A new refined technique for myogenic ptosis correction with resection of myotarsal flap by conjunctival approach

ABSTRACT

The purpose is to present a new refined surgical technique for mild-to-severe acquired myogenic ptosis correction under local anaesthesia (LA) as day cases with resection of myotarsal (MT) flap and demonstrate the safety and efficacy of the technique. MT flap consists of 2 mm tarsal strip with attached levator complex – levator muscle, its aponeurosis, and Müller muscle.

This is a retrospective personal series of 400+ patients, who underwent surgical correction with MT flap resection of 8–24 mm under LA mostly as day cases.

No patient had any complication. Results were satisfactory as assessed on these criteria: (i) elevation of the lid at least above the visual axis; (ii) normal contours of the lid without distortion, with the eyelid conforming to the contours of the globe; (iii) static and dynamic symmetry of upper eyelids; (iv) formation of a normal and symmetrical lid fold; (v) healthy comfortable ocular surface and cornea; and (vi) patient and surgeon satisfaction with the aesthetic outcome.

Resection of the MT flap is a safe and effective, microsurgical technique of ptosis correction, yielding satisfactory results without complications, with ergonomic advantages of the inclusion of a tarsal strip. The versatility of the MT flap extends to its use for correction of upper lid retraction, and for formation of the posterior lamina of full thickness small to subtotal lower lid reconstructions.

KEYWORDS:

• Myotarsal flap resection for ptosis
• new ptosis operation
• refined ptosis operation

Levator resection with excision of the upper portion of the tarsal plate via the conjunctival approach for correction of ptosis was initiated by Bowman in 1857. Blascovics in 1923 reported a similar technique with excision of nearly half the tarsal plate as a separate step, after levator resection. All subsequent techniques that use the conjunctival approach for levator resection are based on these two procedures with minor, but at times significant modifications and simplifications, as reported by Agatston, Berke, and Iliff. Beard himself used Agatston’s simplification with modifications such as restoring tarsectomy as a separate step. Beard also suggested modifications to remedy the shortcomings of the Iliff technique.

Mehta further refined, modified, and greatly simplified the “Iliff–Beard” technique by an en bloc one step resection of the levator complex (levator muscle, its aponeurosis, and Müller muscle) with the attached 2 mm tarsal strip, eventually naming this combined entity as the myotarsal (MT) flap. The technique using microsurgical instruments greatly facilitates accurate and clean dissection and separation of anatomical planes to ensure consistently good results. The tarsal strip allows secure, safe, and ergonomic handling of the flimsy and frail muscles which would otherwise fray, button hole, or may even be “lost.” Mehta used his local anaesthesia (LA) technique to achieve preoperative orbital decongestion and pre-cauterisation of the tarsal strip for an “avascular” field to facilitate surgery. Several perioperative practices – like Frost suture and compressive dressing then routinely practised – were abolished for further simplification that allowed patients to be treated as day cases.

Material and methods

The aim of this non-comparative study is to describe an original, refined new technique of ptosis correction, and to demonstrate its consistency and safety in obtaining optimal results in over 400 patients, all with acquired myogenic ptosis, operated upon by the author between 1976 and 1992. The vast majority of patients were between the age of 60 and 75 years. Thorough assessment was carried out at the initial consultation to assess the cause and extent of the ptosis. In majority of patients, moderate MT flap resection of 15+ mm was required.

Tensilon test was carried out to exclude myasthenia gravis. All patients gave informed consent when the decision for surgery was explained to them. Surgery was under LA. The details of the perioperative management are given below. The vast majority of patients underwent surgery under LA as day cases – discharged home 1–2 hours after surgery.

Patients were seen for first dressing at 48 hours and at 7 days for removal of stitches. Subsequent follow-up (FU) visits were at progressively doubled intervals till discharge at 6 months. An eye shield was the only “dressing.” The shield was worn only at night after the first dressing, till the removal of sutures. Antibiotic eye ointment was used twice daily for 1 week, and then nocte for 3 weeks. Antibacterial tablets were prescribed for 5 days.

