Symblepharon

What is Symblepharon

Symblepharon is an adhesion between the palpebral conjunctiva (lining the inner eyelid) and the bulbar conjunctiva (covering the eye surface). These bands of scar tissue tether the eyelid to the eyeball, restricting eyelid movement, limiting ocular motility, and distorting the conjunctival fornix — the recessed pocket where the eyelid lining meets the eye. In severe cases, symblepharon obliterates the fornix entirely (ankyloblepharon), causing functional blindness.

Causes

Symblepharon results from any condition that damages both the palpebral and bulbar conjunctival surfaces simultaneously, allowing them to fuse during healing:

• Chemical burns — alkali burns (lye, ammonia, cement) are most severe; acid burns produce more limited injury. Alkali penetrates rapidly through the cornea into the anterior chamber, with symblepharon developing as conjunctival surfaces heal together.
• Stevens-Johnson Syndrome (SJS) / Toxic Epidermal Necrolysis (TEN) — drug-hypersensitivity reactions causing blistering of mucous membranes including conjunctiva. Symblepharon is a hallmark late sequela of SJS/TEN ocular involvement and may progress over months to years.
• Ocular Cicatricial Pemphigoid (OCP) / Mucous Membrane Pemphigoid — autoimmune subepithelial blistering disease causing progressive conjunctival scarring and shrinkage. Symblepharon formation in OCP follows a characteristic inferior fornix shortening pattern.
• Radiation to the orbit or eye — therapeutic radiation for orbital or periocular tumors causes progressive conjunctival fibrosis.
• Severe conjunctival infections — trachoma (Chlamydia trachomatis) is the leading infectious cause of symblepharon worldwide, particularly in developing countries. Recurrent infections cause progressive conjunctival scarring.
• Trauma — perforating injuries or severe blunt trauma with conjunctival laceration.
• Post-surgical scarring — prior conjunctival surgery, enucleation, or orbital procedures.
• Linear IgA disease and other cicatrizing conjunctivitides

Clinical Staging

Symblepharon severity is graded by the degree of fornix obliteration:

• Grade I: Partial symblepharon — adhesive bands present, forniceal depth reduced but some fornix preserved
• Grade II: Moderate symblepharon — fornix significantly shortened, motility restricted
• Grade III: Severe symblepharon — fornix nearly obliterated, eyelid movement markedly restricted
• Grade IV (Ankyloblepharon): Complete adhesion — eyelid fused to globe, no identifiable fornix

Associated findings include keratinization of the conjunctiva, limbal stem cell deficiency (LSCD) causing corneal vascularization and opacification, and trichiasis from distorted lid margin.

Acute Phase Management

The goal in the acute phase of chemical injury or SJS is to prevent symblepharon formation:

• Immediate copious irrigation — for chemical burns, continuous saline or water irrigation for 30–60 minutes to remove the offending agent; target conjunctival pH 7.0–7.3.
• Symblepharon ring / conformer — a smooth ring or conformer device placed in the fornix to physically separate palpebral and bulbar surfaces during healing. Must be maintained continuously and removed only for medication instillation.
• Fornix sweeping — gentle blunt dissection of early adhesions with a glass rod or spatula, performed daily or multiple times per day in the acute phase under topical anesthesia.
• Amniotic membrane transplantation (AMT) — suturing or gluing amniotic membrane (AM) to the ocular surface in the acute phase of chemical burns or SJS significantly reduces symblepharon formation, promotes re-epithelialization, and reduces inflammation. Both sutured and ProKera® ring-mounted AM devices are used.
• Topical cyclosporine and corticosteroids — to reduce conjunctival inflammation in acute SJS/OCP.

Surgical Treatment of Established Symblepharon

Once symblepharon has matured, surgical lysis and fornix reconstruction are required to restore motility and eyelid function. Surgery is indicated for:

• Restricted ocular motility causing diplopia
• Fornix shortening preventing prosthetic fitting (in anophthalmos)
• Trichiasis from distorted lid margin abrading the cornea
• Functional limitations from eyelid restriction

Mucous Membrane Grafting (MMG)

After surgical lysis of the symblepharon bands, the raw surfaces must be covered with a graft to prevent re-adhesion. Autologous mucous membrane (from buccal mucosa, nasal septum, or hard palate) is harvested and sutured to line the reconstructed fornix. MMG provides a durable, non-keratinizing surface.

Amniotic Membrane Grafting

Amniotic membrane can be used as an adjunct or alternative to autologous mucous membrane for fornix reconstruction. It provides anti-inflammatory, anti-fibrotic, and anti-angiogenic properties, promoting re-epithelialization. Often combined with a conformer to maintain fornix depth post-operatively.

Limbal Stem Cell Transplantation

When symblepharon is accompanied by limbal stem cell deficiency — evidenced by corneal vascularization, conjunctivalization of the cornea, and recurrent epithelial breakdown — limbal stem cell transplantation (LSCT) is necessary before or concurrent with symblepharon repair to restore a stable corneal surface. Sources include:

• Autologous LSCT (CLAU/CLET) — from the fellow unaffected eye; avoids immunosuppression
• Allogeneic LSCT (KLAL/CLET) — from cadaveric donor tissue; requires systemic immunosuppression
• Ex vivo expanded limbal cells (CLET) — cultured on amniotic membrane carrier; now available at specialized centers

Post-operative Conformer Use

A conformer or custom ocular prosthesis is placed immediately after fornix reconstruction and maintained to prevent re-adhesion during healing. In progressive cicatrizing conditions (OCP), the conformer may need to be worn indefinitely.

Systemic Disease Management

In autoimmune cicatrizing conjunctivitis (OCP, SJS), treatment of the underlying systemic disease is essential to halt progression:

• OCP: Dapsone (first-line), methotrexate, cyclophosphamide, or rituximab. Surgery should not be performed on actively inflamed OCP eyes — inflammation accelerates scarring.
• SJS: Cyclosporine, etanercept, or intravenous immunoglobulin in the acute phase may reduce severity. Long-term management focuses on ocular surface rehabilitation.

Oculoplastic management of symblepharon is most effective when performed in collaboration with rheumatology, dermatology, or immunology for systemic disease control.