We report a stable trend in endophthalmitis rate over eight years from 0.01% (2/19 332) in 2015 to 0.01% (2/24 563) in 2022. This is consistent with the current literature, which has also reported stable or decreasing trends in endophthalmitis rates following cataract surgery [4–7]. The study's findings align with the global efforts to improve perioperative strategies, such as eyelid draping, proper use of antiseptics like g. Povidone-Iodine 5%w/v, and the administration of intracameral antibiotics and reflect a commitment to maintaining high standards of surgical care and post-operative management.
Furthermore, risk-stratified selection for Specialty Trainees and Fellows according to skill can decrease rates of surgical complications and subsequent POE [14]. Indeed, the UK Cataract National Ophthalmology Dataset (NOD) showed cataract surgery complicated by posterior capsule rupture (PCR) was associated with an approximately eight-fold increase in POE [2]. Our results do not confirm these observations, and our rates were favourable in comparison, as we measured a PCR rate of 1.19% over the study period. Only 4/18 of the POEs occurred after interventions performed by trainees. Moreover, there were no instances of previous intravitreal injection therapy (IVT) in our POE cohort, previously associated with an increased risk of intraoperative complication and subsequent development of endophthalmitis [15].
We considered the timing of PPV in patients that required this intervention and observed varying BCVA outcomes. One patient who underwent “early PPV” 1-day post-presentation of POE had BCVA 6/6 at final follow up. Similarly, a patient underwent “late PPV” after 103 days had a BCVA 6/9 at final follow-up. In contrast, the one patient underwent “early PPV” 4 days after the diagnosis of POE, had BCVA perception of light (PL) at final follow up. While these observations may suggest a potential benefit of “early PPV” in some cases, it is important to note that these results are based on a small number of cases. The complexity of the case, severity of infection, individual patient characteristics, and other treatment modalities employed contributed to the outcomes observed.
The Endophthalmitis Vitrectomy Study (EVS), published in 1995, was the first landmark study encouraging the standardisation of the management of POE [23]. The EVS concluded that visual prognosis was linked to causative organisms and the presenting visual acuity; and recommended early pars plana vitrectomy for cases presenting with perception of light or worse [23]. A more recent retrospective study reported old age, infection by gram-negative organisms (especially Pseudomonas aeruginosa), short time between cataract operation and signs of endophthalmitis, and poor presenting visual acuity as negative visual prognostic factors [24]. Results from a recent tertiary centre retrospective case series suggest that an increase in the scope of the EVS indications for early vitrectomy could be advantageous [25]. Another research group recommended that early pars plana vitrectomy could be considered if the clinical response was poor within 48 hours following the initial intravitreal antibiotic injection [26]. There remains a lack of high-quality evidence which could be gained through an up-to-date randomised controlled clinical trial on the role of early vitrectomy in managing acute POE.
A limitation of our study is the small number of cases, further observation with a larger sample size allowing for statistical analysis would be beneficial.
Nonetheless, the results suggest that the teaching hospital environment, with its focus on education and supervision, can create a conducive setting for trainees to learn and perform surgeries while maintaining patient safety and minimizing complications like POE.
There was no growth of microorganisms in some cases of post-operative endophthalmitis (POE). It is important to acknowledge the limitations of the culture method used in this study and potential false-negative results. Advances in diagnostic techniques, including RT-PCR and mass spectrometry, hold promise for improving the detection of microorganisms in endophthalmitis cases. Further research and evaluation of these methods are needed to establish their utility and feasibility in routine clinical practice.
In summary, we demonstrate an incidence of POE of 0.012% (18/154 826) following phacoemulsification cataract surgery at Moorfields Eye Hospital NHS Foundation Trust from 2015 to 2022. This low rate of POE is in concordance with reports and trends globally. Such commendable rates are indicative of high-quality surgery, close supervision of trainees and comprehensive post-operative care undertaken to the highest global standards.