Results were assessed by skilled clinicians, on these criteria: (i) elevation of the lid at least above the visual axis; (ii) normal contours of the lid without distortion, with the eyelid conforming to the contours of the globe; (iii) static and dynamic symmetry of upper eyelids; (iv) formation of a normal lid fold, in symmetry with the opposite upper lid fold; (v) healthy comfortable ocular surface and cornea; and (vi) patient and surgeon satisfaction with the aesthetic outcome.

Twenty-three patients were admitted to hospital, 12 for simultaneous bilateral surgery under LA, and the rest for social convenience.

Fifteen random specimens of large (20+ mm) resected MT flap were sent for histology to check the presence of striated (levator) and smooth (Müller) muscle.

Surgical technique

Surgery was under 3× spectacle magnification, using microsurgical instruments – Vannas scissors with straight 3 mm blades, conjunctival micro-forceps, and razor fragment micro-scalpel. Surgical steps shown in Figures 1 and 2 are as follows:

1. Along the upper border of the tarsal plate, draw a skin marking line s-s' for creation of lid fold (Figure 1a). Stay mattress suture of two metric black silk is passed at the margin of upper eyelid from the conjunctival surface.

2. The lid is everted on Desmarres retractor – modified by this author for ergonomic convenience (Figure 1 a'), entwining the stay suture on to the retractor.

3. Lines x–x′ and y–y′ – 2 mm distal and 2 mm proximal to upper border of the tarsal plate, on the conjunctival surface, are dot marked, cautery points applied along these lines, and to prominent blood vessels to minimise bleeding (Figure 1b).

4. Proximal line y–y′ is for creation of fornix-based conjunctival flap. Conjunctiva at the centre of the line is button holed with Vannas scissors. The blade enlarges the incision along the entire y–y′ line (Figure 1c). Müller muscle fibres are snipped off from conjunctiva (Figure 1d), which is undermined up to the superior fornix, to obtain a fornix-based conjunctival flap with a free edge. This flap then covers the cornea to prevent trauma and desiccation during surgery (Figure 2g).

5. Dissection of levator complex in the plane between levator and orbicularis to fashion the flap with levator and Müller muscles attached to the tarsal strip, and to sever the fibrous strands connecting the orbital septum to the aponeurosis, leaving the orbital septum in situ and intact and not requiring to be sutured.

Figure 1. Schema of surgical technique of ptosis correction with MT flap resection. (a') Author’s minor modification of Desmarres retractor for ergonomic conveniences; (a) line w–w′ – orbital sulcus, s–s′ line for formation of skin fold; (b) cautery applied along dotted points of lines x-x' and y-y'; (c) for creation of conjunctival flap, button hole line y-y' and cut along the line with Vannas scissors, and; (d) snip off Müller muscle fibres from conjunctiva; (e) along line x-x' a deep groove is carved with # 15 blade, the centre 4mm of the groove is button holed, and the tarsus cut along the groove with Vannas scissors, to create the MT flap; (f) mobilised MT flap after severance of medial and lateral horns of aponeurosis for resections exceeding 12 mm; (g) double armed sutures coapting conjunctival flap and levator; (h) resection of MT flap distal to sutures; (i-j) sutures being tied onto the bolster.

Figure 2. Composite image of several patients’ intra-operative steps for enhanced understanding. (a) Skin marking for lid fold; (b) gentle orbital compression after LA, 30 min pre-op; (c) resulting orbital decongestion – in a patient needing blepharoplasty and simultaneous MT flap resection; (d) cautery applied along dotted lines; (e) created conjunctival flap; (f) along line x-x' having created the tarsal groove with # 15 blade, the centre 4mm of the groove is perforated by the heel of the blade, and Vannas scissors are insinuated in the button holed tarsus cutting along the entire Groove to create the tarsal strip of the MT flap, which then is mobilised by cutting the medial and lateral horns of the levator aponeurosis; (g) mobilised MT flap, conjunctival flap protecting cornea, and ocular surface; (h) three double armed mattress sutures coapting conjunctival flap and levator; (i) evidence that MT flap contains levator and Müller muscles, shown separated by scalpel handle; (j) resected 18+ mm MT flap; (k) sutured blepahoplasty of (c), white silk sutures surfaced as per L-mnemonic; and (l) rubber bolster at first dressing.

