The Effect of Upper Eyelid Blepharoplasty on Corneal Biomechanical Parameters Measured by Corvis ST (2025)

Abstract

INTRODUCTION

Dermatochalasis, which is a condition associated with aging, is characterized by the accumulation of redundant eyelid skin and, in some cases, herniation of fat through the orbital septum of the upper eyelids.1 Among individuals aged over 45 years, the occurrence rate of dermatochalasis is 16%, with men displaying a higher prevalence (19%) than women (14%).2,3 Dermatochalasis not only results in an unpleasant appearance but can also cause a range of functional problems.4 These functional issues may include restricted movement in lifting the upper eyelids, obstructed vision due to limited peripheral vision, discomfort around the eye, and dry eye symptoms.5,6,7 Furthermore, individuals suffering from ptosis may experience tension-type headaches due to the overuse of their occipitofrontalis muscles, which can be triggered by dermatochalasis.8

The surgical intervention known as upper eyelid blepharoplasty (UEB) is a frequently performed procedure in cosmetic surgery, primarily employed to rectify excess skin and subcutaneous tissue in the upper eyelid resulting from dermatochalasis.2,9 This procedure has been increasingly performed in recent years, in part due to the rising number of the aging population.

Extracting the excess skin in the upper eyelid through surgery can enhance numerous aspects, including the visual field and overall quality of life.5,6,10,11,12 Patients who underwent blepharoplasty surgery to address dermatochalasis have reportedly experienced considerable enhancements in their contrast sensitivity.13,14 It is suggested that the excess and drooping skin impedes light entry into the eye, leading to diffraction. Following the operation, this diffraction is diminished or eliminated, resulting in an improvement in contrast sensitivity.15 Moreover, undergoing UEB can result in a decrease in the electrical activity of the frontalis muscles, indicating a relaxation of these muscles, which in turn may alleviate tension headaches.8,16 Nevertheless, the primary adverse effects associated with UEB include tearing, lagophthalmos, infections, vision-threatening retrobulbar hemorrhage, or even blindness.2,17

The impact of age, conditions such as keratoconus and diabetes, treatments like prostaglandins, and refractive surgeries on the biomechanical behavior of the cornea is now extensively acknowledged. In addition, the influence of corneal biomechanics on intraocular pressure (IOP) measurement, refractive surgery outcomes, and the progression of ectatic diseases has been widely documented in the literature. The increased attention toward corneal biomechanics has stimulated the advancement and refinement of various in vivo measurement methods. Currently, available technologies include optical/imaging systems coupled with noncontact air-puff tonometry.18,19 The Corneal Visualization Scheimpflug Technology (Corvis ST, CVS, Oculus Optikgeräte GmbH, Germany) is a dynamic Scheimpflug analyzer that incorporates a concentric air-puff to induce deformation of the central cornea while simultaneously monitoring its response.20 This device employs an ultra-high-speed camera to capture 140 images of the cornea’s central horizontal meridian over a 32 ms duration equivalent to the length of the air-puff. The instrument analyzes the images in real time to generate various dynamic corneal response parameters. These parameters have been extensively investigated since the device’s introduction into clinical practice in 2010.21

Blepharoplasty, which involves lifting the eyelid and removing extra skin, can result in the redistribution of pressure on the cornea.22,23,24,25 Various tools that evaluate corneal biomechanics, such as the Corvis ST, can be used to record this alteration. Several studies have examined the impact of upper eyelid surgery on various corneal properties, including corneal morphology and biomechanics.22,23,24,26,27,28,29,30 These alterations can potentially impact corneal refraction and astigmatism, resulting in prolonged blurred vision.31,32 Few studies investigated the effect of UEB on corneal biomechanical properties.24

Given the growing demand for blepharoplasty, we set up this prospective study to determine whether undertaking UEB surgery could influence corneal biomechanical parameters assessed by the Corvis ST.

