Ophthalmology – Superior Limbic Keratoconjunctivitis

What the Disorder Represents

Superior limbic keratoconjunctivitis (SLK) is a chronic, recurrent ocular-surface disorder involving the:

• Superior bulbar conjunctiva
• Superior limbus
• Superior corneal epithelium
• Superior tarsal conjunctiva

It is usually:

• Bilateral
• Often asymmetric
• More common in middle-aged women

Typical symptoms include:

• Foreign-body sensation
• Burning
• Photophobia
• Ocular discomfort
• Fluctuating vision

Symptoms may appear disproportionately severe relative to the initial examination.

The Classic Clinical Pattern

The characteristic constellation includes:

• Superior bulbar conjunctival injection
• Redundant or lax superior bulbar conjunctiva
• Marked superior conjunctival staining
• Fine papillary reaction of the superior tarsal conjunctiva
• Superior punctate epithelial keratopathy
• Mucus strands or corneal filaments

This superior distribution is one of the most useful diagnostic clues.

Who Is Most Often Affected

SLK most commonly occurs in:

• Middle-aged adults
• Women more often than men

It can occur at other ages, especially when associated with:

• Thyroid eye disease
• Severe dry eye disease
• Contact lens-related mechanical irritation

Strongest Systemic Association

The classic association is:

Thyroid disease, particularly Graves disease/thyroid eye disease

A substantial proportion of patients with SLK have:

• Current thyroid disease
• Previous thyroid disease
• Clinical signs of thyroid eye disease

Therefore thyroid history should always be reviewed.

Why Thyroid Eye Disease Promotes SLK

Thyroid eye disease can produce:

• Upper-lid retraction
• Tight upper eyelid
• Proptosis
• Increased blink friction
• Exposure
• Tear-film instability

These factors increase mechanical interaction between the:

Upper lid and superior bulbar conjunctiva

and may contribute to development of SLK.

Other Important Associations

SLK is also associated with:

• Aqueous-deficient dry eye
• Meibomian gland dysfunction
• Filamentary keratitis
• Superior conjunctivochalasis
• Chronic contact lens wear

Older reports also described associations with:

• Thimerosal-containing contact lens solutions

which are now much less relevant because thimerosal is rarely used in modern contact lens care.

How the Disease Probably Develops

The exact mechanism is not fully established.

The leading model is:

Mechanical microtrauma + tear-film deficiency + chronic ocular-surface inflammation

Repeated friction occurs between:

• Tight superior eyelid
• Redundant superior bulbar conjunctiva
• Superior limbus

This produces:

• Epithelial injury
• Abnormal conjunctival keratinization
• Inflammation
• Mucus production

Role of Conjunctivochalasis

Some patients have excessive mobility or redundancy of the superior bulbar conjunctiva.

The loose conjunctiva is repeatedly dragged across the:

Superior cornea and limbus during blinking

which may perpetuate inflammation.

This mechanical component explains why procedures that:

• Resect
• Tighten
• Cauterize

the superior conjunctiva can improve refractory disease.

Typical Symptoms

Patients commonly describe:

• Grittiness
• Foreign-body sensation
• Burning
• Photophobia
• Tearing
• Ocular pain or discomfort
• Intermittent blurred vision

Symptoms usually fluctuate with:

• Dry environments
• Prolonged visual activity
• Exacerbation of dry eye

Why Pain May Seem Disproportionate

Surface disease may be localized to a relatively small superior area but remain highly symptomatic because:

• The superior lid repeatedly rubs the inflamed tissue
• Corneal epithelial defects are painful
• Filaments can mechanically pull on corneal epithelium

Therefore symptom severity may exceed the apparent extent of disease.

Superior Bulbar Conjunctival Findings

The hallmark finding is:

Localized superior bulbar conjunctival inflammation

typically from approximately:

• 10 to 2 o’clock

Findings may include:

• Hyperemia
• Thickening
• Redundancy
• Loss of normal smooth surface
• Lissamine green staining

Superior Tarsal Conjunctival Findings

Upper-lid eversion may reveal:

Fine, velvety papillary hypertrophy

of the superior palpebral conjunctiva.

This is generally finer than the giant papillae seen with:

• Giant papillary conjunctivitis
• Vernal keratoconjunctivitis

Corneal Findings

Corneal involvement typically affects the:

Superior cornea

and may include:

• Punctate epithelial erosions
• Superior epithelial keratitis
• Mucus adherence
• Filamentary keratitis

Severe disease can produce significant discomfort and fluctuating vision.

Filamentary Keratitis

Filaments consist of:

• Mucus
• Degenerated epithelial cells

adhering to compromised corneal epithelium.

They may cause:

• Sharp pain
• Foreign-body sensation
• Photophobia

Mechanical removal can provide temporary relief but does not address the underlying SLK.

Tear-Film Abnormalities

Patients frequently demonstrate:

• Reduced tear meniscus
• Short tear break-up time
• Increased mucus
• Reduced Schirmer values

This reflects frequent coexistence of:

Dry eye disease.

