Scleral Ischemia & Melt Frequently Asked Questions
Is it safe to use retrobulbar or peribulbar anesthesia?
Both peribulbar and retrobulbar anesthesia, if not done properly, can induce orbital congestion and hemorrhage that will distort the tissue planes and make isolation of the Tenon's capsule difficult.
Can I retrieve the Tenon from the caruncle area?
No. It is better not to do so because Tenon's capsule retrieved from the caruncle area might result in contracture, leading to motility restriction. Therefore, it is better to take Tenon from the superior or the inferior fornix.
Do I always need to perform lamellar corneal graft?
No. If the scleral melt is not full thickness and large, multiple layers of cryopreserved amnion graft are sufficiently strong to restore the scleral integrity. That is why lamellar corneal graft is not used in acute chemical burns when there is scleral ischemia without melt. However, when the scleral melt is near full-thickness and large in size, it is necessary to reinforce the tectonic support. In addition to lamellar corneal graft, one can also consider scleral graft or pericardium graft (also see Literature Summary).
Should the amnion graft be trimmed while still on the paper or after being laid on the defect?
As a personal preference, the entire amnion graft is best laid on the defect without trimming. The excessive graft and fibrin gel can be trimmed after the glue has set. This avoids the graft being cut too small to cover the defect.
What is the real value of using fibrin glue?
The use of fibrin glue eliminates sutures, which can be very difficult to do especially if the melt is close to the equator. Due to the lack of sutures, the surgical time is shortened to the point topical anesthesia is feasible in most cases.
Should I perform tarsorrhaphy at the end of the surgery?
For most cases, it is not necessary to do so. However, for severe chemical burn, especially if the lid margin is also involved and if there is a thermal component (e.g., firework injury), it is a good idea to bring the lid margin together with tarsorrhaphy, which will prevent exposure (due to lack of effective blink and closure) and wound contracture to the lid tissue.
Should I perform transplantation of limbal stem cells at the same time in acute chemical burns?
No. It is better to wait until the limbal tissue has been fully vascularized by the aforementioned procedures before transplantation of autologous or allogeneic stem cells. Therefore, it is better not to do it at the same time.
Why is cryopreserved amnion graft (AMNIOGRAFT®) recommended?
AMNIOGRAFT® is the only commercially available cryopreserved amnion graft in the U.S. The method of cryopreservation retains the biologic actions of the tissue in utero (anti-scarring, anti-inflammation, antiangiogenesis, and promotion of healing).
What if the patient experiences pain after surgery?
This complaint is infrequently observed using the surgical methods detailed above. If it is, use analgesics.
Is it necessary to use ointment and patch at the end of surgery?
Application of an antibiotic/steroid ointment such as Tobradex® and a patch at the end of surgery maintained overnight, stabilizes and secures the graft.
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