Revision plan and results of anterior and posterior ptosis surgery

Abstract

Purpose

To assess the outcomes of revision ptosis surgeries performed using a surgical technique different from the initial procedure—either Müller muscle conjunctival resection (MMCR) or external levator surgery (ELS) based on the phenylephrine-induced change in margin reflex distance-1 (MRD-1).

Methods

This retrospective cohort study reviewed medical records of 780 patients who underwent MMCR or ELS for ptosis between January 2019 and December 2023. Revision surgery was required in 108 patients (15%). Among these, 32 eyes of 28 patients underwent a revision surgery using a technique different from the initial approach. Patient demographics, surgical details, and MRD-1 values at key clinical stages (pre-primary surgery, post-primary surgery, pre-revision surgery, and post-revision surgery) were recorded, along with levator function and postoperative complications.

Results

Twenty-eight patients (11 female, 17 male) were included. ELS was performed as the initial procedure in 13 eyes, and MMCR in 19 eyes. Surgical method for revision was determined based on the pre-revision phenylephrine response. Patients who initially underwent MMCR were classified as Group 1; those with initial ELS as Group 2. The mean interval between surgeries was 33.3 ± 38.2 months, and the mean follow-up duration was 42.5 ± 22.9 months. No significant difference in levator function or baseline MRD-1 values was observed between groups. A significant improvement in MRD-1 was noted after both primary and revision surgeries in each group. Eyelid symmetry was achieved in all patients.

Conclusion

Satisfactory functional and cosmetic outcomes can be obtained in revision ptosis surgery using an alternative technique to the primary approach. Preoperative phenylephrine testing and comprehensive patient evaluation are critical for surgical planning.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12886-026-05135-7.

Key messages

What is already known on this topic

Phenylephrine testing is widely used to predict outcomes in primary blepharoptosis surgery, but its utility in revision procedures is not well established.

What this study adds

This study demonstrates that selecting revision techniques (MMCR vs. ELS) based on phenylephrine-induced MRD-1 response yields significant functional and cosmetic improvements, ensuring eyelid symmetry even after different primary procedures.

How this study might affect research, practice or policy

Findings support phenylephrine-guided planning as a practical approach to improve revision outcomes, highlighting the potential for broader adoption of individualized strategies in secondary ptosis management.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12886-026-05135-7.

Introduction

Blepharoptosis, more commonly known as ptosis, is the abnormal drooping of the upper eyelid, resulting in narrowing of the palpebral fissure and potential obstruction of vision in primary gaze [1, 2]. It may cause upper visual field defects and cosmetic concerns [3]. Evaluation, diagnosis and treatment planning are essential for effective management.

Based on onset, ptosis is categorized as congenital or acquired. Another classification is based on etiology: myogenic, aponeurotic, neurogenic, mechanical, or traumatic [1]. Clinical measurements used in diagnosis and grading include margin reflex distance-1 (MRD-1), margin crease distance (MCD), levator function (LF) and palpebral fissure height. When assessing MRD-1, a light is directed at the pupillary center, and the patient is asked to gaze at it. Normal MRD-1 is 4–5 mm, and ptosis is classified as mild (≥ 2 mm), moderate (≥ 1 mm), or severe (< 1 mm) [4, 5]. MCD is the distance from the eyelid margin to the upper lid skinfold in downgaze. Normal values are 7–8 mm in males and 8–10 mm in females. It is increased in aponeurotic ptosis and often absent in congenital cases [6]. To evaluate LF, the brow is stabilized to inhibit frontalis muscle use, and the patient is instructed to look upward. Excursion above 15 mm is normal; 8–14 mm is good, 5–7 mm fair, and ≤ 4 mm poor. This measurement helps guide surgical technique selection [7]. Palpebral fissure height, measured at the pupillary plane, is normally 7–10 mm in males and 8–12 mm in females [8]. According to Suga et al., a 25% decrease corresponds to an MRD-1 of ~ 0 mm, while a 5% change equates to ~ 1 mm MRD-1 difference [9].

