The presence of a medial epicanthal fold, also known as Mongoloid fold or Mongolian wrinkles, is attributed to the overdevelopment of the orbicularis oculi and related structures (1), predominantly observed in Asians. Recent shifts in aesthetic preferences have led to concerns that a medial epicanthal fold might give the eyes a smaller or less refined appearance. Consequently, many individuals choose epicanthoplasty to correct this feature. Several studies on epicanthoplasty have been conducted, indicating successful outcomes (2–10). However, practical experience has shown complications such as excessive exposure of the lacrimal caruncle, conjunctival ectropion, and scar contracture due to overcorrection, increasing the demand for medial epicanthal fold reconstruction. To date, prior techniques for medial epicanthal fold restoration, specifically the reverse skin redraping method and the V-Y method/modified V-Y method, have been inadequately documented (11–17). While these studies detailed the skin flap design, they often overlooked the significance of deep skin orbicularis oculi reconstruction. This oversight could lead to complications, such as incision dehiscence, under-correction, and scar formation. In this retrospective study, a comparison was made between the myocutaneous flap V-Y procedure and the skin flap-only V-Y procedure.

A total of 104 patients (2 males and 102 females, male/female ratio 1/51) underwent medial epicanthal restoration surgery utilizing the V-Y advancement method. In group A, the preoperative intercanthal distance ranged from 28.7 mm to 38.2 mm (mean 33.5 ± 3.4 mm), and postoperatively, it ranged from 30.2 mm to 40.6 mm (mean 36.6 ± 3.2 mm), indicating a mean increase of 3.0 mm (P < 0.05). In group B, preoperative intercanthal distance ranged from 28.8 mm to 38.0 mm (mean 33.6 ± 3.3 mm), while postoperative values ranged from 32.2 mm to 41.5 mm (mean 37.5 ± 2.9 mm), reflecting a mean postoperative increase of 3.9 mm compared to the preoperative values (P < 0.05). The postoperative intercanthal distance significantly exceeded the preoperative intercanthal distance in both groups, with the increase being greater in group B than that in group A (P < 0.05) (Table 2). Moreover, the ratio of the intercanthal distance to the palpebral width was calculated and presented in Table 2. In group A, 14.29% of patients (3/21) reported being very satisfied, 42.86% of patients (9/21) were somewhat satisfied, 19.05% of patients (4/21) expressed somewhat dissatisfaction, and 23.81% of patients (5/21) reported being very dissatisfied. In group B, 34.94% of patients (29/83) were very satisfied, 54.22% of patients (45/83) reported somewhat satisfaction, 6.02% of patients (5/83) expressed somewhat dissatisfaction, and 4.82% of patients (4/83) were very dissatisfied (Table 3). Representative cases are illustrated in Figures 7–9.

During the follow-up evaluation, none of the patients experienced poor incision healing or a hypertrophic scar. There were 8 patients with inadequate correction in group A vs. only 2 patients in group B. In group B, one patient complained of a small intercanthal distance due to overcorrection, whereas no such a complication was found in group A. Besides, 6 patients experienced asymmetry in group A, compared to 3 in group B (Table 4).

In China, epicanthoplasty, frequently performed alongside blepharoplasty, is a popular cosmetic procedure aimed at correcting the medial epicanthal fold. This surgery widens the palpebral fissure, giving the eyes a more elongated appearance and enhancing the smoothness and aesthetics of the eyelid curve. However, the rising prevalence of this surgery has led to an increase in unsatisfactory outcomes. Issues such as excessive exposure of the lacrimal caruncle, conjunctival ectropion, and scar contracture due to overcorrection have caused varying levels of physical and psychological distress to patients, presenting significant challenges to cosmetic surgeons. Regrettably, unlike many epicanthoplasty techniques, restoration surgery for the medial epicanthal fold has been scarcely documented. The V-Y advancement method was first reported by Shin, Y. H. et al. (11), followed by Chung, Y. J. et al., who introduced the reverse skin redraping method and later made improvements to the technique (12, 14).

Our surgical technique is based on the V-Y advancement method. We defined the length of AB as the amount of restoration, used the ECD flap from the lid margin as the new flap, and determined the amount of new flap to be reconstructed by adjusting the distance between these two vertical lines.

The proposed technique simplified the procedure by eliminating the need for a new incision for flap transfer, thereby avoiding additional incisions and tissue dissection. Consequently, it is surgically simpler and potentially reversible. One patient expressed regret after the restoration surgery and opted for reversal the day after the procedure, involving the removal of all sutures and resuturing according to the original incision.

