Nocardia Keratitis: Clinical Course and Effect of Corticosteroids

Abstract

Purpose To compare the clinical course of Nocardia spp keratitis with keratitis due to other bacterial organisms, and to assess the effect of corticosteroids as adjunctive therapy using data collected from the Steroids for Corneal Ulcers Trial (SCUT). Design Sub-group analysis of a randomized controlled trial Methods Setting Multicenter randomized controlled trial Study Population 500 patients with bacterial keratitis, randomized 1:1 to topical corticosteroid or placebo who had received at least 48 hours of topical moxifloxacin Intervention/Observation Procedure Topical prednisolone phosphate 1% or placebo; clinical course of Nocardia keratitis Main outcome measures Best spectacle-corrected visual acuity and infiltrate/scar size at 3 months from enrollment Results Of 500 patients enrolled in the trial, 55 (11%) had a Nocardia corneal ulcer. Patients with Nocardia ulcers had better presentation visual acuity compared to non-Nocardia ulcers (median Snellen 20/45 compared to 20/145, P<0.001), and comparable 3-month visual acuity (median 20/25 versus 20/40, P=0.25). Nocardia ulcers had approximately 2 lines less improvement in visual acuity compared to non-Nocardia ulcers (0.21 logMAR, 95% CI 0.09 to 0.33 logMAR, P=0.001). This difference may reflect the better starting visual acuity in patients with Nocardia ulcers. In Nocardia ulcers, corticosteroids were associated with an average 0.4 mm increase in 3-month infiltrate/scar size (95% CI 0.03 to 0.77mm, P=0.03). Conclusion Nocardia ulcers responded well to treatment. They showed less overall improvement in visual acuity than non-Nocardia ulcers, but had better presentation acuity. Corticosteroids may be associated with worse outcomes.

Visual Outcomes in Treated Bacterial Keratitis: Four Years of Prospective Follow-up

“…Because previous analyses of SCUT have shown that Nocardia ulcers did poorly with topical steroids, we performed a similar analysis stratified by causative organism. 10 Although these analyses were consistent with a harmful effect of topical corticosteroids for Nocardia ulcers and a beneficial effect for non-Nocardia ulcers, we found no statistically significant difference between the treatment arms: in Nocardia ulcers, corticosteroids were associated with a 2. …”

Nocardia Arthritidis Keratitis: Case Report and Review of the Literature

“…Once the correct diagnosis was confirmed and amikacin started, steroids were again applied, this time without incident. However, recent research indicates that corticosteroids may actually be detrimental in Nocardia species keratitis and may lead to larger scars at 3 and 12 months (Srinivasan, et al, 2014), (Lalitha, et al, 2012), (Garg & Vazirani, 2013). In light of this recent research and our own experience with this case, we believe that corticosteroids should not be applied in the treatment of Nocardia species keratitis.…”

Corticosteroids as a therapy for bacterial keratitis: an evidence-based review of ‘who, when and why’

“…Even with the use of antimicrobial agents, corticosteroids still may be associated with less favourable outcomes in treating keratitis related to some microorganisms such as Nocardia 46 and atypical Mycobacteria 51 52. Moreover, there is no convincing evidence of benefit from the addition of corticosteroids to the treatment of fungal keratitis; it is more likely to be harmful as corticosteroids interfere with the efficacy of many antifungal agents in vivo, and enhance fungal replication 53–56.…”