|LETTER TO THE EDITOR
|Year : 2016 | Volume
| Issue : 5 | Page : 406-407
Comment on: Bilateral lateral rectus myotoxicity after retrobulbar anesthesia
Madhurima K Nayak
Department of Ophthalmology, Kasturba Medical College, Mangalore, Karnataka, India
|Date of Web Publication||6-Jul-2016|
Dr. Madhurima K Nayak
C II 12, KMC Staff Quarters, Light House Hill Road, Mangalore - 575 002, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nayak MK. Comment on: Bilateral lateral rectus myotoxicity after retrobulbar anesthesia. Indian J Ophthalmol 2016;64:406-7
|How to cite this URL:|
Nayak MK. Comment on: Bilateral lateral rectus myotoxicity after retrobulbar anesthesia. Indian J Ophthalmol [serial online] 2016 [cited 2020 Jun 3];64:406-7. Available from: http://www.ijo.in/text.asp?2016/64/5/406/185633
The article titled, "Large exotropia after retrobulbar anesthesia," by Kim and Kim  is well-written and a very rare and an interesting one. I commend the authors for the workup of the case and its management.
An observation made is that lateral rectus alone is affected in both the eyes. Due to similarity, though asymmetry, of affection, a question, whether the muscle and the individual are susceptible to myotoxicity, is raised. Direct injection into the muscle is another possibility which can be ruled out if the extraocular movements were tested after inserting the needle and before injecting the anesthetic.
Myotoxicity either due to injection of anesthetic into the muscle or its proximity causes degeneration followed by regeneration of muscles in a span of 3-4 weeks as shown by some studies , whereas permanent restriction was reported in a few cases. , In the present case, there was progressive deterioration of contracture of lateral recti which is a rare phenomenon.
The right eye was operated first followed by the left. Was there any restriction of movements noted in the gap of 1 month? It is also not clear, exotropia was observed after how many days following surgery. This information provided by the authors may help practitioners to anticipate and correlate the condition. Histologically, there is the appearance of macrophages within the muscle fibers which phagocytose fragmented cytoplasm, seen as early as 14 hours.  The role of inhibitors of macrophage recruitment to the site of inflammation has to be elucidated in future. At molecular level, increased intracellular Ca 2+ appears to be a necessary element in myotoxicity.  Hence, intervention at molecular level may open doors to such myotoxicity.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Kim CH, Kim US. Large exotropia after retrobulbar anesthesia. Indian J Ophthalmol 2016;64:91-2.
Benoit PW, Belt WD. Destruction and regeneration of skeletal muscle after treatment with a local anaesthetic, bupivacaine (Marcaine). J Anat 1970;107(Pt 3):547-56.
Zink W, Graf BM. Local anesthetic myotoxicity. Reg Anesth Pain Med 2004;29:333-40.
Rainin EA, Carlson BM. Postoperative diplopia and ptosis. A clinical hypothesis based on the myotoxicity of local anesthetics. Arch Ophthalmol 1985;103:1337-9.
Capó H, Roth E, Johnson T, Muñoz M, Siatkowski RM. Vertical strabismus after cataract surgery. Ophthalmology 1996;103:918-21.