RYAN VOLUME 3 - Techniques of Scleral Buckling #102 Flashcards
How to perform peribulbar anesthesia?
50:50 lidocaine + bupivacaine or levobupivacaine +/- hyalase.
Advantage: less ballooning of the anterior Tenon tissue.
Disadvantage: globe perforation risk.
In theory, sub-Tenom anesthesia is unsufficient. Why?
Because the inervation of the eylids and palpebral conjunctiva is by lacrimal, frontal and infraorbital nerves, which do not pass through the muscle cone. In practice, sub-Tenon injection is equivalent to other techniques (overspill of anesthetic agents into the peribulbar space).
May be useful adjunct to general anesthesia since it blocks vagus nerve and promotes analgesia in immediate postop period.
What is the best positioning of the head for a buckle?
The orbital rim should be horizontal during surgery - tilt nose away from the operated eye.
If the palpebral aperture is deemed too narrow, what may be done?
Lateral canthotomy.
Conjunctival peritomy
3 - 4 mm (may be 2 mm) behind the limbus. Relieving incisions at 3 and 9 o´clock.
A 360° peritomy is not required if a local explant is planned. 4/0 silk rectus bridle sutures can be passed transconjunctivally.
How can very posterior “sweeps” of muscles hooks be harmful?
They risk damaging the vortex veins.
How to reduce the risk of hooking the superior oblique?
Passing the superior rectus muscle hook from the TEMPORAL side of the muscle and keep the sweep of the hook PRE-EQUATORIAL.
The superior oblique insertion if frequently encountered on the temporal side of the muscle and can be an obstacle to scleral suturing. What can be done?
Division of a small (less than 1/3) portion of the muscle insertion.
Note that a vortex vein is usually present under the temporal edge of the superior oblique insertion.
How to reduce the chance of inadvertently hooking the inferior oblique while passing a muscle hook under lateral rectus?
Pass the hook from the superior side.
