COT Surgical Assisting Procedures 4 — Questions and Answers
Question 1: Which parameter does the technician monitor on the phacoemulsification machine to prevent thermal wound burns during cataract surgery?
- Irrigation flow rate and aspiration vacuum (Correct answer)
- Intraocular pressure readout only
- Footpedal position sensor feedback
- Microscope illumination intensity
Correct answer: Irrigation flow rate and aspiration vacuum
Adequate irrigation flow must always exceed aspiration to cool the phaco tip and prevent frictional heat from burning the corneal incision.
Question 2: When preparing a toric IOL for implantation, why must the surgeon mark the axis on the cornea preoperatively?
- To align the toric lens to the correct meridian for astigmatism correction (Correct answer)
- To identify the location for the main incision placement
- To document preoperative corneal curvature for billing
- To guide the capsulorhexis direction
Correct answer: To align the toric lens to the correct meridian for astigmatism correction
Toric IOLs correct astigmatism only when their cylinder axis aligns with the steep corneal meridian, requiring accurate preoperative ink marking.
Question 3: The technician notices the surgeon is using a 23-gauge trocar for a small-gauge vitrectomy. What advantage does this instrument size offer over 20-gauge systems?
- Sutureless self-sealing sclerotomies and reduced surgical trauma (Correct answer)
- Greater infusion flow rates for faster vitreous removal
- Better visualization of peripheral retina
- Lower risk of endophthalmitis postoperatively
Correct answer: Sutureless self-sealing sclerotomies and reduced surgical trauma
Small-gauge (23/25-gauge) systems create self-sealing wounds that typically do not require suture closure, reducing operative time and postoperative inflammation.
Question 4: During enucleation surgery, an orbital implant is placed after globe removal. The technician should prepare which material most commonly used for modern orbital implants?
- Porous polyethylene (Medpor) or hydroxyapatite (Correct answer)
- Silicone solid sphere
- PMMA acrylic sphere
- Titanium mesh plate
Correct answer: Porous polyethylene (Medpor) or hydroxyapatite
Porous polyethylene and hydroxyapatite are favored because fibrovascular ingrowth allows direct pegging and superior prosthetic motility.
Question 5: When assisting during a dacryocystorhinostomy (DCR), the technician should have silicone intubation tubes available for what purpose?
- To stent the newly created nasolacrimal ostium and prevent closure (Correct answer)
- To irrigate the lacrimal sac during dissection
- To measure the canalicular diameter intraoperatively
- To deliver topical anesthesia to the nasal mucosa
Correct answer: To stent the newly created nasolacrimal ostium and prevent closure
Silicone bicanalicular stents are passed through the new ostium into the nose to maintain patency while the mucosal anastomosis heals.
Question 6: A surgeon performing a penetrating keratoplasty requests a trephine. What is the function of this instrument?
- To cut a circular button of donor and recipient corneal tissue (Correct answer)
- To measure corneal thickness at the graft margins
- To apply tension to the host cornea during suturing
- To remove Descemet membrane from the donor button
Correct answer: To cut a circular button of donor and recipient corneal tissue
A trephine is a cylindrical punch used to create precisely sized circular cuts in both the donor graft and the recipient bed for keratoplasty.
Question 7: During retinal detachment repair with scleral buckling, the technician assists with cryotherapy application. What is the purpose of cryotherapy in this procedure?
- To create a chorioretinal adhesion that seals the retinal break (Correct answer)
- To reduce intraocular pressure prior to buckle placement
- To lyse vitreoretinal traction bands
- To shrink the scleral buckle element after placement
Correct answer: To create a chorioretinal adhesion that seals the retinal break
Cryotherapy freezes the tissue around retinal tears, inducing inflammation that forms a permanent adhesive scar between retina and choroid.
COT Surgical Assisting Procedures 4
Which parameter does the technician monitor on the phacoemulsification machine to prevent thermal wound burns during cataract surgery?