 Involutional entropion |
 Tightening of lower eyelid retractors and lateral canthoplasry |
Entropion is a lid malposition with an inward rotation of the lid margin toward the globe.
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Involutional entropion |
Tightening of lower eyelid retractors and lateral canthoplasry |
Terminology
Entropion may be classified in several categories :
-Involutional entropion. Several etiological factors are advanced for the development of involutional entropion : Migration of the preseptal orbicularis muscle over the pretarsal orbicularis muscle, horizontal lid laxity from tarsus and canthal tendons, age-related enophthalmos.-Congenital entropion Aetiology could be hypertrophic changes in pretarsal and preseptal orbicularis muscles in the medial part of the lid.
-Cicatricial entropion is associated with posterior lamella retraction from a thermal injury, a trachoma or any case of conjunctival scarring.
Treatment
Treatment of involutional entropion includes tightening of lower lid retractors via transcutaneous or transconjunctival approach, associated with horizontal lid shortening by lateral canthoplasty.
Treatment of cicatricial entropion depends on its severity :
-A mild upper lid cicatricial entropion where there is an apparent migration of the posterior meibomian glands orifices may require an anterior lamellar reposition which lifts the pretarsal anterior lamella with the lashes in front of the tarsus.
-A marked upper lid cicatricial entropion, with lashes abrading cornea may be corrected with anterior lamellar reposition associated with a split of the lid margin just anterior to the orifices of the meibomian glands and an eversion of all the lashes. Thickening of a scarred tarsus may require an excision of a wedge of tarsal plate.
 Cicatricial upper eyelid entropion |
 Lateral view |
 Postoperative view after fifteen days |
 Postoperative lateral view after fifteen days |
 Postoperative view at four months |
 Postoperative lateral view at four months |
Terminology
Trichiasis is an eyelash abnormality in which lashes have a normal position but have an abnormal direction toward the globe.
Trichiasis can be isolated or associated with entropion.
Treatment
Isolated trichiasis limited to one, two or three widely separated lashes may be managed with argon laser treatment. The laser is focused at the base of the lash to destroy the lash follicle.
Trichitic lashes grouped in a localised area may be removed by a full-thickness lid wedge resection.
Correction of entropion is necessary if associated with trichiasis.
Terminology
Distichiasis refers to a second row of eyelashes that arise from meibomian gland orifices in the tarsal plate.
Distichiasis is usually congenital.
Treatment
Surgical excision of distichiatic lashes is done using operating microscope : the lid margin is split adjacent to the abnormal lashes, then lash follicles are exposed and excised.
Cryotherapy is an alternative treatment for distichiasis : the lid is split into an anterior and posterior lamellae ; the cryoprobe is applied close to the tarsal plate, at the base of the distichiatic lashes.
If a thermocouple is used, freezing of the tarsus is continued until a temperature of -20 C is reached. If a thermocouple is not available, freezing is done during 20 seconds in the lower lid, 25 seconds in the upper lid. All areas are treated with two freeze-thaw cycles. Then abnormal lashes are epilated.
