Chronic Postoperative Endophthalmitis
Chronic postoperative endophthalmitis has a distinctive clinical course, with multiple recurrences of chronic indolent inflammation in an eye that had previously undergone surgery, typically cataract extraction. Chronic anterior segment inflammation, hypopyon, keratic precipitates, intracapsular plaques, and/or vitritis may be present. Inflammation may respond to corticosteroid therapy but often recurs after steroids are tapered. This recurrent indolent inflammation may occur at any point during the postoperative course, but it is often delayed by many months to years. Inflammation may cause corneal decompensation or even iris neovascularization in the most severe cases. This course is quite different from the explosive onset of acute postoperative endophthalmitis. The incidence of acute postoperative endophthalmitis varies between 0.07% and 0.1%. The incidence of chronic endophthalmitis, however, has not been well established, as the condition may often go undiagnosed. Chronic postoperative endophthalmitis can be divided into bacterial and fungal varieties.
Figure 12-1 View of chronic postoperative endophthalmitis caused by Propionibacterium acnes infection. Note granulomatous keratic precipitates and white plaque in the capsular bag.
(Courtesy of David Meisler, MD.)
Chronic postoperative bacterial endophthalmitis is most commonly caused by Propionibacterium acnes. Additionally, gram-positive bacteria with limited virulence (eg, Staphylococcus epidermidis and Corynebacterium species), gram-negative bacteria, or Mycobacterium species may also cause similar chronic infection. P acnes, a commensal, anaerobic, gram-positive, pleomorphic rod, is commonly found on the eyelid skin or on the conjunctiva. P acnes may sequester itself between an IOL implant and the posterior capsule. In this relatively anaerobic environment, the organism grows and forms colonies, which manifest as whitish plaques between the posterior capsule and the IOL implant (Fig 12-1). A Nd:YAG capsulotomy can trigger chronic endophthalmitis by liberating the organism into the vitreous cavity, resulting in a more severe vitreous inflammation and an exacerbation of the underlying infection.
Shirodkar AR, Pathengay A, Flynn HW Jr, et al. Delayed- versus acute-onset endophthalmitis after cataract surgery. Am J Ophthalmol. 2012;53(3):391–398.
Chronic postoperative fungal endophthalmitis may present in a very similar fashion to that caused by P acnes. Numerous fungal organisms have been implicated in this chronic inflammatory process, including Candida parapsilosis, Aspergillus flavus, Torulopsis candida, and Paecilomyces lilacinus, as well as Verticillium species. Certain clinical signs may be helpful in differentiating a fungal from a bacterial etiology, including the presence of corneal infiltrate or edema, mass in the iris or ciliary body, or development of necrotizing scleritis. The presence of vitreous “snowballs” with a “string-of-pearls” appearance in the vitreous may also be indicative of a fungal infection. The intraocular inflammation may worsen after topical, periocular, or intraocular steroid therapy, which should automatically raise the suspicion of infection.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.