Lens and Cataract Flashcards
7 cards from real Board Certified Ophthalmologist practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Lens and Cataract flashcards as text
Which organism is most frequently isolated in acute postoperative endophthalmitis after cataract surgery?
Answer: Coagulase-negative staphylococci
The Endophthalmitis Vitrectomy Study found coagulase-negative staphylococci (mainly S. epidermidis) in about 70% of culture-positive cases.
A patient has diffuse limbus-to-limbus corneal edema and an anterior chamber reaction 18 hours after uneventful phacoemulsification, with no vitritis. What is the most likely diagnosis?
Answer: Toxic anterior segment syndrome
TASS starts within 12-48 hours with widespread corneal edema from endothelial toxicity, and the inflammation stays in the anterior segment.
Intraoperative floppy iris syndrome is most strongly associated with which systemic medication?
Answer: Tamsulosin
Tamsulosin selectively blocks alpha-1A receptors in the iris dilator muscle, which causes billowing, prolapse and progressive miosis.
During phacoemulsification the posterior capsule ruptures and a large nuclear fragment drops into the vitreous. What is the most appropriate next step?
Answer: Do an anterior vitrectomy, place a suitable IOL, close, and refer for pars plana vitrectomy
Trying to retrieve a posteriorly dislocated nucleus from the anterior approach risks retinal tears, so the fragment should be removed later by pars plana vitrectomy.
Clinically significant pseudophakic cystoid macular edema (Irvine-Gass syndrome) most commonly peaks at what time after surgery?
Answer: 4-6 weeks
Irvine-Gass CME usually appears 4-12 weeks after surgery and is most common around 4-6 weeks.
During cataract surgery the anterior chamber suddenly shallows, the eye becomes firm, and the red reflex darkens. What is the most important immediate action?
Answer: Immediately close all incisions
A suspected suprachoroidal hemorrhage requires rapid wound closure to tamponade the bleeding and prevent expulsion of intraocular contents.
What is the most common cause of a corneal incision thermal burn during phacoemulsification?
Answer: Occlusion of aspiration with dense viscoelastic or a tight incision that restricts flow
Reduced fluid flow around the vibrating tip stops heat dissipation, which leads to collagen contracture and wound burn.