A new retrospective review from Ireland sheds more light on the rare presentation of Moraxella keratitis, which presented at the Royal Victoria Eye and Ear Hospital in Dublin just 41 times in the five-year span between 2012 and 2017. Most patients with the condition presented with an oval-shaped paracentral infiltrate with a mean diameter of 4.2mm. The researchers discovered previous ocular surgery and diabetes were the most common risk factors.

In following these patients through treatment, they also discovered its often a long road to recovery. The mean time to complete epithelialization was 32 days, although recovery ranged anywhere from seven to 109 days. Patients were on antibiotics for an average of 54 days, again with a vast range from nine to 124 days. Although the majority recovered with medical management, 22% required surgical intervention with penetrating keratoplasty, corneal glueing or evisceration.

Perhaps most telling what the identification of Moraxella subspecies, which was associated with worse outcomes for some. Of the 41 cases, 16.39% were nonliquifaciens, 15.36% were lacunata, 4.10% were osloensis, 2.50% were catarrhalis and 10% were were inconclusive. The researchers note that patients with M. nonliquifaciens and M. lacunata presented with larger infiltrates, required more surgical intervention and had longer treatment durations.

McSwiney TJ, Knowles SJ, Murphy CC. Clinical and microbiological characteristics of Moraxella keratitis. Br J Ophthalmol. February 1, 2019. [Epub ahead of print].