Müller Muscle Conjunctival Resection Versus External Levator Advancement
A droopy eyelid can significantly affect your vision; if your vision is compromised ptosis surgery may be required. Ptosis may be acquired when the levator muscle separates or is stretched away from the eyelid or may be caused by other conditions such as mechanical, myogenic, neurogenic, or traumatic injury.
We were recently asked about two common surgical interventions that are very different treatments for ptosis surgery; we will show you the differences here in this article. The techniques are both providing eyelid elevation with different interventions. One procedure is done with an external approach repairing the levator tendon, while the other technique is an internal repair of the müllers muscle, tarus, conjunctive, or levator tendon. We are going to look at both methods; one is called Müller's Muscle Conjunctival Resection (MMCR) and a Levator Advancement (LA).
Prior to any procedure being done, the patient is tested for levator function. According to Opthalmology Web, "On clinical evaluation, it is important to measure palpebral fissure height, levator function, and marginal reflex distance. If the patient has good levator function, a CMMR or LA may be appropriate. Many will test the patient in a clinic by putting one to two drops of phenylephrine underneath the ptotic lid to check whether Muller's muscle responds and the lid elevates. If the lid responds, the patient is likely a good candidate for a CMMR. If the lid does not respond, some will proceed with a CMMR regardless, but many will resort to a LA."
Internal/transconjunctival repair of the Müller's muscle, tarsus, conjunctiva, or levator complex
A Mullerectomy 67908 is surgical resection, removing the muscle procedure in which the Müller's muscle and underlying conjunctiva are resected to treat a mild case of ptosis. A Mullerectomy is most commonly done where ptosis is less than 3 mm, and the patient has good levator function and spares the tarsus. The AMA description for the procedure is; "Repair of blepharoptosis; conjunctivo-tarso-Muller's muscle-levator resection."
The classical levator resection (LR) technique for correcting ptosis involves separating the levator palpebrae superioris muscle (LPS) completely, with the intention of the muscle collapsing. I have also seen this procedure called CMMR Conjunctival Müller's Muscle Resection.
- Internal Repair
- ptosis is less than 3 mm
- the patient has good levator function
External/transcutaneous repair of the levator complex
67904 Repair of blepharoptosis; (tarso) levator resection or advancement, external approach
In cases of more severe blepharoptosis that is greater than 3 mm, an external levator advancement is recommended and often done with the removal of excess skin and fat.
- External approach
- Severe blepharoptosis that is greater than 3 mm
- Shortens the levator tendon until the lid is at the proper level.
To read more about these procedures, see the following resources.