Infectious keratitis progressing to endophthalmitis: a 15-year study of microbiology, associated factors, and clinical outcomes

Abstract

Purpose: To describe the incidence, microbiology, associated factors, and clinical outcomes of patients with infectious keratitis progressing to endophthalmitis.

Design: Nonrandomized, retrospective, consecutive case series.

Participants: All patients treated for culture-proven keratitis and endophthalmitis between January 1, 1995 and December 31, 2009, at the Bascom Palmer Eye Institute.

Methods: Ocular microbiology and medical records were reviewed on all patients with positive corneal and intraocular cultures over the period of the study. Univariate analysis was performed to obtain P values described in the study.

Main outcome measures: Microbial isolates, treatment strategies, and visual acuity (VA) outcomes.

Results: A total of 9934 corneal cultures were performed for suspected infectious keratitis. Only 49 eyes (0.5%) progressed to culture-proven endophthalmitis. Fungi (n = 26) were the most common responsible organism followed by gram-positive bacteria (n = 13) and gram-negative bacteria (n = 10). Topical steroid use (37/49 [76%]) was the most common associated factor identified in the current study, followed by previous surgery (30/49 [61%]), corneal perforation (17/49 [35%]), dry eye (15/49 [31%]), relative immune compromise (10/49 [20%]), organic matter trauma (9/49 [18%]), and contact lens wear (3/49 [6%]). There were 27 patients in whom a primary infectious keratitis developed into endophthalmitis, and 22 patients in whom an infectious keratitis adjacent to a previous surgical wound progressed into endophthalmitis. Patients in the primary keratitis group were more likely to be male (22/27 [81%] vs 8/22 [36%]; P = 0.001), have history of organic matter trauma (8/27 [30%] vs 1/22 [5%]); P = 0.030), and have fungal etiology (21/27 [78%] vs 5/22 [23%]; P<0.001). Patients in the surgical wound-associated group were more likely to use topical steroids (20/22 [91%] vs 17/27 [63%]; P = 0.024). A VA of ≥ 20/50 was achieved in 7 of 49 patients (14%), but was <5/200 in 34 of 49 (69%) at last follow-up. Enucleation or evisceration was performed in 15 of 49 patients (31%).

Conclusions: Progression of infectious keratitis to endophthalmitis is relatively uncommon. The current study suggests that patients at higher risk for progression to endophthalmitis include patients using topical corticosteroids, patients with fungal keratitis, patients with corneal perforation, and patients with infectious keratitis developing adjacent to a previous surgical wound. Patients with sequential keratitis and endophthalmitis have generally poor visual outcomes.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.

Figure 1

A, A 56-year male with a history of radial keratotomy developed Fusarium keratitis and consequent endophthalmitis after a weekend of camping. Presenting visual acuity was 6/200. B, Appearance of the patient from figure A one month after undergoing treatment with topical natamycin, intracameral voriconazole, and penetrating keratoplasty. The patient eventually regained 20/20 visual acuity with use of a hard contact lens. C, A 47-year-old male developed Pseudomonas aeruginosa keratitis and subsequent endophthalmitis after a non-perforating corneal abrasion from a tree branch. D, Appearance of the patient from figure C two years following management with topical tobramycin, intravitreal ceftazidime, penetrating keratoplasty, and subsequent extracapsular cataract extraction with secondary intraocular lens. He regained hand motions vision. E, A 26-year-old male developed Mycobacterium chelonae endophthalmitis after a 4 month history of chronic keratitis following LASIK surgery. Presenting vision was hand motions. F, Appearance of the patient from figure E eight months after management with topical amikacin, topical clarithromycin, subconjunctival amikacin, and penetrating keratoplasty with anterior chamber washout. The patient recovered 20/30 visual acuity.