Dear Editor

The authors wish to thank Gandorfer and colleagues for their interest in our paper [1] and for the kind comments and encouragement with regard to our work. Certainly, these correspondents are compiling evidence concerning the effect of indocyanine green (ICG) on the retina in both their published and unpublished studies.[2,3]

In our report, we restricted our comments regarding retinal damage and dye usage to the specimens wherein an epiretinal membrane (ERM) was present.[1] Evidence of retinal damage was observed in four of these five specimens, mostly in the form of neural and glial elements adherent to the retinal side of the inner limiting membrane (ILM). The apparent lack of such elements in some ERM specimens may reflect partial separation of the ILM due to traction from the membrane prior to surgery. [4] Nevertheless, in one of our specimens a substantial fragment of neuroretina was also present.[1] We have, indeed, long considered such fragments as potential confounding factors in immunohistochemical studies of surgically-excised ERMs.[5,6] Since they are present in ERMs removed without the use of any dye at all, we cannot blame their presence on these surgical aids. Perhaps these fragments are avulsed as a result of enhanced adhesion between the ERM and retina via glial anchorage sites running through dehiscences in the ILM.[5] It is clear that our investigation does not exclude an effect of ICG on the retina [2,3] and we wholeheartedly agree with Gandorfer and coworkers that agents such as trypan blue warrant further evaluation as aids to ERM and ILM peeling.

References

(1) Li K, Wong D, Hiscott P, Stanga P, Groenewald C, McGalliard J. Trypan blue staining of internal limiting membrane and epiretinal membrane during vitrectomy: visual results and histopathological findings. Br J Ophthalmol 2003;87:216-9.

(2) Gandorfer A, Haritoglou C, Gass CA, Ulbig MW, Kampik A. Indocyanine green-assisted peeling of the internal limiting membrane may cause retinal damage. Am J Ophthalmol 2001;132:431-3.

(3) Gandorfer A, Haritoglou C, Gandorfer A, Kampik A. Retinal damage from indocyanine green in experimental macular surgery. Invest Ophthalmol Vis Sci 2003;44:316-23.

(4) Michels RG. A clinical and histopathologic study of epiretinal membranes affecting the macula and removed by vitreous surgery. Trans Am Ophthalmol Soc 1982;80:580-656.

(5) Hiscott PS, Grierson I, Trombetta C, Rahi AHS, Marshall J, McLeod D. Retinal and epiretinal glia an immunohistochemical study. Br J Ophthalmol 1984;68:698 707.

(6) Morino I, Hiscott P, McKechnie N, Grierson, I. Variation in epiretinal membrane components with clinical duration of the proliferative tissue. Br J Ophthalmol 1990;74:393 9.

Dear Editor

We thank Dr Masood for his interest in our manuscript [1]. Clearly in some cases of giant cell arteritis (GCA), treatment with high dose corticosteroids alone is insufficient. The use of adjunctive heparin proved to be beneficial in our patient, although the reason is not clear [1]. Thrombocytosis has been shown to occur in a large percentage of patients with GCA [2, 3]. However, there is no convincing evidence that thrombocytosis plays a direct role in the ischemic complications of GCA [3].

While anticoagulation may have been responsible for the improvement of blood flow in our patient, other biochemical activities of heparin such as prevention of inflammation may have also been at work. The value of adjunctive aspirin therapy may not lie with its anti-thromobotic effect, but rather with an interruption of the inflammatory cascade.

While the preliminary data regarding the value of adjunctive aspirin use in the treatment of GCA is compelling [4], we believe that there is insufficient evidence at this time to place all patients on adjunctive aspirin therapy. We advocate further research to compare the effectiveness the combination of corticosteroid and aspirin treatment versus corticosteroid therapy alone.

References

(1) Buono LM, Foroozan R, de Virgiliis M, Savino PJ: Heparin therapy in giant cell arteritis. Br J Ophthalmol 2004, 88:298-301.

(2) Foroozan R, Danesh-Meyer H, Savino PJ, et al.: Thrombocytosis in patients with biopsy-proven giant cell arteritis. Ophthalmology 2002, 109:1267-71.

(3) Costello F, Zimmerman MB, Podhajsky PA, Hayreh SS: Role of thrombocytosis in diagnosis of giant cell arteritis and differentiation of arteritic from non-arteritic anterior ischemic optic neuropathy. Eur J Ophthalmol 2004, 14:245-57.

(4) Nesher G, Berkun Y, Mates M, et al.: Low-dose aspirin and prevention of cranial ischemic complications in giant cell arteritis. Arthritis Rheum 2004, 50:1332-7.

Dear Editor

We read with interest the paper by Alwitry showing that the use of surgical facemasks significantly reduced the contamination of agar plates placed in the sterile field during cataract surgery.[1] Previous work has shown that, compared to remaining silent, talking significantly increases the dispersal of bacteria to agar plates placed 30 cm in front of and below the face, particularly if required to speak loudly.[2,3] The use of a surgical facemask prevents contamination of agar plates placed in front of the talking operator.[4] Similar reductions in contamination may be found when agar plates are placed below the operator’s mouth, although this may be partially offset in bearded male operators compared to female operators and clean shaven males as dermabrasion by the mask may increase shedding of skin and bacteria.[5,6]

During cataract extraction using topical anaesthesia it is not uncommon for the operator to continue talking with the patient giving reassurance and directing eye movements. It might be expected that in these circumstances there would be an increase in bacterial dispersal compared to akinetic anaesthetic techniques where such communication is seldom required. Consequently, it would be interesting to know from Alwitry’s study whether there was any difference in anaesthetic techniques between the masked and unmasked groups as this may significantly alter bacterial colony counts.

