Question 1

Which of the following is a primary defense mechanism of the eye that directly destroys bacterial cell walls?

Accepted Answer

Lysozyme

Question 2

A patient presents with a red, itchy eye and watery discharge that began in one eye and spread to the other. Which is the most likely causative agent?

Accepted Answer

Adenovirus

Question 3

Which of the following best explains why contact lens wearers are at increased risk for microbial keratitis?

Accepted Answer

Contact lenses can introduce microbes and disrupt the corneal epithelium

Question 4

Which of the following is the leading cause of preventable microbial blindness worldwide?

Accepted Answer

Trachoma

Question 5

A newborn develops severe conjunctivitis after birth. Which two bacteria are most likely responsible for this infection?

Accepted Answer

Neisseria gonorrhoeae and Chlamydia trachomatis

Question 6

Which of the following statements about the ocular microbiome is correct?

Accepted Answer

A dozen or so bacterial species dominate the conjunctiva, while a different set dominate the cornea

Question 7

A patient presents with a rough, scarred conjunctiva and inward-turning eyelashes. Which is the most likely diagnosis?

Accepted Answer

Trachoma

Question 8

Which of the following is the most appropriate first-line treatment for trachoma in endemic regions?

Accepted Answer

Single oral dose of azithromycin

Question 9

Which of the following best describes the mechanism by which lactoferrin in tears protects the eye from infection?

Accepted Answer

It binds free iron, limiting bacterial growth

Question 10

Acanthamoeba keratitis is most commonly associated with which of the following risk factors?

Accepted Answer

Swimming with contact lenses in

Question 11

Which of the following is the most common cause of viral keratitis in the United States?

Accepted Answer

Herpes simplex virus type 1

Question 12

Which of the following is a distinguishing feature of bacterial conjunctivitis compared to viral conjunctivitis?

Accepted Answer

Thick, purulent (yellow/green) discharge

Question 13

Which of the following is NOT a recommended prevention strategy for viral conjunctivitis?

Accepted Answer

Wear contact lenses during infection

Question 14

Which of the following statements about river blindness (onchocerciasis) is correct?

Accepted Answer

It is transmitted by the bite of an infected blackfly

Question 15

A patient with a history of chickenpox develops a painful vesicular rash in a band on one side of the body and corneal lesions. Which virus is most likely responsible?

Accepted Answer

Varicella-zoster virus

Question 16

Which of the following is the most appropriate treatment for bacterial keratitis caused by Pseudomonas aeruginosa?

Accepted Answer

Antibiotic eye drops

Question 17

Which of the following is a key reason why fungal keratitis is more difficult to treat than bacterial keratitis?

Accepted Answer

Antifungal drugs often require months of treatment and surgery may be needed

Question 18

Which of the following best describes the transmission of trachoma?

Accepted Answer

Contact with contaminated hands, fomites, or flies

Question 19

Which of the following is the main function of the lacrimal gland in ocular defense?

Accepted Answer

It produces tears that rinse away dirt and contain antimicrobial factors

Question 20

Which of the following best explains why newborns in the U.S. receive antibiotic eye drops at birth?

Accepted Answer

To prevent bacterial conjunctivitis caused by Neisseria gonorrhoeae or Chlamydia trachomatis

Microbial Eye Infections

Study Guide - Practice Questions

Study Guide - Flashcards