METHODS

The present study was a prospective study and was carried out at the oculoplastic division of the Farabi Eye Hospital, Tehran, Iran. The protocol of the study was approved by the Ethics Committee of the Tehran University of Medical Sciences (ethic approval code: IR.TUMS.FARABIH.REC.1401.028) and adheres to the tenets of the Declaration of Helsinki. Before participating in this study, informed consent to participate was obtained from all of the participants to utilize their data for analysis and publication purposes.

Inclusion criteria were patients 40 years old or older with significant dermatochalasis who had best-corrected distance visual acuity of 20/40 or greater. A minimum follow-up of 4 months after the operation was also ensured. In addition, only patients who underwent their initial blepharoplasty procedure were considered for inclusion in this study. The exclusion criteria were as follows: Margin-reflex distance 1 (MRD1) of <3 mm and >5 mm, corneal ectatic diseases, previous corneal refractive surgery, pterygium, severe dry eye, posterior segment diseases such as diabetic retinopathy or age-related macular degeneration, and glaucoma. All patients who did not exhibit intact lid closure and those with poor bell’s phenomenon were also excluded from the study population.

Upon presentation, all patients with dermatochalasis who were included in the study underwent a comprehensive history-taking and standard ophthalmic examination. These study participants were constantly followed by the ophthalmologist for 4 months after the procedure. Pre- and postoperative data of these patients who were followed for 4 months after UEB surgery were evaluated. The measurement of the MRD1 involves calculating the distance between the inferior margin of the upper eyelid and the pupillary light reflex, whereas the patient is in their primary position of gaze. Biomechanical measurements were performed before (upon the day of) and 4 months after the operation through Corvis ST. The following variables were provided by the Corvis ST before and 4 months after the operation: First applanation (A1) deformation amplitude, second applanation (A2) deformation amplitude, A1 applanation time, A2 applanation time, A1 velocity, A2 velocity, A1 deflection length, A2 deflection length, A1 deflection amp, A2 deflection amplitude, delta arc length at the first applanation (A1 dArc length), delta arc length at the second applanation (A2 dArc length), A1 deflection area, A2 deflection area, highest concavity (HC) dArc length, HC deformation amplitude, HC deflection length, HC deflection amplitude, HC deflection area, HC time peak distance, deformation amplitude max deflection amplitude, max deflection amplitude, max dArc length, max inverse radius, IOP, biomechanical-compensated IOP (bIOP), pachymetry, pachymetry slope, whole eye movement max, deformation amplitude ratio max, Ambrosio’s relational thickness integrated radius, stiffness parameter A1, Corvis biomechanical index (CBI), stress-strain index (SSI), and CBI-laser vision correction.

In this study, all participants underwent an UEB procedure under local anesthesia. All blepharoplasty surgeries were performed by a single expert oculoplastic surgeon (SMR). The surgeon initially marked the excessive lid skin, whereas the patient was sitting and supine with closed and open eyes. Using a fine marker, the surgeon made an inferior mark in the upper eyelid crease (about 9 mm in women and 8 mm in men from the upper eyelid margin). The mark was carried out medially, not exceeding the upper lacrimal punctum, and extended laterally to about the orbital rim. The pinch technique was utilized to evaluate the extent of excess skin following the demarcation of the skin crease. The highest point of the skin incision was delineated so that at least 10 mm of skin remained between the lower edge of the eyebrow and the lower mark. Following the marking, infiltration anesthesia (xylocaine 2% with epinephrine 0.001% [1: 100,000], mine GmbH Arzneimittel, Germany) was administered. The surgeon made an incision using a scalpel and then excised the skin using the surgical scissor. The length of the horizontal skin incision ranged from 25 to 35 mm in all patients, and the amount of vertically excised skin was 10–16 mm at the point of the greatest width, measured while tightening the skin in a supine position before skin excision. Then, along the created defect, a strip of orbicularis muscle with a thickness of about 1–2 mm was resected. Next, the medial fat pocket was identified in the medial part, and some of the prolapsed fat was removed. Following bipolar cauterization and wound disinfection, some separate skin sutures were used to close the wound. The suture was nonabsorbable, monofilament, synthetic-proline 6-0, and had a P 1 needle made by Ethicon. The wound was disinfected again, and leukostrips measuring 4.0 mm × 38 mm (Smith and Nephew) were applied over the suture. The sutures were removed 9–12 days after the surgery.

