Endophthalmitis is a rare but dreaded complication of cataract surgery that may lead to severe loss of vision or loss of the eye. The symptoms of endophthalmitis include mild to severe ocular pain, vision loss, floaters, and photophobia. Early diagnosis and prompt treatment are essential, because delayed treatment can substantially alter the visual prognosis. Recent large retrospective studies of the incidence of endophthalmitis after cataract surgery reveal rates between 0.04% and 0.20%. Factors that increase the risk of infection include diabetes mellitus, older age, male sex, complicated or prolonged surgery, vitreous loss, posterior capsule rupture, wound leaks, and possibly the use of clear corneal incisions.
To reduce the incidence of postoperative endophthalmitis, it is important to use preoperative povidone-iodine skin prep, povidone-iodine 5% drops, careful eyelid and eyelash draping, and sterile technique. Meticulous attention to watertight incision closure is also important in preventing endophthalmitis, particularly when clear corneal incisions are used. Prophylactic preoperative and postoperative topical antibiotics are often prescribed for cataract surgery, although no randomized clinical studies support this practice.
In 2006, the Endophthalmitis Study Group of the European Society of Cataract and Refractive Surgeons (ESCRS) conducted a prospective, randomized, partially masked cataract surgery study and reported that the endophthalmitis rate was 0.07% in patients given intracameral cefuroxime 1 mg at the conclusion of surgery compared with a rate of 0.34% in patients given topical levofloxacin drops alone. The ESCRS also reported a 5.88-fold increase in risk with the use of clear corneal incisions instead of scleral tunnels.
A report based on outcomes of more than 600,000 consecutive cataract surgeries performed between 2014 and 2016 at Aravind Hospitals in India showed a decrease in endophthalmitis rates from 0.07% without intracameral antibiotics to 0.02% with intracameral moxifloxacin. In the phacoemulsification group, the incidence decreased from 0.07% to 0.01% with intracameral moxifloxacin.
Although the practice is not universally accepted, many surgeons use an intraocular antibiotic such as preservative-free moxifloxacin, cefuroxime, or vancomycin at the conclusion of cataract surgery. Although no commercially available preservative-free antibiotics are currently marketed for intracameral use in the United States, multiple 503B compounding pharmacies provide medications for intraoperative use. Surgeons must consider the reduction in endophthalmitis rates against the risk of TASS from dilutional errors for intraocular medications. The use of intraocular vancomycin for prophylaxis has decreased since reports of vancomycin-associated hemorrhagic occlusive retinal vasculitis (HORV; see the discussion of HORV later in this chapter).
See BCSC Section 12, Retina and Vitreous, for additional discussion of endophthalmitis.
Endophthalmitis Study Group, European Society of Cataract & Refractive Surgeons. Prophylaxis of postoperative endophthalmitis following cataract surgery: results of the ESCRS multicenter study and identification of risk factors. J Cataract Refract Surg. 2007;33(6):978–988.
Haripriya A, Chang DF, Ravindran RD. Endophthalmitis reduction with intracameral moxifloxacin prophylaxis: analysis of 600 000 surgeries. Ophthalmology. 2017;124(6):768–775.
Shorstein NH, Winthrop KL, Herrinton LJ. Decreased postoperative endophthalmitis rate after institution of intracameral antibiotics in a Northern California eye department. J Cataract Refract Surg. 2013;39(1):8–14.
Infectious endophthalmitis may present in an acute form or a more indolent or chronic form. Acute endophthalmitis, defined as inflammation occurring within 6 weeks of surgery, typically develops 3–10 days postoperatively and runs a fulminant course. The hallmark of acute endophthalmitis is vitreous inflammation, but other signs include eyelid or periorbital edema, ciliary injection, chemosis, anterior chamber inflammation, hypopyon, decreased visual acuity, corneal edema, and retinal hemorrhages (Fig 11-18).
Acute infectious endophthalmitis must be differentiated from TASS (discussed earlier in this chapter). The clinical presentation is often diagnostic, but occasionally the clinician may be able to diagnose sterile endophthalmitis only by excluding possible infectious causes with appropriate aqueous and vitreous cultures.
In contrast, chronic endophthalmitis may develop weeks or months after surgery. It may be characterized by chronic iridocyclitis or granulomatous uveitis and is often associated with decreased vision, little or no pain, and a nidus of the infectious agent within the eye. The chronic form is associated with organisms of lower pathogenicity; the most common are P acnes, S epidermidis, and fungi. (See also BCSC Section 9, Uveitis and Intraocular Inflammation, and Section 12, Retina and Vitreous.)
Figure 11-18 Endophthalmitis.
(Courtesy of Karla J. Johns, MD.)
In the Endophthalmitis Vitrectomy Study (EVS), most cases of endophthalmitis presented within 3–10 days of surgery, with a median of 6 days, and 25% presented without pain. Later onset also occurred; 22% of cases presented 2–6 weeks after surgery. The most common bacterial causes in that study were gram-positive coagulase-negative S epidermidis (70%), Staphylococcus aureus (9.9%), Streptococcus species (9.0%), other gram-positive bacteria (3.1%), Enterococcus species (2.2%), and gram-negative bacteria (5.9%). Most infections are caused by organisms similar to the patients’ own periocular bacterial flora. Drug-resistant strains are becoming more common.
The recommended approach to the management of postoperative endophthalmitis is based on the results of the EVS. As soon as a clinical diagnosis of endophthalmitis is suspected, assessment of visual acuity will help direct management decisions. Immediate pars plana vitrectomy and antibiotic injections are indicated when the patient’s visual acuity is light perception. When the visual acuity is hand motions or better, a less-invasive anterior chamber and/or vitreous biopsy for cultures with immediate subsequent intravitreal injection of antibiotics is indicated (a “tap-and-inject” procedure).
A tap-and-inject procedure can be performed in the office under sterile conditions. Because clinical features do not distinguish between gram-positive and gram-negative organisms, the mainstay of treatment remains broad-spectrum intravitreal antibiotics for both classes of bacteria. Currently, vancomycin 1 mg and ceftazidime 2.25 mg are preferred, with amikacin 0.4 mg administered for cephalosporin-allergic patients. Topical cycloplegic and corticosteroid drops may be helpful. Although oral or intravenous antibiotics, fortified topical or subconjunctival antibiotics, and intravitreal corticosteroids are sometimes used, they were not beneficial in a controlled study.
Chronic or delayed-onset endophthalmitis is also best treated with vitreous biopsy and intraocular antibiotics. However, because of sequestration of infectious material in the capsular bag or vitreous, a vitrectomy and posterior capsulectomy or even IOL exchange is often necessary to remove the nidus of infection.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.