The medial epicanthal fold formation is intricately linked to the preseptal part of the orbicularis oculi muscle that encircles the orbital region and is responsible for eyelid closure (18, 19). Certain epicanthoplasty methods entail dissection or resection of the orbicularis oculi muscle to achieve stable postoperative outcomes. Liu H.P. et al. pointed out that the epicanthal fold results from a mispositioned orbicularis oculi muscle and emphasized the crucial step of releasing skin tension by resecting the orbicularis oculi muscle in correcting the epicanthal fold in Chinese patients. Additionally, Sun W. et al. reported an epicanthoplasty technique based on orbicularis oculi muscle resection. They separated the orbicularis oculi in the medial canthus and excised a triangular flap of muscle tissue to fully alleviate tension (20, 21). Our previous observations revealed that many epicanthoplasty patients exhibit a thin, disrupted, or partially absent medial epicanthal fold, necessitating careful attention during restoration surgery.

In the initial approach, restoration surgery relied solely on a skin flap, neglecting the essential reconstruction of the orbicularis oculi ring. Postoperatively, a tendency toward incision dehiscence was observed, leading to recurrence and resulting in a notably low postoperative satisfaction rate. Between April 2017 and September 2019, 21 procedures were conducted in group A, employing skin flap reconstruction (without a myocutaneous flap) to establish a new medial epicanthal fold. However, the follow-up revealed a satisfaction rate of only 57.15% (comprising very satisfied or somewhat satisfied patients), primarily due to insufficient correction.

This complication was attributed to excessive local tension caused by the absence of a complete orbicularis oculi ring. Consequently, the procedure was modified to incorporate orbicularis oculi ring reconstruction.

In this modified approach, deep plane dissection beneath the orbicularis oculi muscle was crucial, occasionally extending to the orbital region of the orbicularis oculi muscle to enhance local soft tissue mobility. Vertical tissue displacement, specifically, ensured more effective reconstruction of the orbicularis oculi ring. Between October 2019 and June 2022, 83 procedures were performed in group B, utilizing myocutaneous flap reconstruction (not a skin flap) to create a new medial epicanthal fold. Subsequent follow-ups revealed a significantly improved satisfaction rate of 89.16% (consisting of very satisfied or somewhat satisfied patients).

It is important to highlight that most literature reports describe the upper lid incision line as continuous with the double eyelid line. However, based on our clinical observations, we have determined that the line should be positioned approximately 1 mm above the level of the eyelid line. This design aims to create an infold type double eyelid without altering the curvature of the double eyelid line, a feature perceived as a natural double eyelid by the majority of Asians.

Park J.W. et al., in their cadaveric anatomical studies, discovered that individuals with a medial epicanthal fold exhibit a connection between the orbicularis orbitalis septum of the upper and lower eyelids at the medial canthus, a feature absent in individuals without a fold. They proposed that during embryonic development, the eyes move closer, leading to the narrowing and densification of connected orbicularis fibers at the medial canthus, forming the core structure of the medial epicanthal fold19. im, J., et al. emphasized that during V-Y advancement, relying solely on a skin flap may create a cavity (dead space) in the medial canthus. This situation can result in postoperative complications, including poor wound healing, infection, scar contracture, local stiffness, and pain. To address this issue, they utilized an orbicularis muscle strip obtained from the blepharoplasty incision and filled it with an autologous fat tissue graft. Postoperative follow-up results indicated that this method effectively reduced complications and enhanced the restorative outcome (15).

Integrating the findings from the aforementioned studies and our own clinical expertise underscores the critical importance of reconstructing the orbicularis oculi ring in medial epicanthal fold restoration. However, our study has several limitations. Firstly, there is a possibility of recurrence in patients with thin skin and orbicularis muscle if the suture is not adequately tightened. Secondly, individuals with extremely thick skin and orbicularis oculi may experience a newly formed fold that appears thick and differs from the congenital fold, leading to dissatisfaction among some patients. Moreover, due to the varying strength of the orbicularis oculi muscle ring, the new epicanthal fold may exhibit a round shape. Addressing these issues necessitates further exploration and improvement in subsequent studies.

In conclusion, the V-Y myocutaneous flap advancement method, grounded in the principle of orbicularis oculi ring reconstruction, proves to be significantly more effective than using the skin flap alone for restoring the medial epicanthal fold. Its straightforward design and execution lead to high patient satisfaction rates. This procedure effectively addresses postoperative issues like excessive exposure of the lacrimal caruncle or an overly wide intercanthal distance resulting from overcorrection. Moreover, the incidence of complications such as incisional dehiscence and recurrence is markedly reduced compared to the V-Y advancement method using the skin flap alone. Consequently, this technique stands out as the preferred surgical approach in such cases.