Surgical correction depends on etiology and severity. Techniques include external levator surgery (ELS), internal Müller muscle conjunctival resection (MMCR), and frontalis suspension [10–13]. MMCR, commonly used in mild-to-moderate ptosis with good LF and positive phenylephrine response, was introduced by Putterman and Urist in 1975 [14]. In follow-up studies, over 90% of acquired and 100% of congenital ptosis cases achieved symmetry, with minimal need for revision [15–16].

This study investigates whether changing the surgical technique improves outcomes in patients undergoing revision after suboptimal results in initial ptosis surgery.

Materials and methods

This study was designed as a retrospective cohort study. The records of 780 patients who underwent surgery for ptosis between January 2019 and December 2023 in the Oculoplastic and Reconstructive Surgery Clinic of the tertiary eye center were retrospectively analyzed.

The files of the patients who underwent ptosis surgery on the specified dates were retrospectively reviewed and the patients who underwent revision surgery were identified. The medical records were comprehensively reviewed to extract demographic data, follow-up durations and intervals between procedures. Eyelid parameters were systematically recorded at four distinct clinical stages: (1) before and after the phenylephrine test prior to the primary surgery, (2) after the primary surgery, (3) before and after the phenylephrine test prior to the revision surgery and (4) following the revision surgery. Additionally, specific surgical techniques, LF, resection amounts, and postoperative complications were evaluated. Patients who presented with residual ptosis, defined as a postoperative MRD-1 value of ≤ 3 mm and/or an intereyelid asymmetry of > 1 mm at the examination performed at least 2 months after the primary surgery, were included in the study. The indication for revision surgery was based strictly on these objective criteria of undercorrection (MRD-1 ≤ 3 mm or asymmetry > 1 mm) accompanied by the clinician’s assessment of persistent undercorrection and subsequent discussion with the patient regarding the benefits of a secondary intervention. Patients with a history of trauma, those who have undergone any eyelid or eyebrow surgery other than the primary procedure, patients whose initial surgery was frontalis suspension, those with any systemic disease that could affect the eyelid (such as neuromuscular disorders like myasthenia gravis or thyroid ophthalmopathy), patients with additional ocular diseases that could cause eyelid anomalies (such as idiopathic orbital inflammatory syndrome), and those with incomplete follow-up were excluded from the study.

In the follow-up, evaluation and surgical decision of patients, the MRD-1 values, calculated using the upper eyelid margin and the light reflex in the pupil was utilized. The MRD-1 value was measured using a millimetric ruler and recorded. To assess the phenylephrine response, one drop of 2.5% phenylephrine was instilled into the lower conjunctival fornix, and the change in the MRD-1 values was evaluated and recorded after 10 minutes. In cases where blepharoptosis developed in the contralateral eye, phenylephrine was also applied to that eye and the response was assessed. The LF of each patient was measured using a millimetric ruler. After stabilizing the frontalis muscle with a finger, the change in the lower border of the upper eyelid crease during downward and upward gaze was recorded. At all preoperative and postoperative visits, photographs of the patients were taken under the same lighting and environmental conditions, using a reference point between the eyebrows, in right gaze, left gaze, upward gaze, downward gaze, primary position and with eyes closed. In patients who underwent MMCR, after unilateral phenylephrine, if symmetry was achieved 9 mm of resection was performed. If approximately 1 mm of ptosis remained in the phenylephrine-treated eye, 10 mm of resection was performed. If excessive correction occurred in the phenylephrine-treated eye the resection amount was planned to be 8 mm. The selection of the revision surgical technique was strictly guided by an objective phenylephrine response algorithm. A ‘sufficient’ response was defined as achieving a post-instillation MRD-1 value of > 3.0 mm along with acceptable upper eyelid symmetry, specified as an intereyelid MRD-1 difference of < 1.0 mm compared to the contralateral normal eye, which indicated a MMCR. Conversely, an ‘insufficient’ response was defined when the post-instillation MRD-1 remained ≤ 3.0 mm or the inter-eyelid asymmetry was > 1.0 mm, which directed the revision surgical strategy toward an ELS.

