Corneal ulcer

Corneal ulcer

A corneal ulcer is a crater-shaped defect of the cornea due to its necrosis due to an infectious lesion (primary or secondary after traumatization, trophic disorders, etc.). It is necessary to distinguish between the concepts of erosion and corneal ulcer. A corneal ulcer implies a violation of the integrity of not only the corneal epithelium (which is typical for erosion), but also the anterior boundary membrane, so a corneal ulcer always heals with the formation of a corneal scar (leukoma). The ulcer may be central or marginal. Etiology and risk factors. For the occurrence of a corneal ulcer, 2 conditions will be needed – a decrease in local resistance (including a violation of the integrity of the corneal epithelium) and colonization of the cornea with an infectious agent

• • Factors leading to corneal defects and/or reduced local resistance
  • Dryness of the cornea (for example, with lagophthalmos)
  • Eye burns
  • Mechanical damage (including when wearing contact lenses)
  • Irrational use of local anesthetics, antibiotics or antiviral products, antidepressants, glucocorticoids
  • Diabetes
  • Immunodeficiency
  • Hypo- and avitaminosis
  • Microorganisms
  • Gram-positive bacteria (staphylococci, streptococci)
  • Gram-negative microorganisms (diplococci, rods)
  • Blue-purulent stick
  • Viruses (for example, HSV)
  • Mycobacterium tuberculosis
  • Fungi.

Pathomorphology. Staining products according to Gramuy Romandwsky-Giemsa allows you to detect bacteria, fungi or intranuclear inclusions characteristic of viral lesions.

Clinical picture

• • Creeping corneal ulcer (corneal ulcer of bacterial etiology is caused by Frenkel-Vekselbaum pneumococcus, Morax-Aksenfeld diplobacillus, staphylococcus, streptococcus, Pseudomonas aeruginosa)
  • Severe pain of a cutting nature, suppuration, lacrimation, severe blepharospasm, chemosis, mixed injection
  • Yellowish-gray infiltrate of the cornea, rapidly disintegrating with the formation of an ulcer that has 2 edges – regressive and progressive (undermined, loosened and surrounded by a rim of purulent infiltrate). The ulcer rapidly increases in volume due to the progressive edge, gradually capturing most of the cornea. Vessels (pannus) sprout from the limbus to the ulcer
  • Often join iritis, iridocyclitis, probably the development of endophthalmitis.
  • Tuberculous ulcer of the cornea
  • The presence in the body of a focus of tuberculosis infection
  • Along with ulcers of the correct rounded shape, there are grayish-yellow infiltrates surrounded by branched vessels (the infiltrate is located in a basket of vessels – conflict), progressing with the formation of ulcerative defects
  • The course is long, with prolonged remissions, rough corneal scars form at the site of ulcers.
  • Herpetic ulceration of the cornea is characteristic of dendritic and ulcerative keratitis – tree-shaped ulcers form in place of dendritic infiltrates.
  • Ulceration of the cornea due to hypo- and avitaminosis
  • With vitamin A deficiency, keratomalacia develops – against the background of bilateral clouding of the cornea (milk cornea), ulcers are found that are not accompanied by pain. Xerotic dry plaques form on the conjunctiva of the sclera
  • Vitamin B2 deficiency – corneal vascularization, dystrophic changes in the epithelium, ulcerative lesions appear. Usually the course is long and relatively benign.

Laboratory research

• • Isolation of a culture of microorganisms from an ulcer, if necessary, determination of their sensitivity to antibacterial products
  • Determination of signs of the underlying disease (changes in the leukocyte formula, characteristic of tuberculosis, a decrease in the content of vitamins in the blood during hypo- and avitaminosis, etc.).

Treatment:

Mode. Hospitalization is recommended only in severe cases or when outpatient treatment is improbable. In any case, a referral to an ophthalmologist is mandatory. Tactics of conducting

• • You will immediately need to start topical antibiotic treatment without waiting for the culture results. It also shows the appointment of antibacterial products inside and their introduction under the conjunctiva in the form of injections.
  • The use of cycloplegics
  • Administration of glucocorticoids is contraindicated
  • During the period of attenuation of the process – absorbable therapy to prevent the formation of a rough corneal scar. Surgery. With a long non-healing of the ulcer and the threat of perforation of the cornea, a through or layered therapeutic keratoplasty is indicated. After the ulcer has healed, corneal opacities often remain. In this case, keratoplasty is performed to improve visual acuity. Drugs of choice
  • Sulfacyl sodium nbsp; – powdering the ulcer with crushed powder 5-6 r / day until complete epithelization, then instillation of 30% solution.
  • Gentamicin and tobramycin locally – with the defeat of Pseudomonas, Enterobacter, Klebsiella and aerobic gram-negative bacteria; cephalosporins (for example, cefazolin 50 mg / ml) – with the defeat of gram-negative bacteria. At the beginning of treatment, the combination of aminoglycoside derivatives and cephalosporins is most effective.
  • Fluoroquinolone derivatives, for example, ciprofloxacin (0.3%), for Pseudomonas lesions.
  • Amphotericin B parenterally – for candidiasis and aspergillosis, the use of clotrimazole, miconazole, ketoconazole, econazole is also likely.
  • With ulcers of viral etiology
  • Idoxuridin locally 0.1% solution, 2 drops in the conjunctival sac every hour during the day and after 2 hours at night for no more than 2 weeks – with a viral etiology of the ulcer.
  • Poludan 100 mcg is dissolved in 2-5 ml of distilled water, instilled into the conjunctival sac 6-8 r / day, as the inflammation subsides – 3-4 r / day – with a viral etiology of the ulcer. Apply only in a hospital setting.
  • a Leukocyte Interferon – 200 IU is dissolved in 2-5 ml of distilled water, instilled into the conjunctival sac, 2 drops 6-8 r / day. Alternative products: interlock, reaferon.
  • Zovirax (acyclovir) is placed in the conjunctival sac as a 3% eye ointment 3 times a day for 7-10 days.
  • Potassium iodide , 2-3 drops of 3% solution, is instilled into the conjunctival sac 4-5 r / day – as absorbable therapy in the formation of opacities.
  • Taufon nbsp; – 2-3 drops in the eye 4-5 r / day, solution of bee honey 3-5 r / day.
  • Electro-faresis with a solution of potassium iodide, lidase, collalizin – 10-15 sessions.

Complications

• • Corneal scarring and vision loss
  • Iritis, iridocyclitis
  • Endophthalmitis
  • Posterior synechiae of the iris
  • Corneal perforation with iris prolapse
  • Loss of an eye. Course and forecast
  • With adequate therapy, the prognosis is favorable
  • With a long-term non-healing ulcer, the diagnosis should be reconsidered (the etiology is incorrectly determined) and / or treatment tactics
  • With a corneal ulcer caused by fungal infections, most often there is a prolonged, asymptomatic course.
  • Ulcers caused by herpes infection are extremely difficult to treat.

Associated pathology. Chronic ulceration may be associated with neurotrophic keratitis due to pathological changes in the trigeminal nerve that innervates the cornea. Most often, neurotrophic keratitis occurs in people with thyroid diseases, diabetes mellitus, and immunodeficiency states.

Prevention

• • Avoid damage to the cornea and take precautions when using contact lenses
  • Treatment of diseases that can lead to the formation of a corneal ulcer.

See also Tuberculosis, Keratitis, Herpes simplex, Hypovitaminosis A, Hypovitaminosis B2 ICD H16.0 Corneal ulcer