Endophthalmitis rates increasing

Modern vitrectomy techniques improving results in acute endophthalmitis

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Andrew Chang MD, PhD, FRANZCO
Modern microincisional vitrectomy surgery is effective in improving vision in patients presenting with acute endophthalmitis, Andrew Chang MD, PhD, FRANZCO, told delegates attending the 19th EURETINA Congress in Paris. “Advances in vitrectomy technology and instrumentation allows the option of earlier vitrectomy compared to traditional guidelines based on the Endophthalmitis Vitrectomy Study (EVS),” he said. Progress in surgical technology allied to the changes in patient presentation, with significantly more postoperative infections related to intravitreal injections (IVI), means that a review of the EVS guidelines is perhaps overdue, said Dr Chang. “Much of what we do in terms of decision-making stems from the 1995 EVS study, but much have progressed since then. We now have more modern vitrectomy technology, newer antibiotics and we are dealing with a different patient group with more post-IVI endophthalmitis. In the real world, there is a trend towards earlier vitrectomy for debridement of bacteria, toxins and inflammatory debris, better diffusion of antibiotics and potentially a more rapid visual recovery,” he said. Infective endophthalmitis remains a feared and devastating complication of intraocular surgery including cataract surgery and, increasingly, post-intravitreal injections, said Dr Chang. The five cardinal clinical signs of infection to watch for are pain, redness, swelling, discharge and loss of function. He noted that there has been an exponential rise in the number of intravitreal injections (IVI) and the risk of endophthalmitis in recent years. An initial study of 101 patients with acute endophthalmitis carried out at Sydney Eye Hospital from 2007-2010 identified 53 patients with post-IVI endophthalmitis and 48 with post-cataract surgery infections.
Severe endophthalmitis
“In this cohort the post-IVI infections had poorer visual outcomes, with increased numbers of streptococcus infections and an increased likelihood of a final visual acuity less than counting fingers. In eyes that did have streptococcus as the causative organism, there was a decreased likelihood of improving vision and a 17 times greater chance of evisceration or enucleation,” he said. In another more recent study at the Sydney Eye Hospital of 248 patients from 2012 to 2017, Dr Chang and co-workers observed a changing spectrum of endophthalmitis. “Among the changing patterns we observed was an increase in post-IVI endophthalmitis (57%). Staphylococcus epidermis was still the most common organism, although, surprisingly, there was less streptococcus in post-IVI cases, possibly related to greater use of masks and reduced talking when administering intravitreal injections. There were no differences in outcomes between post-cataract and post-IVI endophthalmitis in this cohort,” he said. Vitrectomy was performed in 135 cases out of 248, said Dr Chang. “Those patients were more likely to have presenting vision of light perception or worse, positive culture and streptococcus as the organism responsible. The prognosis was also poor if streptococcus was found to be the responsible organism,” he added. To try to determine predictive factors for better visual outcomes in early vitrectomy in acute endophthalmitis, another retrospective study at the Sydney Eye Hospital was carried out that included 64 consecutive patients treated between 2009 and 2013. All received vitrectomy within 72 hours of presentation with acute endophthalmitis from a range of inciting procedures. All patients were treated immediately on presentation with a 23-gauge vitreous tap and injection of vancomycin and ceftazidime. The next step was the vitrectomy, which was performed within 72 hours of presentation. The mean time of onset from the inciting procedure was 5.7 days and the mean time between tap and inject to vitrectomy was 0.8 days, noted Dr Chang. The inciting procedures were phacoemulsification in 53%, IVI in 36% and trabeculectomy in 3%. Responsible organisms were staphylococcus epidermis in 43% and streptococcus in 33%. Vision improved from a mean of 3.1 logMAR (hand motion) baseline to 1.02 logMAR at one year. Vision improved in 89% of patients, and 42% had a final vision better than logMAR 0.477. Patients with post-cataract surgery endophthalmitis had better visual outcomes than post-IVI. Those that were culture negative also did better than those that were culture positive. Complications included intraoperative retinal detachment in six eyes, postoperative retinal detachment in four eyes, epiretinal membrane in six eyes and hypotony in one eye. Two of the 64 eyes were eviscerated. Andrew Chang: achang@sydneyretina.com.au
Tags: endophthalmitis, intravitreal injections, vitrectomy