Conjunctivitis

Ocular involvement in systemic infections

In a number of cases, inflammation of the eye's mucous membrane is a secondary complication of dangerous infectious diseases.

In particular, the measles virus can affect the visual apparatus, clinically manifested by the development of conjunctivitis, as well as involvement of the eyelid margins (blepharitis) and cornea (keratitis).

Of particular note is the conjunctival form (ophthalmitis), which is a rare variant of the cutaneous form of anthrax.

• Clinical presentation: characterized by marked edema of the surrounding tissue and the development of severe serous-hemorrhagic inflammation of the eye tissues.
• Complications: the process has a high tendency toward generalization. Inflammation easily spreads into the cranial cavity, causing anthrax hemorrhagic meningoencephalitis.
• Pathomorphology: in brain involvement, a dark red exudate densely covers the convex surface of the hemispheres. This pathognomonic macroscopic sign is known as the “cardinal's cap” sign. A colossal number of pathogens are found within the exudative masses. The outcome of this form is most often fatal.

Acute gonococcal conjunctivitis

The disease is distinguished by a bilateral pattern of involvement and an aggressive course. Patients complain of a sharp decrease in visual acuity and intense pain.

Objectively, pronounced hyperemia of the eyeball is revealed. The discharge is profuse and purulent; its volume is so large that it physically prevents the physician from performing a thorough examination of the visual organ.

Pathogenesis of corneal involvement in gonococcal infection consists of three key factors:

1. Rapidly increasing conjunctival edema mechanically compresses the vessels of the marginal arcade network.
2. Maceration of the corneal epithelial layer occurs with the formation of superficial defects.
3. Gonococci and the toxins they secrete exert a direct destructive (toxic) effect on the tissues.

Dynamics of the corneal ulcer: On the first day, the ulceration does not penetrate deeply, but rapidly creeps across the surface, engulfing a significant portion of the cornea. After 3–5 days, the depth of the lesion critically increases — there is a high risk of corneal perforation with subsequent development of purulent inflammation of the internal membranes of the eye (endophthalmitis).

Acute Pseudomonas conjunctivitis

The causative agent is the Gram-negative bacterium Pseudomonas aeruginosa. Unlike gonococcal infection, the infection is more frequently localized to only one eye and begins extremely acutely.

Risk factors:

• Prolonged contact lens wear.
• Uncontrolled topical use of glucocorticosteroids (reduces local antibacterial resistance).
• Eye trauma and prior ophthalmic surgeries.

Symptomatology: patients suffer from cutting pain, photophobia, and lacrimation. An abundance of purulent or mucopurulent exudate accumulates in the conjunctival cavity. The eyelid conjunctiva becomes loose, edematous, and red. The development of chemosis — pronounced edema of the scleral conjunctiva — is characteristic.

In the absence of early treatment, the cornea becomes involved in the process. A mixed injection of the eyeball develops, and a purulent infiltrate forms. As early as the first day, a central or paracentral ulcer forms, the bed of which is filled with mucopurulent masses, making it difficult to assess the depth of the defect. The ulcer is capable of rapidly engulfing the entire cornea.

Principles of diagnosis and therapy for purulent forms

Any prolonged inflammation or the presence of profuse purulent exudate requires mandatory etiological diagnosis — performing bacteriological and microscopic analysis of smears for precise verification of the pathogen.

Local therapy includes:

• Sanation: regular rinsing of the conjunctival cavity with weak antiseptic solutions (e.g., nitrofural solution 4–5 times a day).
• Antibacterial treatment: drops (20% sulfacetamide solution) or targeted agents are instilled into the outer corner of the eye after identifying the specific microorganism. Application of antibacterial eye ointments is also effective.

Class and exam questions

What else to study on this topic

• Pathological anatomy and morphology of measles interstitial pneumonia
• Specific giant cells in measles (Warthin–Finkeldey and others)
• Morphogenesis of the primary anthrax carbuncle and changes in lymph nodes
• Pulmonary form of anthrax (wool-sorter's disease)
• Macro- and microscopic picture of gland involvement in mumps

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.