Superior Limbic Keratoconjunctivitis: Symptoms, Risks, and Care

Superior limbic keratoconjunctivitis (SLK) is a rare, chronic inflammatory condition affecting the upper part of the eye, primarily involving the superior conjunctiva and cornea. While not life-threatening, its persistent nature can significantly impact quality of life if left untreated.

Understanding contributing factors and available diagnostic and treatment options is essential for effective management.

Typical Signs And Symptoms

SLK presents with distinct ocular symptoms that fluctuate in severity. Patients frequently report a persistent foreign body sensation, as if grit or sand is trapped beneath the upper eyelid. This irritation worsens with blinking, as the inflamed conjunctiva repeatedly contacts the corneal surface. Unlike acute infections, SLK does not typically produce significant discharge, though mild mucus accumulation may occur, particularly in the morning.

Redness primarily affects the superior bulbar conjunctiva, creating a striking contrast with the relatively unaffected lower conjunctiva. The intermittent nature of this redness can mislead patients into believing the condition is resolving, only for symptoms to return unpredictably. In some cases, inflammation extends to the tarsal conjunctiva, intensifying discomfort and contributing to lid swelling.

Photophobia, or light sensitivity, is common, particularly in bright environments. Chronic corneal irritation can lead to punctate epithelial erosions, causing transient blurriness that improves with blinking. In more advanced cases, persistent epithelial defects may develop, resulting in prolonged visual disturbances.

Tearing, often mistaken for dry eye syndrome, occurs as a response to ocular surface irritation rather than tear deficiency. This paradox can complicate diagnosis, as patients may assume their eyes are overproducing tears. Additionally, some individuals report a burning or stinging sensation, particularly after prolonged screen use or exposure to dry environments.

Risk Factors And Contributing Conditions

Several underlying conditions and anatomical factors can predispose individuals to SLK. One of the strongest associations is with thyroid dysfunction, particularly hyperthyroidism and Graves’ disease. Studies indicate that 30% to 50% of SLK patients also have thyroid abnormalities (Ophthalmology, 2012). Chronic inflammation and fibrosis of periocular tissues may contribute to mechanical friction between the superior conjunctiva and tarsal plate, exacerbating irritation and epithelial breakdown.

Mechanical trauma and ocular surface irregularities also play a role. Patients with tight upper eyelids or prominent globes may experience excessive friction during blinking, leading to chronic microtrauma at the superior limbus. Contact lens wearers, particularly those using rigid gas-permeable lenses, face increased risk due to prolonged mechanical interaction with the superior conjunctiva, which can alter tear distribution and cause localized irritation (Cornea, 2019).

Tear film instability further contributes to SLK. While not classified as a primary dry eye disorder, many affected individuals exhibit tear film abnormalities, including increased osmolarity and reduced mucin production. These changes compromise lubrication, making the superior conjunctiva more vulnerable to frictional damage. Meibomian gland dysfunction (MGD), a common cause of evaporative dry eye, has been observed in some SLK patients, exacerbating symptoms. A study in the American Journal of Ophthalmology (2020) found that SLK patients with concurrent MGD experienced more severe symptoms and required more intensive management.

Surgical history and prior ocular procedures can also increase SLK susceptibility. Patients who have undergone upper eyelid surgeries, such as ptosis repair or blepharoplasty, may develop subtle anatomical changes that alter blinking dynamics and tear distribution. Similarly, individuals with conjunctival scarring disorders, such as Stevens-Johnson syndrome or ocular cicatricial pemphigoid, may experience structural changes that predispose them to SLK-like symptoms.

Diagnostic Tools And Procedures

Evaluating SLK requires a combination of clinical observation and specialized diagnostic techniques. Slit-lamp biomicroscopy is the primary tool for identifying characteristic findings, including superior bulbar conjunctival hyperemia, redundant conjunctival tissue, and punctate epithelial erosions at the superior cornea. Blinking often triggers a distinctive rolling or wrinkling of the superior conjunctiva, a hallmark feature distinguishing SLK from other inflammatory conditions.

Dye staining enhances visualization of epithelial disruptions, with rose bengal and lissamine green particularly useful in highlighting devitalized conjunctival cells. Unlike fluorescein, which marks areas of epithelial breakdown, rose bengal delineates regions of poor mucin coverage, a common finding in SLK. This staining pattern is most pronounced at the superior limbus and adjacent conjunctiva, offering further diagnostic confirmation.

Tear film analysis provides additional insights, as SLK frequently presents alongside tear instability. While tear break-up time (TBUT) is not a definitive marker, shortened TBUT values suggest underlying tear dysfunction. Impression cytology, which collects superficial conjunctival cells for histological analysis, can reveal epithelial changes such as squamous metaplasia and goblet cell loss, helping distinguish SLK from other chronic conjunctival disorders.

Pharmacologic And Supportive Treatments

Managing SLK requires a combination of pharmacologic and supportive therapies to reduce inflammation, alleviate symptoms, and minimize mechanical irritation. Lubricating eye drops, particularly preservative-free artificial tears, serve as a first-line approach by reducing friction between the superior conjunctiva and cornea. Formulations containing carboxymethylcellulose or hyaluronic acid provide prolonged hydration and mucin stabilization, improving ocular surface integrity. More viscous gels or ointments may be recommended for nighttime use to prevent irritation during sleep.

Topical corticosteroids, such as loteprednol etabonate or fluorometholone, may be used short-term to control persistent inflammation. These low-potency steroids suppress conjunctival hyperemia and epithelial damage without the high risk of intraocular pressure elevation associated with stronger agents like dexamethasone. However, prolonged steroid use requires careful monitoring due to potential complications such as cataract formation and glaucoma.

For recurrent or severe SLK, topical cyclosporine 0.05% has shown promise in reducing inflammation and improving long-term symptom control by modulating immune responses and enhancing tear film stability. Tacrolimus, another calcineurin inhibitor, has been explored in refractory cases, though its use remains off-label for SLK.

Surgical Interventions

For patients with persistent or severe SLK unresponsive to pharmacologic and supportive treatments, surgical intervention may be necessary. These procedures aim to reduce mechanical friction, improve ocular surface stability, and alleviate chronic inflammation.

Superior conjunctival resection, one of the most common procedures, involves excising redundant conjunctival tissue to reduce friction between the conjunctiva and upper eyelid. This technique provides significant symptom relief in most cases, with studies reporting improvement in over 80% of patients (Ophthalmology, 2015). The procedure, performed under local anesthesia, removes a strip of conjunctiva from the superior limbus, followed by suturing or cauterization to promote smooth healing. Postoperative care includes lubricants, antibiotics, and mild anti-inflammatory agents to minimize complications.

For recurrent SLK despite conjunctival resection, additional surgical options may be explored. Thermocautery, which applies controlled heat to shrink excessive conjunctival tissue, helps tighten the conjunctiva and reduce its tendency to fold over the limbus during blinking. Amniotic membrane transplantation, though less commonly performed for SLK, may aid in ocular surface healing by providing anti-inflammatory and regenerative properties. This approach may be beneficial in cases complicated by severe conjunctival damage or coexisting ocular surface disease.

Long-term outcomes following surgical intervention are generally favorable, though some patients may require repeat procedures if conjunctival laxity redevelops.