RESULTS

A total of 35 eyelids of the right eyes of 35 patients with dermatochalasis who underwent UEB were included in the present study. The mean age of patients was 56.9 ± 8.9 (range, 40–75) years (30 [85.7%] females and 5 [14.3%] males). Comparison of the first and second applanation deformation amplitude, time, velocity, deflection length, deflection amplitude, dArc length, and deflection area parameters before and 4 months after surgery are reported in Table 1. As shown in this table, only A1 and A2 applanation times increased significantly after the procedure (P < 0.001).

Table 2 shows data about the comparison of the HC length, amplitude, area, and time parameters before and 4 months after surgery. Based on the obtained results from this table, the HC deflection length and amplitude decreased 4 months following surgery (P = 0.025 and P = 0.034, respectively). In addition, the HC time measurements showed a significant increase 4 months after the operation (P < 0.001).

The obtained results reported in Table 3 showed that only the maximum deflection amplitude decreased (P = 0.041). Also, the maximum deflection amplitude increased 4 months after surgery (P = 0.055).

Table 4 represents the data related to the comparison of IOP, pachymetry, and other biomechanics indices before and 4 months after surgery. As the table shows, there were increases in IOP, bIOP, and stiffness parameter A1 4 months following surgery (P < 0.05). Furthermore, the mean amount of pachymetry decreased by 5.91 μm following surgery (P = 0.023). In addition, CBI and SSI decreased (P < 0.05).

After applying a Bonferroni corrected significance level of P < 0.001 to account for multiple comparisons, the only corneal biomechanical parameters that showed statistically significant changes following UEB surgery were A1 time, A2 time, HC time, IOP, and bIOP.

DISCUSSION

In the present study, we examined the postoperative changes in various corneal biomechanical indices measured by Corvis ST in patients who underwent UEB surgery. We found that most corneal biomechanical parameters did not show differences before and after UEB surgery, except A1 time, A2 time, HC time, IOP, and bIOP following UEB surgery.

Previous studies investigated the effects of UEB on different properties of the cornea, including the corneal topographic parameters.3,22,23,26,29,30 During UEB, the reduction of orbital fat may lead to considerable alterations in the morphology and structure of the cornea.15 These changes are associated with variations in corneal topography measurements.26,33,34 In a study conducted by Brown et al., the impact of UEB surgery on corneal topography was examined 3 months after the operation.26 The study involved 18 eyelids that underwent UEB. The results indicated that the average astigmatic change was 0.55 D, which was a significant change. The authors concluded that repositioning the eyelid after UEB surgery can result in significant astigmatic changes in the cornea that may affect the vision of the patients after the procedure. According to the findings of Zinkernagel et al., UEB surgery can cause modifications in the corneal shape and refractive properties.22 The study observed a significant decrease in astigmatism following blepharoplasty surgery. These results highlight the potential impact of upper eyelid surgery on corneal topography and the importance of assessing its effect on ocular health after the procedure. These findings were confirmed by Kim et al., which reported that 6 weeks after blepharoplasty, 12.5% of the operated eyes experienced an increase in corneal power, whereas 37.5% demonstrated a decrease.23 Regarding corneal astigmatism, 16.7% of the eyes showed a decrease, 16.7% exhibited an increase, and 66.6% demonstrated no change in patients who underwent blepharoplasty. These findings suggest that blepharoplasty can have varying effects on corneal topography and astigmatism and should be evaluated on a case-by-case basis. In a prospective long-term study, Bhattacharjee et al. analyzed long-term changes in some corneal topography indices (K1, K2, cylinder value, and the axis) in 60 eyes of 30 patients 12 months after the bilateral UEB surgery.3 The authors reported a significant difference between the cylinder values before and after the surgical procedure. Meanwhile, no statistically significant difference was observed for other topographical measurements. However, Dogan et al. noted that UEB surgery did not produce notable changes in the main corneal indices as measured by Pentacam.35 In contrast, Simsek et al., in their study (sample size of 23 patients, 43 eyes) observed that 60.5% of eyes experienced a discernible elevation in corneal astigmatism after UEB surgery.29 On average, there was a change of 0.15 diopters in astigmatism. There are some pieces of evidence indicating the changes in the morphology of corneal epithelial thickness after the UEB procedure. In a recently published study, Arslan et al. measured the pre- and postoperative corneal epithelial thickness through anterior segment optical coherence tomography in 90 eyes of patients with dermatochalasis who underwent the UEB procedure.30 They reported a significant increase in corneal epithelial thickness 6 months after the operation.

