a. Fluorescein dye or strips

b. Wood lamp or other blue light source

2. Equipment for obtaining specimen

a. Choose topical anesthetic (optional):

(1) 0.5% preservative-free tetracaine in unit-dose containers (Alcon Laboratories, Fort Worth, Texas)

(2) Preservative-free lidocaine (Elkins-Sinn, Cherry

Hill, New Jersey)

(3) Cocaine 4% preserved with 0.5% sodium benzoate (Schein Pharmaceuticals, Melville, New York)

diluted to 1% to 2% with sterile water. A 222C

DEA form must be completed to be able to order.

Many topical ophthalmic anesthetics contain

preservatives that may inhibit bacterial growth in

culture. For this reason, some physicians choose

to perform the procedure without anesthetic.

Nevertheless, this may be quite painful for the

Chapter 24 ■ Ophthalmic Specimen Collection 131

infant. The above-mentioned anesthetics are

preservative-free or have been shown to minimally inhibit bacterial growth (13,14).

b. Sterile cotton swabs may be used to evert the eyelids

but are not recommended for specimen collection

(Fig. 24.1).

c. Choose instrument to obtain cultures.

(1) Calcium alginate swabs

(2) Sterile Dacron polyester-tipped applicator

(Harwood Products Company, Guilford, Maine)

Calcium alginate swabs have been shown to

yield equal or better organism retrieval in cultures than spatulas or Dacron swabs (15,16).

Moistening the swab with trypticase soy (Becton

Dickenson and Company, Franklin Lakes, New

Jersey) broth or other culture medium enhances

results. However, spatulas have been shown to

provide better samples in smear than swabs.

Spatulas preserve the conjunctival epithelial

cells better, thus providing better opportunity for

diagnosing pathogens with intracellular organisms or inclusions (17). Calcium alginate swabs

may interfere with immunoassays.

d. Choose instrument for scraping the conjunctiva.

(1) Kimura Platinum spatula E1091 (Storz

Ophthalmics, Division of Bausch & Lomb,

Rochester, New York) (Fig. 24.2)

(2) Nasopharyngeal swab with metal handle bent

for scraping

(3) Calcium alginate swabs

 If spatulas are not available, then swabs

should be used vigorously on the tarsal conjunctival surface so as to débride epithelial cells.

e. Equipment for obtaining microscope slides

(1) Frosted, etched glass slides

(2) Microslide holders

(3) Pencil or marker for labeling

E. Equipment for Identifying

Chlamydia and Viral Agents

1. Equipment for nonculture chlamydial studies

a. The McCoy culture was considered the “gold

standard” for identification of Chlamydia. However,

cultures take several days to provide results, and

specimens collected in the first few days of life may

have less yield on culture because elementary bodies often take several days to form in neonates

(18,19).