Man presents with blurry vision and floaters after cataract surgery
The right eye had persistent iritis that did not respond to steroid drops.
A 73-year-old Caucasian man was referred to the uveitis service at Tufts Medical Center for persistent iritis of the right eye associated with cloudy vision and floaters. He underwent uncomplicated cataract surgery of the right eye approximately 10 months before his presentation. One month after surgery, he presented to his primary ophthalmologist with iritis and hypopyon of the operative eye. He was started on hourly prednisolone, fluorometholone ointment nightly and oral NSAIDs. The iritis reportedly resolved with steroid treatment but recurred after tapering steroids. He then had persistent iritis that did not improve despite restarting prednisolone drops.
The patient had a medical history of hypertension and deep vein thrombosis. His ocular history was significant for bilateral cataract surgery about 10 months before presentation. He reported smoking a half pack of cigarettes daily and using alcohol occasionally. He denied any drug use. His medication list included warfarin, hydrochlorothiazide, lisinopril, atenolol and amlodipine. On review of systems, he denied any history of cold sores or shingles, and he complained of some arthritis in one ankle. He denied any breathing issues, skin problems or rashes.
On presentation to the uveitis clinic, the patient’s best corrected visual acuity was 20/25-1 in the right eye and 20/20-3 in the left eye. Both pupils were equally round and briskly reactive, and there was no afferent pupillary defect. IOP was 19 mm Hg in the right eye and 15 mm Hg in the left eye. He had moderate blepharitis in both eyes. He had conjunctival cysts in both eyes without conjunctival granulomas. The right cornea had active endothelial pigment dusting, and there were 1+ cells in the right anterior chamber. There was a dense white intracapsular plaque temporally (Figure 1) in the right eye and trace posterior capsular haze in the left eye. The vitreous in the right eye had 1+ anterior cells, 1+ central haze and 2+ haze inferiorly. Cup-to-disc ratio was 0.3 in the right eye and 0.2 in the left eye. Neither eye had signs of retinitis, choroiditis or vasculitis. OCT of the macula of both eyes was within normal limits without intraretinal fluid or subretinal fluid. OCT signal of the right eye was attenuated by vitreous haze (Figure 2).
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The differential diagnosis for persistent iritis after cataract surgery includes infectious and inflammatory etiologies. The dense white intracapsular plaque in the right eye increased suspicion of chronic endophthalmitis, which could be caused by Propionibacterium acnes, Staphylococcus epidermidis, fungal strains or other bacteria. Other possible infectious etiologies included syphilis, tuberculosis and viral infections such as herpes simplex, varicella zoster or cytomegalovirus. Inflammatory causes included sarcoidosis, HLA-B27-related uveitis and idiopathic inflammation.
The referring ophthalmologist performed serum testing including ANA, rheumatoid factor, HLA-B27 and treponemal antigen, which were all negative. ACE level was also found to be low, but given that the patient was taking an ACE inhibitor, the level could be falsely decreased. On initial presentation to the uveitis clinic, an anterior chamber paracentesis was performed, and aqueous fluid was sent for gram stain, culture and PCR for herpes simplex 1 and 2, varicella zoster and cytomegalovirus. The patient was also switched from prednisolone four times daily to Durezol (difluprednate ophthalmic emulsion 0.05%, Alcon) four times daily in the right eye.
Diagnosis and management
Gram stain of anterior chamber flud was negative for neutrophils, squamous epithelial cells or organisms. The culture of anterior chamber fluid grew P. acnes from the broth only. Viral PCR was negative. This confirmed the diagnosis of chronic endophthalmitis secondary to P. acnes. After the results were obtained, the patient received an intravitreal injection of vancomycin 1 mg. His treatment options, including surgery to remove the IOL, were discussed, and he elected to observe after intravitreal injection.
He followed up 2 weeks after injection, and he was noted to have minimal improvement. He followed up 6 weeks after injection, at which time the inflammation had decreased and the white intracapsular plaque had become less dense. Durezol was decreased to three times daily. He followed up 11 weeks after injection, at which time two new plaques were noted temporally on the right posterior capsule. He was referred to a retina specialist for pars plana vitrectomy, lensectomy and capsulectomy. Unfortunately, the patient died unexpectedly before the procedure due to myocardial infarction.
P. acnes is a slow-growing, anaerobic-preferential, gram-positive bacillus. It is part of the normal human flora and lives primarily in sebaceous and sweat glands. Previously, it was thought to only be pathogenic in skin conditions such as acne vulgaris. More recently, it has been implicated in deeper infections of prosthetic devices including IOLs. P. acnes has a propensity to form biofilm matrices. It is sensitive to many antibiotics targeting gram-positive organisms. However, there has been evidence that it has increased resistance to erythromycin, tetracycline and clindamycin.
P. acnes is a common cause of chronic endophthalmitis after cataract surgery. Uveitis symptoms typically start 2 to 3 months after surgery and can persist for months or years until ultimate diagnosis. Patients with chronic endophthalmitis are more likely to have better visual acuity at presentation and less likely to present with hypopyon than patients with acute endophthalmitis. A large proportion of patients with P. acnes present with a white intracapsular plaque. Initial treatment for chronic endophthalmitis could include vitreous tap with injection of intraocular antibiotics, pars plana vitrectomy with injection of intraocular antibiotics, or pars plana vitrectomy with partial posterior capsulectomy and injection of intraocular antibiotics. Most eyes that are initially treated with more conservative approaches ultimately require total capsulectomy with removal of the IOL. Multiple case series have reported similar treatment outcomes.
Chronic endophthalmitis secondary to P. acnes should be strongly suspected in any case of uveitis with hypopyon or intracapsular plaque after cataract surgery. Chronic endophthalmitis often presents as delayed-onset inflammation with variable response to topical steroids. While treating conservatively with intraocular injection of antibiotics without disruption of the lens capsule is a reasonable initial strategy, most patients ultimately require partial or total capsulectomy for treatment of chronic endophthalmitis.
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- For more information:
- Deborah Witkin, MD, and Lana Rifkin, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.
- Edited by Aubrey R. Tirpack, MD, and Astrid C. Werner, MD. They can be reached at the New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.