Surgical technique

MMCR

In MMCR surgery was performed under local lidocaine-epinephrine anesthesia. After temporal exteriorization of a 6/0 polypropylene suture and marking at the corneal limbus and pupil center, a 4/0 silk traction suture was placed to separate Müller muscle and the levator. The tarsus and Müller muscle were clamped, and a 6/0 polypropylene horizontal mattress suture was secured with a bolster. The conjunctiva–Müller complex was excised, the eyelid reverted, and antibiotic ointment applied. Topical treatment continued for 10 days, with suture removal on day 10.

ELS

In ELS was performed under local lidocaine-epinephrine anesthesia. The eyelid line was identified, and marks were placed at the lash margin aligned with the limbus and pupil. Dissection was performed between orbicularis and septum, exposing and freeing the levator. A 6/0 polypropylene suture was placed centrally, temporarily fixed to the tarsal plate, and the conjunctiva inspected. After adjusting lid height, permanent sutures were placed centrally, medially and laterally. During the procedure, the amount of levator advancement/resection was adjusted progressively based on the intraoperative eyelid height, contour and direct comparison with the contralateral eye to achieve optimal symmetry. The adjustment was finalized once satisfactory symmetry and margin reflex distance were achieved on the operating table. The incision was closed, the eye kept shut with antibiotic ointment for 1 day, and sutures removed on postoperative day 10.

Surgical success criteria

Surgical success for the revision procedure was defined based on the following objective criteria at the final postoperative follow-up: acceptable postoperative MRD-1 range (between 3.0 mm and 4.5 mm), inter-eyelid asymmetry of ≤ 1 mm, the absence of overcorrection, and no requirement for further revision surgery. All postoperative eyelid measurements were performed during live clinical examinations using a standard millimeter ruler by an independent observer who was masked to the surgical procedure.

The statistical analysis was performed with the Statistical Package for Social Sciences (SPSS version 23). The normality of continuous variables was evaluated using the Shapiro-Wilk test. Since the majority of MRD-1 values did not demonstrate a normal distribution (p < 0.05), non-parametric methods were applied for operational analyses. Categorical data were presented as frequencies (n) and percentages (%). Continuous variables were described using the mean ± standard deviation (SD) and absolute ranges to enable direct clinical comparison with previous literature, while median and interquartile range (IQR) thresholds were utilized during non-parametric inference testing. Quantitative analyses of dependent intra-group changes were performed using the Wilcoxon signed-rank test, and the Mann-Whitney U test was applied for inter-group comparisons. Spearman’s Rho test was used for correlation analyses. A p value of < 0.05 was considered statistically significant. Statistical analyses were performed using both patient-based and eye-based approaches depending on the variable types. Demographic characteristics, including age and gender, were calculated and analyzed on a patient-based level (n = 28). Conversely, all clinical measurements (MRD-1 outcomes), the interval between the primary and revision surgeries, and postoperative complications were evaluated on an eye-based level (n = 32) to accurately reflect the individual surgical outcomes of bilateral cases. To account for potential inter-eye correlation in bilateral cases, a sensitivity analysis was subsequently conducted by restricting the dataset to one eye per patient. A sample size calculation was indeed performed based on the study by Karlin et al., which investigated revision ptosis surgery for undercorrection following Müller’s muscle-conjunctival resection [17]. Using the MRD-1 measurements from their post-revision surgery outcomes as a baseline, the effect size was determined to be 0.8. With a significance level (α) of 0.1 and a statistical power (1- β) of 0.90, the minimum required sample size was calculated as 21.

Results

Demographic and baseline characteristics

The study included 28 patients who underwent ELS or MMCR surgery for blepharoptosis correction and were found to have residual ptosis during follow-up [11 (39%) females, 17 (61%) males]. ELS was performed as the primary surgery on 13 eyes of 12 patients, while MMCR was performed as revision surgery for residual ptosis and MMCR was performed as the primary surgery on 19 eyes in 16 patients, whereas ELS was used as revision surgery for residual ptosis. The group with MMCR as primary surgery was defined as group 1 and the group with ELS as primary surgery was defined as group 2. MRD-1 measurements were evaluated at each visit and compared with the photographs taken at each visit. The demographic characteristics, mean time period between the surgeries, preoperative and postoperative MRD-1 outcomes, and postoperative complications of the study groups are presented in Table 1. The mean preoperative LF was 13.57 ± 3.56 (range, 10–18) in group 1 and 14.61 ± 2.50 (range, 10–18) in group 2, calculated on an eye-based level. Mean LF values were similar between the groups (p > 0.05). There was no statistically significant correlation found between preoperative LF and postoperative MRD-1 values (p > 0.05, Spearman’s Rho test). Surgical decision was based on MRD-1 values measured with phenylephrine.

