Concept of Double-eyelid Segments Ratio: Practical Application in Asian Blepharoplasty

Abstract

Background: There have been few articles on the vertical dimension of the Asian upper eyelid, the eyelid crease segment, and the upper palpebral segment. The eyelid crease height manifests differently depending on whether it is closed (on extreme downgaze), open, or on upward gaze. This study will investigate a ratio practical for use in Asian blepharoplasty (external incisional method).

Methods: The central vertical dimensions of Asian upper eyelids were measured, together with the upper palpebral segment and eyelid crease height when present. These parameters were recorded preoperatively and following double-eyelid surgery, and remeasured at 1 week and 2 months postoperative with eyelids closed and with eyes open looking straight ahead. The ratios of anatomic upper/lower segments and apparent (eyes opened) upper/lower ratio were tabulated for each case.

Results: The mean vertical height of upper eyelid skin among Asian women 30 years of age and younger was 23.4 mm, and between 31 and 50 years of age was 25.4 mm. The design of Asian upper eyelid crease and determination of skin tissues that can be safely removed include designing crease height to be 7 mm or slightly less and leaving an upper eyelid segment of at least a length 2 times or more of the crease height, to yield an aesthetically desirable double-eyelid segments ratio.

Conclusions: The study confirms the practical application of the upper/lower segments ratio at surgery and at full recovery (2 mo) using such technique and shows its progression to a desirable range of double-eyelid segments ratio. It has proven effective and useful for patients seeking Asian blepharoplasty.

Fig. 1.

Anatomic CH (red), tilted CH (blue), and apparent CH (green). The anatomic CH normally is located along the superior tarsal border and is measured with eyelids on extreme downgaze or closed; the tilted CH is the anatomic CH’s measured vertical equivalent when viewed frontally with eyes opened and with eyelid fold lifted up to expose its true view, whereas the clinical apparent CH represents the net frontal view (vertical equivalent) of the crease without interference on any eyelid fold which may be present.

Fig. 2.

Drawing of an Asian-born patient with a natural crease, showing designation of upper and lower segments of the upper eyelid with eyelids closed versus opened. The values are different for each dimension. A, Anatomic crease height and upper segment with eyelids closed. B, The same individual's apparent crease height and upper segment when viewed with eyes in OFN position. Position A produces an anatomic U/L ratio, whereas B yields an apparent U/L ratio.

Fig. 3.

Preincisional planning shows measurements using paper ruler and caliper to measure the vertical dimension of the whole upper eyelid, the designed crease height, and the upper eyelid segment to preserve. A, Preoperative evaluation for a male patient: the whole upper eyelid segment measured 23 mm. B, During primary Asian blepharoplasty for this patient, crease height was set at 6 mm, and the upper segment designed was designed at 13 mm. The marked tissue for removal between the upper and lower incision lines was 4 mm.

Fig. 4.

Immediate postprocedure photographs. A, Confirmation that crease height constructed was 6 mm. B, The remaining upper segment stayed set at 13 mm. Anatomic (U/L) ratio is 13/6 = 2.17.

Fig. 5.

Length of upper eyelid segments among different age categories of Asian women, showing primary Asian blepharoplasty cases (44 patients; 87 eyelids) and revisional cases (16 patients; 32 eyelids). In the primary surgery group, the distribution among the three age categories were 13 patients (30 y or younger), 16 patients (31–50 y), and 15 patients (51 years of age or older).

Fig. 6.

Among 44 Asian women for primary Asian blepharoplasty, preoperative upper eyelid vertical dimension (the y-axis on left side) vs anatomic upper-to-lower segment ratio (U:L) implemented at surgery (right side, secondary y-axis). The blue symbol phi represents the mean of anatomic U/L ratio at surgery among the three age groups of Asian women; it is posted next to each column. Overall mean anatomic U/L ratio was 2.25.

Fig. 7.

Among the 15 cases (30 eyelids) of Asian women who underwent primary Asian blepharoplasty with completed 2-month follow-up, their 2-month mean anatomic U/L ratios (phi values) are positioned near their respective apparent U/L ratio (green columns, double-eyelid segment ratio, secondary y-axis), showing a roughly additional +50% correspondence in value going from anatomic U/L to apparent U/L ratio. There were five cases in each age group. Overall mean U/L (double-eyelid segments) ratio was 3.40.

Fig. 8.

Preoperative and postoperative views at 1 week and 2 months, respectively. A, Preoperative view straight and downgaze for a 24-year-old woman, and 1 week after Asian blepharoplasty, illustrating a typical recovery, with a lower apparent U/L ratio due to inherent lower eyebrow position. The whole upper eyelid preoperatively measured 23 mm; designed 7 mm CH, resected 2.5 mm, upper segment remaining measured 13.5 mm. B, At the 2-month postoperative visit, apparent crease height was 3 mm, whereas the upper segment was 7 mm.

Fig. 9.

Measurement of upper segment of same left upper eyelid with eyes looking down (anatomic) compared with straight ahead (apparent). A, Anatomic measurement of upper segment was 18 mm. B, In open eye position, the upper segment was only 10 mm.

Fig. 10.

Side-views of left upper eyelid before and after Asian blepharoplasty procedure by Chen, showing improvement in upper eyelid contour. A, Preoperative view. B, Postoperative view at 1 week: there is elimination of eyelid fold overhang on the eyelid margin, deflation of upper eyelid contour, thinning of pretarsal fullness, slight upturning of lash angle, and addition of an upper eyelid crease.

Fig. 11.

Preoperative and 2-month postoperative views. A, Case 1, a 24-year-old female patient. The whole upper eyelid was 23 mm; intraoperatively designed 7 mm CH, resected 2.5 mm, upper segment remaining measured 13.5 mm. B, Apparent double-eyelid segments ratio upon full recovery at 2 months is 7 ÷3 = 2.33, as in Figure 8B.

Fig. 12.

Preoperative and 2-month postoperative views. A, Case 2, a 17-year-old female patient, whose whole upper eyelid was 22 mm; intraoperatively designed 7 mm CH, resected 2 mm, upper segment remaining measured 13 mm. B, Apparent double-eyelid segments ratio upon full recovery is 7.5 ÷3 = 2.5.

Fig. 13.

Preoperative and 2-month postoperative views. A, Case 3, a 29-year-old female patient who had a rudimentary crease on right upper eyelid. The whole upper eyelid was 24 mm; intraoperatively designed 7 mm CH, resected 2.5 mm, upper segment remaining measured 14.5 mm. B, Apparent double-eyelid segments ratio upon full recovery in the right eye is 9 ÷2.5= 3.6; the left eye is 10 ÷2.5= 4.0.