Müller’s Muscle-Conjunctival Resection (MMCR) Blepharoptosis Repair

Original article contributed by:	Austin Michael Pharo, MD, Adham al Hariri, MD
All contributors:	Austin Michael Pharo, MD, Cat Nguyen Burkat, MD FACS and Monte A Del Monte, MD
Assigned editor:	Cat Nguyen Burkat, MD FACS
Review:	Assigned status Up to Date by Cat Nguyen Burkat, MD FACS on October 26, 2017.

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Contributing Editors:	add

Introduction

Figure 1) Local anesthetic is injected into the anterior lamella at the mid margin. Photo courtesy of Adham al Hariri, M.D.

First described by Putterman and Urist in 1975 as a modification of the Fasanella-Servat procedure, which includes the excision of 3mm tarsus, MMCR is another posterior eyelid ptosis repair technique which spares the tarsus. Obviously, the advantage being that tarsus is saved, possibly for use in later procedures if needed, the tarsal Meibomian glands remain undisturbed, and it maintains the normal eyelid contour, although some suggest that good eyelid contour can still be achieved with tarsectomy in MMCR. There have been several modifications on the technique originally described, and there are is a significant amount of literature regarding how much resection should be done via interpretation of the phenylephrine test. The mechanism by which MMCR elevates the lid has been a matter of some contention. Some authors state that the effect of the MMCR is actually from advancement of levator aponeurosis. Other authors question this theory and claim that MMCR lid elevation results from a shortening of the posterior lamella, plication (not resection) of the levator aponeurosis, and internal advancement of the levator palpebrae superioris. They make this claim as the Muller’s muscle is easily separated from the aponeurosis, no histologic evidence of levator aponeurosis has been found in histologic specimens of MMCR lids, and plication of the levator aponeurosis was appreciated in histologic specimens.

Figure 2A) A 4-0 Silk traction suture is placed through the upper lid margin. B,C) The 4-0 Silk and a q-tip are used to evert the lid, D) exposing the underlying palpebral conjunctiva, tarsus and Müller’s muscle. Photo courtesy of Adham al Hariri, M.D.

Regardless, MMCR remains an effective tool for the repair of small amounts of blepharoptosis. MMCR gives more predictable results compared to levator aponeurotic procedures, and is cosmetically valuable as it is a posterior ptosis repair with the incision being through the conjunctiva and not through skin, leaving no visible scar behind.

Indications

This procedure is a good choice for a mild to moderate amount of ptosis, good levator function and a response to Phenylephrine. Since it is a posterior approach and leaves no visible scar, MMCR is a great tool in a cosmetic surgeon’s repertoire for ptosis repair

After the surgeon determines that a patient has ptosis, the surgeon must determine if the patient is a good candidate for MMCR. An ideal candidate for this procedure has a small amount of ptosis (approx. 2.5mm) and has good levator function.

If the patient has poor levator function (i.e. <15mm), involutional ptosis may be the etiology of the patient’s presentation, and MMCR surgery may not adequately correct his ptosis. Instead, the surgeon should consider an external levator resection for ptosis repair. Also, if excess skin is present, this is often removed by a blepharoplasty surgery that is separate from the conjunctivo-mullerectomy procedure.

Figure 3A) The superior tarsal margin is marked with a marking pen, and B) calipers are used to mark the half of the desired resection distance superiorly from the margin of the tarsus. Photo courtesy of Adham al Hariri, M.D.

Phenylephrine test (PE test)

Muller’s muscle is smooth muscle that is innervated by the sympathetic nervous system, and when the muscle is contracted, it elevates the lid approximately 2.5mm. Phenylephrine is an adrenergic stimulant which stimulates the sympathetically innervated Muller’s muscle to contract and thus elevate the lid.

A comparison between 2.5% and 10% Phenylephrine did find a difference in the elevation of the upper lid of less than 0.4 mm between the two concentrations but such a small difference is not felt to be significant enough to cause a change in the surgical outcome.

To perform the PE test, first measure the MRD1 prior to instilling any drops. Now, place topical proparacaine or tetracaine drops into the eyes, tilt the patients head back, elevate the upper lid, and instruct the patient to look downwards. A drop of 2.5% or 10% Phenylephrine is then placed into the superior fornix, repeating 2-3 times within 1 minute and then a final drop one minute later. Allow 5 mins to pass after receiving the last drop of phenylephrine, and re-measure the MRD1. The degree of improvement of the MRD1 from the pre-PE test MRD1 is the amount of desired resection.

