Epicanthoplasty is performed to widen the medial canthus both horizontally and vertically to enhance the eye appearance. It is typically performed in conjunction with blepharoplasty and ptosis correction surgery, rather than as a standalone procedure [1]. After ptosis correction surgery [2], functional improvements, such as easier eye opening, reduction of heaviness, and specific morphological changes characterized by an increased palpebral fissure and eyebrow descent, are observed. However, the authors have noted that some patients still report a heavy feeling when opening their eyes, despite improved functional and aesthetic satisfaction after the surgery. In these cases, the authors noted that lifting the midface toward the lower eyelids resulted in decreased skin tension in the epicanthic fold, leading to a reduction in the sensation of heaviness. To investigate the extent to which epicanthoplasty contributes to the improvement of uncomfortable symptoms and its effect on eyebrow descent, we measured changes in the eyebrows and eyelids by taking photos and patients’ satisfaction regarding comfort in opening the eyes in both lying and sitting positions immediately after performing epicanthoplasty in patients undergoing ptosis correction surgery.

The study was approved by the Institutional Review Board of the Pusan National University Yangsan Hospital (IRB no. 55-2024-153). Written informed consent was obtained from all participants.

Patient selection

Among the 15 patients who underwent epicanthoplasty with ptosis correction surgery at a Seoul cosmetic surgery clinic between October 2018 and March 2019, nine patients (eight females and one male) were included. Six patients were excluded due to photographic errors.

Changes in eyebrow descent, palpebral fissure morphology based on preoperative and postoperative photographs, and patient satisfaction with changes in posture were assessed.

Preoperative markings and T-epicanthoplasty

Preoperative marking was performed with the patient in a standing position, as shown in Fig. 1A. T-epicanthoplasty [3] was conducted under infiltrative anesthesia with 1% lidocaine by incising the skin and muscle with a No. 15 blade in the order of bc, cd, and da (Fig. 1B).

Figure 1. Preoperative markings and T-epicanthoplasty. (A) Boundaries of the Mongolian fold (MF); a: caudal boundary of the MF, b: mucocutaneous boundaryof the MF, c: nasal boundary of the MF, d: cranial blundary of MF at supine position, d’: cranial boundary of the MF at sitting position. I: Upper portion of the MF, and II: Lower part of the MF, (B) A skin incision starts from b to the midportion of d and a (a white dotted line) by No. 15 surgical blade, (C) Excision of the Orbiculi Oris muscle and fibrotic bands originated from the medial canthal tendon, (D) The flap should be completely released from the medial canthal tendon. A 6-0 blue nylon suture is performed on the incisional margins of the middle portion of the fold (a and c) and the medial part of the canthal tendon simultaneously, and (E) The skin closure of the lower portion of the flap is performed with a 6-0 Nylon. (F) Trimming of the lower flap is done performed at the upper portion of the fold without any tensions. Finally, closes the upper flap incision line (ad) with 6-0 nylon.

Electrical cautery was used for subcutaneous dissection while simultaneously releasing the fibrotic band originating from the medial canthal tendon (Fig. 1C). The lower part of the fold (Fig. 1A - “I”) was completely mobilized towards the upper eyelid, requiring complete dissection from the medical canthal tendon, leaving only the skin. Using No. 6 nylon, points a, c, and the medial part of the medial canthal tendon were sutured together (Fig. 1D). After suturing between b and a-c, excess skin, muscle, and fibrotic bands were excised, and the cd incision line was closed without tension.

Measurement of shape changes and satisfaction

The levels of the eyebrows, intercanthal width, and nasion height were measured using a ruler from preoperative and postoperative photographs of the patient, as shown in Fig. 2.

Figure 2. Measurement of the heights of the eyebrow and intercanthal width in sitting position immediately after the epicanthoplasty. a (a’): a vertical alar line, b (b’): a vertical mid-pupillary line, c (c’): a lateral canthal line, A (A’): a heigh of the medial brow on the line a, B (B’): a heigh of the middle brow on the line b, C (C’): a height of the lateral brow on the line c, D: Intercanthal width.

Patient satisfaction regarding the improvement of the heavy sensation when opening the eyes after surgery in both lying and sitting positions was assessed using a 5-point Likert scale (Table 1) [4].

Table 1 . Likert scale of subjective satisfaction (5 levels) about the comfortable feeling of heaviness while opening the eye.

Very unsatisfied	0	Much heavier
Unsatisfied	1	Heavier than before
Neutral	2	No change
Satisfied	3	Lighter than before
Very satisfied	4	Much lighter than before

Statistics processing method

The mean and standard deviation of each group were calculated within a 95% confidence interval. Chi-square test (χ²) was used to evaluate the independency between subgroups.