With acknowledgements to PostScript Media Pvt Ltd.

Along entire cautery line x–x′, a deep groove is carved in the tarsus with #15 blade (Figure 1e). The centre 4 mm of the groove is perforated by the heel of the blade. One blade of Vannas scissors is insinuated in the button-holed tarsus, which is cut through along the groove to obtain the 2-mm tarsal strip of required width, with the attached twin muscles of levator complex. Ptosis clamp or mosquito forceps are applied to distal edge of the strip (Figure 1f). Tarsal strip allows a firm, secure, and safe handling of the attached flimsy and frail levator complex, which could otherwise fray, button-hole, and may even be unidentifiably “lost,”.

• (VI)Division of the medial and lateral horns of the levator aponeurosis is carried out to obtain a mobile MT flap (Figures 1f and 2g-i), for resections larger than 12 mm.

• (VII)Three double-armed mattress sutures of 1 metric white silk equally spaced are passed above the free edge of the conjunctival flap, with the lateral arm of each suture kept longer for an L-mnemonic explained below.

• (VIII)These mattress sutures are then passed through the levator muscle – 3 mm proximal (superior) to the intended extent of resection (Figure 1g). The conjunctival flap and the levator are approximated by pulling on the sutures.

• (IX)The MT flap distal to the sutures is then carefully resected and discarded (Figures 1h and 2j).

• (X)The needles of the three double-armed sutures are passed at (not through) the upper edge of residual tarsus to emerge on the pre-marked skin line and sutures are tied on to rubber bolster – the lateral arm emerging lower – below the skin line(Figures 1i-j and 2k-l). This L-mnemonic avoids confusion should the sutures get entwined or twisted, (Figure 2k-l).

Results

There were no complications or poor results, which almost always ensue faulty technique. None of the day patients needed to be seen earlier than at their scheduled FU. No patient had post-LA, intra or post-operative haematoma or oedema of eyelids, ocular irritation, or corneal exposure despite absence of Frost sutures or compressive dressing. Judged by the comprehensive criteria listed above, the results were mostly satisfactory, with formation of normal and symmetrical lid folds (Figure 3). The 2-mm tarsectomy did not produce a secondary crease in the eyelid, which retained its normal cosmesis. There was good eye closure during sleep, and on examination.

Figure 3. Female of 54, with severe acquired myogenic ptosis and spastic entropion RLL – satisfactory result after 20 mm MT flap resection. (a) Pre-op; (b) left eye at one week post-op, note worsening of RUL ptosis, as predicted by Herring’s law; (c) right eye, one week post-op, MT flap resection, and entropion correction. (d) Final satisfactory result at 3 months.

Reproduced from Br J Ophthalmol. Mehta HK, The contralateral upper eyelid in ptosis: some observations pertinent to ptosis corrective surgery, 63(2):120–124. Copyright 1979, with permission from the BMJ Publishing Group.

Twenty-one patients had suboptimal cosmesis – 14 under corrections (Figure 4): one gross over correction that needed two further operations to balance the levels of the two eyelids, with preserved fascia lata graft, and a further levator resection confined to the medial half of the eyelid with satisfactory outcome (Figure 5). Six patients had minimal slanting of the lateral half of the eyelid margin, not needing further surgery as the eyelid margins were above the visual axis. The suboptimal outcomes were from my over cautiousness, or momentary timidity, and not because of any shortcoming of the technique. Such outcomes also result from an adverse idiosyncratic response or anatomical quirk of the involved tissues of that particular patient.