Table 1.

Demographic characteristics, preoperative and postoperative MRD-1 outcomes and postoperative complications of the study groups

Parameters	Group 1	Group 2
Demographic Data
Age (years)	Mean ± SD (Range)	Mean ± SD (Range)
	35.25 ± 21.18 (8–68)	51.5 ± 13.60 (30–68)
Gender n (%)
Female	5 (31.25%)	6 (50%)
Male	11 (68.75%)	6 (50%)
Mean Time Period Between the Primary and Revision Surgeries (months)	16 ± 13.57 (2–53)	58.61 ± 48.36 (7–90)
MRD-1 Outcomes (mm)	Mean ± SD (Range)	Mean ± SD (Range)
	(Min-Max)	(Min-Max)
Preoperative values without phenylephrine before primary surgery	1.47 ± 0.96	0.92 ± 1.03
	0–3	-1–2
Preoperative values with phenylephrine before primary surgery	3.47 ± 1.03	1.15 ± 0.80
	2–6	0–2
Postoperative values after primary surgery	2.26 ± 1.04	2.53 ± 1.05
	0–5	1–4
Preoperative values without phenylephrine before revision surgery	1.31 ± 0.94	0.76 ± 1.01
	-1–3	-1–2
Preoperative values with phenylephrine before revision surgery	1.31 ± 1.2	2.69 ± 1.31
	-1–4	0–4
Postoperative values after revision surgery	3.33 ± 0.97	3.00 ± 1.04
	2–5	0–4
Postoperative Complications n (%)
Lagophthalmos	1 (after primary surgery) (6.3%)	1 (after primary surgery) (8.3%)
	4 (after revision surgery) (25%)
Overcorrection	0	0
Corneal Epitheliopathy	0	0
Lid Contour Asymmetry	0	0
Surgical Success Rates n (%)
Final Eyelid Symmetry (After revision surgery) (< 1.0 mm difference)	16 (100%)	12 (100%)

MRD-1: Margin Reflex Distance-1, Max: Maximum, Min: Minimum, SD: Standard deviation

Note: Demographic parameters (age, gender), mean time period between the primary and revision surgeries, postoperative complications, surgical success rates were evaluated based on patients (n = 28), whereas clinical outcomes were analyzed based on individual eyes (n = 32)

Primary surgery outcomes

In eyes that underwent MMCR as primary surgery, 10 mm conjunctiva and Müller muscle were excised in thirteen eyes (68.4%), 9 mm in five eyes (26.3%) and 8 mm in one eye (5.2%). In eyes that underwent MMCR surgery as revision surgery, 8 mm conjunctiva and Müller muscle were excised in three eyes (23%), 9 mm in five eyes (38.4%) and 10 mm in five eyes (38.4%). When the data related to the primary surgery were analyzed, the mean preoperative MRD-1 values of patients in group 1 without phenylephrine were 1.47 ± 0.96 (range, 0 to 3 mm). The mean MRD-1 values of patients in group 2 without phenylephrine were 0.92 ± 1.03 (range, -1 to 2 mm). There was no statistically significant difference in preoperative MRD-1 values without phenylephrine between groups (p = 0.155, Mann-Whitney U test). The mean preoperative MRD-1 values of patients in group 1 with phenylephrine were 3.47 ± 1.03 (range, 2 to 6 mm). The mean preoperative MRD-1 value with phenylephrine in group 2 was 1.15 ± 0.80 (range, 0 to 2 mm). There was a statistically significant in preoperative MRD-1 values with phenylephrine between groups (p < 0.001, Mann-Whitney U test). The mean MRD-1 values increased to 2.26 ± 1.04 mm (range, 0 to 5 mm) in the group 1 after primary surgery and to 3.00 ± 1.04 mm (range, 0 to 5 mm) in group 2. There was no statistically significant difference in postoperative MRD-1 values after primary surgery between groups (p = 0.49, Mann-Whitney U test) For both groups, there was a statistically significant difference between the MRD-1 values before and after primary surgery (p = 0.005 for group 1, p = 0.006 for group 2, Wilcoxon Signed Ranks).

