Every year we see a handful of soft contact lens wearers who present with significant stem cell deficiency (LSCD). Unlike acute stem cell changes associated with chemical injury, surgery, radiation, trauma or congenital deficiencies caused by aniridia, stem cell deficiencies associated with lens wear have features that include chronicity.^1-3 And that distinction gives us a window of opportunity to control its course.

The cause is most likely multifactorial and seems to be driven by an underlying inflammation and hypoxia, toxicity from the use of multipurpose solutions, and a mechanical component from overwear of soft lenses.

Many of the patients I’ve seen with this condition also have an accompanying ocular surface disease such as rosacea, meibomian gland dysfunction, dry eye or other additional drivers of inflammation. Of great interest, a disproportionate number of female wearers are affected, perhaps due to additional confounding factors (e.g., number of hours of lens wear, make-up, dry eye, etc.).³

As eye care practitioners who fit contact lenses and manage their complications, it’s important to first recognize the problem, and second to be able to manage the complication in a timely and appropriate fashion.

In this month’s Corneal Consult column (page 30), Jim Thimons highlights the many facets of early recognition of limbal stem cell deficiency, with a special focus on treatment options.

Look for the Signs
Early signals of stem cell deficiency (exhaustion) can encompass a multitude of signs. A few examples include a whorl keratopathy and a confluent staining in a saw-tooth pattern, representing a difficulty in repopulating the epithelium in that region of the cornea.¹

All of this ultimately leads to a non-healing defect and extensive irregularity of the corneal surface; conjunctivalization of the cornea can also occur wherein the conjunctiva grows past the limbus because there is no intact barrier.^1-3 A marked drop in acuity (increase in with-the-rule astigmatism), tearing, foreign body sensation and pain may occur.

One method of identifying LSCD, impression cytology, is done by pressing filter paper to the limbus. This simple procedure can detect a deficiency by confirming the presence and density of goblet cells from the cornea and conjunctiva. Confocal microscopy and even OCT imaging can help detect early changes of stem cell deficiency by characterizing the stem cell niche or palisades of Vogt.¹

Holland and Schwartz have proposed a grading system whereby >50% clock-hour involvement and/or visual axis incursion constitutes severe disease.³ Unfortunately, when left unchecked and untreated, progression may require surgical intervention.

Stem cell autografts, although negating the need for immunosuppression, often are not an option because both eyes are generally involved (though the fellow eye may be subclinical). This requires allograft surgery with immunosuppression, using either cadaver or living relative limbal stem cell donors.^2,3

There are several options for immunosuppression, including medications such as cyclosporine, tacrolimus, mycophenolate mofetil and corticosteroids.¹ Also, patients will require very close monitoring for possible side effects.¹

Practitioners should continue to pay close attention to the limbus and peripheral corneal epithelium, as well as any accompanying ocular surface disease in every soft lens wearer. Ongoing surveillance for mild forms of the disease is critical! Remember the hallmarks—LSCD is insidious and recalcitrant, and I suspect it’s an under-recognized complication of lens wear.³

It’s important to stress that early recognition and intervention may prevent the need for surgical intervention.³ Additionally, a lens wear holiday or hiatus with a modification in wearing time, a change in solution or a switch to GP lenses may help ward off potentially serious complications associated with this disease.

1. Raju LV: Stem cell deficiency: how to recognize it, what to do about it. Ocular Surgery News (suppl.); Feb., 2014.
2. Jeng BH, Halfpenny CP, Meisler DM, Stock EL: Management of limbal stem cell deficiency associated with soft contact lens wear. Cornea. 2011 Jan.;30(1):18-23.
3. Chan CC, Holland EJ: Severe limbal stem cell deficiency from contact lens wear:patient clinical features. Am J Ophthalmol. 2013 Mar;155(3)544-549.