact-lens-wear 2.http://www.healio.com/optometry/contact-lenses-eye-wear/news/print/primary-care-optometry-news/%7B439954b5-99f0-4f42-bf50-8863c187fb7d%7D/suspect-limbal-stem-cell-deficiency-in-all-contact-lens-wearers 3. http://www.aaopt.org/bilateral-limbal-stem-cell-deficiency-soft-contact-lens-wearer 4. http://iovs.arvojournals.org/article.aspx?articleid=2413233 5. http://www.hindawi.com/journals/sci/2016/9798374/