The diagnosis of chronic postoperative endophthalmitis is confirmed by obtaining aerobic, anaerobic, and fungal cultures of the aqueous, capsular plaques (if present), and vitreous at the time of pars plana vitrectomy. Gram and fungal stains of undiluted specimens, capsular plaques, and vitreous snowballs should also be obtained. The value of such stains should not be underestimated, especially in cases of fungal endophthalmitis. In addition, polymerase chain reaction (PCR) studies of primers for P acnes or pan-fungal and pan-bacterial primers are helpful if available. The bacterial and fungal stains or PCR may yield immediate information, enabling the clinician to tailor therapy and improve clinical prognosis long before the results of the cultures turn positive. Because of the slow-growing and fastidious nature of the organisms that cause chronic endophthalmitis, cultures must be retained by the microbiology laboratory for 2 or more weeks.
The differential diagnosis of chronic postoperative endophthalmitis includes noninfectious causes such as lens-induced uveitis from retained cortical material or retained intravitreal lens fragments, intraocular inflammation from iris chafing resulting from IOL malposition, uveitis-glaucoma-hyphema syndrome, and intraocular lymphoma masquerade syndrome.
Lai JY, Chen KH, Lin YC, Hsu WM, Lee SM. Propionibacterium acnes DNA from an explanted intraocular lens detected by polymerase chain reaction in a case of chronic pseudophakic endophthalmitis. J Cataract Refract Surg. 2006;32(3):522–525.
Meisler DM, Mandelbaum S. Propionibacterium-associated endophthalmitis after extracapsular cataract extraction. Review of reported cases. Ophthalmology. 1989;96(1):54–61.
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.