Bleb-related infection can be a devastating complication following glaucoma surgery. Bleb-related infection has traditionally been categorized as either a blebitis or bleb-related endophthalmitis, and is typically late onset in its presentation occurring 3.2 years following
trabeculectomy. The identification and treatment of late-onset bleb leak is important in preventing the formation of bleb-related infection, as this is a risk factor for progression. Below, we will review a few pearls in the management of bleb-infection.
What are the presenting signs and symptoms of blebitis?
Presenting symptoms including redness, photophobia, decreased vision, and eyebrow ache can be associated with the slit-lamp finding of mucopurulent infiltrate of a bleb. Additional presenting signs include Hypotony, Endophthalmitis, Leak, and Pain, thus the acronym HELP syndrome has been advocated in the literature in reference to bleb-related infection.
When should one be concerned that a blebitis has progressed into a bleb-related endophthalmitis?
A blebitis is defined as a mucopurulent infiltrate of a bleb. There can be associated mild to moderate anterior segment inflammation as part of a blebitis. The diagnosis changes to one of bleb-related endophthalmitis once one of the following characteristics is present on examination: hypopyon, cells in the anterior vitreous face, or culture positive aqueous or vitreous humor biopsy.
What risk factors are associated with blebitis or bleb-related endophthalmitis?
- Late-onset bleb leak
- Use of anti-fibrotic agents (5-Fluorouracil, Mitomycin-C)
- Younger age
- African American race
- Inferior placement of filtering bleb
- Severe blepharitis
- History of recurrent bacterial conjunctivitis
How should I treat a suspected blebitis when no hypopyon is present?
When there is no hypopyon present, we recommend the use of (1) hourly use of a topical fourth generation fluoroquinolone antibiotic and (2) oral antibiotic coverage, typically with a fluoroquinolone. Careful follow-up examination is recommended with particular attention to the bleb, anterior chamber, and anterior vitreous face. B-scan ophthalmic ultrasound is recommended to assess the vitreous and rule-out the progression to a fulminant endophthalmitis. A bandage contact lens or cyanoacrylate glue can be used for late-onset bleb leak.
What about when a hypopyon is present?
At this point, the process has progressed from a blebitis to a bleb-related endophthalmitis and treatment should be ratcheted up accordingly. Consultation with a vitreo-retinal specialist should be considered.
What is the treatment of bleb-related endophthalmitis?
The treatment of bleb-related endophthalmitis should be made in coordination with a vitreo-retinal specialist. Treatment options include vitreous tap-and-injection of antibiotics and pars plana vitrectomy (PPV). It is important to note that bleb-related endophthalmitis differs from endophthalmitis following cataract surgery in presentation, infecting organisms, prognosis, and treatment and thus the results of the Endophthalmitis Vitrectomy Study (EVS) are not applicable to this set of patients. Additionally, recent literature has demonstrated a significantly worse final visual acuity and significantly higher rate of no light perception vision in patients treated with vitreous tap-and-injection, arguing for prompt PPV in these patients.
Acknowledgements:
Dr. Terry Kim and Dr. Leon Herndon contributed to the above article.
References:
- Awdeh RM, Kim T, Herndon L. Chapter 43: What factors increase the risk of bleb-related infection? How should I treat blebitis and bleb-related endophthalmitis if it develops? in Curbside Consultation in Glaucoma. Heuer DK Editor. Slack Inc., 2008.
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