This study was conducted to observe the effects of epicanthoplasty on eyebrow descent and midfacial morphology, yielding the following results: Among the nine participants, there were eight females and one male, with an average age of 19.0±4.1 years. The height of the lateral nose, measured from the cornea at the nasion level, was 5.5±3.1 mm. The intercanthal width decreased from 3.92±0.27 mm to 3.59±0.20 mm after epicanthoplasty. The overall shape of the eyebrows changed to a flatter configuration, with a descent in the medial region.

The descent of the right eyebrow at the lateral (A), central (B), and medial (C) positions was measured as 0.97±1.44, 1.44±1.04, and 1.69±1.33 mm, respectively. For the left eyebrow (A', B', C'), the descent was 0.72±0.97, 1.56±1.01, and 1.86±1.13 mm, respectively.

No significant difference was noted in the eyebrow descent between the medial, central, and lateral positions (right eyebrow: χ²=1.150, p=0.563; left eyebrow: χ²=4.964, p=0.084) (Table 2). Post-surgery patient satisfaction regarding reduced discomfort when opening the eyes averaged 3.78±0.67 in the lying position but decreased to 2.33±0.87 in the sitting position.

Table 2 . Statistical analysis for changing of the eyebrow after epicanthoplasty.

No. of case	Sex	Age	CS	Change of IW (mm)			Descent of eyebrow height (mm)								Vertical length of palpebral fissure (mm)						Change of LSSSc)
				Before	After		Righta)				Leftb)				Right			Left			Ld)	Se)
							(A)	(B)	(C)		(C’)	(B’)	(A’)		Before	After		Before	After
1	F	24	Ptosis correction surgery	3.9	3.5		2.0	1.75	1.0		2.25	2.0	0		11	11		11.5	12		4	2
2	F	19	Ptosis correction surgery	3.9	3.5		-0.25	0	0		0	0	0		8.5	8.0		8.5	8.0		3	1
3	F	17	Ptosis correction surgery	3.6	3.4		0	1.25	2.5		2.0	1.5	0		13	14		13	14.5		4	2
4	F	26	Ptosis correction surgery	4.1	3.7		0	0.5	0.5		0.5	0.5	0		11.5	11.5		12.25	12.25		3	2
5	F	16	Ptosis correction surgery	3.9	3.6		-0.5	0.25	1.25		1.75	1.5	1.0		10	10.75		10.25	10.5		5	4
6	F	15	Ptosis correction surgery	4.2	3.7		0	1.5	0.75		2.0	1.0	0		11	11		12	12		3	2
7	F	23	Ptosis correction surgery	4.4	4.0		2.5	3.0	3.75		2.0	2.0	1.0		8.5	8		8.5	9		4	3
8	M	16	Ptosis correction surgery	3.65	3.4		1.5	2.25	2.0		2.25	2.0	2.0		12	12		11.5	11.5		4	3
9	F	17	Ptosis correction surgery	3.7	3.59		3.5	2.5	3.5		4.0	3.5	2.5		11.5	11.5		11.25	11.75		4	2
Average		19		3.92	3.59		0.97	1.44	1.69		1.86	1.56	0.72		10.8	10.9		11.1	11.3		3.78	2.33
Standard deviation		4.1		0.27	0.20		1.44	1.04	1.33		1.13	1.01	0.97		1.5	2.0		1.7	1.9		0.67	20.87

CS, combined surgery; IW, intercanthal width; LSSS, Likert scale of subjective satisfaction..

^a)A: lateral brow, B: central brow, C: medial brow..

^b)A’: lateral brow, B’: central brow, C’: medial brow..

^c)5 levels..

^d)Lying position after medical epicanthoplasty..

^e)Sitting position after medial epicanthoplasty..

The vertical length of the palpebral fissure changed from 10.88±1.52 mm preoperatively to 11.07±1.85 mm postoperatively, but this change was not statistically significant (Z=–1.461, p=0.144) (Table 2).