Testing the Mobility of the Superior Conjunctiva

After topical anesthesia, the examiner may gently manipulate the superior bulbar conjunctiva.

In SLK, it may be unusually:

• Mobile
• Redundant

and may be displaced toward the superior cornea more easily than normal.

This supports a mechanical component but is not required for diagnosis.

Ocular Surface Staining

Lissamine green is especially useful for highlighting abnormal superior conjunctival epithelium.

It may show intense staining of the:

• Superior bulbar conjunctiva
• Superior limbal region

Fluorescein is useful for detecting:

• Corneal epithelial disease

Rose bengal can also stain damaged epithelium but is used less often because it causes more discomfort.

Why Lissamine Green Is Preferred

Lissamine green:

• Highlights devitalized or mucin-deficient epithelium
• Is usually better tolerated
• Is particularly useful for documenting the superior conjunctival component

The distribution of staining can be more diagnostically useful than total staining severity.

Schirmer Testing

Schirmer testing may be useful when aqueous-deficient dry eye is suspected.

A reduced result supports coexisting:

Keratoconjunctivitis sicca

but does not itself diagnose SLK.

Thyroid Evaluation

Patients without a known thyroid disorder should be assessed for symptoms or signs such as:

• Weight change
• Heat intolerance
• Palpitations
• Tremor
• Lid retraction
• Proptosis

Laboratory evaluation may include:

• TSH
• Free T4

with further thyroid testing guided by clinical findings.

Routine parathyroid testing is not standard in modern evaluation unless there is another clinical indication.

What Pathology Shows

Histopathology may demonstrate:

• Squamous metaplasia
• Keratinization of conjunctival epithelium
• Inflammatory cell infiltration
• Goblet-cell abnormalities

These changes support chronic epithelial trauma and inflammation.

Biopsy is:

Not usually necessary for diagnosis.

Conditions That Can Mimic SLK

Important differentials include:

• Dry eye disease
• Filamentary keratitis
• Allergic conjunctivitis
• Giant papillary conjunctivitis
• Vernal keratoconjunctivitis
• Atopic keratoconjunctivitis
• Contact lens-related disease
• Conjunctivochalasis
• Toxic medicamentosa
• Mucus fishing syndrome

Distinguishing It From Giant Papillary Conjunctivitis

SLK

• Superior bulbar conjunctival staining
• Superior limbal involvement
• Fine papillary tarsal reaction
• Often associated with dry eye or thyroid disease

GPC

• Large papillae on upper tarsal conjunctiva
• Often associated with contact lenses or exposed sutures
• Mucous discharge and lens intolerance are prominent

Distinguishing It From Vernal Keratoconjunctivitis

Vernal disease more commonly features:

• Younger patients
• Severe itching
• Giant cobblestone papillae
• Limbal Horner-Trantas dots
• Seasonal exacerbation

SLK more often affects:

Middle-aged adults with superior bulbar conjunctival disease and mechanical friction.

First Treatment Priority

Management should begin by treating contributing ocular-surface disease.

Common first steps include:

• Preservative-free artificial tears
• Lubricating gel or ointment
• Management of meibomian gland dysfunction
• Reduction of toxic topical medications
• Modification or discontinuation of contact lens wear when contributory

Treating Coexisting Dry Eye

Dry eye management may include:

• Frequent preservative-free tears
• Nighttime ointment
• Warm compresses
• Lid hygiene
• Environmental modification
• Moisture-chamber glasses

Improving the tear film can substantially reduce:

Friction and epithelial injury.

Anti-Inflammatory Eye Drops

A short course of:

Topical corticosteroid

may be useful for significant inflammatory flares.

Because repeated steroid treatment can cause:

• Ocular hypertension
• Glaucoma
• Cataract

IOP should be monitored when treatment is prolonged or recurrent.

Steroid-Sparing Surface Therapy

Longer-term inflammatory control may include:

• Topical cyclosporine
• Lifitegrast in selected patients
• Other dry-eye anti-inflammatory agents

These are particularly useful when significant dry eye coexists.

Filament Management

Filamentary keratitis may be treated with:

• Intensive lubrication
• Mechanical filament removal
• Topical N-acetylcysteine in selected cases
• Bandage contact lens when appropriate

Recurrence is common unless the underlying ocular-surface disease is controlled.

Role of Autologous Serum Tears

For severe refractory surface disease, autologous serum tears can provide:

• Epitheliotrophic growth factors
• Improved lubrication
• Better epithelial healing

They may be particularly useful when significant dry eye coexists with SLK.

Punctal Occlusion

Punctal plugs or cautery may help patients with substantial:

Aqueous tear deficiency

but significant surface inflammation should generally be controlled first.

Therapeutic Contact Lenses

A:

• Bandage soft contact lens
• Scleral lens

may reduce friction and improve symptoms in selected cases.

However, contact lens-associated mechanical irritation can also worsen SLK in some patients, so treatment must be individualized.

Silver Nitrate – Historical Perspective

Older treatment protocols frequently used:

0.5–1% silver nitrate

applied to the superior conjunctiva.

