A Decade Of Change: Annual Trends In Microbial Keratitis At Southampton Eye Unit (2014-2023)

Published 2026 - 44th Congress of the ESCRS

Reference: FP10.03 | Type: Free paper | DOI: 10.82333/g15e-ms63

Authors: Dr Shi Ian Soh* ¹ , Dr Mohamed Ahmed ¹ , Dr Kordo Saeed ¹ , Dr Dave Browning ¹ , Mr David Anderson ¹ , Mr Aris Konstantopoulos ¹ , Prof. Parwez Hossain ¹ , Mr Harinderjeet Sandhu ¹

¹Southampton Eye Unit,University Hospital Southampton NHS Foundation Trust,Southampton,United Kingdom

Purpose

Ting et al. recently reported increasing coagulase-negative staphylococci (CoNS) and Acanthamoeba keratitis in North East England, whilst Tan et al. demonstrated increasing Moraxella in Manchester. We performed a 10-year retrospective analysis at Southampton Eye Unit to determine whether similar annual trends exist in Southern England, and to identify emerging pathogens requiring local surveillance.

Setting

Southampton Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK.

Methods

All culture-positive corneal scrapes from Southampton Eye Unit (January 2014 - December 2023) were reviewed. Organisms were classified into Gram-positive, Gram-negative, fungi, and Acanthamoeba, with subtypes analysed individually. Annual trends were assessed using Spearman rank correlation. Two-period comparison (2014-2018 vs 2019-2023) was performed using chi-square tests.

Results

Of 798 corneal scrapes, 512 (64.2%) were culture-positive (mean age 53.2 ± 20.7 years; 49.0% female). Gram-positive organisms predominated (310; 60.5%), followed by Gram-negative (152; 29.7%), fungi (29; 5.7%), and Acanthamoeba (21; 4.1%). Significant trends included declining Acanthamoeba from 12.5% (2014) to 0% (2021-2023) (r=-0.832; p=0.003); emergence of Serratia marcescens from 0 cases (2014-2015) to 3 annually by 2023 (r=0.833; p=0.003); and declining Moraxella within Gram-negatives (r=-0.796; p=0.006). Within Gram-positives, CoNS decreased (64.0% to 49.3%; p=0.009) whilst Staphylococcus aureus increased (14.6% to 27.4%; p=0.006). Pseudomonas increased from 4 (2014) to 21 (2023) without reaching significance (r=0.448; p=0.194).

Conclusions

This study highlights important geographic variation in UK microbial keratitis epidemiology. In contrast to Northern Centres, Southampton demonstrates a progressive increase in Serratia isolates and declining Acanthamoeba. This may reflect changing contact lens behaviours, environmental exposure, or evolving diagnostic practices. Ongoing local microbiological surveillance remains essential to guide empirical treatment.