Management of blebitis in the United Kingdom: a survey
- Correspondence to Patrick Chiam, Ophthalmology Department, Stoke Mandeville Hospital, Aylesbury HP21 8AL, UK; pjtchiam{at}yahoo.com
- Accepted 2 March 2011
- Published Online First 15 April 2011
Abstract
Aim To investigate the current management trend in blebitis among glaucoma consultants registered with the Royal College of Ophthalmologists (London).
Method An anonymous survey consisting of 13 questions to ascertain blebitis management was posted to the glaucoma consultants. A χ2 test was used to analyse the correlation patterns among respondents' answers to the questionnaire.
Results Out of 112 questionnaires, 68 (61%) were returned. Fifty-five per cent of the consultants admit blebitis patients into hospital for treatment. Seventy-four per cent obtain a conjunctival swab, and 28% instil iodine on the conjunctiva as part of their treatment regime. Thirty-four per cent use topical fluroquinolone monotherapy, 28% cefuroxime and gentamicin, 18% fluroquinolone with cefuroxime, and 9% ceftazidime and vancomycin. Fluroquinolones are the only oral antibiotics used by those who routinely prescribe oral treatment (69%). One-fifth of respondents use intravitreal antibiotic in treating blebitis patients. Eighty-two per cent surveyed include topical corticosteroids as part of their treatment regime. Ninety-one per cent use a topical cycloplegic. Twenty-three per cent of the respondents treat blebitis as endophthalmitis, even without or with only mild anterior chamber (AC) activity. Thirty-eight per cent would do so if there was moderate AC activity, and 34% if there was severe AC activity including a hypopyon.
Conclusion A wide variation exists in the management of blebitis among glaucoma consultants. A standard treatment regime does not exist at the moment. Further research is needed to ascertain effective strategies to manage this condition.
Introduction
Antiproliferative agents are well reported to increase the success rate of trabeculectomy by reducing scarring at the filtration site.1 ,2 However, their frequent use has led to an increased incidence of postoperative complication including blebitis.3–5
Blebitis has been defined as mucopurulent infiltrate within the bleb and may be associated with mild to moderate anterior segment inflammation without vitreous involvement.5 Bleb-related endophthalmitis, on the other hand, is characterised by severe anterior segment inflammation with vitritis.5 However, in some cases, blebitis has been suggested to represent a continuum of infection involving the tissues in the region of the bleb to early endophthalmitis.6 The two forms of bleb-related infections are clinically distinct, with different presentations, prognoses and outcomes. The incidence of bleb-related endophthalmitis after glaucoma-filtering procedures has been reported to be higher than most other intraocular procedures.7 The prevalence of acute postoperative endophthalmitis after any type of intraocular surgery is estimated to be 0.093%.8
The incidence of blebitis per se has not been widely reported; however, bleb-related infection which encompasses blebitis to bleb-related endophthalmitis has been reported in a few retrospective trials and a recently published interim outcome of a prospective study. The incidence for 5-fluorouracil-treated eyes with a follow-up of 1–12 years is reported to be 1.9–13.0%,9–11 and 1.5–13.8% in cases using mitomycin C followed up for 16 months to 8 years.4 ,12–14 It is estimated that the incidence of blebitis in trabeculectomy with mitomycin C is 2.2% in 2.7 years15 to 5.7% at the 5-year follow-up.16
A survey to investigate the management of blebitis by the members of the American Glaucoma Society was published a decade ago, which showed a significant variation in the clinical practice pattern among the respondents.6 Aggressive treatment of early blebitis has been advocated to prevent progression to endophthalmitis and significant visual loss.17 Unlike endophthalmitis, the precise recommendations and clinical trials to study the outcomes with different management of blebitis have been lacking.
In this survey, the authors looked at the current trend in the management of blebitis by glaucoma consultants who are registered with the United Kingdom's Royal College of Ophthalmologists. It must be emphasised that treatment guidelines should not be based on such a survey but should be based on substantial evidence generated from appropriate clinical studies.
Methods
A questionnaire was sent to each member of the Royal College of Ophthalmologists (UK) registered as a practising glaucoma consultant. The contact details were obtained from the institution, and the consultants contacted by post.
The questionnaire consisted of 13 questions, some with multiple parts. The survey was designed to ascertain the clinician's management of a patient presenting with blebitis (not bleb-related endophthalmitis). No opinions regarding recommendations were solicited.
A χ2 test was used to compare patterns of behaviour among respondents' answers to the questionnaire when considering two or more variables.
Results
The questionnaire was sent to 112 glaucoma consultants, and 68 (61%) replied. The questionnaires were meant to be returned anonymously. There was no certainty as to whether all intended receivers received their post or whether those who did not respond chose not to do so. Three returned the questionnaire uncompleted, stating either they have not seen a case of blebitis for many years or they no longer perform trabeculectomies and thus are not well versed in blebitis management. The data from the remaining 65 questionnaires are illustrated in table 1.