Revision surgery outcomes

When the data related to the revision surgery were analyzed, the mean MRD-1 values before revision surgery without phenylephrine were 1.31 ± 0.94 mm (range, -1 to 3 mm) in the first group and 0.76 ± 1.01 mm (range, -2 to 2 mm) in the second group. There was no statistically significant difference in preoperative MRD-1 values without phenylephrine before revision surgery between groups (p = 0.10, Mann-Whitney U test). In group 1, the mean MRD-1 values with phenylephrine before revision surgery were 1.31 ± 1.2 mm (range, -1 to 4 mm), while in group 2, the mean MRD-1 values with phenylephrine before revision surgery were 2.69 ± 1.31 (range, 0 to 4 mm). There was a statistically significant difference in preoperative MRD-1 values with phenylephrine before revision surgery between groups (p < 0.001, Mann-Whitney U test). The mean MRD-1 values increased from 1.31 ± 0.94 mm (range, -1 to 3 mm) to 3.33 ± 0.97 mm (range, 2 to 5 mm) after revision compared to preoperative values in group 1. In group 2, it increased from 0.76 ± 1.01 mm (range, -2 to 2 mm) to 2.53 ± 1.05 mm (range, 0 to 4 mm). There was no statistically significant difference in postoperative MRD-1 values after revision surgery between groups (p = 0.06, Mann-Whitney U test). There was a statistically significant difference between the MRD-1 values before and after revision surgery (p < 0.001 for group 1, p = 0.001 for group 2, Wilcoxon Signed Ranks). There was a statistically significant difference between MRD-1 values at the last control after revision surgery and before the primary surgery (p = 0.001 for the group 1, p = 0.005 for the group 2, Wilcoxon Signed Ranks). When MRD-1 values after primary surgery and after revision surgery were compared, a statistically significant difference was observed in group 1, whereas no statistically significant difference was found in group 2 (in order, p = 0.002, p = 0.66, Wilcoxon Signed-Rank test).

Correlation analysis

MRD-1 measurements were evaluated at each visit and compared with the photographs taken at each visit. The changes in the mean MRD-1 values of group 1 and group 2 are shown in Fig. 1. When assessing the correlation between preoperative and postoperative MRD-1 values, a statistically significant positive correlation was found in group 2 between the MRD-1 values with phenylephrine before revision surgery and the MRD-1 values after revision surgery (p = 0.006, Spearman’s Rho = 0.713). There was no statistically significant correlation for the other MRD-1 values compared (p > 0.05, Spearman’s Rho test). The images of one patient each in group 1 and group 2 before primary surgery, after primary surgery, before revision surgery and after revision surgery are shown in Figs. 2 and 3.

Fig. 1.

Changes in mean MRD-1 values of group 1 and 2

Fig. 2.

Detailed clinical photographs of patient 1 (refer to Fig. 1 panels a-e) who underwent primary MMCR followed by revision ELS. The sequence is shown chronologically. (a) Preoperative baseline, right eye ptosis before any intervention. (b) Right eye after administration of 2.5% phenylephrine, taken approximately 10 min post-drop instillation. (c) Postoperative outcome, after completion of the primary MMCR. (d) Preoperative view of the right eye before the second surgery. (e) Final postoperative outcome, after completion of the revision ELS

Fig. 3.

