|Lid and Ptosis
Abnormal drooping of upper eyelid or inability to lift up upper eye lid is known as ptosis. Normally Upper lid covers 1 to 2 mm of limbus of cornea. Upper lid is lifted up by normally innervated levator papabrae superioris muscle.
The ptosis may be due to congenital cause or acquired. Congenital ptosis is associated with myogenic dystrophic changes of levator muscle resulting in poor functioning of lid. Acquired ptosis is Neurogenic , Myogenic, Traumatic, Mechinal and Pseudosis.
Post traumatic, may be because of unrepeared levator muscle at the time of trauma to upper eyelid. Mechinal ptosis is due to a tumour or cyst, or enlarged lacrimal gland pushing the lid down.
Preoperative detail history, careful examination, measure of supratarsal fold and symmetry, evaluation of lid contour, measure of ptosis in millimetre, difference of palpebral fissure, measure levator function ( lid excursion with brow static), visual acuity of eye, function of extraocular muscle, Bells phenomena, jaw winking. Also see for myasthenia gravis or Horner's syndrome.
Ptosis classification---Mild.1 to 2 mm, Moderate..3 mm, Severe...4+ mm,
Classification of levator function---excellent..12to 15 mm, Good 18 to 12 mm, Fair..5 to 7mm, Poor.2 to 4mm.
MANAGEMENT OF PTOSIS Depends on grade of ptosis and levator function.
Severe ptosis with poor levator function, then frontalis sling is procedure of choice. In this, tensor facia lata sling attaches frontalis muscle directly to lid margin, so as lid is lifted secondary to lifting of frontalis muscle.
If levator function is good with minimal ptosis many types of levator muscle reconstructive procedures can be done. Basic of all of them is to improve levator excursion, either by muscle shortening or levator muscle / apponeurosis plication.
POSTOPERATIVE Lid swelling is most common problem, which settles within a week. Second common may be inability to close eye completely. Patients should be explained about these in detail. Eye ointment in night should be advised. In cases of frontalis sling physiotherapy is started after 4 weeks of surgery. Patients should be examined at monthly interval at least for six months. Sometimes patient might need little adjustment of sling for final correction. This correction can be done under local anaesthesia as outdoor procedure.
Here are few examples of Ptosis.
Moderate ptosis.Facia lata frontalis sling used. Bilateral severe ptosis, First medial canthoplasty followed by bilateral Facia lata frontalis sling. Result at two weeks.
Severe ptosis. Siliastic rubber band used for retinal detachment surgery used as sling.As patients father refused to take facia lata
Moderate ptosis with moderate levator function. Levator muscle resection and its advancement done. Early result.