Figure 4. Progressive worsening of severe ptosis of 20 years enforcing head posture in a patient of 76, with suboptimal acceptable under correction. Left image: preoperative head posture – exposed nostrils. Right image: acceptable under correction despite 24 mm MT flap resection, suboptimal result from my over cautiousness and brief timidity, the MT flap excision should have been 26 mm. No further surgery needed, as the visual axis is clear without CHP.

With acknowledgements to PostScript Media Pvt Ltd.

Figure 5. Seesaw relationship of upper lids – over correction of ptosis in patient aged 68. (a) LUL ptosis after intracapsular cataract extraction and iris-clip IOL (1976); (b) pupil dilatation after retrobulbar LA injection would have dislocated the IOL to prevent that subconj injection of pilocarpine 0.1 ml, 4%, given 5 min before retrobulbar LA with effective miosis; (c) 8 mm MT flap resection resulted in over correction; (d) attempted correction with a rectangular preserved fascia lata graft and resulting medial half slanting lid margin; (e) further corrective surgery with 4 mm levator complex resection confined only to medial half at one week; and (f) final satisfactory result.

With acknowledgements to PostScript Media Pvt Ltd.

Histology of all 15 random specimens of the MT flap resections confirmed the presence of striated (levator) and smooth (Müller) muscles.

Discussion

Prior to 1857, surgical correction of ptosis was by skin excision, at times with the underlying orbicularis. Levator resection via the conjunctival approach was initiated by Bowman in 1857,¹ though Blascovics 1923² is mostly credited with pioneering the technique. His excision of 5 mm of tarsus resulted in distortion of the eyelid. Further modifications and simplifications were reported by Agatston,⁶ Berke,⁷ and Iliff.^8,3 Iliff described a variation wherein a few millimetres of the upper edge of the tarsus with levator aponeurosis, Müller muscle, and their conjunctival lining were resected en bloc as a single step procedure. The lower edge of aponeurosis was then sutured to the upper edge of residual tarsus, the sutures ultimately emerged through the skin above the lash line to be tied on to a bolster.

Beard 1976⁴ considered that the Iliff technique sacrificed too much of conjunctiva and that the sutures emerging onto the skin just above the eyelashes may produce ectropion. Beard suggested emergence of the sutures at the upper border of tarsus to form a normal skin fold. Beard himself preferred conjunctival approach, using his own modification of Agatston’s technique, adding excision of the tarsal strip as a separate step,⁵ and suturing the levator to the residual tarsus. The technique required two layers of sutures.

Mehta considerably refined, modified, and simplified the “Iliff–Beard” technique, by a one step, en bloc resection of levator muscle, aponeurosis, and Müller muscle attached to a 2-mm tarsal strip, eventually naming this composite entity as the MT flap.⁹ The technique needs only one layer of sutures – those coapting the conjunctival flap and the residual levator muscle. They are then passed at (not through) the upper border of the remaining tarsus (i.e., not suturing to the tarsus), passing through the orbicularis to emerge at the pre-marked line on the skin to be tied onto a rubber bolster as per the L-mnemonic, to obtain a normal skin fold (Figures 3, 4, and 6). Mehta also discarded several perioperative rituals and fetishes like Frost sutures, taping of the eyelids, compressive dressing, and admitting patients to hospital. Thus, simplifying and refining the technique, Mehta “de-Frosted” in the last 28 of his 30+ years surgical experience.

Figure 6. (a) Congenital ptosis and compensatory retraction of fellow upper lid in a child of 8. Compensatory retraction affecting contralateral upper and lower lids. Parents and child were as much concerned about the drooping eyelid as about the staring R eye; (b) total inaction of levator and sup rectus muscle on attempted up gaze. Absence of lid fold aggravates poor cosmesis. The L eye also remained half open in sleep; therefore, a deliberately small – 8 mm MT flap – resection was carried out to attain mild improvement of ptosis, but predominantly to elicit reduced retraction of both eyelids of the right eye; (c) 1 week post-op; and (d) final predicted cosmetic improvement enhanced by the lid fold.

Reproduced from Br J Ophthalmol. Mehta HK, The contralateral upper eyelid in ptosis: some observations pertinent to ptosis corrective surgery, 63(2):120–124. Copyright 1979, with permission from the BMJ Publishing Group.

