Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Would a head to head comparison help?
- Sampath Venkatasreekanth, M20 4XR (23 July 2004)
-
What does "History of conjunctivitis" really mean?
- Anthony N Glaser (24 July 2004)
-
How many eyes?
- Philip J Hughes, James Crick (27 July 2004)
-
What about Chlamydia?
- Janette Clarke (29 July 2004)
-
Three more questions for "conjunctivitis"
- Anna Fierz (30 July 2004)
-
Why say itchying counts against bacterial infection in conjunctivitis
- Richard L Davies (1 August 2004)
-
Dilemmas of Acute Conjunctivitis
- John M Gardner (23 August 2004)
-
Diagnosing causes of conjunctivitis
- Scott J Robbie (21 April 2005)
|
|
|||
|
Sampath Venkatasreekanth, Clinical Observer CHRISTIE HOSPITAL, Manchester, M20 4XR
Send response to journal:
|
The results seem promising and I wonder whether doing a head to head comparison as follows would help us to be sure that they are true indeed. 1. Form two equal groups of culture positive and culture negative cases from the patients you have studied. 2. Match them for age and sex. 3. See if the criteria are still satisfied. Statistics sometimes makes us believe things which are too good to be true. Applying these criteria empirically can be accepted into general medical practice only if we do a trial comparing usage of this criteria and use of empirical antibiotics and show that using these criteria shows atleast a similar rate of resolution of symptoms with reduced costs. Competing interests: None declared |
|||
|
|
|||
|
Anthony N Glaser, Private practice of family medicine Summerville, SC, USA
Send response to journal:
|
This is a very interesting and potentially very valuable study. But can the authors please clarify what they mean by a "history of conjunctivitis"? Do they mean a prior history of conjunctivitis, recent injected conjunctivae, or what? What was the question patients were actually asked - surely they did not ask "do you have a history of conjunctivitis?" or its Dutch equivalent? Competing interests: None declared |
|||
|
|
|||
|
Philip J Hughes, Principal in General Practice Eastfield Surgery, 1 Eastway, Eastfield Scarborough. YO11 3LS, James Crick
Send response to journal:
|
We read the above paper with interest however we are unclear as to how many eyes were recruited. In the methods the authors state that for each patient one eye was designated as the study eye, or if both were diseased then the worst eye was chosen. In their scoring method and in table 1 they discuss "two glued eyes" and bilateral conjunctivitis. We are uncertain whether the 2 glued eyes refers to both eyes or one eye on 2 occasions. In addition we feel this matter needs clarifying as this may influence the statistical analysis. Competing interests: None declared |
|||
|
|
|||
|
Janette Clarke, Consultant physician in genitourinary medicine Leeds General infirmary LS1 3EX
Send response to journal:
|
This interesting paper on distinguishing bacterial conjunctivitis from other causes omitted to mention chlamydial conjunctivitis as a possible cause for adult "sticky eyes". It was disappointing that detection and screening for chlamydia was not included in their laboratory protocol. A small but steady number of referrals to our sexual health clinic come from ophthalmologists screening for chlamydia in adult conjunctivitis. Although symptoms of chlamydial disease may be mild, it should be considered in the spectrum of clinical presentations likely in this study. A better understanding of prevalence of this condition within the cohort tested might have strengthened the paper. Competing interests: None declared |
|||
|
|
|||
|
Anna Fierz, ophthalmologist in private practice 8037 Zürich, Switzerland
Send response to journal:
|
This is a very nice study. It seems churlish to quibble, but... aren't there more important questions? How much harm do GPs do when they prescribe antibiotics? The real damage is done when keratitis is missed; here, the steroid often given with the antibiotic is the bigger culprit. Steroids will dampen the immune response, permitting resistent corneal pathogens to mushroom. In early keratitis, this causes a significant delay in referral. Patients believe they're better since the eye is less red - until vision drops. Detecting small corneal lesions without a slitlamp is all but impossible. A few pertinent questions may help prevent corneal scarring and visual loss. The most useful are: Do you wear contacts? Does your eye hurt, or does bright light hurt you? Is your vision worse? If the answer to any of these is yes, don't prescribe. Refer. If you can't, give contact wearers an antibiotic that works for Pseudomonas - without steroids. Please forgive me for seizing the occasion for a slightly off- topic lecture. Competing interests: None declared |
|||
|
|
|||
|
Richard L Davies, GP Partner Glenlea Surgery, 703 Leeds & Bradford Road, Stanningley, Pudsey, LS28 6PE
Send response to journal:
|
