September 2011

 

CATARACT

 

When post-cataract endophthalmitis arises, some surgeons reach for steroids


by Matt Young EyeWorld Contributing Editor
     

Patients treated with steroids and antibiotics improved by more Snellen lines

Two views of post-op endophthalmitis Source: Nick Mamalis, M.D.

Obviously when infectious endophthalmitis arises, surgeons reach for potent antibiotic treatment, but few treat the inflammatory component of the disease. "Endophthalmitis is defined as inflammation of the contents or cavity of the eye and usually represents an infection of the vitreous," according to Eric Albrecht, M.D., Department of Ophthalmology, University of Cape Town, South Africa.

The inflammatory side of endophthalmitis may be considerable, but only 17% of all post-cataract endophthalmitis patients in the United Kingdom received intravitreal steroids as part of their treatment, Dr. Albrecht noted in a report published online in February in Ophthalmology. That's understandable considering the lack of clear guidelines in treating the inflammatory aspect of endophthalmitis, Dr. Albrecht reported. However, Dr. Albrecht's researchalong with at least one previous reportsuggests there is merit to using steroids in the treatment of endophthalmitis. By far, this is inconclusive data. Small sample pools and other research that came to opposite conclusions mean the debate should continue on the steroids-for-endophthalmitis issue. Endophthalmitis patients deserve the best treatment for this often blinding condition. If steroids helpand that's still a big ifthen perhaps they should be used more frequently for these patients.

Steroids for endophthalmitis?

Dr. Albrecht's research was based on 62 patients who had presumed bacterial endophthalmitis, 30 of whom received intravitreal dexamethasone as part of their treatment. The other 32 received an intravitreal placebo. All patients received intravitreal antibiotics. Major subgroups included post-cataract surgery endophthalmitis (32 patients, of whom 17 received the steroid), bleb-related endophthalmitis (13 patients, of whom nine received the steroid), endogenous endophthalmitis (three patients, of whom one received the steroid), and endophthalmitis following pars plana vitrectomy (six patients, of whom four received the steroid). The study looked at Snellen visual acuity at baseline and at 3 months to determine the outcome of treatment. Mean improvement for the steroid group was 2.76 lines (range 3-9) compared to only 1.79 lines (range 3-9) in the placebo group. This difference could not be determined to be statistically significant. There was more of a difference in the post-cataract endophthalmitis group, with mean improvement in the steroid group at 4.1 lines (range 3-9) compared to only 2.7 lines (range 3-9) in the placebo group. "Although small numbers meant that the p value was only 0.330, a clinically significant beneficial trend was demonstrated," Dr. Albrecht wrote. There is much less understanding of the impact of steroids in other endophthalmitis groups. "The role of intravitreal steroids was inconclusive in the bleb-related endophthalmitis group and the other endophthalmitis group as the very low numbers in each group resulted in p values of nearly 1," Dr. Albrecht reported. "The number of lines of improvement/deterioration and the final visual categories achieved in each group appeared clinically similar."

Importantly, though, Dr. Albrecht found that no adverse reactions were caused directly by steroid usage. In one previous report, Gan et al found a trend of better visual acuity in a dexamethasone/antibiotic group who had post-op endophthalmitis. Outcomes were measured at 3 and 12 months. A placebo was used as a control in that study, which included 29 patients. However, another previous report by Shah et al found that in 57 endophthalmitis cases, patients who were given intravitreal antibiotics alone did better than patients who received intravitreal steroids alone.

"Patients who received steroids had a significantly reduced likelihood of obtaining 3-line improvement," Dr. Albrecht noted. All of these studies had relatively small patient populations, which subjects them to being statistically weak. Dr. Albrecht believes there is merit in combining the results, however. "We had only 25% power to detect a statistically significant difference between those randomised to steroid and placebo in the post cataract subgroup," Dr. Albrecht reported. "Although the results from this study did not achieve statistical significance, when we combined these findings with those of Gan et al, whose results were highly consistent, the resulting measure of the benefit of steroid in preventing poor visual outcome is clear. Although caution must be exercised in merging the data from two studies with slightly different methods, management practices and determination of outcomes, this analysis points to the likely value of steroids in post cataract endophthalmitis."

John D. Sheppard, M.D., professor of ophthalmology, microbiology, and immunology, Eastern Virginia Medical School, Norfolk, Va., said his clinic has been using intravitreal dexamethasone for decades as part of endophthalmitis treatment. "For one, it's short acting," Dr. Sheppard said. "Also, it's available preservative-free." The steroid helps because of the eye's reaction to infection, he said. "The eye is such a vascular structure that the host response tends to overwhelm the structural integrity of the eye," Dr. Sheppard said. "It's certainly incumbent upon the clinic to limit the damage either directly from the bacteria or from the immune system's collateral agents." Still, steroids can be harmful in certain endophthalmitis cases, Dr. Sheppard said. "When pseudomonas is involved, we know from keratitis models that steroids are deleterious," Dr. Sheppard said. "And of course with fungal endophthalmitis, steroids are deleterious."

Still, Dr. Sheppard said it's hard to be conclusive about the impact of steroids in endophthalmitis cases. "When you're addressing steroid research even in a prospective manner, an infection as rare as post-cataract endophthalmitis will make it difficult to obtain significant numbers," Dr. Sheppard said.

Editors' note: Dr. Albrecht has no financial interests related to this study. Dr. Sheppard has no financial interests related to his comments.

Contact information

Albrecht: albrecht@telkomsa.net
Sheppard: 757-622-2200, docshep@hotmail.com

When post-cataract endophthalmitis arises, some surgeons reach for steroids When post-cataract endophthalmitis arises, some surgeons reach for steroids
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