Tarsectomy came into disrepute by the overzealous excision of 5 mm of tarsus advocated by Blascovics. It has been maligned, as an unnecessary mutilation that is dreaded to produce gross deformity of the eyelid. The first recorded tarsectomy was by Bowman, 1857.¹A small tarsectomy of 2–3 mm is an excellent and benevolent addition to ptosis surgery, fully endorsed and practised by Beard, “… the first surgeon to excise a strip of tarsus made the first real step forward in the treatment of ptosis.”¹⁰Mehta has carried out 2–3 mm tarsectomy in over 500 patients – 400+ ptosis corrections and over 150 full thickness reconstructions of lower eyelids using MT flap – without complications, establishing the merit and boon of a small tarsectomy. Beard implemented tarsectomy as a separate step, whereas my tarsectomy is an en bloc one step MT flap resection with the ergonomic advantages of the tarsal strip mentioned below.

Obtaining a 2-mm tarsal strip from the proximal tarsus leaves the distal 8 mm of tarsus in situ with its meibomian glands, and produces no distortion of lid contours, or ocular surface problems. This tarsal strip – Figures 1 and 2 – allows a firm, secure, safe, and ergonomic handling of the fragile and frail levator complex. Müller muscle is only 0.5 mm in thickness. Iliff states, “This muscle is extremely fragile … and firmly adherent to the conjunctiva. … For these reasons few surgeons are able to isolate it as a distinct entity at the time of the operation.”¹¹ It is therefore gratifying to demonstrate that with this refined technique, isolation and identification of Müller muscle has always been possible under direct visualisation, (Figure 2i).

Not all surgeons will think it necessary to carry out the Tensilon test in all patients with acquired myogenic ptosis. As the test was positive in 7 of the 400+ cases, I feel justified in advocating it. The presenting symptom in all seven patients was ptosis only without lid lag or other signs or symptoms of myasthenia gravis. They were referred to physicians, who controlled their myasthenia – including the ptosis – with pyridostigmine without need for surgery.

Any proven reliable technique of LA can be used for MT flap resection for ptosis correction, as long as it induces effective anaesthesia and abolishes blepharospasm during surgery. Long-acting LA agent bupivacaine mitigates postoperative pain and discomfort. I used my LA technique,^12,13 which I had standardised for all major intraocular and oculoplastic surgery, using retrobulbar and van Lint facial block 30 min preoperatively, followed by careful gentle orbital compression (Figure 2b-c), to achieve orbital decongestion for a hypotensive “avascular” field. This coupled with cauterisation along the margins of the tarsal strip, and of any prominent blood vessels, yields a bloodless or “less-blood” surgical field. Absence of intraoperative orbital haemorrhage or haematoma facilitated accurate surgery in all patients.

Intraoperative suture adjustment to assess the lid elevation is being practised and advocated by many surgeons. As I did not practise this in any of the 400+ patients of this study, administration of van Lint facial block presented no disadvantage. Similarly, I have never practised intraoperative suture adjustment for strabismus surgery or for correction of upper lid retractions.

Sub-Tenon’s block was not available during this study, as it was first reported in the United Kingdom in 1992.¹⁴

For acquired myogenic ptosis, I have adopted the useful working scheme recommended by Beard,¹⁵ for correction of bilateral congenital ptosis: (i) for mild ptosis of up to 2 mm, a small levator resection of 10–13 mm; (ii) for moderate ptosis of 3 mm, a 14–17 mm levator resection; and (iii) for severe ptosis of 4 mm or more, a maximal resection of 23+mm are required. It is easy to calculate from this that 6 mm of levator resection corrects 1 mm of ptosis. For MT flap resection, I include the 2 mm of tarsal strip in the measurement. Therefore, the extent of resected tissues is in (i) almost the entire aponeurosis and the whole of Müller muscle, in (ii) 6 mm of levator muscle, and the whole of aponeurosis and Müller muscle, and in (iii) 14 mm of levator and the whole of aponeurosis and Müller muscle are resected away. With MT flap technique, maximal resection under direct vision is possible. I have used these guidelines with satisfactory results. Sarver and Putterman have also reported satisfactory results in congenital ptosis using their formula derived from preoperative estimation of margin to limbal distance (MLD) to predict the required amount of levator resection.¹⁶

