New algorithm for planning superior tarsal muscle resection for blepharoptosis: description of technique and results

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INTRODUCTION

Surgical treatment of blepharoptosis remains a relevant issue for ophthalmic and plastic surgeons, despite the variety of methods for its correction. Among various methods of surgical treatment of blepharoptosis, three main fields can be highlighted: suspending-type surgeries, transconjunctival techniques involving the superior tarsal muscle (STM), and transcutaneous techniques involving the aponeurosis of the upper eyelid elevator muscle [1–5]. This article focuses on transconjunctival resection of the STM.

Until recently, the main indication for STM resection was the presence of moderate to mild blepharoptosis with good or normal function of the upper eyelid elevator muscle (UEEM), as well as a positive phenylephrine (PE) test [1, 4, 6, 7]. Recently, however, more researchers have indicated the possibility of performing different variants of STM resection in patients with negative (“–”) and weakly positive (“+/–”) responses to the PE test [8–11].

Determination of the extent of STM resection deserves special consideration. There are quite a large number of calculation algorithms. Putterman was one of the first to propose the STM resection algorithm. He believed that to achieve eyelid lift with instillation of 10% PE, 8.5 mm of the STM should be resected, and 1 mm of muscle resection should be added or subtracted for each 0.5 mm of hypo- or hypercorrection in the range of 6.5–9.5 mm [12]. According to Weinstein, for correction of 2 mm of blepharoptosis, it is necessary to excise the STM by 8 mm, and it is assumed that the ratio of these two values is 1:4 [13]. Dresner suggested excising 4 mm of the STM for correction of 1 mm of blepharoptosis, 6 mm for 1.5 mm of blepharoptosis, 8 mm for 2 mm of blepharoptosis, and 11–12 mm for blepharoptosis of ≥3 mm; in case of insufficient effect of the PE test, resection of the tarsal plate should be added [14]. According to the conclusion of Mercandetti et al., based on their own studies, the ratio of the amount of STM resection to the degree of desired correction is 3 : 1 [15]. The algorithm proposed by Perry et al. involves resection of 9 mm of the STM to achieve the same eyelid height as in the test with 10% PE, and with hypocorrection, resection is supplemented with excision of the tarsal plate at a ratio of 1 : 1, but not more than 3 mm to prevent upper eyelid instability [16]. The variety of STM resection algorithms is confirmed by the lack of a universal algorithm, and therefore the search for new algorithms remains relevant. Moreover, in our own studies, we determined that the STM length in patients with blepharoptosis ranged from 8 to 23 mm. In this regard, we do not consider it appropriate to use algorithms that are based on absolute values in millimeters and that do not take into account the initial length of the STM in a particular patient.

MATERIALS AND METHODS

The study included patients with various degrees of blepharoptosis with excellent or good UEEM function (8 mm or more). The exclusion criteria were myogenic or neurogenic blepharoptosis, traumatic blepharoptosis, or a history of surgery for the condition, UEEM function of 7 mm or less, and severe dry eye syndrome.

The main group consisted of patients admitted to the Microsurgical Ophthalmic Department No. 5 of the City Multi-Field Hospital No. 2 between November 2017 and August 2019. The group included 75 patients (103 eyelids): 35 men (46.7%) and 40 women (53.3%). The average age of the patients in the main group was 54.8 ± 12.8 years. It is worth noting that the main group included patients with various responses to the PE test. Thus, among 75 patients, 37 (50 eyelids) had a positive (“+”) response and 38 (53 eyelids) had a negative (“–”) or weakly positive (“+/–”) response to the PE test. The patients in the main group underwent a modified STM resection proposed by the authors for correction of blepharoptosis.

The comparison group consisted of patients admitted to the Microsurgical Ophthalmic Department No. 5 of the City Multi-Field Hospital No. 2 between January 2016 and September 2017. The group included 26 patients (35 eyelids): 10 men (38.5%) and 16 women (61.5%). The average age was 54.9 ± 14.9 years. All patients in this group had a “+” response to the PE test (Table 1). In this group, a retrospective analysis of surgical correction of blepharoptosis was performed. The patients underwent standard open sky STM resection according to the technique proposed by Lake et al. and described below.

 

Table 1 / Таблица 1

Distribution of patients by gender and age within groups

Распределение пациентов по полу и возрасту в пределах групп

Indicator		Main group	Comparison group	Significance in general for the indicator “gender,” р
Gender	Male	46.7 % (35)	38.5 % (10)	0.15
	Female	53.3 % (40)	61.5 % (16)	0.15
Age		54.8 ± 12.8	54.9 ± 14.9	0.51

 

The main parameters for assessing the surgical treatment of blepharoptosis were selected as the degree of ptosis, degree of upper eyelid elevation, width of the palpebral fissure in the center and along the lateral and medial limbus, MRD1, and MRD2. The MRD1 (marginal reflex distance) is the distance from the corneal reflex to the upper eyelid margin in the center at the primary position, and the MRD2 is the distance from the corneal reflex to the lower eyelid margin in the center at the primary position.

