Figure 2. Major Etiological Causes of Dry Eye
Dry Eye
Aqueous-deficient
Tear Film
Instability/Evaporative
Combination
Primary
Secondary
Lacrimal
Deficiency
Lacrimal
Gland Duct
Obstruction
Reflex Block
Systemic
Drugs
Meibomian
Oil Deficiency
Disorders of
Lid Aperture
Low Blink
Rate
Drug Action
e.g.,
isotretinoin
Vitamin A
Deficiency
Topical Drugs
Preservatives
Contact Lens
Wear
Environmental
Factors
e.g., humidity,
allerg y
Sjögren Syndrome
Dry Eye
Non-Sjögren
Dry Eye
Intrinsic Extrinsic
Modified with permission from Lemp MA (Chair). Definition and Classification Subcommittee
of the International Dry Eye Workshop. e definition and classification of dry eye disease:
report of the Definition and Classification Subcommittee of the International Dry Eye
Workshop (2007). Ocul Surf 2007;5:77.
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