Beard explains, “…the levator is a voluntary muscle capable of opening the eye, whereas Müller muscle aids in maintaining the eyelid in an open position….”¹⁷ The moderate MT flap resection of 15+ mm was the commonest procedure in this study, implying that entire aponeurosis, and the whole of Müller muscle, was resected away. Despite this, no patient had difficulty in keeping the eye open. This study indicates that after ptosis correction, Müller muscle is “dispensable,” apart perhaps for its “fright, flight, or fight” adrenergic responses.

It is crucial to understand that MT flap (levator complex) resection is used for ptosis due to deficient levator function. For ptosis resulting from dehiscence or disinsertion of the aponeurosis, the simple technique of aponeurosis repair by conjunctival approach reported by Collin in 1979 is very effective.¹⁸

Surgery for ptosis or indeed any surgical procedure is surrounded by rituals and fetishes, which are inversely proportional to the stage of evolution of the technique, and the insight of the surgeon. With progressive simplification of the technique, such perioperative rituals continue to be discarded, as explained above for Frost sutures. I have never used the Fasanella–Servat procedure, as the MT flap resection can be appropriately calibrated from small (8 mm) to maximal resection. I have always used the conjunctival approach for ptosis correction as it has many advantages, including its simplicity and ease also endorsed by Beard.⁵

Putterman and Urist have reported good results with their modification of Fasanella–Servat procedure for correction of mild ptosis. Their technique without a tarsectomy uses a special clamp to implement 8–9 mm of Müller muscle conjunctival resection. But this sacrifices 8–9 mm of precious conjunctiva.¹⁹

An important point to be made here is that all surgical techniques for correction of ptosis are utilised only to elevate the ipsilateral drooping eyelid. Mehta has additionally used surgery on the drooping eyelid to influence the level of the compensatory retraction of the contralateral upper lid without operating on that eyelid, as follows. The validity of Hering’s law of reciprocal innervation of the levator muscles of the two eyes in ptosis surgery was first reported by Mehta in a case of unilateral congenital ptosis (Figure 6). The second case was of a total and stabilised left third nerve palsy with paralytic ptosis, with gross compensatory retraction of the right upper lid. Despite being aware of the futility of MT flap resection to improve the paralytic ptosis, I carried out MT flap resection on the paretic left upper lid primarily to reduce the retraction of the right upper lid. This strategy improved the cosmesis considerably by reducing the gross retraction of the right upper lid and by providing a lid fold to the permanently drooping left upper lid.²⁰

In conclusion, when several minor but significant modifications of a surgical technique accrue cumulatively, they culminate into an ideal technique reaching perfection, where nothing more needs be discarded or added. Ptosis surgery has undergone this evolution.

All competent surgeons aim to achieve results that balance the patient’s expectation and their own desire to attain near normality of structure and function. In oculoplasty, there is an added factor of cosmesis, in balancing a patient’s realistic expectations, and the artistry of the surgeon. This is succinctly expressed by Roper-Hall, “The results of surgical treatment of ptosis should be judged by the functional ideal of a physiologist, and cosmetic standard of an artist.”²¹ The technique using the finessed MT flap reported here attains these standards and has the added advantage of the versatility of the MT flap, in its additional capability to be used for (i) correction of upper lid retraction where the tarsal strip makes it safe, secure, ergonomic, and easy to suture a spacer to the tarsal strip rather than to the flimsy muscles, and (ii) for reconstruction of full thickness defects of lower lid, where a 3-mm tarsal strip is used for the MT flap to reconstruct the posterior lamina.

Disclosure statement

Author reports no conflict of interest. The author alone is responsible for the content and writing of this article.