Ligneous conjunctivitis is a rare, chronic inflammation affecting the conjunctiva, the clear membrane lining the eyelids and covering the white part of the eye. It is characterized by the formation of thick, firm growths on the conjunctival surface. The term “ligneous” refers to the woody, hard texture of these growths, which are composed primarily of fibrin, a protein involved in blood clotting. This disorder is not contagious and presents as a persistent, recurring issue.
Symptoms and Clinical Presentation
Ligneous conjunctivitis primarily manifests as thick, white, yellow, or reddish plaque-like lesions, often described as pseudomembranes, on the inner surface of the eyelids. These firm growths can also affect the conjunctiva covering the eyeball and, in some cases, the cornea. Patients commonly experience associated symptoms such as eye redness, irritation, and a persistent foreign body sensation.
Excessive tearing and a sticky, mucus-like discharge from the eyes are frequently observed. The presence of these membranes can make it difficult to fully open the eyes and may cause discomfort or pain. If left unmanaged, the growths can lead to corneal damage, including erosions or ulcers, potentially impairing vision or causing vision loss. The symptoms can affect one or both eyes and often recur.
Underlying Cause and Diagnosis
Ligneous conjunctivitis is linked to a severe deficiency of type I plasminogen. Plasminogen is a protein that plays a role in fibrinolysis, the process of fibrin clot dissolution. When plasminogen levels are low, fibrin accumulates excessively in tissues, leading to the formation of the characteristic woody lesions. This deficiency impairs the body’s natural wound healing.
This condition is a genetic disorder, often inherited in an autosomal recessive pattern, meaning it requires mutated genes from both parents. The genetic mutation usually occurs in the PLG gene, which produces plasminogen. Minor trauma, eye surgery, or systemic infections can sometimes trigger episodes or exacerbate the formation of these fibrin-rich deposits.
Diagnosis involves a comprehensive approach, beginning with a detailed eye examination by an ophthalmologist to observe the characteristic thick, woody pseudomembranes. A biopsy of the affected tissue is performed to confirm the composition of the lesions, revealing amorphous subepithelial deposits rich in fibrin. Blood tests measure plasminogen activity and antigen levels. Genetic testing can also confirm mutations in the PLG gene, providing a definitive diagnosis.
Medical and Surgical Treatments
The primary medical treatment for ligneous conjunctivitis involves the application of topical plasminogen eye drops. These drops replace the missing protein, helping to dissolve fibrin accumulations and prevent their recurrence. This therapy aims to restore the natural fibrinolytic balance within the conjunctiva.
Other medical treatments include topical heparin and cyclosporine A. Heparin helps inhibit fibrin formation, while cyclosporine A, an immunosuppressive agent, may reduce inflammation. These adjunctive therapies manage symptoms and promote healing of the ocular surface, often used in combination with plasminogen replacement.
Surgical excision, the physical removal of the pseudomembranes, is often performed to alleviate symptoms and improve vision. However, surgery alone often results in rapid recurrence because it does not address the underlying plasminogen deficiency. Surgical intervention is almost always combined with ongoing medical therapy, such as topical plasminogen, to reduce the likelihood of growths returning. Amniotic membrane transplantation can also be used following surgery to aid in wound healing and provide a scaffold for new tissue growth.
Systemic Involvement and Management
Plasminogen deficiency is a systemic issue, and similar ligneous lesions can form on other mucous membranes beyond the eyes. The most common sites for these growths include the gums (ligneous gingivitis) and various parts of the respiratory tract, such as the larynx and trachea.
Ligneous lesions have also been reported in the middle ear and the female genital tract. Managing these non-ocular manifestations requires a multidisciplinary team of specialists, including ophthalmologists, geneticists, and other experts depending on the affected body system. In severe cases with widespread systemic involvement, treatment may include systemic administration of plasminogen concentrate to boost overall plasminogen levels. A coordinated approach among healthcare providers is important for comprehensive management.