Difference between ptosis and blepharoplasty?

Excess skin of the upper eyelids can cause redundant folds over the upper eyelids. and the skin can hang from the upper eyelid over the upper eyelid margin, when it is severe. Ptosis of the upper eyelid is related to the ability of the person to open his or her eyes. There is a muscle responsible for the eyelid to open. This muscle can become detached from its original position, or not developed as well as it should. when you look at the person with ptosis, they appear to be sleepy.we have a way to measure the ptosis of the eyelid and that is with MRD ( margin-light-reflex). the distance from the upper eyelid margin to the center of the pupil that light reflex can be seen should be around 2.5 to 3.00 mm. Anything less than this, it will be considered ptosis of the upper eyelid.   

Ptosis is when the eyelid is low and the margin of the lid is sitting at or below the upper edge of the pupil.  This is due to a stretched or weakened levator muscle.  Surgery to correct this can be done from either inside/underneath the eyelid, or through the skin at the lid crease.Dermatochalasis is when you have excess skin and fat in the upper lid. A blepharoplasty is done to remove the skin, and sometimes remove some of the fat.  Patients with ptosis frequently have excess skin and in those cases both the ptosis repair (to tighten the muscle) and the blepharoplasty are done at the same time.  

Dermatochalasis is the medical term for excess skin in the eyelids and may be associated with prolapse of fat from the orbit. Blepharoplasty is a general term for the surgical procedure that restores form to the eyelid. Ptosis, a shortened term for blepharoptosis, is a drooping of the lid margin. There are many types of ptosis - congenital, myogenic, aponeurogenic, mechanical, paralytic - reflecting the underlying cause(s). Correction of ptosis involves either surgery on the levator muscle, or less commonly connection of the lid to the frontalis muscle by way of slings (if the muscle is not working properly). Sometimes it is difficult to determine whether the drooping is secondary to a muscle problem or skin and fatty tissue pressing the lid down or both factors. A gentle lift of the brow and skin to observe the lid level will determine which problems should be addressed (levator surgery and/or skin & fat removal and/or brow elevation). The link below provides more information (see the before-after gallery). A thorough examination by an Oculoplastic Surgeon will clarify the diagnosis and management. 

As an eyelid surgeon, this is a question that I am asked every day.  There are two basic problems that can cause the appearance of a droopy eyelid.  These problems are called Ptosis (true drooping of the eyelid due to the action of eyelid muscles) and Dermatochalasis which is excess eyelid skin and/or fat.Ptosis is present when the edge of your eyelid (where the lashes are) hangs to low on your eye.  This are should be about half way between the top of your pupil and the white of your eye starts above the pupil.  If the lid edge is low you have ptosis and ptosis surgery (on the muscle that lifts the lid) may be needed.Dermatochalasis is when there is extra eyelid skin or excess eyelid fat hanging over the front of the eyelid.  This problem is generally treated with removal of the excess skin and/or fat and this procedure is called a blepharoplasty.At times, both problems are present and both ptosis surgery and blepharoplasty are needed.  Hope this is helpful.