Swollen lids, pain, opaque vitreous linked with proven endophthalmitis

ESCRS endophthalmitis study data suggest patients with streptococcal infections had worse visual outcomes than those with staphylococcal infections.

Peter Barry

Swollen lids, pain and opaque vitreous were strongly associated with confirmed endophthalmitis after cataract surgery, according to an analysis of data from the European Society of Cataract and Refractive Surgeons endophthalmitis study.

In addition, patients with streptococcal infections had strikingly worse visual outcomes and showed an earlier onset of disease than those with staphylococcal infections.

This analysis of the multicenter ESCRS study of the prophylaxis of endophthalmitis compared the signs and symptoms of proven and unproven endophthalmitis.

The study previously reported that intracameral injection of 1 mg of cefuroxime yielded an almost fivefold reduction in the rate of postoperative endophthalmitis compared with patient groups that did not receive the antibiotic.

“The most significant finding of the ESCRS endophthalmitis study was that the direct injection of 1 mg of cefuroxime in 0.1 mL of normal saline into the anterior chamber at the end of the case reduced the incidence of endophthalmitis by a factor of five compared to the control study group who received povidone iodine alone and no perioperative antibiotics topically or intracamerally,” Peter Barry, FRCS, the corresponding author, told Ocular Surgery News in an e-mail interview.

The ESCRS study produced similar results to other analyses, such as the Endophthalmitis Vitrectomy Study conducted in the U.S. from 1990 to 1994. For example, a majority of patients in both studies presented with endophthalmitis within 7 days after cataract surgery. Additionally, streptococcal infection showed earlier onset and led to worse visual outcomes than staphylococcal infection in both studies.

Results of the most recent analysis are published in the Journal of Cataract and Refractive Surgery.

The study

The ESCRS study included 16,211 patients, the largest series of patients evaluated for evidence-based prophylaxis of endophthalmitis after cataract surgery in a randomized clinical trial; 8,108 patients received intracameral cefuroxime injections and 8,103 did not receive them.

One group was a control that received a perioperative placebo drop regimen. A second group received a perioperative drop regimen of levofloxacin 0.5%. A third group received an intracameral injection of 1 mg cefuroxime in addition to the placebo. A fourth group received intracameral cefuroxime in addition to the topical levofloxacin.

“Intensive perioperative antibiotic drops, in this study levofloxacin, were not shown to be of benefit,” Dr. Barry said.

All groups received a standard postoperative regimen of topical levofloxacin 0.5%, one drop four times daily, for at least 1 week to prevent wound infection.

Twenty-nine patients presented with postoperative endophthalmitis. Among the 29 endophthalmitis cases, 20 cases were proven and nine were unproven.

“The statistics are robust,” Dr. Barry said. “The incidence of 0.35% endophthalmitis in the control group was higher than anticipated and one of the reasons why the study was terminated, as the beneficial results of the cefuroxime intracamerally were so clear.”

Streptococcal, staphylococcal infections

The median interval to presentation with signs and symptoms was 4.5 days in proven cases and 9 days in unproven cases; the median interval was 5 days. A larger portion of proven cases took place within 7 days after surgery.

After performing multivariable logistic regression modeling, investigators found a strong relationship between proven cases of endophthalmitis and swollen lids (P = .04) and opaque vitreous (P = .05).

Eight cases caused by streptococcal infection correlated with pain, hypopyon, chemotic conjunctiva and clear corneal incisions.

Visual outcomes varied between eyes with streptococcal and staphylococcal infections; outcomes were significantly worse in streptococcal cases.

“Although postoperative visual acuities were not statistically tested, the difference in visual outcome between cases of streptococcal and cases of staphylococcal infections were striking,” Dr. Barry said.

Final postoperative visual acuity among 11 staphylococcal cases ranged from 20/20 to 20/80, with no patients deemed legally blind. Three of the 11 cases received intracameral cefuroxime.

Final visual acuity among eight streptococcal cases ranged from 20/20 to no light perception; five patients were deemed legally blind because of streptococci.

None of the eight streptococcal cases received intracameral cefuroxime.

“To date, intracameral cefuroxime remains the only prophylactic intervention proven to reduce rates of endophthalmitis after cataract surgery,” the study authors said.

Although used widely in Europe, intracameral cefuroxime is not approved in the U.S., Dr. Barry said.

“In Europe, the use of intracameral cefuroxime has become widespread since the conclusion of the ESCRS study,” he said. “In the United States, the use of intracameral antibiotic is increasing. Intracameral cefuroxime is not commercially available in an FDA-approved single unit dose for cataract surgery, but hopefully will be in the future. I predict in the not-too-distant future that the use of intracameral antibiotic will become universal.” – by Matt Hasson

Reference:

• Barry P, Gardner S, Seal D, et al; ESCRS Endophthalmitis Study Group. Clinical observations associated with proven and unproven cases in the ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery. J Cataract Refract Surg. 2009;35(9):1523-1531.

• Peter Barry, FRCS, can be reached at Royal Victoria Eye Ear Hospital, The Eye Clinic, 33 Herbert Ave., Merrion Road, Dublin 4, Ireland; 353-1-283-7203; e-mail: peterbarryfrcs@eircom.net.

Every thoughtful surgeon confronted with a red eye in the immediate postoperative period must consider, however briefly, the possibility of endophthalmitis. This paper provides evidence for the relative frequency and significance of key clinical signs to guide decision-making. Every infection is first a suspected infection; moments count, as any delay in diagnosis and treatment means a deteriorating prognosis. Swollen lids, pain and an opaque vitreous now indicate an immediate vitreous tap or vitrectomy with intravitreal antibiotics.

– Mark Packer, MD, FACS
Drs. Fine, Hoffman and Packer Ophthalmologists, Eugene, Ore.