Argon laser and trichiasis

We were interested to read the approach taken by Sahni and Clark¹ to facilitate the effective argon laser treatment of trichiasis. They have ably reviewed the complications of trichiasis, the different forms of management of trichiasis, the advantages of argon laser treatment in the management of trichiasis, the technique of argon laser trichiasis therapy, and the limitations of lash laser therapy.

We take issue with the authors in two areas. Firstly, the almost certain consequence of using a duration of laser treatment of 0.1 second is that if the laser “takes,” the lash will disappear within the space of a few laser shots, effectively precluding the destruction of that particular lash follicle. We have particularly made it a point that when teaching trainees the technique of lash laser, we ensure that the energy burst lasts long enough to commence visible lash destruction as well as destruction of the subcutaneous lash, as the burn is directed towards the lash follicle. Thus we always use a duration of several seconds, or even continuous energy, and aim to achieve initiation of effective lash destruction above the lid level after the first shot, or certainly within three shots. Thus, 1–3 second duration bursts may be required, depending on the individual lash. Just a few more shots will effectively and completely destroy the subcutaneous lash and its follicle.

Secondly, the article by Bartley and Lowry quoted by the authors, describes using a “drop of ink from a fountain pen” to facilitate lash laser.² Presumable in the interests of sterility, Sahni and Clark have used the ink from a “blue skin marker pen” to allow improved absorption of argon laser energy. While use of a fresh marker pen for each patient may be relatively efficient, it could not be regarded as cost effective. By contrast, in a procedure described by us in 1994,³ we found that transferring a tiny drop of the patient’s own blood, whether still liquid or already coagulated, to the lash base on the lid margin is a simple, rapid, cheap, safe, and highly effective method of getting the laser reaction started when the lashes are pale. We have found that the required amount of blood is invariably present on the patient’s own lid skin at the site of local anaesthetic infiltration. We usually transfer it by picking it up with a sterile drawing up needle. This is achieved remarkably easily on the laser slit lamp, which allows adequate magnification for the accurate siting of the transferred blood.