Blebitis management survey questionnaire
Fifty-five per cent of the consultants would admit blebitis patients into hospital for treatment. Seventy-four per cent of respondents obtain a conjunctival swab, and 28% instil iodine on the conjunctiva as part of their treatment regime. The χ2 test reveals that those who obtain a swab are more likely to include conjunctival iodine in their management (p=0.048).
In terms of topical antibiotic treatment, the majority use fluroquinolone monotherapy (34%). This is the only monotherapy treatment employed by the surveyed respondents. The favourite combination of dual antibiotic therapy is cefuroxime and gentamicin (28%), followed by fluroquinolone with cefuroxime (18%), and 9% use ceftazidime and vancomycin.
Fluroquinolones are the only oral antibiotics used by those who routinely prescribe oral treatment (69%). In this group, 64% prefer ciprofloxacin, and the remaining 36% use moxifloxacin. Just under half of the respondents use subconjunctival antibiotic injection in treating blebitis. Fifty-five per cent choose to use cefuroxime, 23% ceftazidime and 13% a combination of cefuroxime and gentamicin. The χ2 test reveals that those who include subconjunctival antibiotic in their treatment regime are more likely to prescribe topical fluroquinolone monotherapy (p=0.02). Those who prescribe oral fluroquinolone are neither more nor less likely to prescribe topical dual therapy antibiotic (p=0.1) or use subconjunctival antibiotic (p=0.06).
One-fifth of respondents use intravitreal antibiotic in treating blebitis patients. Of these, two-thirds choose the combination of vancomycin and amikacin, and the remaining third ceftazidime and vancomycin. The χ2 test shows that those who use subconjunctival antibiotic are neither more nor less likely to use intravitreal antibiotic (p=0.047). The respondents indicated that they rarely prescribe intravenous antibiotic. Only 6% do, prescribing cefuroxime or ciprofloxacin.
A large majority of glaucoma consultants (82%) surveyed use topical corticosteroids as part of their treatment regime. Forty per cent indicated that they start it between 24 and 48 h, and 41% between 48 and 72 h.
There is a clear consensus (91%) that topical cycloplegic plays a part in the management of blebitis. Most respondents review the patients on a daily basis, with only 8% doing so every other day.
Twenty-three per cent of the respondents would treat blebitis as endophthalmitis, even without or only with mild anterior chamber (AC) activity. Thirty-eight per cent would only do so if there was moderate AC activity, and 34% if there was severe AC activity which includes a hypopyon. Correlation analysis shows that respondents with a lower threshold to treat blebitis as endophthalmitis were neither more nor less likely to use subconjunctival (p=0.3) or oral antibiotics (p=0.9) but were more likely to review the patients twice daily (p=0.02).
There is an almost equal three-way split regarding educating patients about the possible lifelong risk of blebitis. Thirty-four per cent routinely inform the patient about this, 35% indicated they usually do, and 31% indicated they rarely do so.
Discussion
The survey results reveal that the clinical practice of UK's glaucoma consultants differs significantly in certain expects of blebitis management. The treatment of this condition has not been subjected to rigorous clinical trials to established recommended practice patterns. The frequent development of new antibiotics, different availability of healthcare resources and rarity of blebitis may explain some of this disparity in clinical practice.
A similar survey performed among the members of the American Society of Glaucoma 10 years ago also found a significant difference in clinical practice in the management of blebitis.6 The questionnaire return rate was 64%, which is similar to the rate in our study. In that survey, 51% used topical fluroquinolone as a monotherapy, 23% combined it with another antibiotic, and 21% prescribed other combinations. In our study, only 34% use fluroquinolone on its own, 18% choose to combine it with another antibiotic, and 28% prefer cefuroxime and gentamicin. The rate of resistance to second-generation fluroquinolone (eg, ciprofloxacin) among Gram-positive ocular isolates is well documented to have increased over the past years.18 ,19 Resistance to the newer fourth-generation fluoroquinolones (eg, gatifloxacin, moxifloxacin) has also been identified to occur among coagulase-negative staphylococci.20 ,21 This could partly explain why the rate of fluroquinolone as a monotherapy has dropped over the past few years.
Only 6% of the American survey routinely used oral antibiotics (the majority prescribed ciprofloxacin). Our study shows a significant difference. Sixty-nine per cent of our respondents prescribe oral antibiotics. It has been suggested that oral antibiotics may prevent blebitis from becoming endophthalmitis.22 Sixty-four per cent of those who include this in their treatment regime prefer ciprofloxacin. Moxifloxacin has been shown to provide better Gram-positive coverage.23 ,24 The most common bacteria involved in blebitis are mainly Gram-positive bacteria—Staphylococcus epidermidis, Staphylococcus aureus and Streptococcus pneumoniae—which are consistent with the normal flora on the eye.25 ,26 This also suggests that a positive bleb culture may not always differentiate infection from colonisation. No specific research has been carried out on conjunctival culture in blebitis patients. The culture yield rate and the effect of this on the choice of antibiotic treatment remain known. Three-quarters of our respondents routinely obtain a conjunctival swab.
