Surgical Assisting Procedures Flashcards

During a phacoemulsification procedure, the surgeon requests a second instrument to manage a posterior capsular rent. Which maneuver should the scrub technician anticipate next to prevent vitreous prolapse?

Answer: Injecting a cohesive viscoelastic into the anterior chamber to tamponade the rent

A posterior capsular rent risks vitreous prolapse. The immediate response is to inject a cohesive viscoelastic (e.g., Healon GV) into the anterior chamber to tamponade the break, stabilize the remaining lens material, and protect the vitreous face. Lowering bottle height is secondary; increasing aspiration would worsen prolapse; ECCE conversion is a last resort decided by the surgeon.

A surgical technician is preparing the back table for a trabeculectomy with adjunctive mitomycin-C (MMC). Which handling protocol is most critical from an ocular toxicity standpoint?

Answer: Ensuring MMC-soaked sponges never contact the cut edge of the scleral flap and performing copious BSS irrigation before scleral flap suturing

MMC is an antimetabolite that can cause severe avascular blebs, hypotony, and endophthalmitis if it contacts the wound edges or drains inadequately. The critical protocol is preventing MMC sponge contact with cut tissue edges and performing copious BSS lavage (at least 20–30 mL) before suturing. Disposing MMC in the scrub sink violates hazardous waste protocols; exposure time varies by surgeon/concentration; titanium vs. regular forceps is not the key safety point.

During a scleral buckle procedure for a complex retinal detachment, the surgeon has placed a circumferential band and now requests cryotherapy. The technician notices the cryoprobe tip has formed an ice ball that is NOT releasing from the scleral surface. What is the most appropriate immediate action?

Answer: Wait for passive thawing of the ice ball before attempting to remove the probe

If a cryoprobe ice ball adheres to the sclera, the correct action is passive thawing — waiting until the ice ball melts naturally before attempting removal. Applying traction can tear the sclera or underlying choroid. Cold BSS will not thaw the ice and may worsen adhesion. Defrost mode exists on some units, but the safest universal protocol is passive thaw, avoiding any mechanical force.

A COT assisting in a penetrating keratoplasty (PK) must hand the surgeon a trephine of the correct diameter. The donor button is trephined 0.25 mm LARGER than the host bed. What is the primary optical and structural rationale for this size discrepancy?

Answer: To create wound apposition that reduces the risk of wound dehiscence and flattens the graft to reduce astigmatism

Oversizing the donor button by 0.25–0.5 mm relative to the host trephination creates positive wound apposition: the graft fits under slight tension, reducing the risk of wound leak/dehiscence and helping maintain anterior chamber depth. It also tends to flatten the central cornea slightly, counteracting the steepening that suture tension alone would cause. Optisol-GS does not cause clinically significant graft shrinkage; AC shallowing is managed by viscoelastic, not graft size.

While assisting in a vitreoretinal case requiring perfluorocarbon liquid (PFCL) injection, the surgeon asks you to prepare the exchange to silicone oil. Which property of PFCL makes it specifically useful for unfolding a giant retinal tear (GRT) before tamponade?

Answer: Its specific gravity greater than 1.0 causes it to sink posteriorly, mechanically flattening the retina from behind

PFCL has a specific gravity of approximately 1.76–1.94 g/mL — significantly heavier than water or vitreous. In a supine patient, it sinks to the posterior pole and mechanically unfolds and flattens a giant retinal tear against the RPE, preventing the tear from slipping posteriorly and allowing the surgeon to place endolaser retinopexy. Its low viscosity (not high) can actually allow it to pass through large breaks, making surgeon technique important. Osmotic pressure is not its mechanism.

During a DSAEK (Descemet Stripping Automated Endothelial Keratoplasty) procedure, the graft is being inserted with a Busin glide. The technician notices the graft has folded endothelium-to-endothelium inside the anterior chamber. What is the surgeon's most likely next step, and how should the technician prepare?

Answer: Refill the anterior chamber with air and use a 30-gauge cannula to carefully float and unroll the graft

A folded DSAEK graft (endothelium-to-endothelium) is a recognized intraoperative complication. The standard rescue maneuver is to fill the AC with an air bubble, which provides the surface tension needed to float and gently unfurl the graft using a 30-gauge cannula through a paracentesis. The air bubble also helps center and adhere the graft. Cohesive viscoelastic alone cannot unfold it safely; immediate removal discards viable tissue unnecessarily; external sponge pressure risks graft damage and cannot access the fold.