Figure 4) A 6-0 Silk suture is run through the superior-most marks. Photo courtesy of Adham al Hariri, M.D.

Figure 5) The 6-0 Silk suture is pulled towards to ceiling, tenting up Müller’s muscle and palpebral conjunctiva. Photo courtesy of Adham al Hariri, M.D.

Some have found that the PE test underestimates the amount of ptosis by MMCR, by even up to 40%, thus this test is not an absolute guarantee of success. This factoid also seems to support the fact that excision of Muller’s muscle alone is not the sole source of the ptosis correction and that some amount of levator advancement may be in part responsible for the effect seen in this procedure.

Keep in mind that the PE test can be used to unmask contralateral ptosis as well, and the surgeon should be aware of the existence of contralateral ptosis masked by Herring’s law.

PE Test Formulae

There are several formulae devised attempting to correlate the amount of resection performed for the amount of desired lid elevation from the PE test:

1. Putterman and Fett: 8.5mm resection if 10% phenylephrine raises the lid to exactly where you want it, adding or subtracting 1mm of resection for every 0.5mm of desired increased of decreased lid height desired, up to a range of 6.5mm to 9.5mm
2. Weinstein and Buerger: 8mm resection for each 2mm of desired lid elevation and add or subtract 1mm resection for each 0.25mm height difference change in final lid position
3. Dresner: 4mm resection for 1mm of ptosis, 6mm for 1.5mm, 8mm for 2, 10mm for 3mm, 11-12mm for >3mm If PE test undercorrected, the ptosis, 1-2mm more of resection was included. It is hypothesized that perhaps in these cases, the MM has undergone fatty infiltration and is not as responsive.(6)
4. Perry et al: 9mm resection + X mm of tarsus excision (x = distance of undercorrection after ptosis correction. Authors feel that 9mm of resection should result in similar lid height as 10% PE test. Thus, any decrease in height during the PE can be accounted for by tarsal excision (up to a max of 2.5mm of excised tarsus).
   

   Figure 6A) A Putterman clamp is then placed so that the tented apex of the tented Muller’s/conjunctiva complex is between the clamp. B,C) Care must be taken to ensure the teeth are placed at the superior margin of the tarsus only, and that tarsus has not been inadvertently incorporated into the clamp. Photo courtesy of Adham al Hariri, M.D.
   

   Figure 7A,B) 6-0 plain gut suture being used to sew in an anterior to posterior fashion through Müller’s/conjunctiva 1.5-2.0mm below the clamp. This A-P sewing is begun at the lateral edge of the eyelid and sewn to the medial edge, then the course reversed and sewn back in the same manner laterally to finish back at the lateral edge (C,D) Photo courtesy of Adham al Hariri, M.D.
   

   Figure 8A-D) A #11 or #15 blade is used to excise the Müller’s/conjunctiva within the clamp. This is done placing the blade “metal-on-metal” against the clamp superiorly, taking care not to cut the suture inferiorly. Photo courtesy of Adham al Hariri, M.D.

Surgical Procedure

Step 1

If the surgeon chooses, the landmarks of the eyelid can be marked prior to any injection or induction of anesthesia which some claim would distort these landmarks and lead to larger than desired resection.

Local anesthesia consists of creating wheals of anesthetic via injecting 2% Lidocaine with 1:100,000 Epi for hemostasis into the upper lid palpebral conjunctiva and also the skin of the upper eyelid (Figure 1). General anesthesia can also be used if necessary because, unlike in levator resections, the procedure does not require the patient to be awake to make intra-operative adjustments.

Step 2

Now that local anesthesia has been allowed to take effect, a 4-0 Silk traction suture (Figure 2A) is placed in the middle of upper lid at its margin passing through conj, tarsus and skin, and the upper lid is then everted over a Desmarres retractor or q-tip (Figure 2B,C), exposing the upper lid palpebral conjunctiva overlying the tarsus and Muller’s muscle (Figure 2D).

Step 3

The superior border of the everted tarsus is marked with electrocautery or a marking pen (Figure 3A).