References

(1) Alwitry A, Jackson E, Chen H, Holden R. The use of surgical facemasks during cataract surgery: is it necessary? Br J Ophthalmol 2002;86:975-977.

(2) O'Kelly S, Marsh D. Face masks and spinal anaesthesia. British Journal of Anaesthesia 1993;53:239

(3) Schiff FS. The shouting surgeon as a possible source of endophthalmitis. Ophthalmic Surg 1990;21:438-40

(4) Phillips B, Fergusson S, Armstrong P et al. Surgical face masks are effective in reducing bacterial contamination caused by dispersal from the upper airway. Br J Anaesth 1992;53:407-8.

(5) McLure HA, Talboys CA, Yentis SM et al. Surgical face masks and downward dispersal of bacteria. Anaesthesia 1998;53:624-626.

(6) McLure HA, Mannam M, Talboys CA et al. The effect of facial hair and sex on the dispersal of bacteria below a masked subject. Anaesthesia 2000;55:173-6.

Dear Editor

We read with keen interest the recent article by Churchill et al. that reports a multicentre questionnaire studying out-of-hours clinics.[1] The authors are to be commended for their initiative in performing the first appraisal of patient’s attitudes to government proposals to introduce out- of-hours clinics and operating sessions.[1]

However, it is still left unclear to us as to the accuracy of a key concluding remark of the authors, which we believe is contentious, potentially misleading, and should benefit from clarification by the authors to prevent any confusion. Specifically, we are concerned with the statement that the study found that only 4% of patients will ‘opt for’ out -of-hours clinics. This is a statement of considerable import, which we find extremely surprising given our personal experience of patients attending Saturday morning clinics and based upon a series of interviews we have conducted. When earlier reporting their results the authors also use the figure of 4% to quantify the number of patients reported to have stated that an appointment between 8am and 5pm, Monday to Friday, was inconvenient. Since we are so surprised by the sense of the statement that only 4% of patients will ‘opt for’ out-of-hours clinics, we question whether the authors might not have interpreted this figure of 4% by transposing it from the 4% that found a routine weekday appointment inconvenient, in which case their statement becomes very misleading. Clarification is needed both for the regular readership and beyond, for this is the first study of its kind in a key area of clinical debate, and is thus influential. Even if substantiated, this figure of 4% that are stated to ‘opt for’ out-of-hours clinics might mislead, as the study’s own breakdown of results shows that 52% of patients found Saturday morning clinics ‘convenient’. This breakdown also states that 58% found Saturday morning clinics ‘inconvenient’. But a study we conducted disputes these findings, and suggests instead a spectrum of opinions which by and large resonate with the government’s proposals in this regard.

In a series of interviews conducted by us, 102 consecutive patients who actually attended out-of-hours Saturday morning eye clinics at the Hillingdon Hospital were specifically asked by the examining ophthalmologist whether they preferred a Saturday morning clinic appointment, a routine 9-to-5 weekday clinic, or if they did not mind one way or the other. The results are strikingly different to that suggested by Churchill et al. A slight majority, or 51 patients (50%) simply did not mind whether they were seen on a Saturday morning or in a routine weekday 9-to-5 clinic. The second largest group of 42 patients (41%) said that they actually preferred a Saturday morning clinic, while the smallest group were 9 patients (9%) who said that they preferred a weekday 9-to-5 clinic appointment. Total number of female patients was 65, and male patients 37. Of those preferring Saturday morning clinics 41 % were female and 59% were male. Mean age of patients who preferred Saturday morning clinics was 62, while of those who preferred a weekday appointment it was 70. Reasons for preferring Saturday morning clinics included the following: it was easier for working people and students, which accounts for the younger mean age of patients preferring Saturday morning clinics; reduced traffic; car parking was easy; the hospital was relatively quiet on a Saturday morning making access easy, which was especially important for older people; finally, recent introduction of the weekday ‘congestion charge’ in central London meant that a Saturday morning clinic best suited older patients as friends or relatives saved on the cost of the journey by avoiding travel through central London to pick up the patient and transport them to the hospital – however, this is a factor at present unique to London. Amongst those who were not concerned whether they had a 9-to-5 weekday appointment or one on a Saturday morning, the overwhelming majority, or 86%, were retired. Reasons given for preferring a 9-to-5 weekday clinic appointment were, with six young mothers, children under the age of 12 at home, as the children were at school or nursery during weekdays but not weekends; hospital transport was felt to be easier to obtain on a weekday; surprising reasons were found in two patients who said that they preferred a 9-to-5 weekday appointment so as to have an extra day off work by going to the doctors, while one patient felt a Saturday morning hospital appointment was an infringement into ‘leisure’ time.

While this interview study has fewer patients, there is no missing data for all patients responded at interview - unlike the multicentre study in which only 54% of the despatched questionnaires were used for the analysis. Importantly, these interviews might also be more realistic in that they take into account the experiences of people who have actually attended an out-of-hours clinic. Alternately, it is possible that the markedly different results have arisen as we interviewed patients attending only Saturday morning clinics, while the concluding statement of the authors concerned out-of-hours clinics in general. However, even if this is the case, interviews suggest that the attitude amongst the public to Saturday morning clinics is positive.

Reference

(1) Churchill AJ, Gibbon C, Anand S, McKibbin M. Public opinion on weekend and evening outpatient clinics. Br J Ophthalmol 2003;87:257-8.