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.