Detailed clinical photographs of patient 2 (refer to Fig. 2 panels a–d) who underwent primary ELS followed by revision MMCR. The surgical sequence is shown chronologically. (a) Preoperative baseline photograph showing right eye ptosis before any intervention; phenylephrine was not administered for this patient. (b) Postoperative photograph after completion of the primary ELS, demonstrating residual undercorrection of the right eye. (c) Preoperative view of the right eye before the second surgery. (d) Final postoperative outcome showing stable alignment and successful correction after completion of the revision MMCR

In primary surgery, both groups demonstrated statistically significant changes in MRD-1 following preoperative phenylephrine testing and surgical intervention (p = 0.03 for group 1 and p = 0.007 for group 2, as determined by the Wilcoxon signed-rank test). For secondary surgery, a statistically significant association between the preoperative phenylephrine-induced change in MRD-1 and the surgical change in MRD-1 was found in group 1 (p = 0.001), but not in group 2 (p = 0.48), using the Wilcoxon signed-rank test. Notably, in group 2, the relationship between the revision surgery-induced change in MRD-1 and the preoperative phenylephrine response was statistically significant (p < 0.001 for group 1 and p = 0.003 for group 2, Wilcoxon signed-rank test). A statistically significant correlation was demonstrated between the difference in MRD-1 values at the initial presentation and after revision surgery and the phenylephrine response assessed before primary surgery (p < 0.001 for group 1, p = 0.001 for group 2, Wilcoxon signed-rank test). The evaluation and comparison of MRD-1 values based on eye units are presented in Table 2.

Table 2.

Evaluation and comparison of MRD-1 values based on eye units

MRD-1	Evaluation for group 1	Evaluation for group 2	Comparison of group 1 and 2
After revision surgery vs. before primary surgery	p  = 0.001*	p  = 0.005*
After primary surgery vs. after revision surgery	p  = 0.00*	p  = 0.001*
Before and after primary surgery	p = 0.31*	p = 0.62*
Before primary surgery			p = 0.15 †
After primary surgery			p = 0.49†
Before revision surgery			p = 0.10†
After revision surgery			P = 0.06†

* Wilcoxon Signed Ranks for evaluation ^† Mann-Whitney for comparison

Postoperative complications

Lagophthalmos was observed in one primary MMCR case, one primary ELS case and four ELS revision cases. All cases resolved completely within a mean timeline 2 weeks postoperatively with local ice, massage and temporary lubricant drops. No overcorrection occurred after primary or revision surgery. Postoperative punctate epitheliopathy in lagophthalmos cases resolved with lubricants, and no ulceration or corneal infiltrates developed. No lid contour, apposition or asymmetry issues were noted. After revision, eyelid symmetry was achieved with ≤ 1 mm difference between sides.

Sensitivity analysis

To verify that the inclusion of bilateral eyes did not introduce inter-eye correlation bias, a sensitivity analysis was conducted by excluding the 4 paired eyes from bilateral cases. The re-analysis of the remaining 28 completely independent eyes yielded identical statistical significance levels and clinical trends. These findings confirm the robustness and stability of our primary outcomes.

Discussion

Blepharoptosis is a condition that should be treated surgically because it can affect vision by closing the pupillary range and cause cosmetic problems. Treatment planning and surgery of ptosis, which is a common problem, is performed by oculoplastic surgeons.

Blepharoptosis can be congenital or acquired, and thus can occur in individuals of all ages. Congenital blepharoptosis is present from birth, while acquired blepharoptosis, which can result from neurogenic, myogenic, mechanical or aponeurogenic causes, tends to manifest in older age [18, 19]. In the presented study, the majority of patients are those with acquired blepharoptosis (89%, 25 patients).

