Schirmer Tear Test

General

Synonym/Acronym:
N/A

Rationale
To assess tear duct function.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings

  • 10 mm of moisture on test strip after 5 min. It may be slightly less than 10 mm in older adult patients.

Critical Findings and Potential Interventions
N/A

Overview

(Study type: Sensory, ocular; related body system: Nervous system.)

The tear film, secreted by the lacrimal, Krause, and Wolfring glands, covers the surface of the eye. Blinking spreads tears over the eye and moves them toward an opening in the lower eyelid known as the punctum. Tears drain through the punctum into the nasolacrimal duct and into the nose. The Schirmer tear test simultaneously tests both eyes to assess lacrimal gland function by determining the amount of moisture accumulated on standardized filter paper or strips held against the conjunctival sac of each eye. The Schirmer test measures both reflex and basic secretion of tears. The Schirmer II test measures basic tear secretion and is used to evaluate the accessory glands of Krause and Wolfring. The Schirmer test is performed by instilling a topical anesthetic before insertion of filter paper. The topical anesthetic inhibits reflex tearing of major lacrimal glands by the filter paper, allowing testing of the accessory glands. The Schirmer II test is performed by irritating the nostril with a cotton swab to stimulate tear production.

In many cases, the discomfort caused by a tearing deficiency or related inflammation, also known as “dry eye,” can be treated successfully either with over-the-counter eyedrops or prescription eyedrops. Other, more invasive resolutions include the insertion of punctal plugs to help tears remain on the surface of the eye longer or by expression of the meibomian glands to release the oily meibum required to prevent rapid tear film evaporation. Both procedures can be completed during an office visit. Punctal plugs are small, sterile, biocompatible medical devices that are inserted into the puncta (drainage duct openings in the inner corners of the upper and lower eyelids) to prevent draining of tears from the eye. Temporary plugs are made of dissolvable collagen material, and permanent plugs are usually made of silicone or acrylic material; the placement of the plug also determines the length of time the plug remains inside the duct and whether removal, if needed, would require a surgical procedure. Expression of the meibomian glands is required when the openings of the glands become occluded and a condition called evaporative dry eye develops. The procedure to unblock the meibomian glands, which are located along the edge of the eyelids near the base of the eyelashes, begins with application of warm compresses to the eyelids, after which forceps are used to manually express any hardened substances obstructing the openings of the meibomian glands. Significant pressure must be applied to the eyelids, and this procedure may be considered quite uncomfortable by the patient. There is an automated, in-office treatment for meibomian gland expression; it is reported to produce good results with less discomfort but may not be covered by health insurance.

Indications

  • Assess adequacy of tearing for contact lens comfort and for successful LASIK surgery.
  • Assess suspected tearing deficiency.

Interfering Factors

Factors that may alter the results of the study

  • Rubbing or squeezing the eyes may affect results.
  • Clinical conditions such as pregnancy may temporarily result in dry eye due to hormonal fluctuations.

Potential Medical Diagnosis: Clinical Significance of Results

Abnormal Findings In:

  • Tearing deficiency related to aging, dry eye syndrome, or Sjögren syndrome.
  • Tearing deficiency secondary to leukemia, lupus erythemastosus, lymphoma, rheumatoid arthritis, or scleroderma.

Nursing Implications, Nursing Process, Clinical Judgement

Before the Study: Planning and Implementation

Teaching the Patient What to Expect

  • Discuss how this procedure can assist in evaluating tear duct function.
  • Explain that the test takes 15 min to complete.
  • Review the procedure with the patient.
  • Explain that some discomfort may be experienced after the test when the numbness wears off from anesthetic drops administered prior to the test.


Procedural Information

  • Positioning for this procedure is in the seated position looking straight ahead, keeping the eyes open and unblinking.
  • Topical anesthetic is instilled in each eye and provided time to work.
  • A test strip is inserted into each eye, and the eyes are gently closed for 5 min.
  • Afterward the test strips are removed and measured for the amount of moisture present.

Potential Nursing Actions

  • Instruct the patient to remove contact lenses or glasses.

After the Study: Implementation & Evaluation Potential Nursing Actions

Avoiding Complications

  • Corneal abrasion can be caused by the patient rubbing the eye before topical anesthetic has worn off.
  • Instruct the patient to avoid rubbing the eyes for 30 min after the procedure.
  • Assess for corneal abrasion caused by patient rubbing the eye before topical anesthetic has worn off.

Treatment Considerations

  • If appropriate, instruct the patient not to reinsert contact lenses for 2 hr.
  • Explain how to use any ordered medications, usually eyedrops intended to provide additional lubrication and/or treat an underlying inflammatory process.
  • Discuss significant adverse effects associated with the prescribed medication.
  • Emphasize the importance of adhering to the therapy regimen.
  • Encourage a review of corresponding literature provided by a pharmacist.
  • Be supportive of pain related to decreased lacrimation or inflammation.
  • Discuss the implications of abnormal test results on the lifestyle choices.

Clinical Judgement

  • Consider what type of clinical support is needed to facilitate understanding of any associated immune disorders.

Followup Evaluation and Desired Outcomes

  • Acknowledges contact information provided for patient education on the topic of eye care, such as the American Academy of Ophthalmology (www.aao.org) or American Optometric Association (www.aoa.org or www.allaboutvision.com).

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