Trichiasis And Distichiasis

Distichiasis and trichiasis are eyelash problems that cause considerable pain and damage to the eye. Such eyelash problems, superficially seen, may seem to be of not much concern and easy to treat. But in this condition, constant rubbing of the eye may result in severe corneal disease or may even cause blindness. Moreover, in this aggravated state, surgeries are risky, carrying higher chances of failure as well as recurrence of the problem. Hence to prevent such eventualities it is necessary to be well familiar with the underlying disease as well as the resulting anatomical deformity 
Distichiasis is a rare disorder defined as the abnormal growth of lashes from the orifices of the meibomian glands on the posterior lamella of the tarsal plate.

Two types of distichiasis can be identified, acquired and congenital. In the acquired form, most cases involve the lower lids. Lashes can be fully formed or very fine, pigmented or nonpigmented, properly oriented or misdirected. The congenital form is dominantly inherited with complete penetrance. It can be isolated or associated with ptosis, strabismus, congenital heart defect, or mandibulofacial dysostosis. This defect may be related to the epithelial germ cells failure to differentiate completely to meibomian glands, instead they become pilosebaceous units.

Cosmetic treatment for focal areas can be tried with epilation or epilation with electrolysis. For larger areas, a selective destruction of the distichiatic hairs growing at the back may be tried with a cryoprobe applied to the tarsoconjunctival surface. In addition, the eyelid can be split along the gray line and the rear part of the eyelid margin can be treated with cryotherapy. In a study, 17 eyelids in 5 patients with a variety of causes were treated. It was observed that 6 eyelids were free of distichiasis for one year, 4 eyelids needed simple epilation with electrolysis, 4 eyelids underwent cryotherapy and 1 patient had to undergo a repeat treatment. No complications were faced during the study.

Another procedure is to split along the eyelid margin and surgically remove the rear portion of the margin and tarsal plates containing the follicles of these distichiatic hairs. To cover the scarring caused, a mucous membrane graft can then be done.

Trichiasis

Trichiasis is a more common eyelash problem. In this condition the eyelash hairs grow from the normal portion of the eyelid but their growth is directed towards the eyes. Patients with this condition get the sensation of a foreign body in their eyes and also suffer from eye pain. If left untreated, corneal abrasion, infection or scarring of the cornea may result. Causes of trichiasis are several and include eyelid trauma, chemical burns, leprosy, trachoma, blepharitis and eye surgeries.

Treatment, at first, should be an attempt to simply remove or epilate these wrongly directed hairs by using forceps. But if the hair re-growth continues to be towards the eye some other permanent method must be resorted to. Normally electrolysis, with a hyfrecator or a radio frequency unit can be used to treat a few eyelashes. For a larger area, cryotherapy may be used. It is advisable to use a thermocouple to monitor the tissue temperature. This is recommended not only to prevent tissue necrosis from excessive freezing but also to ensure that the right treatment temperature is achieved. A double freeze-thaw treatment down to -20°C is advised.

A more recent method of treating trichiastic hairs is by using argon laser has given good results. In one study 60 lids of 45 patients were treated with argon laser. Recurrence of the condition was observed in 25% of cases after one treatment. Among the complications seen were mild hypo-pigmentation and mild lid notching. A study was also carried out on the effect of argon laser photocoagulation in the treatment of trachomatous trichiasis. Of the 36 eyelids of 22 patients treated, 55.5% were reported as successful after one treatment session. The success rate further increased to 88.9% after two to three treatment sessions with argon laser