INTRODUCTION
In 1912, the first known fat grafts were performed in two facial lipoatrophy patients by Eugene Hollander [
1]. Liposuction had become quite popular after the introduction of the Illouz method, and fat grafting developed along with it [
2,
3]. However, fat grafting showed unpredictable results before Coleman developed the structural fat graft in 2001 [
4,
5], which strongly influenced the development of modern fat graft surgery by improving fat harvesting methods, fat refinement, and fat placement for better long-term survival and volume replacement.
Fat may be the ideal filler material in reconstructive or cosmetic surgery. Harvesting the patient’s own fat can provide sufficient quantities, and the fat is biocompatible, with no immune reaction after transplantation. For that reason, fat grafting, as a primary or adjuvant procedure, has become one of most common plastic surgeries. The best results are obtained by fat harvesting using small cannulas, by preinjection-fat preparation by centrifugation, and by the latest developments for fat placement into the tissue and postoperative care [
6-
8].
As fat grafting has become more commonplace, so have complications such as infections, surface irregularities, palpable masses, and unfavorable results due to poor planning. However, eye-related complications are not common. Blindness due to ophthalmic artery occlusion after fat grafting is usually reported, because it is a serious condition; however, few reports regarding other eye-related complications have been published.
The author has successfully treated several patients with acute or chronic ocular swelling after forehead fat grafting and suggests treatment modalities for similar cases.
DISCUSSION
These days, most doctors can achieve optimal results with fat graft surgery, which has over 90% survival rate [
9,
10].
As fat grafting has become more popular, complications have also become more common. In 2009, a task force formed by the American Society of Plastic Surgeons assessed autologous fat grafting techniques to determine their safety and efficacy [
11]. The task force made specific recommendations regarding harvest techniques, graft preparation, injection techniques, injection sites, graft storage, and use of epinephrine and lidocaine at the donor site to optimize fat graft viability. They reported that fat grafting is safe for a variety of medical conditions, with a lower risk of complications than other types of surgery. Potential risks associated with fat grafting are anesthesia-related complications, infection, bleeding, poor outcome, interference with breast cancer detection, and unexpected, life-threatening complications such as fat embolism, stroke, lipoid meningitis, and septic shock. However, eye-related complications were not mentioned. Complications involving the eye are not common after fat grafting. Although blindness caused by ophthalmic artery occlusion after cosmetic filler injection or other eye surgery has been reported [
12-
15], few reports have described eyelid-associated complications [
16].
Despite the development of blunt-tipped cannulae some doctors still use sharp cannulae, which are more likely to pierce vessels, resulting in a fat embolism. Fat grafts accidentally injected into the facial artery or its branches, supraorbital artery, or supratrochlear artery may cause serious problems such as partial or total blindness, or tissue necrosis around the eyes or nose [
13,
14] Even with a blunt-tipped cannula, these complications could occur causing vascular damage during pre-tunneling procedures or high-volume or high-pressure injections into a small area. The cannula should be gently inserted, and the fat slowly injected while withdrawing the needle to prevent blindness after facial fat grafting.
Periorbital swelling after facial fat grafting is underestimated because of failure to adequately examine patients. Although physiological swelling is a typical finding after fat grafting and gradually subsides, pathological periorbital swelling occurred in the five cases presented here. The patients experienced marked orbital swelling, beginning 5 to 7 days after the operation. The swelling was intermittent, with heat and dull pain that did not decrease with positional changes or time. The symptoms worsened at times, making it difficult to open the eyes. Ptosis often occurred on one or both sides.
Mechanisms underlying ocular swelling after forehead fat grafting include oil leaking from the forehead into the periocular area through the supraorbital or supratrochlear foramen. The method of fat placement is an important consideration. For successful fat grafting, Coleman suggested diffuse infiltration with multiple passes, placing extremely small amounts of fat with each pass, and separating the newly grafted fat parcels from each other. This technique ensures a large area of contact between capillaries and the grafted fat, promoting nutrition and respiration [
4,
5] However, many rapid strokes of the cannula can produce bleeding and edema, with increased pressure in the grafted area and decreased circulation. As a result, more fat cells rupture, and the free oil that leaks into the forehead can move to the ocular area through the supraorbital or supratrochlear foramen, especially if the foramen is wide or not closed (i.e., notch), free oil is more likely to leak into the periocular area.
Another possible explanation for orbital swelling after forehead fat grafting is weakening of the orbicularis retaining ligament, which is attached to the periosteum approximately 2–3 mm above the superior orbital rim. Normally, this acts as a barrier between the forehead and orbital area to prevent the spread of infection to the orbital area. Injecting material below or crossing this ligament can result in intraocular placement [
13]. Infiltration during surgery or swelling afterward can weaken this structure, allowing free oil to leak into the orbit.