Fifty-five per cent of glaucoma consultants would admit the patient for treatment. Outpatient treatment has been shown to be efficacious and 78% less expensive than inpatient treatment in an American setting.25 No similar data are available for the UK. With prompt and aggressive treatment at the early stage, the prognosis for visual recovery is good.25
Blebitis usually responds well to intensive topical antibiotics treatment, with the subsequent visual acuity and intraocular pressure returning to preinfection levels.26 However, given the potentially devastating effect of bleb-related endophthalmitis, 23% of the respondents treat blebitis as endophthalmitis, even when there is low AC activity. Interestingly, the survey among American Society of Glaucoma members revealed similar findings (24%).6 Not surprisingly, 20% of our respondents use intravitreal antibiotic as part of their blebitis treatment regime. However, one has to balance the benefit of aggressive treatment with the potential adverse events arising from such intervention.
Topical corticosteroid forms part of the blebitis treatment regime in 82% of the respondents. There are no studies looking at the use of corticosteroid specifically for blebitis. Corticosteroids have a potent anti-inflammatory effect and have been used for this purpose in corneal disease processes, such as the treatment of corneal haze following refractive procedures and the treatment of interstitial keratitis caused by herpes simplex virus.27–29 However, their use in the treatment of bacterial keratitis has been consistently debated out of concern that the relative immunosuppression induced by corticosteroids will decrease inflammation but also may allow for increased bacterial survival and proliferation. Thus, the timing of steroid administration may be important in maximising their therapeutic benefits while minimising potentially negative effects. Eighty-one per cent of respondents start topical corticosteroid between 24 and 72 h after antibiotic treatment. A few studies have shown that topical steroid treatment in bacterial keratitis provides little benefit and may even be harmful in some cases.30 ,31 Indeed, nearly a fifth of our respondents do not use topical steroid in the management of blebitis.
Seventy-two per cent of clinicians in this survey instil povidone-iodine in the conjunctiva at the time of diagnosis of blebitis. This solution is an antiseptic with a broad microbicidal spectrum and a high degree of antimicrobial efficiency against bacteria and fungi.32 One drop of 5% povidone-iodine for 2 min has been shown to reduce the culture-positive swabs from 75% prior to instillation to 28% after.33 However, a randomised controlled trial assessing a single 10 min povidone-iodine instillation before corneal scrape in patients presenting with bacterial keratitis did not reveal a statistically significant difference between the pre- and postinstillation load of pathogen.34 In the povidone-iodine form, the majority of iodine is in the non-toxic stable tri-iodide form.35 Free iodine is a strong oxidising agent of the functional groups of amino acids, nucleotides, and unsaturated fatty acids. It causes pore formation in the cell wall, which leads to loss of cytosol material and enzyme denaturation.36 Bleb leakage is encountered in 48% of blebitis.6 It is possible that free iodine can enter the bleb and cause further inflammation. The use of iodine in blebitis requires further evaluation.
There are several weaknesses in this survey. The questionnaire was designed to be a page long so that it would require only a short time to complete. This has been shown to increase the rate of response.37 ,38 The return rate of 61% in this survey was deemed to be good. The drawback is the limited amount of information collected, and questions such as the visual status of the eye or fellow eye, the viability of the bleb on presentation and other factors that may influence treatment were not included. We are aware that the clinicians who did not reply may have managed blebitis in a different fashion.
Only consultant ophthalmologists specialising in glaucoma were selected for this survey, although blebitis could be treated by other ophthalmologists with a different subspecialty. This was intentional to provide a specialist view on the management of an uncommon problem. Judging from some of the written comments on the returned questionnaires, the interpretation of the questions may be limited by the lack of definition of isolated blebitis. For example, some of the respondents who have ticked the intravitreal antibiotic box as part of their blebitis treatment regime have commented that they would only use it if it was early endophthalmitis.
We are grateful to the respondents who have participated in this survey. Their responses have provided a snapshot of the management of blebitis by glaucoma specialists in the UK. It is hoped that this survey will generate points for discussion in this uncommon condition. Nonetheless, treatment recommendation should not be based on such a survey but should be based on the appropriate clinical trials. Judging from the significant variation shown in the management practice, a standard treatment regime for blebitis does not exist at the moment. Further research is needed to ascertain effective strategies to tackle this potentially devastating condition.
Footnotes
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Competing interests None.
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Provenance and peer review Not commissioned; externally peer reviewed.
