Endophthalmitis is an inflammation of the eye of infectious origin. Most of the time, the infection is caused by microorganisms infiltrated through a surgical incision or lesion of the eyeball. Endophthalmitis often manifests as severe pain in the eye, decreased vision, and/or extreme sensitivity to light. The infection is treated with antibiotics, antifungals, and/or corticosteroids. In some cases, surgical removal of the vitreous body is recommended.
What is endophthalmitis?
Endophthalmitis is an inflammation of the eye of infectious origin. When it occurs following an operation, endophthalmitis is said to be acute when it sets in during the first postoperative week. The subacute form extends from the second to the end of the fourth postoperative week while the chronic form begins after the first month. Thus, postoperative endophthalmitis is almost always considered a nosocomial infection.
Most of the time, endoocular infection is caused by microorganisms infiltrated through a surgical incision or lesion of the eyeball. More rarely, these microorganisms can reach the eye through the blood. In this case, blood infection can be caused by dental surgery, intravenous injection of drugs, abscess, skin ulcers, and infections (pneumonia, sepsis).
Most cases of endophthalmitis are caused by a gram-positive bacterium, such as Staphylococcus epidermidisorS. aureus. Endophthalmitis caused by Gram-negative organisms tends to be more virulent and has a poorer prognosis. Finally, endophthalmitis can also be caused by fungi or protozoa.
Diagnosis requires great attention in any at-risk patient, especially in cases of recent eye trauma or surgery. It is initially based on the observation of symptoms and an ophthalmological examination.
The doctor systematically carries out several additional examinations:
- Gram staining: a laboratory technique that identifies bacteria from their shape, size, and affinity to different dyes.
- Culture of the anterior chamber and vitreous samples
Any patient suspected of endogenous endophthalmitis should also undergo:
- Blood culture: seeding of samples taken from the eye on appropriate culture media for a pathogenic germ
- Cytobacteriological examination of urine (ECBU)
The persons concerned
When endophthalmitis is of exogenous origin, it occurs in 0.07% to 0.32% of cataract surgeries.
During cataract surgery, the incidence of endophthalmitis is multiplied by four in case of secondary implantation, in case of capsular rupture (a complication of the operation), and in diabetics.
Symptoms of endophthalmitis
Even if they are not present in every case, three symptoms are warning signs to be taken seriously, especially following cataract surgery:
- Increasing pain in intensity
- A drop in visual acuity
- Photophobia: extreme sensitivity to light
- Loss of retinal reflection (red reflection)
- Hypopyon: the presence of pus in the anterior chamber of the eye (space between the iris and the innermost surface of the cornea)
- Aqueous mood disorder (the fluid in the anterior chamber of the eye)
- Increased intraocular pressure
- Eye redness around the cornea
- Cellular deposits at the intraocular lens deposited during surgery
- Retinal hemorrhage
- Conjunctival hyperemia: accumulation of blood in the vessels of the conjunctiva, the mucosa that covers the inside of the eyelids
- Intraocular inflammation in the anterior chamber and vitreous
- Oedema of the eyelid and/or cornea
- Fibrin (a blood plasma protein that contributes to clot formation) in the anterior chamber of the eye
- Exophthalmos: protrusion of the eyeball out of the orbit
- Petechiae (small purplish-red spots) of the iris
- Ptosis: fall of the upper eyelid
- Epiphora: discharge of tears on the cheeks, in cases where they can not pass through the tear points.
- Fever, nausea, fatigue
Initial treatment includes:
- An intravitreal injection of broad-spectrum antibiotics, most commonly vancomycin (reference product for gram-positive germs) and ceftazidime (against gram-negative). Along with antibiotics, corticosteroids such as dexamethasone can be injected. Fungal infections are treated with antifungals, including Fungizone.
- The patient with endogenous endophthalmitis should receive antibiotics in the eye or intravenously. The choice of antibiotic therapy is then adapted according to the pathogens identified.
Vitrectomy (surgical removal of the vitreous body) with intraocular corticosteroid injection should be considered in patients whose vision is already severely impaired at the time of diagnosis. Surgery removes infected tissue, increasing the chances of stopping the infection.
During intraocular surgery, the prevention of endophthalmitis involves the care of asepsis and antisepsis.
To limit the irreversible consequences on vision, endophthalmitis should be considered a medical emergency because the visual prognosis is directly related to the time interval between the onset of the infection, and its treatment. In extreme cases, a delay of a few hours can even cause irreversible vision loss.
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