Endophthalmitis is inflammation of the internal contents of the eye. Infectious endophthalmitis refers to inflammation caused by an invading organism. Bacteria and fungi are the most common agents. The most common routes of invasion are after surgery or intravitreal injection, hematogenous (originating in the blood stream), or traumatic. This review concentrates on infectious endophthalmitis after cataract surgery.

A cataract occurs when the lens inside the eye, located behind the iris, becomes cloudy. Cataract formation is a normal aging process, but can also be congenital or the result of trauma. Symptoms of cataract include glare, halos, and blurred vision. As the cataract progresses, blurred vision will worsen, eventually leading to blindness. Fortunately, cataract surgery is available.

During cataract surgery, ultrasound or laser is used to break up the cataract. The pieces are removed using a probe inserted through a small corneal incision. A clear lens implant is then placed into the eye. This procedure usually takes 15 minutes to complete, and no stitches are required.

Cataract surgery is the most common ocular surgery performed in America. As with any incisional surgery, there is a risk for postoperative infection. In modern cataract surgery the risk of endophthalmitis is estimated to be 0.1%.

Risk Factors

Preoperative risk factors for developing endophthalmitis include diabetes, HIV infection, blepharitis, contact lens wear, and the use of contaminated eye drops.

Operative risk factors for endophthalmitis include lengthy surgical time, capsular rupture, vitreous loss, and wound leak.

Symptoms & Evaluation

Acute onset postoperative endophthalmitis is infection presenting within 6 weeks of surgery. The symptoms include pain, redness, light sensitivity, and vision loss.

 Findings include conjunctival injection, marked inflammation, hypopyon, and often vitritis.

Treatment

Antibiotics, given urgently are the standard of care. The majority of patients undergo a vitreous and sometimes aqueous sampling, then the antibiotics vancomycin and ceftazidime are injected intravitreally. Dexamethasone, a steroid, may also be injected to reduce inflammation. Some surgeons recommend systemic antibiotics as well, though their benefit is not certain. Anti-inflammatory therapy with topical steroids is usually recommended. The frequency of drop administration is customized to the individual eye.

Urgent vitrectomy may be recommended in certain cases of endophthalmitis. This is usually determined by the judgement of the vitreoretinal surgeon.

Pathogen

Staphylococcus and Streptococcus species are the most common infectious agents that cause endophthalmitis. Gram negative bacteria and fungi are less common. When fungus is suspected, antifungal therapy is necessary.

Prophylaxis

Povidone-iodine antiseptic prep, preoperative lid hygiene, and topical antibiotics are common methods to reduce the incidence of endophthalmitis. Antibiotics in the operative irrigation fluid or given intracamerally are preferred by some surgeons.

Prognosis

The visual outcome of endophthalmitis ranges from 20/20 to no light perception. The majority regain vision of 20/40 or better. The outcome depends on the type of bacteria. Coagulase-negative Staphylococcus and culture-negative cases have a more favorable prognosis. Cases involving Staphylococcus aureus, Streptococcus species, and gram negative bacteria follow a worse course. Also, the duration of the endophthalmitis infection impacts the outcome, therefor urgent intervention is necessary.

From the Expert…

Postoperative infection is the most feared complication of ocular surgery. While the frequency has decreased with improved surgical technique, when it occurs the results can be devastating. Prevention, including lid hygiene to reduce bacterial growth, antiseptic prep with povidone-iodine, and careful surgical technique greatly reduce the risk for infection. Urgent intervention and careful monitoring of endophthalmitis patients improves the outcome in most cases.

Additional Resources

Scott IU, Flynn HW. Endophthalmitis After Cataract Surgery: Management by the Retinal Physician. Retinal Physician. Published 1 Oct 2008. https://www.retinalphysician.com/issues/2008/october-2008/endophthalmitis-after-cataract-surgery-management. Accessed October 7, 2019.

Hashemian et al. Post-cataract surgery endophthalmitis: Brief literature review. Journal of Current Ophthalmology 2016;28:101-105.

Spadea L. Treatment of Postoperative Endophthalmitis. US Ophthalmic Review 2014;7:146-53.

Jabbarvand M et al. Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors. Ophthalmology 2016;123:295-301.

Flynn HW and Pathengay A. Endophthalmitis Following Cataract Surgery: Prophylaxis and Treatment. American Academy of Ophthalmology, EyeWiki. https://eyewiki.aao.org/Endophthalmitis_Following_Cataract_Surgery%3A_Prophylaxis_and_Treatment. Accessed October 7, 2019.

Retina Health Series. Endophthalmitis. The Foundation of the American Society of Retina Specialists. https://www.asrs.org/content/documents/fact_sheet_26_endophthalmitis_new.pdf. Accessed October 7, 2019.