The development of easy to use clinical rules to help discriminate between bacterial and culture negative acute conjunctivitis would be welcomed in primary care but are the three simple questions proposed by Rietveld et al the right questions?(1) One major problem is the use of itching to count against the liklehood of bacterial infection.Itching was present in 33 of 57 culture positive patients. Itching was sligtly more prevelent in the culture negative group 63% verses 58%. Using itching to count for or against is wrong as both before and after logistic regression there is no significant difference. I would not use the answer to this question to make treatment decisions based on the data presented. A history of conjunctivitis seems helpful in a minority of patients but this would not affect treatment choice in the majority. The best question seems to be are both your eyes glued in the morning with the biggest odds ratio after logistic regression analysis of 14.99. I am puzled by the odds ratio of 2.68 for one eye glued in the morning as the numbers of 53% culture positive and 62% culture negative would suggest an odd ratio of below 1.0? Possibly a question for the author. One last point the conclusion suggests the assesment could possibly be done over the telephone but in their exclusion criteria ciliary redness is mentioned and most doctors would be hard pressed to diagnose this over the telephone. Rietveld RP, et al.predicting bacterial cause in infectious conjuntivitis: cohort study on informativeness of combinations of signs and symptoms.BMJ 2004;329@206-8 Competing interests: None declared |
|||
|
|
|||
|
John M Gardner, clinical assistant Leicester Royal Infirmary, LE1 5WW, UK
Send response to journal:
|
EDITOR-Rietveld et al studied adults with acute (presumed infectious) conjunctivitis diagnosed by general practitioners.1 They describe a clinical scoring system that helps identify bacterial infection. As an illustration, the authors use a threshold score of +2, with a topical antibiotic being offered to patients with a score at or above this level. With this threshold score, their model has a sensitivity of 67% in identifying cases with positive bacterial cultures, and a specificity of 73% in identifying culture negative cases. These measures do not directly address the dilemmas faced by patients and their doctors. Patients may wonder if consulting the doctor is worthwhile, asking themselves, “If I use a topical antibiotic, what is the chance of my benefiting from it?” When patients attend the doctor but are not prescribed an antibiotic, they may wonder, “How sure is the doctor that an antibiotic would not help?” Using the authors’ data, these questions may be partly answered as follows. Patients with a score of less than +2 may be told that evidence suggests that they may be 82% confident that an antibiotic would not help them. Patients with a score of at least +2 should be warned that the chance of an antibiotic helping is perhaps only 54%. Some patients with sticky red eyes treat themselves with an over-the- counter drug such as propamidine. Experience with topical antibiotic therapy suggests that if there is no response, changing the antibiotic is unlikely to help, however, specific therapy is needed for chlamydia. Blepharitis and tear film dysfunction are common causes of persistent symptoms. Careful assessment is needed in cases with unilateral disease or recent contact lens wear. Serious disease is suggested by loss of vision (after cleaning away any pus), photophobia, and pain when focussing on a close object. John M Gardner 1 Rietveld RP, ter Riet G, Bindels PJE, Sloos JH, van Weert HCPM. Predicting bacterial cause in infectious conjunctivitis: cohort study on informativeness of combinations of signs and symptoms. BMJ 2004;329:206-8. (24 July.) Competing interests: None declared |
|||
|
|
|||
|
Scott J Robbie, SpR Ophthalmology Queen Elizabeth II Hospital, Welwyn Garden City
Send response to journal:
|
Editor Ultimately it should be the aim of a general practitioner to identify the most likely cause of a patient's conjunctivitis and treat it appropriately. Unfortunately this study can only partly claim to help in this direction since the evidence only indicates that if a patient has had 'sticky eyes' on waking that they are more likely to have a positive bacterial culture - this does not translate to a diagnosis of bacterial conjunctivitis. An attempt to establish the presence of an adenoviral cause as well as chlamydial culture in these patients with a comparison of the results, might have led to different conclusions. Similarly, no mention was made of treatment outcomes in the study cohort. The key features of adenoviral conjunctivitis are well documented: patients frequently complain of watering and 'grittiness' (initially in one eye before involvement of the other), pre-auricular lymphadenopathy is also a helpful sign. Symptoms may take up to three weeks to resolve, and in my experience the patient has often been on topical antibiotics for a protracted period at the time of referral - these contain preservatives which may trigger an allergic response in an already inflamed eye thereby exacerbating the patient's symptoms. A diagnosis of chlamyidal conjunctivitis or allergic conjunctivitis is more likely to be made in intractable cases than one of bacterial conjuctivitis. In addition, given the plethora of bacterial commensals in the eye, the temptation to treat a swab result rather than the patient should be resisted. Any attempt to simplify the diagnosis of a condition is to be supported. However, the use of topical antibiotics in the treatment of adenoviral conjunctivitis in the community is so widespread that it is likely that either insufficient knowledge of the condition or misplaced belief in a high incidence of bacterial conjunctivitis in the population, lie at the root. Refining the questions worth asking in a history will only go some way towards addressing this problem. Competing interests: None declared |
|||