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Bacterial keratitis
Last reviewed: 07.07.2025
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Bacterial keratitis usually manifests itself as a creeping ulcer. Most often it is caused by pneumococcus, sometimes by streptococci and staphylococci contained in the stagnant contents of the lacrimal sac and conjunctival cavity. The immediate provoking factor is usually trauma - the introduction of a foreign body, accidental scratches from a tree branch, a sheet of paper, a fallen eyelash. Often minor injuries remain unnoticed. For the introduction of coccal flora, minimal entry gates are enough.
[ Symptoms of bacterial keratitis
Bacterial keratitis begins acutely: lacrimation, photophobia, the patient cannot open the eye independently, and is bothered by severe pain in the eye. During examination, pericorneal injection of vessels and a yellowish infiltrate in the cornea are revealed. After its disintegration, an ulcer is formed, which tends to spread. While one of its edges is epithelialized, the other remains infiltrated, undermined in the form of a pocket. In a few days, the ulcer can occupy a significant area of the cornea. The iris and ciliary body are quickly involved in the inflammatory process, eye pain and pericorneal injection increase, and symptoms characteristic of iridocyclitis appear. A creeping ulcer is often accompanied by the formation of a hypopyon - a sediment of pus in the anterior chamber with a smooth horizontal line. The presence of fibrin in the moisture of the anterior chamber leads to the adhesion of the iris to the lens. The inflammatory process "creeps" not only along the surface, but also deep down to the Descemet membrane, which resists the lytic action of microbial enzymes the longest. Descemetocele is often formed, and then perforation of the cornea. The causative agent of the creeping ulcer penetrates the anterior chamber, significantly complicating the course of the inflammatory process. In a weakened body and with insufficient treatment, microbes penetrate into the posterior part of the eye, causing focal or diffuse purulent inflammation in the vitreous body (endophthalmitis) or melting of all the membranes of the eye (panophthalmitis). When foci of infection appear in the vitreous body, urgent removal of purulent contents from the eye cavity (vitrectomy) with washing it with antibiotics is indicated, which allows preserving the eye as a cosmetic organ, and sometimes residual vision.
In cases where the inflammatory process subsides after corneal perforation, a rough corneal opacity begins to form, usually fused with the iris.
With a creeping ulcer, there are no ingrown vessels for a long time. With the appearance of neovascularization, the scarring process is faster.
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Treatment of bacterial keratitis
Prevention of exogenous keratitis should be carried out with any, even minor, corneal injury: a speck of dirt, an eyelash, an accidental light scratch. In order to prevent corneal erosion from becoming an entry point for infection, it is enough to instill any antibacterial eye drops into the eye 2-3 times a day, and at night put an eye ointment with antibiotics behind the eyelid. The same should be done when providing first aid to a patient who has been diagnosed with superficial keratitis, only instillation of antibacterial drops should be carried out every hour until the patient gets an appointment with a specialist. If keratitis is diagnosed at an ophthalmologist's appointment, a smear of the conjunctival cavity contents or a scraping from the surface of a corneal ulcer is first taken to identify the pathogen and determine its sensitivity to antibacterial drugs, then treatment is prescribed to suppress the infection and inflammatory infiltration, improve corneal trophism. Antibiotics are used to suppress the infection: chloramphenicol, neomycin, kanamycin (drops and ointment), cipromed, okacin. The choice of antimicrobial drugs and their combination depend on the type of pathogen and its sensitivity to drugs.
In severe cases, sulfonamides and antibiotics are administered subconjunctivally or parabulbarly, observing the recommended dosages.
In order to prevent iridocyclitis, mydriatic instillations are prescribed. The frequency of their instillation is individual and depends on the severity of inflammatory infiltration and pupillary response.
Steroid drugs are prescribed locally during the period of resorption of inflammatory infiltrates after the ulcer surface has epithelialized. At this time, drugs containing a broad-spectrum antibiotic and a glucocorticoid (garazon) are effective. Along with these drugs, proteolysis inhibitors, immunocorrectors, antihistamine and vitamin drugs are used locally and orally, as well as agents that improve trophism and the process of corneal epithelialization (balarpan, taufon, solcoseryl, actovegin, carnosine, etaden, etc.).
Prognosis for bacterial keratitis
Bacterial keratitis most often ends with the formation of a more or less dense corneal leukoma. If the opacity is located centrally, restorative surgical treatment is performed no earlier than a year after the inflammatory process has subsided.