| KERATITIS SICCA / DRY EYE SYNDROME  SIGNS
AND SYMPTOMS
As the name implies, patients with keratitis sicca or dry eye syndrome
typically present with complaints of dry, burning eyes and a "sandy" or
"gritty" foreign body sensation. Occasionally, patients will report excess
tearing (epiphora). Often, the symptoms are exacerbated by poor air quality and low
humidity, and are more prominent later in the day. Upon inspection, most patients
demonstrate a relatively white and quiet eye. Key slit lamp findings include a negligible
tear meniscus at the lower lid and a reduced tear break-up time (TBUT), generally less
than ten seconds.
Fluorescein staining will usually reveal punctate epithelial keratopathy
in the interpalpebral region. In severe cases, the cornea and/or conjunctiva may also
stain with rose bengal. Filaments-tags of mucus, epithelial cells and tear debris-may also
stain with fluorescein and rose bengal; filamentary keratitis is an extreme sequela of
keratitis sicca.
PATHOPHYSIOLOGY
Dry eye syndrome results primarily from compromise to either the quantity
or quality of the precorneal tear film. Tears are composed of a mucin layer, a water or
aqueous layer, and an oil layer. Deficiencies in any one of these components may create a
tear film which is incapable of properly moistening the eye, resulting in desiccation and
symptomatic complaints. In addition, irregularities in the blink mechanism or conditions
affecting the regularity of the ocular surface (e.g., pterygia, keratoconus) may further
interfere with proper wetting of the cornea. Many drugs can also temporarily decrease
lacrimal gland secretions, such as antihistamines, phenothiazine anti-anxiety medications,
oral contraceptives and atropine derivatives. Collagen vascular disorders such as
rheumatoid arthritis and Sjögren's syndrome also have a high association with dry eye
syndrome.
MANAGEMENT
Management is aimed at replenishing the eyes' moisture and/or delaying
evaporation of the patient's natural tears. Begin by recommending that the patient instill
an ophthalmic lubricant every hour or more as needed, then taper the therapy based upon
patient response and compliance. A lubricating ointment used at bedtime may provide
additional comfort. For those patients who derive little relief from this therapy, or who
fail to comply, punctal occlusion may offer a more realistic and less complicated
management strategy. First, test the patient's response using dissolvable collagen plugs
to ensure the therapy will provide relief from symptoms without epiphora. If successful,
occlude the inferior puncta using silicone plugs. In severe cases consider occluding both
the inferior and superior puncta, or recommend surgical cautery.
CLINICAL PEARLS
Often, patients with dry eye syndrome are more
symptomatic than their clinical signs would imply. Typically, the diagnosis is based more
on subjective complaints than slit lamp findings.
Educate patients early and often that dry eye syndrome
cannot be cured outright. Rather, the therapy aims to control symptoms and reduce
discomfort.
Other reports in this section
|
|