This can chemically cauterize abnormal epithelium and occasionally relieve symptoms.

However, silver nitrate is now used much less frequently because of the risk of:

• Chemical injury
• Corneal toxicity
• Scleral injury

and because safer medical and surgical options are available.

Important Silver Nitrate Safety Point

If silver nitrate is used by an experienced clinician:

Solid silver nitrate sticks should never be applied directly to the ocular surface.

They can produce severe chemical burns.

When Surgery Is Considered

Surgery is appropriate when:

• Symptoms remain severe
• Medical therapy fails
• Redundant superior conjunctiva is prominent
• Mechanical friction is clearly contributing

Superior Conjunctival Resection

One of the most effective surgical approaches is:

Resection of redundant superior bulbar conjunctiva

often with removal of adjacent:

Tenon tissue

The goal is to reduce:

• Conjunctival redundancy
• Superior friction
• Recurrent epithelial trauma

Conjunctival Resection With Tenonectomy

Removing both redundant conjunctiva and abnormal underlying Tenon tissue may reduce recurrence.

Treatment typically involves the superior region spanning roughly:

10 to 2 o’clock

although the extent is individualized.

Conjunctival Cauterization

Thermocautery or other controlled conjunctival cautery can:

• Tighten redundant tissue
• Reduce mobility
• Decrease mechanical trauma

It can be effective in appropriately selected patients.

Why Mechanical Procedures Work

Surgical and cautery procedures do not primarily suppress inflammation.

Instead they address the mechanical cycle:

Redundant conjunctiva → lid friction → epithelial injury → inflammation

by physically reducing conjunctival redundancy.

Supratarsal Steroid Injection

Supratarsal corticosteroid injection has been reported to improve refractory SLK.

However, it is not a routine first-line treatment because it can cause:

• IOP elevation
• Steroid response
• Other injection-related complications

It should be reserved for selected cases under specialist supervision.

Relationship to Thyroid Treatment

Treating systemic thyroid dysfunction is important for overall health.

However:

Correction of thyroid hormone levels alone does not necessarily eliminate SLK

because associated mechanical abnormalities such as:

• Lid retraction
• Proptosis
• Tight upper eyelid

may persist.

When Eyelid Surgery May Matter

In patients with significant thyroid eye disease and upper-lid retraction, correction of eyelid position may reduce:

• Exposure
• Mechanical friction

and can sometimes improve recurrent ocular-surface disease.

Follow-Up Approach

Follow-up depends on severity.

Monitor:

• Symptoms
• Superior conjunctival staining
• Corneal staining
• Filaments
• Tear-film status
• IOP if corticosteroids are used

Stable mild disease may be reviewed periodically, while severe epithelial disease requires closer observation.

Expected Clinical Course

SLK is usually:

Chronic and relapsing

Patients may experience:

• Exacerbations
• Partial remissions
• Long symptom-free intervals

Some cases improve spontaneously over time.

Visual Prognosis

The visual prognosis is generally:

Excellent

because SLK usually does not cause permanent intraocular damage.

Vision may fluctuate due to:

• Tear-film instability
• Corneal epithelial disease

Severe permanent visual loss is uncommon.

Problems That Can Develop

Potential complications include:

• Filamentary keratitis
• Persistent corneal epithelial defects
• Severe dry-eye symptoms
• Contact lens intolerance
• Steroid-induced ocular hypertension from treatment
• Rare chronic corneal surface damage

High-Yield Takeaways

• Superior limbic keratoconjunctivitis is a chronic inflammatory and mechanical disorder of the superior ocular surface.
• The classic pattern is superior bulbar conjunctival injection/staining + redundant superior conjunctiva + fine superior tarsal papillae + superior punctate keratitis or filaments.
• SLK is usually bilateral but asymmetric and occurs most often in middle-aged women.
• The strongest systemic association is thyroid disease, particularly thyroid eye disease.
• Mechanical friction between a tight upper lid and redundant superior bulbar conjunctiva is thought to be central to pathogenesis.
• Coexisting aqueous-deficient dry eye and meibomian gland dysfunction are common and should be actively treated.
• Lissamine green staining of the superior bulbar conjunctiva is particularly useful diagnostically.
• Fine superior tarsal papillae differ from the giant papillae of GPC or vernal keratoconjunctivitis.
• Initial treatment emphasizes preservative-free lubrication and management of associated dry eye.
• Short courses of topical corticosteroid can control inflammatory flares, while cyclosporine or other steroid-sparing dry-eye agents may be useful for chronic disease.
• Filamentary keratitis may require filament removal, intensive lubrication, and N-acetylcysteine in selected cases.
• Silver nitrate is a historical treatment and is used much less often today because of the risk of chemical ocular injury.
• Refractory disease with prominent conjunctival redundancy may respond well to superior conjunctival resection with or without Tenonectomy or controlled cauterization.
• Supratarsal steroid injection is an option in selected cases but requires awareness of steroid-induced IOP elevation.
• The disorder often follows a relapsing-remitting course, but long-term visual prognosis is generally excellent.