Ptosis is not an uncommon problem and can occur in any age group. We see congenital ptosis in children and levator dehiscence in senescence, with a myriad of conditions between. There are many different approaches to repair.
The most important part in the decision-making is the clinical exam. (1) What is the palpebral fissure height in primary gaze, (2) what is the levator function and (3) what is the marginal reflex distance? Levator function (4) is the measurement that is going to guide one to make the surgical decision. We categorize levator function into 3 basic types: poor levator function = 0 – 4mm, moderate levator function = 5 – 8mm, and good levator function = above 9mm. If the levator function is poor, you know you must use another muscle to elevate the eyelids. This muscle is the frontalis.
Frontalis suspensions are most commonly done in children who were born with fat and fibrosis infiltrating their levator muscle. Suspension materials include silicone rods, supramid sutures, banked fascia lata or autogenous fascia lata. If you are to use the patient's own fascia lata, they must be at least 5 years of age in order to harvest a long enough segment from the leg. The frontalis can be suspended in a double rhomboid fashion, pentagon or double triangle. In any case, the patient will learn to contract their forehead in order to lift the lids. Paramount to any ptosis repair, especially in children, is the need for copious lubrication post-operatively in the case of lagophthalmos.
An option if a patient has about 4 – 5mm of function is to perform a Whitnall's Sling, which is basically a maximal levator advancement with suspension of Whitnall's ligament to the periosteum of the superior orbital rim.
With moderate levator function, the muscle works, but needs to be shortened via a levator resection. The aponeurosis is advanced and the muscle is trimmed, salvaging what function there is of the levator.
With good levator function, a levator advancement can be performed via an external incision. As another option, in the clinic, 2 drops of phenylephrine can be applied to the affected eye to stimulate Muller’s muscle. If the patient reacts nicely, you know you can perform a conjuntival-mullerectomy with predictive results.
The above is a very general and precise guide to choosing a surgical approach to ptosis repair. Obviously, one must rule out less obvious causes for ptosis that deserve attention prior to repair, such as an orbital mass, eyelid tumor, nerve palsy, or enophthalmos.