This study details the surgical extraction of the inferior lacrimal gland (ILG) in rabbits, focusing on the methodology and anatomical considerations. The ILG plays a crucial role in tear production, and understanding its removal can provide insights into related physiological processes.
In rabbits, the lacrimal glands - endocrine glands within the eyelid and the eye orbit that secrete tears - consist of two types: a larger inferior lacrimal gland, ILG, and a smaller superior lacrimal gland, SLG.
The ILG extends along the inferior and posterior regions of the orbital rim or the margin of the eye socket. To extract the ILG, prep an anesthetized rabbit, removing the fur from its face to visualize the anatomical landmarks.
Using an electro micro-dissection needle, make a precise curvilinear incision through the skin and underlying superficial muscles at the posterior and anterior eye orbits, minimizing the blood loss via tissue coagulation. Identify the fascia or the connective tissue surrounding the cheekbone.
The bulbous anterior ILG portion, known as the head of ILG partially lies on the external surface of the cheekbone, transitioning into the posterior tail of ILG. Make a small incision over the capsule surrounding the ILG head. Cut the orbital septum or the membranous boundary along the inferior orbital rim to expose the posterior ILG tail portion.
Extend the dissection posteriorly along the tissue plane to expose and remove the entire ILG, without disrupting the blood supply. Close the surgical incision. The prepared rabbit model could be studied for the effect of ILG removal on tear production.
To resect the larger inferior lacrimal gland or ILG, use the Colorado microdissection needle to incise and separate the skin, the depressor muscle of the inferior palpebra, the zygomaticolabial part of the zygomatic muscle, and the orbicularis muscle. Maintain hemostasis with the monopolar cautery.
As the incision is carried deeper through the skin marking, look for the sheen of a fascial plane over the zygomatic bone or superficial part of the masseter muscle. At this point, maintain the tissue plane and carry it superiorly toward the orbital rim.
Identify and incise the capsule surrounding the ILG, then, identify the tan tissue of the ILG. Only the anterior portion of the ILG head will be visible, but it can be followed medially as it passes beneath the zygomatic arch and transitions into the tail.
Use tenotomy scissors to cut the orbital septum along the inferior rim, exposing the more posterior portion of the ILG tail. Once the tissue plane is identified, extend the dissection posteriorly along the entire incision line. Use extreme care to not damage the blood supply, which the ILG receives from branches of the carotid artery.
Once the entire ILG has been exposed, remove it. If the tail terminates under the posterior canthus, see the manuscript for excision directions. Due to its large size, it can be preferable to cut the gland in half, and remove the head separately from the tail.
After the gland has been removed, close the deep connective tissue plane with multiple interrupted 5-0 ethylene terephthalate sutures. Then, close the superficial muscles and skin with a running 6-0 polyglactin 910 suture, using 0.3 tissue forceps and a needle driver.
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