Endophthalmitis: Types, Epidemiology, Symptoms, Diagnosis, and Treatment

What Is Endophthalmitis?

Endophthalmitis is a condition with severe inflammation of the inner tissues and fluids resulting from infectious organisms. Both anterior and posterior chambers of the eye may get infected. It is a serious condition and needs immediate medical assistance. If left untreated, it may lead to a serious condition called panophthalmitis (an infection that may spread in all parts of the eyeball), which requires enucleation treatment to be done.

Endophthalmitis can affect the aqueous humor and the vitreous humor of the eye. The aqueous humor is the clear fluid present between the lens and cornea at the front region of the eye. The vitreous humor is a clear gel between the lens and retina toward the posterior part of the eye.

What Are the Types of Endophthalmitis?

Upon examination by the ophthalmologist, the type of endophthalmitis can be found such as based on the mode of entry of the organism, it is divided into exogenous or endogenous. Depending upon the causative event, the exogenous endophthalmitis can be either post-traumatic or postoperative. Therefore according to that, endophthalmitis can be classified as -

I. Mode of Entry -

• Exogenous Endophthalmitis - This occurs when an infectious agent gets into the eye through a breach or injury in ocular coats.

• Endogenous Endophthalmitis - This type may develop due to fungal or bacterial infection in another body part that may spread to the eye through the blood. This is less common than exogenous endophthalmitis.

II. Based on Time -

• Fulminant - Endophthalmitis occurs within four days of surgery.

• Acute - Endophthalmitis occurs within six weeks of surgery (average 5 to 12 days).

• Chronic - Endophthalmitis occurs after six weeks of surgery.

III. Microorganism -

• Bacterial.

• Fungal.

What Is the Epidemiology of Endophthalmitis?

Endophthalmitis is a rare condition, and most of the cases of exogenous endophthalmitis are postoperative, occurring after 0.02 to 0.26 percent of cataract surgeries. Therefore, old age patients of age, more than 85 years, are more prone to this condition as they usually have cataract surgery.

Endogenous endophthalmitis is very rare compared to exogenous endophthalmitis, and according to a study in the United States of America, it has been found that annually an average of 5 in 10000 people gets hospitalized due to this condition.

What Are the Common Causative Pathogens in Endophthalmitis?

The common causative pathogens seen in endophthalmitis may vary by the cause, which may include -

• Coagulase-negative staphylococci are the most common causes of post-surgical (cataract) endophthalmitis.

• Coagulase-negative staphylococcal bacteria and viridans streptococci cause most cases of post-intravitreal (injecting medicine directly into the eye) anti-VEGF injection endophthalmitis.

• Staphylococcus aureus and Streptococcus species are responsible for endogenous endophthalmitis associated with endocarditis.

• Bacillus cereus is a primary causative organism of post-traumatic endophthalmitis.

• Klebsiella pneumonia is mostly responsible for the cases of endogenous endophthalmitis in association with liver abscess. This is commonly seen in Southeast Asia.

• Candida albicans (most commonly) and other Candida species are responsible for endogenous fungal endophthalmitis commonly seen in hospitalized patients.

• Apart from that, some other pathogens which may cause endophthalmitis include:

  • Viruses - Herpes simplex.

  • Bacteria - Pseudomonas aeruginosa.

  • Protozoans - Toxoplasma gondii.

What Are The Symptoms of Endophthalmitis?

Some of the most common symptoms of endophthalmitis include -

• Intense pain in the eye that may worsen with time.

• Sudden pain in the eye after a surgical procedure or after an eye injury.

• Sensitivity to bright light.

• Swollen eyelids.

• Redness of eyes.

• Yellow or white discharge from the eyes.

• Impaired or blurred vision.

Without any treatment, these symptoms may get worsen and can even lead to total blindness or enucleation of the eyeballs.

What Are the Risk Factors for Endophthalmitis?

Some of the commonly seen risk factors associated with endophthalmitis include -

• Loss of vitreous gel or vitreous humor.

• Disrupted posterior capsule.

• Poor wound closure.

• Prolonged surgery.

Additionally, some other risk factors based on different scenarios include -

I. After Trauma Includes -

• Retained intraocular foreign body (presence of foreign material in the eye following an injury).

• Delayed surgery (longer than 24 hours).

• Soil contamination.

• Damage to the lens.

II. Surgical Risk Factors -

• Multiple or combined surgical procedures.

• Long duration operative time.

• Posterior capsular rupture.

• Wound leakage.

III. Sources of Contamination -

• Infection from the patient's bacterial flora, such as skin, eyelids, or conjunctiva.

• Contaminated instruments or other surgical pieces of equipment.

• Contamination of donor cornea in case of a cornea transplant.

IV. Patient Factors -

Systemic conditions such as

• Diabetes.

• HIV infection.

How Is Endophthalmitis Diagnosed?

The initial diagnosis of endophthalmitis can be made by

• Slit-lamp examination, in which a microscope is used to examine the eyes.

• An ultrasound may also detect any foreign particles in the eyes.

However, the diagnosis can be confirmed by taking a sample of vitreous fluid for culture, also called a diagnostic surgical vitrectomy. This helps identify the causative microorganism, and antibiotics are prescribed based on that.

• In the case of endogenous bacterial endophthalmitis and candida-associated endophthalmitis, additional tests may be indicated such as a complete blood count (CBC) and blood cultures.

• Polymerase chain reaction (PCR) may help differentiate between fungal and bacterial infections.

• CT (computed tomography) or MRI (magnetic resonance imaging) scan of the orbit may help to rule out other ophthalmic conditions.

Other investigations may also be required to exclude differential diagnosis such as erythrocyte sedimentation rate (ESR) to help rule out rheumatoid arthritis and to check creatinine levels to assess renal function.

What Is the Treatment of Endophthalmitis?

Endophthalmitis is a serious medical condition; without any treatment, it can be dangerous, and the patient may even lose their eyes.

The treatment usually includes antibiotic therapy and sometimes steroid therapy or surgery, depending upon the severity of the infection.

• Antibiotics Therapy - Immediate treatment is provided with antibiotics to prevent vision loss and to protect the health of the eye. Delay of a few hours may even result in irreversible vision loss. The choice of antibiotic is made after finding the type of causative organism and the medicine can be either directly injected into the eye or given intravenously or both.

• Corticosteroids - Steroids can be given to patients with poor vision. These can be either given orally after a few days of antibiotic treatment or can be directly injected into the eye.

• Surgery - In severe cases, surgery may have to be performed to remove the infected tissue from inside the eye.

How to Prevent Endophthalmitis?

The risk of endophthalmitis may be reduced by below steps -

• Using protective eye gear while working in jobs where an object like a piece of machinery or a tool might injure the eye.

• Wearing protective gear while playing sports also.

• Do not touch the eyes with contaminated hands.

• Following all the precautions given by the healthcare provider after the surgery.

Conclusion:

Endophthalmitis is a complicated condition with serious outcomes. If a patient experiences symptoms like declining vision, sharp pain, or redness in the eyes after surgery or injury, they should immediately contact a healthcare provider. This is a medical emergency and immediately requires appropriate medical attention. The treatment is needed as soon as possible to improve the chances of recovery.