For each individual, demographic information, medical history, and psychiatric and medication information were collected. Demographic information, health status, medical history, psychiatric diagnoses (e.g., PTSD and depression), and medication information were gathered via a chart review of the VA administrative database. Specifically, lifetime and current PTSD and depression diagnoses were coded using the International Classification of Disease-9 (ICD-9) by the patient's treating physician. Current antidepressant and antianxiety medication use was categorized by drug category. Antidepressants were categorized as selective serotonin reuptake inhibitors (SSRIs), other, or none. This categorization was used due to small sample sizes in the non-SSRI categories; antidepressant medications included in the “other” group included serotonin and norepinephrine reuptake inhibitors (SNRIs), aminoketones, and piperazinoazepines. Even though SSRIs and SNRIs are similar in their inhibition of reuptake of serotonin, SNRIs are a distinct therapeutic class because these agents also block the reuptake of norepinephrine, and were thus classified in the “other” group. Similarly, antianxiety medication use was categorized as benzodiazepines, other, and none. Other antianxiety medications included atypical anxiolytics and antihistamines (i.e., only when used for anxiety treatment purposes).
The validated five-item Dry Eye Questionnaire (DEQ5) was administered to all patients.
21 The DEQ5 comprises questions regarding the frequency and intensity of dry eye symptoms, such as eye discomfort, eye dryness, and watery eyes. The total score ranges from 0 to 22, with a score of zero indicating no dry eye symptoms and a score of 22 indicating that the subject experiences the most frequent and intense symptoms. Based on previous validation studies, the presence of mild symptoms was defined as a score ≥ 6, and the presence of severe symptoms score was defined as a score ≥ 12.
21
The ocular surface examination, in the order performed, consisted of tear osmolarity (measured once in each eye; TearLAB, San Diego, CA), TBUT (measured twice in each eye and averaged per eye), conjunctival and corneal staining (punctuate epithelial erosions [PEE]; range, 0–5),
22,23 Schirmer's strips with anesthesia,
23 and morphologic and qualitative eyelid and meibomian gland information. For the TBUT, a fluorescein strip (Fluorets; Laboratoire Chauvin, Aubenas, France) was wetted with the application of one drop of nonpreserved saline to the lower one-fourth of the strip. Excess fluid was gently removed such that the saturated tip delivered approximately 3 to 5 μL liquid sodium fluoride (NaFl). With the patient gazing up, the examiner introduced the NaFl into the lower fornix. Starting with the right eye, timing was stopped upon visualization of the first break (one or more black [dry] spots) appearing in the precorneal tear film or after 15 seconds had elapsed. The procedure was then repeated for the left eye. Morphologic information collected included the degree of eyelid vascularity (0 = none; 1 = mild engorgement; 2 = moderate engorgement; 3 = severe engorgement)
24 and the presence of inferior eyelid meibomian orifice plugging (0 = none; 1 = less than one-third lid involvement; 2 = between one-third and two-thirds involvement; 3 = greater than two-thirds lid involvement). Meibum quality was graded on a scale of 0 to 4 (0 = clear; 1 = cloudy; 2 = granular; 3 = toothpaste; 4 = no meibum extracted).
25 For each participant, data from the worst eye were used.