The levator palpebrae superior originates from the orbital apex and travels anteriorly, changing direction at Whitnall’s ligament, and continues inferiorly as an aponeurosis, attaching to the tarsal plate. The aponeurosis is positioned on the anterior portion of the tarsal plate. External levator surgery has been the first-choice technique for many years due to its successful outcomes and the lack of development of alternative techniques [20–22]. Another muscle involved in eyelid elevation is the Müller muscle. Müller muscle originates from the undersurface of the levator muscle and attaches to the superior aspect of the tarsal plate. Any dysfunction occurring in the levator muscle, its aponeurosis, or the Müller muscle can lead to ptosis of the eyelid [23]. Over the years, the development of MMCR as a minimally invasive and safe technique has created a need to compare the outcomes of this surgical approach. In the planning of MMCR surgery, it is thought that the effect observed during the phenylephrine test, where the Müller muscle contracts and shortens due to the effect of the drop, results from the shortening of the muscle length during the resection performed in surgery [24]. In the study conducted by Chaenac et al., which evaluated the postoperative outcomes of patients undergoing ELS for involutional blepharoptosis, a significant correlation was found between the preoperative phenylephrine test and postoperative surgical success. However, no statistically significant relationship was demonstrated between LF and surgical outcomes. This study highlights the undeniable role of the Müller muscle in the development of ptosis and underscores the importance of considering it during surgical planning. Additionally, it is believed that the folding of the levator muscle during the surgery also contributes effectively by acting similarly to ELS [25]. Marcet et al. demonstrated that by performing MMCR, the weaker portions of the Müller muscle were resected, and the thicker, more effective portions were preserved, contributing to the correction of ptosis through enhanced elevation [26]. Similarly, in the present study, no statistically significant correlation was found between preoperative LF and postoperative MRD-1 values. A relationship was found between the effect of the preoperative phenylephrine test on MRD-1 and the successful outcomes achieved with revision surgery. However, in group 2, no significant association was observed between the MRD-1 change following the pre-revision phenylephrine test and the MRD-1 change after revision surgery. This may be attributed to adhesions resulting from previous levator surgery, which could potentially affect the phenylephrine response. It is thought that the reason for the statistically significant difference in phenylephrine response between the two groups before revision surgery is that the anatomical changes due to the first surgery affect the function of the muscles.

In this context, evaluating MMCR in terms of clinical efficacy, complication rates, and long-term patient outcomes in comparison with other surgical techniques is crucial for identifying its advantages and potential limitations. In the literature, analyzing the results of studies conducted on different patient groups and across various surgical centers allows for a more comprehensive assessment of the reliability and effectiveness of MMCR [27]. In the meta-analysis conducted by Karam et al., seven studies from the literature were reviewed, including a total of 1038 eyelids operated on for ptosis. Surgical outcomes, complications, and the learning curve of the surgical procedures were evaluated. The analysis revealed no statistically significant difference in postoperative MRD-1 values between the two groups. However, the patient group that underwent ELS showed a higher rate of overcorrection and re-operation requirements. While primary outcomes were similar, secondary outcomes indicated that the MMCR group had fewer complications and provided an advantage with a shorter operation time. This meta-analysis found both surgical techniques to be similarly successful in ptosis correction but demonstrated that MMCR was more predictable. The learning curves for both surgeries were found to be comparable [28]. In their study, Saonanon compared the outcomes of MMCR and ELS surgeries in patients with moderate ptosis and found that both procedures demonstrated similar effects in correcting ptosis. However, the MMCR group achieved better cosmetic outcomes and experienced less eyelid asymmetry [29].

Although success can be achieved with a single surgery, there are cases in the literature that require revision surgery due to postoperative residual ptosis. Blepharoptosis may occur due to insufficient development of the levator muscle or inadequate sympathetic innervation of the Müller muscle. Accurate identification of the etiology and selection of the appropriate surgical technique are crucial for achieving successful aesthetic and functional outcomes [30]. In revision surgery, complications such as scar tissue formation and changes in normal anatomy following primary surgery make it more challenging to identify the tissues, thereby complicating the feasibility of the procedure [31–36] In levator muscle surgery for revision purposes, the higher success rate of early reoperation is a disadvantage compared to MMCR surgery [37]. Studies evaluating the outcomes of patients who underwent MMCR or ELS for the correction of residual ptosis after MMCR are available in the literature. One of which Karlin et al. in a study of 16 patients who did not achieve complete correction after MMCR and underwent MMCR or ELS for revision surgery, the criteria for revision were a MRD-1 value below 3.5 mm or an asymmetry of more than 0.5 mm between the two eyelids. The patients were divided into 2 groups as those who underwent MMCR or ELS as revision surgery and the mean MRD-1 in both groups was found to be significantly higher after revision compared to preoperative and initial surgery. However, patients with residual ptosis after ELS were not included in this study [17]. In another study, Radmall et al. examined 12 eyelid ptosis in 11 patients who underwent MMCR for primary surgery and underwent MMCR again for revision surgery. In these patients, the amount of eyelid elevation after the second surgery was lower than after the primary surgery, but complete correction of ptosis was achieved [38]. In the study by Ozturk Karabulut et al., 23 eyelids of 23 patients who underwent ELS as primary surgery and subsequently required revision surgery who underwent MMCR were evaluated. The mean increase in MRD-1 was found to be statistically significant at the first, third, and sixth months postoperatively compared to both preoperative values before the primary surgery and before the revision procedure. This study demonstrated that MMCR can achieve successful outcomes as a revision procedure in patients who underwent ELS for ptosis correction, provided they exhibit no contour abnormalities and have a positive response to phenylephrine [39].

