bubble_chart Overview

Dry keratoconjunctivitis can occur not only due to primary lacrimal secretion insufficiency but also in the following situations: 1. Chronic sexually transmitted diseases such as endocrine disorders, anemia, and vitamin deficiencies. 2. Acute sexually transmitted diseases like acute exfoliative dermatitis, Stevens-Johnson syndrome, and ocular pemphigoid. 3. Trauma and surgery involving the eyelid and conjunctiva may injure most of the basic and reflex secretor ducts. Primary lacrimal secretion insufficiency is clinically often referred to as Sjögren's syndrome. It is divided into two types: broad and narrow. The so-called broad Sjögren's syndrome (abbreviated as SJS) refers to cases where, in addition to dry mouth and eyes, there are other systemic autoimmune-related diseases (such as rheumatoid arthritis). The narrow SJS refers specifically to dry keratoconjunctivitis (abbreviated as KCS).

bubble_chart Etiology

The exact cause of this disease remains unknown to date. In recent years, it has been classified under connective tissue diseases in internal medicine. Since this disease is often associated with other autoimmune disorders and shows increased levels of immunoglobulins in the blood, it may be related to autoimmunity.

bubble_chart Diagnosis

Insufficient tear secretion and dry mouth are the main diagnostic criteria for this disease. Based on comprehensive clinical and laboratory findings, the following points aid in diagnosis:

1. Subjective symptoms include dry eyes, burning sensation, increased discharge, photophobia without tearing, and no increase in tears when emotionally stimulated. Patients experience a painful state of wanting to cry but being unable to produce tears.

2. Schirmer's test I: Filter paper wetting less than 10 mm, with a tear meniscus width of less than 0.1 mm, indicates insufficient tear secretion.

3. Tear film breakup time (BUT): Less than 10 seconds indicates tear film instability, a prominent marker of KCS due to mucin deficiency in tears, suggesting severe damage or loss of goblet cells in the conjunctival membrane.

4. The conjunctival sac (especially the lower fornix) contains sticky, stringy secretions, and the corneal surface exhibits filamentary or punctate infiltrates.

5. 1% rose bengal test: Staining points form a triangle with the base toward the corneal limbus and the apex pointing toward the inner and outer canthi, mainly concentrated in the conjunctival epithelium of the palpebral fissure area. Sometimes, the epithelium in the lower third of the cornea also stains. Methylcellulose affects the positive rate of this test.

6. Conjunctival biopsy (fornix): Shows conjunctival epithelial hyperplasia, superficial keratinization, lymphocyte infiltration between basal cells, and reduced or absent goblet cells. Subepithelial connective tissue hyperplasia and neovascularization accompany lymphocyte infiltration.

7. Sialography: Contrast medium is injected into the parotid or submandibular duct, and imaging is performed during the filling phase. After removing the catheter, a salivary stimulant (e.g., lemon juice) is given to induce saliva secretion, and a second image is taken after 5 minutes. In normal individuals, the contrast medium is cleared within 2 minutes due to saliva secretion, whereas SJS and KCS patients show punctate dilation of peripheral ducts, resembling mulberry fruit in severe cases, or cavity formation.

8. Salivary gland scintigraphy: Normal glands produce a distinct scintigraphic image after uptake of ^99mtechnetium. Intravenous injection of sodium pertechnetate labeled with ⁹⁹technetium is followed by scintigraphic recording of ^99mtechnetium uptake at 3, 8, and 15 minutes. The results resemble those of sialography.

9. Labial gland biopsy: Reveals diffuse lymphocyte infiltration around lobular ducts without ductal epithelial hyperplasia. If labial gland biopsy is inconclusive, lacrimal or salivary gland biopsy is performed for further confirmation.

10. Pathological changes in the lacrimal gland: Classified into 4 stages. Stage 0: Normal gland; Stage I: Grade I chronic inflammatory cell infiltration, irregular duct arrangement, and intralobular fibrosis; Stage II: Destruction of normal lobular structure, extensive lymphocyte infiltration, and acinar atrophy; Stage III: Only a few residual acinar cells remain, with the gland largely fibrotic.

11. Hematological tests often show grade I anemia, eosinophilia, and increased erythrocyte sedimentation rate.

12. Immunological tests: Serum albumin is decreased, globulin is increased, and IgA, IgM, and IgG levels are elevated. Lymphoblast transformation rate indicates low cellular immunity.

bubble_chart Treatment Measures

If the insufficient secretion is caused by systemic diseases, corresponding treatments such as thyroid tablets, diethylstilbestrol, testosterone, or vitamin A should be administered based on the disease cause. Generally, the effects are good, and symptoms are significantly relieved after medication.

The treatment of SJS or KCS can target the following four aspects:

1. **Supplementing Tears** Artificial tears remain the primary treatment, typically using 1% methylcellulose or 1.4% polyvinyl alcohol eye drops. However, these only maintain corneal moisture for about half an hour. In recent years, various sustained-release artificial tears have been developed abroad. Our hospital often adds a certain amount of chondroitin sulfate to artificial tears. Due to the hydrophilic properties of mucopolysaccharides, this may enhance the stability of the artificial tear film and impart some physiological functions.

2. **Reducing Tear Loss** Hydrophilic soft contact lenses combined with artificial tear punctum occlusion can be somewhat effective for grade I and grade II KCS, though severe cases may not tolerate it. Occluding the lacrimal punctum to prevent tear drainage can be achieved by cauterizing the punctum with a 50 mA current for 5–10 seconds, preserving the patient’s precious minimal tear volume until evaporation. Postoperatively, Schirmer’s test and tear meniscus height show significant improvement, with symptom relief. Some also advocate using synthetic plugs to occlude the punctum.

3. **Eliminating Mucous Secretions** A 2% acetylcysteine eye drop (buffered to pH 8.0) effectively dissolves mucus. After use, secretions decrease, subjective comfort improves, and vision may also enhance.

4. **Personal Hygiene** Patients with insufficient tear secretion have reduced local defense mechanisms, making them more susceptible to pathogenic infections. The presence of abundant yellow secretions in the conjunctival sac suggests bacterial infection (often staphylococcal), warranting bacterial culture and sensitive antibiotic eye drops. Corticosteroid eye drops should be avoided as they further suppress local immunity and increase infection risk. Additionally, many KCS patients are allergic to penicillin or sulfonamides, requiring caution.

For systemic treatment of KCS, the exact etiology remains unclear, so no universally accepted rational regimen exists. In recent years, we have encountered many cases of acute-onset dry keratitis, presenting with explosive mucopurulent conjunctivitis in both eyes and oral ulcers. The condition progresses rapidly, often leading to corneal dryness, ulcers, or even perforation within weeks. For these acute cases, we trialed oral cyclophosphamide (150 mg/day) combined with low-dose prednisone (15 mg/day), along with topical 2% acetylcysteine and artificial tear punctum occlusion. This regimen may reverse the condition within 2–4 weeks, healing ulcers and resolving inflammation. Vision can recover from counting fingers to near-normal levels. After the acute phase, conventional four-pronged maintenance therapy can preserve visual function in these idiopathic-like dry keratoconjunctivitis cases.