AOA Contact Lens Practice

Question 1

Which contact lens material parameter describes the amount of oxygen that actually reaches the cornea?

Accepted Answer

Dk/t (oxygen transmissibility)

Answer

Water content

Answer

Base curve radius

Answer

Modulus of elasticity

Question 2

Extended wear contact lenses are most associated with which serious complication?

Accepted Answer

Microbial keratitis

Answer

Giant papillary conjunctivitis

Answer

Superior epithelial arcuate lesions

Answer

Contact lens-induced acute red eye

Question 3

Orthokeratology (ortho-K) lenses work primarily by:

Accepted Answer

Reshaping the corneal epithelium during overnight wear

Answer

Surgically flattening the stroma

Answer

Increasing corneal thickness centrally

Answer

Reducing aqueous production

Question 4

Giant papillary conjunctivitis (GPC) in contact lens wearers is best managed by:

Accepted Answer

Switching to daily disposable lenses and reducing wear time

Answer

Increasing lens replacement frequency to monthly

Answer

Switching to higher water content soft lenses

Answer

Prescribing topical antibiotic drops

Question 5

Which fitting relationship describes a rigid gas-permeable (RGP) lens that is steeper than the corneal curvature?

Accepted Answer

Steep (vaulting) fit

Answer

Flat fit

Answer

Alignment fit

Answer

Interpalpebral fit

Question 6

What is the FDA oxygen transmissibility threshold for extended-wear soft contact lenses?

Accepted Answer

Dk/t ≥ 87 ISO units

Answer

Dk/t ≥ 24 ISO units

Answer

Dk/t ≥ 125 ISO units

Answer

Dk/t ≥ 50 ISO units