Few studies examined the postoperative changes in corneal biomechanical parameters following the UEB procedure.24 In a prospective study, Sommer et al. examined the impact of the UEB procedure on the biomechanical properties of the cornea, as well as the topographic and tomographic characteristics in 42 eyes of 35 patients who underwent the UEB procedure.24 They conducted measurements both before and 4 weeks after the surgery to determine any changes in these parameters. In contrast to the present study that used Corvis ST to assess the corneal biomechanical changes, they used the ORA (Reichert Ophthalmic Instrument, Buffalo, NY, USA) device. Accordingly, they reported fewer corneal biomechanical indices (corneal hysteresis [CH] and corneal resistance factors [CRF]) than the numerous indices represented in our study. The authors reported an increase in postoperative measurements of CH and CRF 4 weeks after the operation. The measurements showed an increase from 9.4 ± 2.3 to 10.2 ± 2.2 mmHg for CH and 9.7 ± 2.1 to 10.5 ± 2.2 mmHg for CRF. However, these changes did not reach statistical significance. Regarding corneal biomechanical indices, we found a significant increase in A1 time, A2 time, HC time, IOP, and bIOP. A possible hypothesis is that the decrease in pressure exerted on the cornea due to the reduction in eyelid weight could be the underlying cause of the alteration in corneal biomechanics. Notably, Sommer et al.24 also found no significant changes in Goldmann-correlated IOP and the corneal compensated IOP 4 weeks after the UEB surgery. In contrast, we found that IOP and bIOP measurements significantly increased 4 months after the UEB procedure. Therefore, it can be deduced that the type of device for measuring corneal biomechanical properties and the time period after the operation can make some differences in postoperative biomechanical outcomes.

UEB can exacerbate or induce dry eye, affecting corneal biomechanical measurements. Dry eye can alter corneal surface properties, impacting the accuracy of measurements taken by the Corvis ST. Despite including only images with an “OK” quality score to minimize errors, the presence of dry eye may still influence postoperative biomechanical parameters. Future studies should include evaluations of tear film stability to better understand the impact of dry eye on corneal biomechanics and consider managing dry eye symptoms to reduce its confounding effects.

This study acknowledges several limitations, including a small sample size of 35 eyes and a relatively short follow-up period of 4 months, which may potentially miss long-term effects. The absence of a control group makes it challenging to account for confounding factors and natural variations in corneal properties over time. In addition, the study did not consider diurnal variability in measurements or conduct comprehensive dry eye evaluations before and after surgery, which could impact the findings given that blepharoplasty can affect tear film stability. Despite these limitations, the authors assert that their study provides valuable insights into the effects of UEB on corneal biomechanical properties and suggest that future research addressing these limitations would further enhance understanding of the topic.

To the best of our knowledge, the present study is the first to analyze the effect of blepharoplasty surgery on corneal biomechanical properties measured by the Corvis ST device. To quantify the changes, we conducted preoperative and postoperative measurements using the Corvis ST device. We observed that altered eyelid pressure after UEB surgery could induce significant changes in certain parameters, such as A1 time, A2 time, HC time, as well as postoperative IOP measurements. However, most corneal biomechanical indices remained unaffected. Therefore, we should advise practitioners to evaluate postoperative IOP measurement carefully in patients undergoing UEB surgery due to its potential impact on corneal biomechanical properties.

Funding Statement

Nil.

REFERENCES