Eyelid malposition

Eyelid malpositions are changes to the correct position of the eyelids, upper or lower. These changes are frequent and affect the normal appearance of the eyelids. They may cause visual problems in certain cases. 

Depending on the type of eyelid malposition, a patient's symptoms may be different. If it affects the axis vision, ptosis may cause a reduction of the visual field. Patients with entropion may feel rubbing against the eye's surface, eye watering, irritation or if it causes corneal lesions it may affect the vision.  

Ectropion may cause irritation, reddening of the eye's surface, foreign body sensation, eye watering and a predisposition to suffering infections of the eye's surface.

The change in the position of the eyelids is usually a side effect of a loss of tissue elasticity due to ageing, although it may also apper as a result of an facial nerve paralysis or scars. Ageing is the main cause.  

• Ptosis is a drooping upper eyelid, with difficulty in opening the eyelid voluntarily. In some cases, it is so severe that the eyelid covers the axis of the pupil and hinders correct vision in the affected eye.  
• Entropion is the eyelid turning inward towards itself. It may be the lower eyelid (most commonly) or the upper eyelid, causing the eyelashes to rub against the cornea and eye surface. 
• Ectropion is the rotation towards the outside of the lower eyelid. Very often, it causes the tears to build up at the mid point without being able to drain and it is normal that the patient notices their eye watering. 

Malpositions cannot be prevented, but they can be treated early, because they can be diagnosed in an eye exam.

Malpositions are treated with surgery. The purpose of the surgery is to reposition the eyelid so its function and aesthetic appearance are restored. In the case of patients with ptosis, surgery acts on the levator muscle of the upper eyelid, repositioning it so that it the height of the eyelid is correct and the patient can see properly. 

This can be carried out by the external route (through the skin) or the internal route (through the conjunctiva): the choice of technique depends on the result of a test carried out in the consultation with the ophthalmologist. 

In entropion and ectropion, it is important that all the eyelid structures are properly assessed in order to select the best treatment option in each case. For example, patients who have undergone surgery or have scars from accidents, the surgical technique of choice will aim to rebuild the affected eyelid layer, be it the skin or the conjunctiva via implants. 

In the event that the eyelid malposition is due to age, surgery is usually a canthal strip, whereby a small incision in the external canthus of the eye is made to anchor the eyelid edge to the bone ridge and put it back in its normal position. In the majority of cases, the different surgeries offer an immediate solution to eyelid malposition and its associated complications.