Finally, orbital swelling can occur through excessive retro-orbicularis oculi fat pads, which may extend over the orbital septum, allowing free oil to leak through the spaces between them and spread into the orbit.
Free oil can spread to the lower half of the orbital fat over the levator sheath due to gravity. Surgical findings of cases 3, 4, and 5 showed that the lesions were vacuoles containing free oil or hard masses in the orbital fat. Histologic findings for all cases revealed the accumulation of inflammatory cells around numerous lipid-filled vacuoles of various sizes, with some fibrosis (
Fig. 9). In a case of chronic swelling, the histology results revealed a foreign body reaction to the free oil. Cryopreserved fat was used in cases 3 and 4, which may have been the cause of ocular swelling. Cryopreserved fat is fragile, with a higher percentage of free oil compared with freshly harvested fat; therefore, the fat cells are more likely to rupture and leak free oil. For that reason, cryopreserved fat must be centrifuged again (>3,000 rpm for 5 min). In addition, cryopreserved fat are more likely to become contaminated with bacteria or fungi. Contamination can occur during processing (e.g., harvesting, centrifugation) and microorganisms can grow at low storage temperatures and anaerobic conditions. Even low-virulence microorganisms can cause chronic infections after fat grafting in this ideal growth environment; therefore, persistent ocular swelling can indicate a weak immune system. There was some response to antibiotic and steroid therapy, indicating the possibility of infection with low-virulence microorganisms.
All patients reported ptosis on one or both sides. Ptosis after fat grafting is related to free oil-containing vacuoles located just above the levator sheath. In case 5, a hard lump (1×1×0.5 cm) was located in the lower half of the intra-orbital fat lobules on the lateral side, just above the levator. It was separated from the levator tendon by the levator sheath and fat lobule sheath, and attached to these sheaths by an inflammatory adhesion, preventing the eye from opening completely and causing ptosis. A mass adhering to the levator tendon moves along with the levator oculi but is checked by the transverse ligament or other intraocular structures. If ptosis was present before surgery, it may worsen with ocular swelling after fat grafting. This type of ptosis may become more severe with successive forehead fat grafting.
Conservative treatment may be helpful for acute ocular swelling after forehead fat grafting. This includes watchful waiting, cooling the eyes with ice, anti-inflammatory drugs, steroids, diuretics, and sometimes antibiotics. Minimal swelling typically subsides with ice and positional treatment; lying in a supine position allows the free oil to drain into the scalp area or other facial areas. Weakened orbicularis oculi ligaments may resume the normal barrier function with anti-inflammatory drugs, steroids, and diuretics, which reduce the inflammatory swelling around this ligament. Antibiotics are helpful if a subclinical infection contributes to the swelling. If symptoms do not respond or worsen with conservative treatment, surgical treatment may be considered. Lesions were treated by direct removal of the encapsulated emulsified or free oil in cases 3 and 4, and by direct excision of the mass adherent to the surrounding tissues without encapsulation.
Paik et al. [
16] reported two cases of unusual unilateral eyelid swelling with multiple small lumps. The patients had undergone autogenous fat injection for cosmetic forehead augmentation approximately 6 months and 9 months previously. The small (diameter, 5–10 mm), palpable, hard, nonmobile lumps were evaluated by magnetic resonance imaging (MRI). All masses were situated deep in the tissue, near the superior or lateral orbital rim, which were deeper than the cases presented in the present study. Histological findings revealed foreign body lipogranuloma, chronic inflammation, and fibrosis, similar to the cases in the present study. Treatment consisted of excision of all masses to relieve symptoms (e.g., swelling, moderate ptosis, lagophthalmos) [
16]. The authors did not use conservative treatment in these chronic cases but suggested that conservative treatment may be effective in the acute stage (<1 month). Although, Paik et al. described lesions near the superior or lateral orbital rim, they would appear the same on MRI as the lesions described in the present case series. Making the incision on the lateral one-third of the natural double eyelid crease allows easy access to the lateral portion of the orbital fat. In the present case series, the lesions appeared to involve the skin or muscle over the orbital septum; however, surgery revealed that the main lesion involved intraocular fat, primarily in the lower portion parallel to the levator.
In summary, the author describes the successful treatment of five patients who experienced ocular swelling of varying duration after forehead fat grafting. Cases involving previous ptosis require ruling out diseases or drugs as the cause of ptosis before surgery. Some cases of ocular swelling may be related to the use of cryopreserved fat; therefore, fresh fat should be used if possible. Injecting excessive amounts of fat into the forehead at one time is not recommended. In acute cases of ocular swelling after fat grafting, conservative treatment is recommended, followed by surgical treatment, if necessary.