The Mongolian folds are structures located on the inner eyelids that are characteristic features in individuals of Asian descent, making the eyes appear increasingly smaller and closer. These folds are often removed for aesthetic improvement [1]. Various epicanthoplasty techniques have been developed and utilized [5], including T-epicanthoplasty as described by Kim and Kang [3], which aimed to reduce the vertical tension in the folds by removing the soft tissue tension factors and moving the lower part of the fold towards the upper eyelid. One of the primary goals of epicanthoplasty is to address aesthetic concerns regarding the perceived intercanthal distance. As shown in Fig. 3–5, there was a notable reduction in the space between the eyes after removal of the Mongolian folds. The average intercanthal width for Koreans is reported to be 37.5±2.9 mm for males and 36.2±2.7 mm for females [6], with an ideal value approximating 3.5 mm [7]. In this study, the intercanthal width decreased from 3.92±0.27 mm to 3.59±0.20 mm, indicating that T-epicanthoplasty has sufficiently achieved its intended purpose (Table 2). Epicanthoplasty is primarily performed for cosmetic reasons in conjunction with upper eyelid surgery, leading to a lack of studies on its specific additional effects. Interestingly, this study observed changes in eyebrow shape and descent after surgery, as shown in Fig. 3–5, and Table 2. When examining changes in the eyebrows while sitting, a more pronounced descent was noted in the medial region, resulting in an overall flatter eyebrow appearance. Although a significant decrease was observed in the medial (alar line), central (midpupil line), and lateral (lateral canthal line) regions, statistical comparisons of the descent amount across these areas did not show significant differences. This suggests that the overall morphological changes were subjectively assessed based on the appearance of the medial ends, outer two-thirds, and lateral ends of the eyebrows, whereas the statistical measurements focused on specific points on the eyebrow, potentially explaining the discrepancies between these observations. Meanwhile, Liu et al. [7] reported that after blepharoplasty and ptosis correction surgery, eyebrow descent of 2.52 mm and 2.10 mm was observed, respectively, but no significant changes were observed in the shape of the eyebrows. The authors also noted that variations in eyebrow descent measurements could result from differences in surgical techniques and measurement locations. In this study, as the procedure involved removing the Mongolian folds, we chose the alar line as a reference point that remained unchanged before and after surgery, differing from the measurement location of the medial palpebral fissure to the brow used by Liu et al [7]. This study showed a significant average eyebrow descent of 1.38 mm after performing epicanthoplasty alone. While blepharoplasty and ptosis correction surgery typically affect the entire length of the eyebrows, the removal of Mongolian fold appears to primarily affect the medial region. This may explain the greater descent rates observed in the medial and central areas in this study. However, no statistically significant differences were observed, indicating that further research with a larger population is required to obtain more meaningful results.

Figure 3. Photos of case 1. (A) Before, and (B) immediately after the medial epicanthoplasty. A 24-year-old female patient had performed medial epicanthoplasty before upper blepharoplasty with ptosis correction. The left epicanthal fold is longer than that of the right eyelid (A). The eyebrow descents mainly occurred at the medial and central positions after the epicanthoplasty. The eyes look closer, the interpalpebral fissure seems increased and the contour of the lower lid looks tightened (B).

Following ptosis correction surgery, an increase in palpebral fissure and brow descent was observed due to improved eye-opening function. However, this study, which focused solely on the results of epicanthoplasty, did not observe a statistically significant increase in palpebral fissures. Morphological observations revealed inconsistent results, with increases in Fig. 3, decreases in Fig. 4, and ambiguous differences in Fig. 5. These discrepancies may stem from various reasons, such as the limited impact of epicanthoplasty, effects of local anesthesia, persistence of preoperative eye-opening habits, emotional tension due to position changes during surgery, or variations in photographic conditions. Further research involving patient selection, standardized photographic conditions in a larger population, and analyses using artificial intelligence are warranted. The degree of comfort felt by the patients when opening their eyes while lying down compared to sitting was measured using a 5-point Likert scale [4]. The notable decrease in satisfaction when transitioning from a lying to sitting position suggests that changes in posture influence the descent of the midfacial soft tissues, affecting the vertical vector of the Mongolian folds.

Figure 4. Photos of case 2. (A) Before, and (B) immediately after the medial epicanthoplasty. A 19-year-old female patient had performed medial epicanthoplasty before upper blepharoplasty with ptosis correction. The nasal dorsum and intercanthal width look flat and widen separately. The total contour of the eyebrows was not significantly changed. The eyebrow descent is also not obvious. However, the transverse forehead wrinkles were developed in the center of the forehead. The palpebral fissure also seems the same as before.

Figure 5. Photos of case 5. (A) Before, and (B) immediately after the medial epicanthoplasty. A 16-year-old female patient had performed epicanthoplasty before upper blepharoplasty. The eyebrow contours were dominantly changed in the medial and central parts of the eyebrows (B). The interpalpebral fissures were not obscure because of eyelid swelling. However, they were not looked to decrease (B).

From this perspective, additional research is needed to understand how the degree of midfacial development affects epicanthoplasty outcomes. This study is significant because it is the first attempt to analyze the changes in patient satisfaction related to eye-opening comfort and its effects on eyebrow descent after epicanthoplasty. However, discrepancies between the statistical and morphological results indicate that using a larger population and more precise measurement tools could yield clearer findings that support the morphological results.

In conclusions, the standalone procedure of epicanthoplasty resulted in a morphological change characterized by the lowering of the medial eyebrow tail and overall eyebrow descent, and increased patient satisfaction regarding the ease of eye opening.

This study was supported by 2023 research grant from Busan National University Yangsan Hospital.

The authors have nothing to disclose.