Initially titled in 1818 by Graefe, blepharoplasty is currently one of the most commonly performed aesthetic procedures but is still regarded as a technically challenging operation that requires thorough understanding of anatomy and function of the eyelids. 
As the lower eyelid ages, excess skin, muscle, and fat cause an unattractive bulge to develop below the eye. The orbital septum becomes lax with aging, and this can lead to bulging of the orbital fat through the weak septum. Traditionally, these problems have been addressed by a transcutaneous blepharoplasty, where an incision is made through the skin to resect excessive orbital fat, redundant muscle, and skin if needed. The transconjunctival blepharoplasty is receiving increasing attention as an alternate technique to traditional transcutaneous blepharoplasty. With the transconjunctival technique, an incision is made through the lower lid conjunctiva, thereby avoiding an external incision through the skin and leaving no obvious scar. Many of the lower lid malpositions appear to be obviated by the use of this technique. [2, 3]
Potential complications that may occur after a classic transcutaneous blepharoplasty have been well described, including a postoperative change in the shape of the aperture, inferior scleral show, and malposition of the lower eyelid. Transconjunctival blepharoplasty has been advocated to limit the incidence of these complications, particularly in patients with minimal skin and muscle laxity or predominant fat herniation who otherwise would not require skin excision. 
As the transconjunctival technique of lower lid blepharoplasty is more widely used and reported, experience suggests that the transconjunctival approach is a safe and effective procedure with minimal complications. Specifically, this approach avoids violation of the orbital septum, which may lead to less eyelid malposition postoperatively. This technique is useful in the younger patient with isolated fat excess who does not need skin excision, as well as in the older patient with manifestations of mild-to-moderate skin redundancy. This approach can be used for lower lid fat removal, fat redraping and redistribution, and as an access point to the midface. 
History of the Procedure
This technique has been practiced in Europe for nearly 80 years. The first description by Bourget in 1928  was followed by the account of Tessier in 1973  of this approach for blepharoplasty, trauma, and congenital deformities. Isolated reports of this technique for blepharoplasty began appearing in the North American literature during the 1970s  and 1980s  , but the landmark contribution by Zarem and Resnick in 1991  propelled this procedure into more widespread acceptance.
Although earlier studies focused on the young patient with isolated fat excess, indications for the procedure may be expanded to include older patients with some degree of cutaneous redundancy. Many studies now report excellent results and a reduced incidence of postoperative lower lid complications. As more experience with this technique is shared and results reviewed, reports have shown fewer complications and less apparent morbidity than with the transcutaneous approach.
Preoperative evaluation includes a thorough history and physical examination. Careful attention to medical history regarding presence of hypertension, current medications, history of bleeding diathesis, and history of dry eyes or eye surgeries. The physical examination must be performed in a complete and sequential manner to assess periorbital anatomy. Eyelids are evaluated for shape and function. In addition, the eyebrows should be evaluated for ptosis and symmetry.  Visual acuity as well as field of vision should be evaluated in all patients. Any evidence of herniated fat pads as well as the degree of skin laxity of the lower lid should be noted. As several authors have observed, fat pad herniation is best tested with the patient's eyes in an upward gaze. 
The finding of scleral show on preoperative evaluation can be caused by a prominent eye, excess lower lid laxity, and poor infraorbital support. Lower lid tone should be assessed via the lower lid "snap back" test in all patients. In this test, the central lower lid is pulled gently away from the eye and is then observed as it returns to its normal resting position. These findings often require lateral canthopexy, wedge excision of redundant tissue, possible midface lift, or orbital rim augmentation. 
Patients should also be evaluated for the presence of Bell phenomenon, as patients with poor response may have increased postoperative corneal dryness. These patients and any patient with a history of dry eyes require preoperative tear film evaluation, including a Schirmer test. The Schirmer test uses paper strips inserted into the eye for several minutes to measure the production of tears. 
Transconjunctival blepharoplasty has been recognized as useful in patients with fat excess and fine skin wrinkling and in those with apparent skin and fat excess in whom fat excision alone allows for redraping of the lower lid skin into an acceptable contour with elimination of the skin laxity. Although initial reports focused on the young patient with isolated fat herniation, the indications have been broadened somewhat to include patients with modest skin laxity.  Furthermore, the transconjunctival lower blepharoplasty has been shown to be safe and effective along with resecting a pinch of excessive skin to address skin laxity. 
In the aging face the nasojugal groove, or tear trough, can become a significant cosmetic issue resulting from changes in the infraorbital region causing the tear trough deformity. This deformity can occur along with excessive lower eyelid fat herniation or alone.  Multiple options for correction of the tear trough deformity have become available and are often considered a part of the blepharoplasty procedure.
Lower lid blepharoplasty (transcutaneous or transconjunctival) is not meant to address fine skin wrinkling. This issue may be better addressed with either chemical peels or laser/mechanical resurfacing.
Inferior periorbital fat is contained posteriorly by the capsulopalpebral fascia and overlying conjunctiva of the posterior fornix.
The capsulopalpebral fascia fuses superiorly with the inferior tarsal muscle, which inserts into the lower border of the tarsal plate. Anteriorly, the fat is bounded by the orbital septum, which separates it from the overlying orbicularis oculi muscle and lower lid skin (see the images below). With age, these tissues may relax, and the orbital fat may herniate forward, which presents as unnatural fullness of the lower lid. This bulging of the lower lid can also cause a hollowed look of the upper lid, as the entire orbital contents drop.
Transconjunctival blepharoplasty permits access to the orbital fat by an incision through the inferior conjunctiva and capsulopalpebral fascia without any disruption of the skin and orbicularis muscle of the lower lid. This approach avoids violating the inferior orbital septum, which may result in less postoperative eyelid retraction, scleral show, and changes in the shape of the aperture, which may complicate the transcutaneous approach.
The inferior oblique muscle is an important anatomic landmark. It arises from the anteromedial portion of the orbital floor and passes posterolaterally, separating the medial and central fat compartments during its course. The lateral and central fat compartments are separated by the arcuate expansion of the inferior oblique muscle. This diaphanous structure inserts into the orbital rim anterolaterally.
The upper lid classically is divided into an anterior (skin and orbicularis) and a posterior (tarsus and conjunctiva) lamella. The supratarsal fold results from a fusion of levator aponeurosis, orbital septum, and fascia on the deep surface of the orbicularis muscle. The fused layer acts as a sling for the periorbital fat and is higher medially than laterally. In an attempt to divide the orbital septum medially in a conventional blepharoplasty, this fused layer may be damaged inadvertently.
Generally, the presence of either 2 or 3 upper lid fat pads is accepted.  The medial fat pad is typically pale yellow or white and lies medial to the levator aponeurosis at the root of the nose. It has a greater connective tissue component and is innervated by the supratrochlear nerve. The middle and lateral fat pads lie on the levator and are a rich butter yellow color. They are innervated by the supraorbital nerve.
Dry eye exposure is a risk of any surgical manipulation of the upper or lower lids. Patients who have undergone corrective vision procedures such as laser in situ keratomileusis (LASIK) or keratotomy have an increased risk of dry eye problems and should be cleared for further surgery by their refractive eye surgeon.
Patients wearing contact lenses pose a particular risk when blepharoplasty is considered. Eyes may dry out as a patient ages, and this process is often hastened by chronic contact lens use. Additionally, eyelid surgery such as blepharoplasty, canthopexy, or other lid altering procedures may subtly affect the curvature of the cornea, making use of contact lenses uncomfortable or even dangerous. Patients should discontinue the use of contact lenses weeks before surgery and not restart use for several weeks postoperatively to allow healing without any eyelid manipulation.