The Endophthalmitis Paradigm Shift: Lessons From 25 Years of Changing Ophthalmic Practice

The article “Lessons Learnt from 25 Years of Endophthalmitis: Causes, Microbiology and Visual Outcomes” provides highly valuable insights into endophthalmitis of all etiologies managed at a tertiary referral centre over a 25‐year period [1]. By analysing long‐term trends, the authors are able to document major changes in epidemiology, microbiological profiles, and visual outcomes associated with this devastating condition. During the past two decades, postoperative endophthalmitis has undergone profound changes. Cataract surgery has become increasingly safer owing to intracameral antibiotic prophylaxis, while the exponential growth of intravitreal injections (IVIs) has shifted the epidemiology of endophthalmitis worldwide. The current study elegantly illustrates these changes over a remarkable 25‐year period.

Although cataract surgery remained the leading cause of endophthalmitis overall, its relative contribution declined markedly over time, whereas IVI‐related endophthalmitis became the predominant aetiology during the later years of the study. This finding differs from previous analyses based on French data collected between 2009 and 2018 [2], where cataract surgery remained the main cause of endophthalmitis even in recent years. Rather than indicating that IVIs have become more hazardous, these findings illustrate how profound changes in ophthalmic practice have modified the epidemiology of endophthalmitis. This discrepancy most likely reflects the study design, which reports the distribution of endophthalmitis cases rather than the procedure‐specific incidence. Accordingly, the study cannot estimate the risk associated with each procedure. Procedure‐specific incidences remain approximately 0.02%–0.05% after cataract surgery and are of a similar magnitude following IVIs, despite the marked differences in the distribution of endophthalmitis cases. This also explains why vitreoretinal surgery accounts for only a small proportion of endophthalmitis cases despite having a higher procedure‐specific incidence than cataract surgery or IVIs [3]. The authors confirmed that the incidence of post‐cataract surgery endophthalmitis has dramatically decreased following the widespread adoption of intracameral antibiotic prophylaxis, particularly cefuroxime in France and cefazolin in the present series, after publication of the ESCRS trial in 2007 [4, 5]. These findings provide further support for the effectiveness of intracameral antibiotic prophylaxis in cataract surgery.

Conversely, the relative stability of the incidence of endophthalmitis following IVIs has been consistently reported in the literature. Although the type of injected agent appears to have little influence on the risk of infection—except for corticosteroids, which are associated with a higher risk but are generally used as second‐line therapy—several procedural factors may affect the occurrence of endophthalmitis [6]. These include the use of antiseptic prophylaxis, eyelid speculums, preparation of the drug in prefilled syringes, and the administration or omission of topical antibiotic prophylaxis [7, 8]. Such procedural details are often unavailable in retrospective studies despite their potential impact on infection risk except in centres that strictly adhere to IVI guidelines [9]. Unlike cataract surgery, which is generally a one‐time procedure, IVIs are administered repeatedly over long periods. Attempts to simplify injection protocols by reducing aseptic measures could inadvertently increase the risk of infection. However, at the individual patient level, this concern may be partially mitigated by the introduction of longer‐acting therapeutic agents resulting in a reduced number of injections required annually. Although IVI‐related endophthalmitis now represents a major cause of endophthalmitis in tertiary referral centres, this reflects the extraordinary increase in injection volume rather than an increase in the individual risk per injection.

The authors also report changes in the microbiological spectrum of post‐cataract surgery endophthalmitis following the introduction of intracameral cefazolin. Similar shifts in bacterial ecology have been described in association with IVIs during the era of routine topical antibiotic prophylaxis. Such selective pressure may contribute to the emergence of more virulent organisms and increased antimicrobial resistance [10]. By contrast, the low proportion of Streptococcus pneumoniae identified in this study, including among IVI‐related cases, aligns with findings from our large multicentre study [9]. These microbiological changes probably reflect antibiotic selection pressure together with evolving surgical practices, emphasising the need for continuous microbiological surveillance.

The proportion of culture‐positive cases reported in this series is relatively high compared with that observed in many previous studies [11]. This may partly explain why visual outcomes appear somewhat less favourable than those generally reported in the literature, as culture‐positive infections are often associated with more severe disease [12]. The long study period also provides valuable information on evolving surgical management, including the increasing use of delayed vitrectomy. Although this approach appears inconsistent with the recommendations of the Endophthalmitis Vitrectomy Study (EVS), contemporary practice has evolved considerably [13, 14]. Wide‐field imaging, modern vitrectomy systems, improved intravitreal antibiotics, and limited emergency operating room availability have all contributed to a more individualised surgical approach. Accordingly, management is increasingly individualised rather than strictly following the EVS recommendations.

Overall, the history of endophthalmitis over the last quarter century mirrors the evolution of ophthalmology itself: safer cataract surgery, an explosion in intravitreal therapies, changing microbiology, and increasingly individualised management. Endophthalmitis continues to be one of the most devastating complications of intraocular procedures. Its prevention relies on strict adherence to aseptic protocols and continued improvements in prophylactic strategies. With a very long follow‐up, our Australian colleagues further reinforce the value of intracameral antibiotic prophylaxis as a standard preventive measure in cataract surgery. Clinicians should continue to counsel patients undergoing repeated IVIs that, although uncommon, endophthalmitis remains the most vision‐threatening complication of treatment that can result in severe and irreversible visual loss while compromising the management of the underlying retinal disease. Ultimately, this study illustrates a paradigm shift in endophthalmitis. Whereas prevention efforts historically focused on cataract surgery, future strategies will increasingly need to address the growing population of patients receiving repeated IVIs while maintaining antimicrobial stewardship and adherence to aseptic protocols.

Funding

The author has nothing to report.

Conflicts of Interest

The author declares no conflicts of interest.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.