In the presented study, similar to previous findings, significant improvement was observed in residual ptosis following primary surgery in patients who underwent MMCR as revision surgery after ELS. Unlike the literature, in patients who underwent MMCR as primary surgery, ELS was applied as revision surgery, and a significant increase in MRD-1 values was observed compared to both preoperative and postoperative values. Since all of these patients showed a positive result in the phenylephrine test, MMCR was applied as primary surgery.

Shoaib et al. evaluated the results of ELS in 256 ptosis patients and showed that lagophthalmos developed in two patients and improvement was achieved with conservative treatment [40]. In the present study, one patient in group 1 and 1 patient in group 2 developed lagophthalmos after primary surgeries. After revision surgery, lagophthalmos developed in 4 patients who underwent ELS for correction of residual ptosis. Complete recovery was achieved in all patients with conservative treatment and topical treatment.

There are several limitations to this study that should be acknowledged. First, its retrospective design introduces inherent selection biases and limits the ability to control for all confounding perioperative factors. Second, the study is constrained by a relatively small sample size and the absence of a dedicated external control group, which limits the broader generalizability of our clinical conclusions. Third, patients were not categorized or stratified based on distinct blepharoptosis etiologies due to the small sample size, resulting in a somewhat heterogeneous cohort. Fourth, patient satisfaction was not evaluated using a standardized, validated patient-reported outcome measure, which restricts the subjective assessment of the aesthetic and functional improvements. Additionally, the follow-up periods were non-uniform and varied among individuals, and the study lacks a standardized evaluation of long-term outcomes following the revision surgery. Furthermore, the inclusion of both eyes in a small number of bilateral cases (4 patients, 8 eyes) presents a statistical limitation, as it potentially violates the assumption of independence between observations. However, a robust sensitivity analysis confirmed that restricting the dataset to one eye per patient did not alter the statistical significance of our primary clinical outcomes, confirming that this inter-eye correlation did not skew our overall results. Finally, due to the exploratory nature and limited sample size of this revision cohort (n = 28), a formal statistical correction for multiple comparisons (e.g., Bonferroni correction) was not applied during sequential hypothesis testing, which may increase the risk of Type I error.

In conclusion, successful functional and sample outcomes can be achieved in patients with residual ptosis through revision surgeries performed with different techniques. A thorough evaluation of the patient in the case of revision is crucial for determining the appropriate surgical method.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

All authors contributed to the study conception and design. Mehmet Goksel ULAS is the corresponding author and was responsible for writing and editing the manuscript. The other authors contributed to data collection and evaluation.

Funding

No funding was received for conducting this study.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by the Health Sciences University Hamidiye Scientific Research Ethics Committee (Approval No: 2024/15, Decision No: 15/16, dated December 12, 2024) and was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent for participation was obtained from all adult participants. For participants younger than 16 years of age, written informed consent was obtained from their parents or legal guardians prior to inclusion in the study.

Consent for publication

Due to the retrospective nature of the study, participants (or their parents/legal guardians for those under 18) were contacted subsequently to obtain written informed consent for the use of their clinical photographs.

Competing interests

The authors declare no competing interests.