Keratoconjunctiva xerosis

Introduction Keratoconjunctival dryness, commonly known as "dry eye syndrome", is an inflammatory response in which the conjunctival cornea cannot be wet. This disease may be the absence of water or mucus components in the tears.

Cause

Dry eye syndrome can be divided into two categories: lacrimal gland secretion and lacrimal gland secretion function. The latter is due to excessive tear loss, or evaporative dry eye syndrome.

1. Tear Deficiency Dry Eye (TDDE) can be further divided into SS-type and non-SS dry eye health search.

(1) SS dry eye is an exocrine gland autoimmune disease. Can be further divided into primary SS (dry eye plus mouth dry) and secondary SS (add collagen disease, such as rheumatoid arthritis, lupus erythematosus, polyarthritis, etc.).

(2) Non-Sjögren's Dry Eye (NSDE): or KCS, which includes the following lesions:

1 lacrimal gland lesions: A. Primary Lacrimal Deficiency (PLD), congenital no tears, no or lacrimal gland, but lack of secretion; non-SS KCS, sometimes called acquired PLD, or KCS for short .B. Secondary Lacrimal Deficiency (SLD), such as vitamin A deficiency, lymphoma, sarcoma-like disease, human immunodeficiency virus (HIV) infection, and most after lacrimalectomy.

2 neurological disorders: such as VII cranial neuropathy, long-wear contact lens, nerve paralytic keratitis, etc.

3 large area of ocular surface damage caused by lacrimal gland obstruction such as trachoma, heat or chemical eye burns, Stevens-Johnson syndrome, scar ocular pemphigus, hernia defect, atopic keratoconjunctivitis, trauma and so on.

2. Evaporative dry eye

(1) meibomian gland lesions: obstructive meibomitis is the most common cause. Often primary, secondary to burns, conjunctivitis or systemic diseases such as sebaceous glandular dermatitis, rosacea, ichthyosis, psoriasis , meibomian gland cysts, mumps, stones, etc. Sometimes the meibomian glands are congenitally absent secondary hyposecretion, double ciliary, suppurative inflammation, tumors, etc. Sometimes the oil in the meibomian glands is stagnant, seesaw The glandular secretion function seems normal, but the oil is not normal.

(2) blinking abnormal health search: blink reduction or interval extension can cause ocular surface dryness as seen in VDT (Visual Dislpay Terminal) computer workers, or office eye syndrome, Parkinson's disease.

(3) Anterior sputum inflammation.

(4) ocular surface lesions: diseases that cause goblet cell reduction, such as vitamin A deficiency. Any cause of local ocular surface bulge, such as surgical sputum, cleft palate abnormalities, exophthalmos and sacral deformities can cause local ocular surface dry.

(5) Others.

an examination

Related inspection

Tear secretion test

1. The tear secretion test is normally 10-15mm, <10mm is low secretion, and <5m is dry eye. In the absence of ocular surface anesthesia, the secretion function of the main lacrimal gland was tested; after the anesthesia, the secretory function of the lacrimal gland (basal secretion) was detected, and the observation time was 5 min.

2, tear film rupture time <10s for tear film instability.

3, tear fern experimental mucin deficiency, such as eye pemphigus, Stevens-Johnson syndrome, "ferns" reduced or even disappeared.

4. Biopsy and imprinted cytology In patients with dry eye, the density of conjunctival goblet cells decreased, the ratio of nucleoplasmic cytoplasm increased, the squamous metaplasia of epithelial cells, and the conjunctivalization of corneal epithelium. The severity of the disease can be assessed indirectly by calculating the density of goblet cells in the conjunctiva.

5, fluorescein staining positive represents corneal epithelial defects. You can also observe the height of the tear river.

6. The sensitivity of tiger red staining was higher than that of fluorescein staining, and the cells with negative angle and conjunctival staining were positive cells.

7, tear lysozyme content <1 200g / ml, or lytic zone <21.5mm2, it indicates dry eye syndrome.

8, tear osmotic dry eye and contact lens wearer, tear osmotic pressure increased by 25mOsm / L compared with normal people, such as greater than 312mOms / L, can diagnose dry eye syndrome. This item is specific and has a high early diagnostic value.

9. Lactoferrin is less than 1.04bg/ml before the age of 69, and if it is lower than 0.85mg/ml after 70 years old, dry eye syndrome can be diagnosed.

10. The purpose of the tear clearance rate check is to understand whether there is a delay in tear clearance. Detection by fluorometry.

11, dry eye or tear film interference imager to understand the tear film lipid layer, dry eye, especially in patients with LTD, visible tear film lipid layer abnormality, compared with the standard image, can be estimated dry eye severity.

12. Corneal topographic examination to understand the regularity of the corneal surface. The regular parameters of the corneal surface (surface regularity index and surface asymmetry index) of dry eye patients are higher than normal people, and the degree of increase is positively correlated with the severity of dry eye.

13, serological examination to understand autoantibodies, SS patients see ANA antibodies, rheumatoid factor and other positive. This is conducive to the diagnosis of dry eye caused by immune diseases.

Differential diagnosis

The misdiagnosis of this disease is mostly due to the doctor's lack of understanding of the disease, the lack of vigilance, the lack of attention to the patient's dry mouth performance or the consideration of certain organ damage as an independent lesion. In addition to rheumatoid arthritis and systemic lupus erythematosus, diseases that are easily misdiagnosed include autoimmune liver disease, pulmonary fibrosis, and renal tubular acidosis. The identification points of this disease and rheumatoid arthritis and systemic lupus erythematosus are reminded as follows:

1. The main points of systemic lupus erythematosus are: this disease occurs in middle-aged and elderly women, fever, especially high fever, no butterfly-shaped erythema, obvious mouth and dry eyes, renal tubular acidosis is common and mainly Renal damage, hyperglobulinemia is obvious, low complement syndrome is rare, and the prognosis is good.

2. The main point of identification of rheumatoid arthritis is that the progression of joint inflammation and bone damage in this disease is far less pronounced and severe than rheumatoid arthritis, and rarely causes joint deformity and dysfunction. Anti-SSA and anti-SSB antibodies are rare in patients with rheumatoid arthritis.

3. Dry mouth of non-autoimmune diseases such as senile and diabetic patients can be dry mouth, and serum autoantibodies and globulin can be detected.

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