The main stages of the surgery did not differ between the groups and are presented below. The primary differences between the groups included various algorithms for calculating the extent of the surgery.

The skin was treated with an antiseptic solution. Traction suture was applied (vicryl 4.00) to the center of the upper eyelid at the ciliary margin (Fig. 1a). The upper eyelid was everted on a Desmarres eyelid retractor (Fig. 1b). The conjunctiva was cut off with the STM from the upper margin of the tarsal plate, and the STM was mobilized (Fig. 1c). The white line was isolated (Fig. 1d; only in the main group). The assessment of mobility was performed by traction for the center of the STM venter in patients with “–” or “+/–” responses to the PE test (Fig. 1e; only in the main group). A suture fixing the STM to the tarsal plate was applied (Fig. 1f), and the STM was resected (Fig. 1g). Fixation of the STM stump with a U-shaped suture (vicryl 6.0) to the tarsal plate margin was performed (Fig. 1e). A continuous suture fixing the conjunctiva to the tarsal plate was applied (Fig. 1h, i).

Algorithm for calculating the extent of surgery for modified resection of the superior tarsal muscle

 

Fig. 1. Main stages of superior tarsal muscle resection (description in the text)

Рис. 1. Основные этапы резекции верхней тарзальной мышцы (описание в тексте)

 

The algorithm for determining the extent of surgery with modified STM resection is presented in Fig. 2 and described in detail below (patent application No. 2019127580 dated 30.08.2019).

 

Fig. 2. Algorithm of modified superior tarsal muscle resection

Рис. 2. Алгоритм выполнения модифицированной резекции верхней тарзальной мышцы: ВТМ — верхняя тарзальная мышца, ФЭ-тест — фенилэфриновый тест

 

In patients with “+” and a sufficient response to the PE test, two-thirds STM resection was performed. In patients with “+” but an insufficient response to the PE test, a subtotal STM resection was performed. In patients with “–” and “+/–” results of the PE test, the mobility of the white line was additionally evaluated intraoperatively. When the mobility of the white line (in millimeters) corresponded to the expected result (the degree of upper eyelid elevation necessary for complete elimination of ptosis), subtotal STM resection was performed without resection of the upper tarsal plate. When the mobility of the white line was less than the expected result, subtotal STM resection was performed combined with resection of the tarsal plate by the missing value, provided that the residual height of the tarsal plate was at least 5 mm. If tarsal plate resection was not possible due to its height in the required extent, subtotal STM resection was performed in combination with white line displacement. In the absence of mobility of the white line, depending on the degree of ptosis, either the UEEM aponeurosis was resected or the white line was displaced to the tarsal plate.

Algorithm for calculating the extent of surgery of the standard open sky resection of the upper tarsal muscle (in the control group)

It is worth noting that all patients who underwent STM resection in this modification had a “+” response to the PE test. With a sufficient “+” response to the PE test, subtotal STM resection was performed or combined with resection of the tarsal plate by an amount required for the desired result.

Statistical analysis of the study results was performed using the Microsoft Excel 2010 application and the statistical program IBM SPSS Statistics 23 (IBM Corporation). When describing quantitative variables, the indicators were specified, namely the mean value and standard deviation. Normality testing was performed by the Shapiro–Wilk test. The ratio of quantitative variables in two independent groups was assessed by the Van der Waerden test. The differences were considered statistically significant when p < 0.05.

RESULTS

The main parameters for evaluating the efficiency of modified STM resection were the degree of ptosis, the degree of eyelid elevation, the width of the palpebral fissure in the center and along the lateral and medial limbus, MRD1, and MRD2. All the parameters were evaluated before and 3 months after surgery. In the control group, a retrospective analysis of the results of surgical correction of blepharoptosis was performed. The results of surgical correction of blepharoptosis were compared between the main group and the comparison group.

Functional results in the late postoperative period were evaluated within the main group. All indicators were taken into account before and 3 months after surgery. The results are presented in Table 2.

 

Table 2 / Таблица 2

Results of modified superior tarsal muscle resection in the main group (Van der Waerden test)

Результаты модифицированной резекции верхней тарзальной мышцы в основной группе (критерий Ван-дер-Вардена)

Indicator	Before surgery	3 mo after surgery	Significance, р
Degree of ptosis	3.4 ± 0.9	0.09 ± 0.3	<0.0001
Width of the palpebral fissure in the center	5.6 ± 0.9	8.9 ± 0.4	<0.0001
Width of the palpebral fissure along the lateral limbus	4.2 ± 0.9	7.7 ± 0.6	<0.0001
Width of the palpebral fissure along the medial limbus	3.1 ± 0.8	6.6 ± 0.6	<0.0001
MRD1	0.6 ± 0.9	3.9 ± 0.4	<0.0001
MRD2	4.8 ± 0.4	5	0.17
Note. STM, superior tarsal muscle; MRD1, distance from the corneal reflex to the upper eyelid margin; MRD2, distance from the corneal reflex to the lower eyelid margin.

