Meibomian keratitis is a corneal lesion that develops against the background of chronic purulent inflammation of the meibomian glands and a violation of their secretory function. Meibomian keratitis is manifested by corneal syndrome, pain, small superficial infiltrates and corneal opacity, inflammatory injection of the eyeball, decreased vision. The diagnosis is made on the basis of external examination, biomicroscopy of the eye, endothelial and confocal microscopy, keratometry and pachytometry, assessment of visual acuity and corneal sensitivity, microbiological examination of a smear from the conjunctiva. Treatment is carried out in parallel with therapy of meibomitis and blepharitis with the help of local and systemic antibiotic therapy; instillations of mydriatics, keratoprotectors and epithelizing drugs; eyelid massage; if necessary, excimer laser removal of superficial corneal scars and keratoplasty are performed.
Meibomian keratitis occurs as a complication of chronic meibomitis and meibomian blepharitis against the background of hyperproduction and insufficient outflow of secretions of the cartilage glands of the eyelids. Located in the thickness of the upper and lower eyelids, the meibomian (sebaceous) glands secrete a special oily secret, which is an important component of the tear film. With an excess of secretions, they overflow the excretory ducts, which creates a favorable environment for the development of infection. The penetration of pathogenic microorganisms into the cavity of the meibomian glands leads to their purulent inflammation, a change in the composition of the secretion and difficulty in its outflow. Moving to the edges and conjunctiva of the eyelids, the inflammatory process often acquires a persistent recurrent course. Pathologically altered secret of the meibomian glands has a long-term irritating effect on the cornea and provokes the development of meibomian keratitis.
Excessive secretion of the meibomian glands, the presence of prolonged sluggish purulent inflammation of the ciliary edges of the eyelids and damage to the epithelial cover of the cornea of the eye contribute to the development of meibomian keratitis.
Meibomitis in most cases is caused by coccoid forms of bacteria (Staphylococcus, Streptococcus, pneumococcus, diplococci), less often Pseudomonas aeruginosa or E. coli, proteus. Damage to the corneal epithelium can occur as a result of trauma, burns of the eye, ophthalmological operations, ingestion of foreign bodies, wearing contact lenses, with eye diseases that increase the permeability of the cornea (corneal dystrophy, dry eye syndrome, lagophthalmos).
Weakening of the body’s immune defense, living in unfavorable sanitary and hygienic conditions, as well as prolonged eye irritation by wind, smoke and dust are risk factors for the development of inflammation of the meibomian glands and meibomian keratitis.
The clinical picture includes manifestations of background chronic meibomitis and blepharitis: hyperemia and thickening of the eyelids, the presence of oily secretions and grayish-yellowish crusts on the ciliary edges of the eyelids, pain and itching, increased fatigue and sensitivity of the eyes, recurrent chalazions. When pressing on the edges of the eyelid, a cloudy, thick secret is released.
The lesion of the cornea in meibomian keratitis is characterized by the formation of small round surface infiltrates of yellowish-gray color along its edge, which subsequently often ulcerate. Meibomian keratitis is accompanied by the phenomena of corneal syndrome (lacrimation, blepharospasm, photophobia), pronounced inflammatory injection of the eyeball, corneal opacity, a sharp decrease in visual acuity. The transition of the inflammatory process to the deep layers of the cornea with meibomian keratitis is usually not observed.
Chronic inflammation of the meibomian glands leads to curvature and scarring of their excretory ducts, which further aggravates the insufficiency of excretion of secretions outside and contributes to the chronization of meibomian blepharitis and keratitis.
Diagnosis of meibomian keratitis is based on the study of the clinical picture and anamnesis of the disease, the results of laboratory and instrumental studies.
In the diagnosis of meibomian keratitis, the connection of the disease with previous mechanical damage to the eye, ingestion of foreign bodies, ophthalmological operations, existing eye pathology is important.
Examination of eye structures (biomicroscopy, diaphanoscopy) with meibomian keratitis helps to see inflammatory changes in the conjunctiva of the eyelids and cornea (edema, the presence of infiltrates and ulceration), to assess the nature of the lesion.
The thickness of the cornea of the eye with meibomian keratitis is measured using pachymetry, the depth of its inflammatory lesion is measured by confocal and endothelial microscopy. Refractive changes of the eye are detected by keratotopographic examination; the curvature of the anterior surface of the cornea is evaluated by computer keratometry.
With meibomian keratitis, visual acuity is checked and a fluorescein test is performed to detect the presence of corneal damage. Laboratory diagnostics of meibomian keratitis includes bacteriological and cytological examination of a smear from the conjunctiva, PCR and ELISA diagnostics of the contents of the meibomian glands.
Differential diagnosis of meibomian keratitis is carried out with viral, fungal and bacterial keratitis.
Therapy of meibomian keratitis is long-term, carried out in a specialized hospital department; at the same time, the elimination of chronic meibomitis and blepharitis is of decisive importance.
With meibomian keratitis, broad-spectrum antibiotics (aminoglycosides, fluoroquinolones and cephalosporins) are prescribed in the form of instillation of eye drops, laying ointments, parabulbar and subconjunctival injections, oral or parenteral administration. Solutions of antiseptics, NSAIDs and glucocorticoids are also used locally.
The elimination of meiobitis with meibomian keratitis is helped by regular hygiene of the eyelids with the removal of crusts, massage of the edges of the eyelids with a glass stick to enhance the outflow of secretions, followed by lubricating them with a solution of sulfacetamide or diamond green.
In order to prevent complications of meibomian keratitis (adhesive process, involvement of deep layers of the eyeball), solutions of mydriatics are instilled; additionally, antihistamines, immunostimulants, vitamins are indicated. Epithelialization of corneal ulceration is facilitated by the appointment of keratoprotective and wound healing agents (quinine hydrochloride, taurine). With a decrease in visual acuity, it is possible to prescribe physiotherapy: electrophoresis or phonophoresis with medications.
With ulceration of the cornea, microdiathermocoagulation, cryo- and laser coagulation are performed, with superficial corneal scars, an excimer laser procedure is performed to remove them, according to indications – keratoplasty.
Prognosis and prevention
A complication of meibomian keratitis may be clouding of the cornea in the form of an eyesore with a sharp decrease in vision; damage to the deep layers of the cornea, leading to its perforation, keratoscleritis, keratoiridocyclitis, keratouveitis, endophthalmitis and loss of the eye.
Prevention of meibomian keratitis consists in the prevention, timely and thorough treatment of meibomitis and blepharitis, chronic dysfunction of the meibomian glands. For the prevention of meibomian keratitis in ophthalmology, wellness measures are recommended: full-fledged fortified nutrition, occupational and household hygiene, adequate correction of refractive errors and accommodation, regulation of visual load, etc.