Clinical perspective and outcome of culture-negative microbial keratitis: A retrospective study

Indian J Ophthalmol. 2024 Aug 1;72(8):1130-1135. doi: 10.4103/IJO.IJO_2794_23. Epub 2024 Jul 29.

Abstract

Purpose: To study the risk factors, clinical features, and treatment outcomes of patients with culture-negative keratitis (CNK).

Methods: A retrospective data review of 933 patients with CNK was performed from January 2018 to December 2020. The variables such as the history of injury, visual acuity, slit-lamp findings with measurements of size and depth of ulcer, microbiological evaluation, duct patency, blood glucose levels, and treatment were considered, and clinical outcome was analyzed.

Results: Of the 933 patients with CNK, 763 (81.8%) were medically managed, with a mean treatment duration of 2.08 ± 1.7 weeks. Among them, 622 (66.7%) were both smear and culture-negative, and 311 (33.3%) showed only smear positivity. Smear-positive patients showed a positive correlation with the history of injury. A higher incidence of fungal growth on repeat culture was observed. Surgical interventions were done only in 18.2% of the patients; the rest were treated with topical medications alone.

Conclusion: High clinical suspicion, differentiation of causative organisms based on clinical findings, and initiating empirical therapy with broad-spectrum antibiotics and antifungals improve the ultimate prognosis in patients with CNK, even though a standard protocol for empirical medical treatment may differ among institutions and surgeons based on their clinical experience and geographical variations.

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents* / therapeutic use
  • Antifungal Agents / therapeutic use
  • Bacteria / isolation & purification
  • Cornea / microbiology
  • Cornea / pathology
  • Eye Infections, Bacterial* / diagnosis
  • Eye Infections, Bacterial* / drug therapy
  • Eye Infections, Bacterial* / microbiology
  • Eye Infections, Fungal* / diagnosis
  • Eye Infections, Fungal* / drug therapy
  • Eye Infections, Fungal* / microbiology
  • Eye Infections, Fungal* / therapy
  • Female
  • Follow-Up Studies
  • Fungi / isolation & purification
  • Humans
  • Keratitis / diagnosis
  • Keratitis / drug therapy
  • Keratitis / microbiology
  • Male
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Visual Acuity* / physiology

Substances

  • Anti-Bacterial Agents
  • Antifungal Agents