 

The study showed that modified STM resection is an effective method to correct blepharoptosis in patients with various responses to the PE test, provided that the UEEM function is excellent or good. In intergroup comparison of the results, similar data were obtained in both groups, and no significant differences between the indicators were found (Table 3).

 

Table 3 / Таблица 3

Comparative analysis of the results between groups

Сравнительный анализ полученных результатов между группами

Indicator	Modified resection of the STM	Standard resection of the STM	Significance, р
Degree of ptosis	0.09 ± 0.3	0.12 ± 0.8	0.12
Width of the palpebral fissure in the center	8.9 ± 0.4	8.8 ± 0.8	0.2
Width of the palpebral fissure along the lateral limbus	7.7 ± 0.6	7.7 ± 0.8	0.88
Width of the palpebral fissure along the medial limbus	6.6 ± 0.6	6.6 ± 0.7	0.89
MRD1	3.9 ± 0.4	3.8 ± 0.9	0.2
MRD2	5	5	1
Result	2.6 ± 0.8	2.0 ± 0.6	0.035
Note. STM, superior tarsal muscle; MRD1, distance from the corneal reflex to the upper eyelid margin; MRD2, distance from the corneal reflex to the lower eyelid margin.

 

In addition to the above indicators, we compared the frequency of hypo- and hypercorrection between the groups and found that the frequency of hypo- and hypercorrection was significantly higher in the comparison group (Table 4). In our opinion, this was due to inaccuracy in calculating the extent of resection when planning surgical treatment.

 

Table 4 / Таблица 4

The frequency of hypo- and hypercorrections in groups

Частота гипо- и гиперкоррекции в группах

Indicator	Modified resection of the STM	Standard resection of the STM	Significance, р
Hypocorrection	6.8% (7 eyelids)	17.1% (6 eyelids)	0.0001
Hypercorrection	0.97% (1 eyelid)	5.7% (2 eyelids)	0.0001
Note. STM, superior tarsal muscle.

 

DISCUSSION AND CONCLUSIONS

Interest in transconjunctival blepharoptosis correction techniques appeared in 1961, when data on STM resection were first published [5]. In 1975, Putterman and Urist introduced a new modification of STM resection, the essence of which consisted in isolated resection of the STM and conjunctiva without involvement of the tarsal plate [7]. It was believed for a long time that resection of the STM is only a form of resection of the UEEM aponeurosis. However, the results of histological studies have shown that the excised tissue is represented mainly by STM and conjunctiva [5]. The main advantages of transconjunctival techniques are the ease of implementation and predictability of the results.

To date, according to the literature, “–” and “+/–” responses to the PE test restrict the use of STM resection [1, 4, 6, 7]. Nevertheless, an increasing number of authors have reported good results after resection of the STM in patients with “+/–” and “–” responses to the PE test [8–11]. In our opinion, the indications for STM resection should be expanded, and the response to the PE test may not be the only factor to rely on when choosing a surgical correction technique.

The methodology of modified STM resection proposed by the authors and described above enables us not only to expand the indications for STM resection due to the possibility of its use in patients with “–” and “+/–” responses to the PE test, but also to calculate the extent of the required resection. Moreover, with the use of this method, the need for the most sparing resection of the tarsal plate can be determined.

The main distinguishing feature of the proposed technique is the assessment of white line mobility. The white line is a separate structure and is a transition zone between the transversostriated muscles of the UEEM and the STM smooth muscles. Assessment of white line mobility is an integral stage in the planning of modified STM resection in patients with “–” and “+/–” responses to the PE test.

Based on the foregoing, we can formulate the main indications for a modified STM resection:

• Congenital and acquired aponeurotic blepharoptosis of mild to moderate degrees with UEEM function of 8 mm or more;
• “+”, “–”, and “+/–” responses to the PE test.

In conclusion, studies of the possibility of using a modified technique of STM resection for acquired blepharoptosis of myogenic or neurogenic nature are ongoing. At present, this technique has been successfully used in two patients with Horner’s syndrome. However, to expand the indications for this technique, it will be necessary to study the results of the proposed modification of STM resection in a larger sample of patients.

About the authors

Vitaly V. Potyomkin

Pavlov First Saint Petersburg State Medical University; City Multi-Field Hospital No. 2

Email: ageeva_elena@inbox.ru

PhD, Assistant Professor. Department of Ophthalmology

Russian Federation, 197089,  St. Petersburg, Lev Tolstoy str., 6-8, building 16; 194354, St. Petersburg, Uchebniy pereulok, 5

Elena V. Goltsman

City Ophthalmologic Center of City hospital N 2 

Author for correspondence.
Email: ageeva_elena@inbox.ru

ophthalmologist

Russian Federation, 194354, St. Petersburg, Uchebniy pereulok, 5

References

Supplementary files