In this example, a 10mm resection is desired. Calipers are used to measure half of the distance (5mm in this example) of the desired resection starting from the superior border of the tarsus (Figure 3B).

After measuring this distance, three marks 5mm (one medial, one lateral and one middle) equidistant from the superior border of the tarsus are placed with electrocautery or marking pen on the palpebral conjunctiva. A 6-0 Silk running suture is then passed superficially through these marks through the conjunctiva and superficial Muller’s muscle (Figure 4). This suture is then pulled ventrally towards the ceiling, elevating conjunctiva and Muller’s muscle (Figure 5).

NOTE: With Muller’s muscle firmly adherent to conjunctiva, Muller’s muscle should separate easily from the levator aponeurosis to which it is loosely adherent, ensuring that during the resection very little levator aponeurosis is removed. Thus, it is felt that the main reason this procedure works is that there is shortening of the posterior lamella, advancement of the levator palpebrae superioris muscle and plication (not resection) of the levator aponeurosis.

Step 4

Now elevating the conjunctiva and Muller’s muscle with the suture, A Putterman Müller’s muscle–conjunctival resection clamp is placed at the border of the superior tarsus and clamped shut, sandwiching the conjunctiva and Muller’s muscle (Figure 6A).

This clamp has three needles which penetrate through the squeezed conjunctiva and Muller’s muscle so that they do not slip out of the clamp, ensuring the correct desired amount of tissue will be resected (Figure 6B).

Occasionally, tarsus may inadvertently be incorporated into the clamp which is not desired (Figure 6C). If the tarsus has been incorporated, the margin of the lid may be distorted. To evaluate for this, the Desmarres retractor or q-tip is removed, the lid is inverted back into normal position, and the contour of the margin is assessed. If the contour is not normal, tarsus may have been inadvertently grasped by the clamp; therefore, using gentle digital traction, any tarsus is pulled free from the clamp.

Similarly, to ensure levator aponeurosis has not been incorporated, the clamp is then pulled inferiorly while lid skin is pulled superiorly. If there is any tightness, levator aponeurosis may have inadvertently been incorporated, and if this is the case, the clamp needs to be disengaged and placed again.

Figure 9A,B) View showing the 6-0 plain gut being externalized through the lid out at the lateral brow. C,D) Once in satisfactory position, it is tied down, ensuring the palpebral conjunctival defect is successfully closed. Photo courtesy of Adham al Hariri, M.D.

Step 5

To prevent rubbing of the suture knot on the globe surface, we externalize the suture knot. This can be done with or without the use of a bolster to help reduce local skin complications.

Alternatively, if a blepharoplasty is also being performed, the suture can be passed through the wound of the blepharoplasty.

With the clamp successfully in place, the clamp is pulled ventrally to the ceiling, elevating the tuft of conjunctiva and Muller’s muscle. (Figure 7A-B) A 6-0 plain gut suture is then sewn first through skin laterally right above the upper eyelid crease, full thickness through the lid, exiting the conjunctiva near the lateral edge of the superior border of the tarsus. This 6-0 plain gut is then sewn medially in a running fashion 1.5-2.0mm below the inferior margin of the clamp passing full thickness through the conjunctiva and Muller’s muscle. Once the suture reaches the medial edge of the clamp, the suture is then sewn back laterally, again in a running fashion to the lateral edge of the clamp (Figure 7C-D).

Step 6

A #15 or #11 blade (Figure 8) is used to excise the Muller’s muscle-conjunctivo complex enclosed within the clamp from the lid by cutting the complex between the clamp and the sutures, taking care NOT to incidentally cut the sutures with the blade by cutting juxtaposed to the clamp.

Step 7

The suture is then passed back through the palpebral conjunctiva, exiting through the skin near where the suture enters. The Desmarres’ retractor or q-tip is then used to re-evert the lid, and closure of conjunctiva defects is completed via tightening and tying down the 6-0 running plain gut suture to ensure the borders of the conjunctival wound are approximated. The traction suture is then removed from the upper eyelid (Figure 9)

Step 8

If being performed, blepharoplasty can be completed at this point

Antibiotic ophthalmic ointment is placed in the eye at this point

Post-op care

Post-operative care consists of placing antibiotic ophthalmic ointment into the eye and to the suture at the skin three times per day for a total of one week and the patients will follow up for their first post-operative visit after one week.