Abstract
The aim of this prospective explorative study was to evaluate the safety and the effectiveness of topical polyvinylpyrrolidone-iodine (PVP-I) administered during the time-to-results period for pathogen identification and susceptibility testing in patients with infectious keratitis (IK). A corneal swab (CS) for antimicrobial evaluation was performed at enrollment (T0) and topical 0.66%-PVP-I was administered until the laboratory results were available (T1). Ulcer and infiltrate areas and infiltrate depths were compared between T0 and T1 (i.e., time-to-result period). Patients were then shifted to a specific antimicrobial therapy and followed up until resolution of their infiltrates (Tlast-TL). Twenty-five eyes were enrolled, and none showed clinical worsening leading to protocol withdrawal. At T1, ulcer and infiltrate areas showed significant improvement in Gram-positive IK (n = 13–52%; p = 0.027 and p = 0.019, respectively), remained stable in fungal IK (n = 5–20%; both p = 0.98) and increased in those with Gram-negative bacteria (n = 4–16%; p = 0.58 and p = 0.27). Eyes with negative cultures (n = 3–12%) showed complete resolution at T1 and did not initiate any additional antimicrobial therapy. The administration of 0.66% PVP-I during the time-to-result period seems to be a safe strategy in patients with IK while often sparing broad-spectrum antimicrobial agents. In addition, it showed to be effective in eyes with a Gram-positive bacterial infection.
Highlights
Publisher’s Note: MDPI stays neutralInfectious keratitis (IK) is one of the leading causes of monocular blindness worldwide and represents a real challenge for ophthalmologists [1].Identification of the causative organism is central to the successful medical treatment of infectious keratitis (IK) and to avoid their dreaded sequalae [2]
The culture was positive in 22 eyes (88.0%): 13 (59.1%) showed Gram-positive bacteria (n = 7 Streptococci spp, and n = 6 Staphylococci spp), 5 (22.7%) showed Gram-negative bacteria and 4 (18.2%) were positive for fungi
While fungal IK showed little improvement in their infiltrate areas and ulcer depths, Gram-negative bacterial IK showed a slight increase in ulcer and infiltrate areas and ulcer depths
Summary
Publisher’s Note: MDPI stays neutralInfectious keratitis (IK) is one of the leading causes of monocular blindness worldwide and represents a real challenge for ophthalmologists [1].Identification of the causative organism is central to the successful medical treatment of IK and to avoid their dreaded sequalae [2]. Establishing the etiology of IK based on their clinical features can be misleading; Gram staining and cultures are the gold standard diagnostic tests in these cases [3,4] It usually takes from 48 h up to weeks for identification and susceptibility testing of bacterial and fungal pathogens (time-to-result period) [5,6]; during this time frame, an empirical antimicrobial therapy selected upon the ophthalmologist’s clinical experience is generally administered [7]. In case of failure, the ophthalmologist will face many diagnostic and therapeutic challenges At this point, patients might present with an advanced keratitis with blurred clinical features and possibly a concomitant toxic keratitis/medicamentosa [9], leading to the need of a wash out period to reconsider the diagnosis [2] and likely poor with regard to jurisdictional claims in published maps and institutional affiliations
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