NBEO Contact Lenses & Fitting 2

Question 1

Giant papillary conjunctivitis (GPC) is defined by papillae on the upper tarsal conjunctiva that are larger than:

Accepted Answer

1.0 mm

Answer

0.1 mm

Answer

0.3 mm

Answer

0.5 mm

Question 2

Contact lens-induced acute red eye (CLARE) is most commonly associated with colonization by which category of organism?

Accepted Answer

Gram-negative bacteria

Answer

Gram-positive cocci

Answer

Fungi

Answer

Acanthamoeba species

Question 3

Which contact lens-related complication presents with deep stromal infiltrates, significant anterior chamber reaction, mucopurulent discharge, and severe pain, representing the most vision-threatening condition?

Accepted Answer

Microbial keratitis

Answer

Contact lens peripheral ulcer (CLPU)

Answer

Superior epithelial arcuate lesion (SEAL)

Answer

Infiltrative keratitis

Question 4

Superior epithelial arcuate lesions (SEAL) are primarily caused by which mechanism?

Accepted Answer

Mechanical trauma from the edge of a soft contact lens

Answer

Chronic hypoxia from low Dk/t materials

Answer

Toxic reaction to preservatives in multipurpose solutions

Answer

Microbial colonization beneath the superior lens edge

Question 5

Which exposure is considered the primary risk factor for Acanthamoeba keratitis in contact lens wearers?

Accepted Answer

Exposure to tap water or swimming while wearing lenses

Answer

Use of multipurpose solutions without rubbing

Answer

Hydrogen peroxide system non-compliance

Answer

Sleeping in daily wear silicone hydrogel lenses

Question 6

Corneal neovascularization in contact lens wearers is primarily driven by which pathophysiologic mechanism?

Accepted Answer

Chronic hypoxia inducing VEGF release from the corneal epithelium

Answer

Mechanical irritation stimulating limbal cell proliferation

Answer

Toxic preservative accumulation causing limbal inflammation

Answer

Allergic response to lens deposits activating mast cells

Question 7

A contact lens patient presents with a small (<1 mm), round, white peripheral stromal infiltrate with overlying epithelial staining, minimal pain, and no anterior chamber reaction. The most likely diagnosis is:

Accepted Answer

Contact lens peripheral ulcer (CLPU)

Answer

Microbial keratitis

Answer

Acanthamoeba keratitis

Answer

Thygeson superficial punctate keratopathy