Editor,—Trichiasis is a posterior misdirection of eyelashes. Owing to constant corneal irritation it can give rise to discomfort, recurrent infection, corneal ulceration, and pannus formation. Several modalities of treatment exist which include epilation, electrolysis, cryotherapy, and argon laser thermoablation.1 ,2

Argon laser offers the advantage of being a relatively simple, virtually painless method of destroying the eyelash follicle. It is especially useful when there is a need to limit contiguous tissue inflammation and destruction—for example, ocular pemphigoid.3 Argon laser can be precisely applied to the follicle with or without topical anaesthesia. A beam size of 50 μm, for a duration of 0.1 second and energy levels of 400–500 mW is normally used in our clinic.

Thermoablation depends on the absorption of argon laser by pigment. In our experience, patients with chronic trichiasis, who have undergone repeated removal of eyelashes with other available methods, have pale hypopigmented lashes which do not absorb sufficient laser energy. This makes it difficult and sometimes impossible to get a result in spite of increasing the energy levels. Recently, we have used a blue skin marker pen to mark the base of the offending eyelash with the result that argon laser is better absorbed by the blue pigment. Once there is initial uptake subsequent shots down the lash root can be easily completed.

In conclusion, we have found the simple and inexpensive technique of marking eyelash bases useful in increasing the efficacy of argon laser photoepilation.