Ch 23. Corneal infiltrates in contact lens patient

Question 1

What is the most important rist facto for infetious keratitis in contact lens wear?

Answer 1

Extended wear vs single use (being the extended wear the most risky)

Overnight use of any type of lens increase 5-fold the risk of corneal infection.

Question 2

Name signs that differentiate between infectious and sterile corneal infiltrate.

Answer 2

the PEDAL Mnemonic.

Pain

Epitelial defect (>1mm), Edema arround the infiltrate.

Discharge (purulent)

Anterior chamber reaction

Location (central, rather than peripheral)

Question 3

Why is gatifloxacin preferred over ciprofloxacin in the management of and infiltrate in a contact lens patient?

Answer 3

Because of its improved coverage of pseudomonas

Question 4

How could you distinguish acanthamoeba keratitis vs HSV infectious keratitis in the early stages?

Answer 4

Both can start as a superficial keratitis with dendrites, or pseudodendrites (hence the frecuent misdiagnosis).

Acanthamoeba is extremely painful, while HSV causes a mild discomfort and is responsive to medical treatment.

Question 5

What is the prefered empirical topical ATB coverage in a case of suspected infetious keratitis in a contact lens wearer?

Answer 5

• <1mm: Gatifloxacin
• >1mm: fortified tobramicine + cefazolin or vancomicin

in both cases therapy is administerd every 30min arround the clock after a loading dose.

Question 6

Can a patient that presents with a contact lens related corneal abration be treated with eye patching?

Answer 6

NO,

There is a high risk for pseudomonal infection in these patients.