Endophthalmitis is a severe infection inside the eyeball, representing a medical emergency that requires immediate intervention to preserve vision. This infection targets the fluids that fill the eye, known as the vitreous and aqueous humors. The onset of symptoms, such as significant eye pain, redness, and vision loss, signals the need for urgent medical attention.
Initial Diagnostic and Treatment Procedures
Upon suspicion of endophthalmitis, an ophthalmologist’s first step is to confirm the diagnosis. This is done through a vitreous tap, where a small needle is inserted into the eye to withdraw a sample of the vitreous humor, the gel-like substance filling the back of the eye. This fluid is sent to a laboratory to culture and identify the specific bacteria or fungus responsible for the infection, which allows for more targeted treatment.
In many cases, initial treatment is administered at the same time as the diagnostic tap. This involves an intravitreal injection, where medication is delivered directly into the eye’s vitreous cavity. This combined diagnostic and treatment procedure is a standard first-line response, ensuring a high concentration of medication reaches the infection site as quickly as possible.
The procedure is performed in a sterile setting to prevent introducing new microbes. The eye is numbed with anesthetic drops or a small injection, and the area is cleaned thoroughly. While the vitreous sample is collected, the ophthalmologist prepares the medication for injection, ensuring a rapid transition from diagnosis to treatment.
Medication-Based Treatments
The primary treatment for endophthalmitis involves antimicrobial medications. For bacterial infections, the most common cause, broad-spectrum antibiotics are injected directly into the eye. Fungal infections, though less frequent, are treated with antifungal agents administered in the same manner. Depending on the severity of the infection and the response to the initial dose, these intravitreal injections may need to be repeated.
To manage the inflammation that accompanies the infection, corticosteroids are often used. A steroid, such as dexamethasone, may be injected into the eye along with the antimicrobial medication. This helps reduce the inflammatory response, which can cause significant damage to the delicate structures within the eye. Controlling inflammation can help alleviate pain and may improve the final visual outcome.
While direct injection is the most common route, systemic medications may also be used. These medications, given intravenously (IV) or orally, are often reserved for more severe infections. Systemic treatment is a standard approach for endogenous endophthalmitis, where the infection spreads to the eye from another part of the body via the bloodstream. In these cases, treating the source of the infection is also necessary.
Surgical Intervention
When endophthalmitis is severe or does not respond to medication alone, a surgical procedure called a vitrectomy may be recommended. This operation involves removing the infected vitreous humor from the eye. By clearing out the infectious material and inflammatory debris, the surgery reduces the microbial load, which can make antimicrobial medications more effective and help clear the visual axis.
A vitrectomy is considered for patients with very poor vision or a rapid progression of the infection despite initial injections. The decision to proceed with surgery is often guided by the Endophthalmitis Vitrectomy Study (EVS). This study demonstrated that for patients with vision reduced to only being able to perceive light, immediate vitrectomy provided a better visual outcome than injections alone.
During the procedure, a surgeon uses microscopic instruments to enter the eye and suction out the vitreous gel. The vitreous is then replaced with a sterile saline solution or another appropriate substitute. At the conclusion of the surgery, a dose of antimicrobial medication is injected into the eye to fight any remaining infection.
Recovery and Follow-Up Care
The recovery period requires close monitoring and care. Patients will have frequent follow-up appointments with their ophthalmologist to assess the eye’s response to treatment and detect any complications early. The frequency of these appointments is highest in the days and weeks immediately following the initial treatment.
A common part of the post-treatment regimen is the use of intensive topical eye drops. This includes a combination of antibiotic drops to prevent external infection and steroid drops to continue controlling inflammation. The patient is given a detailed schedule for administering these drops, which may need to be applied multiple times throughout the day.
Monitoring vision and intraocular pressure is a standard part of follow-up care. The recovery of vision can be a slow process, and the final outcome is highly variable. It depends on factors like the virulence of the infecting organism, the severity of the initial infection, and how quickly treatment was initiated. Vision may return to near-normal levels, while in other cases, there may be permanent vision loss.