Participants

Consecutive patients between March 29, 2010 and July 19, 2010 seen in the Uveitis and Ocular Inflammatory Disease Clinic at the Francis I. Proctor Foundation, a tertiary care referral center at the University of California, San Francisco, were included in the study. Eligible individuals included patients at least 18 years of age with a diagnosis of noninfectious ocular inflammatory disease, who were English-speaking and able to provide written informed consent. Patients seen at the Francis I. Proctor Foundation clinic undergo a standard evaluation, which includes screening for tuberculosis and syphilis as well as targeted evaluation for other infectious and noninfectious causes of ocular inflammatory disease.

Design and Procedures

After informed consent was obtained, participants completed a self-administered depression screening questionnaire and vision-related quality-of-life questionnaire, as well as a supplemental questionnaire. Participants were given the option to complete the questionnaires at the clinic or complete the questionnaires at home and return them by mail with a prepaid, self-addressed envelope. Medical records were reviewed for each patient in order to gather general demographic information on age, sex, and self-reported race. Additional chart review was conducted to gather information on type of ocular inflammatory disease (uveitis, scleritis, or mucous membrane pemphigoid), location of disease, chronicity and recurrence of disease, associated systemic diseases, current best-corrected visual acuity (BCVA), presence of active inflammation (defined as greater than 0.5+ anterior chamber cell, greater than 0.5+ vitreous haze, active vasculitis, retinitis, choroiditis, or active scleritis), and current and past treatments. The status (active or inactive), location, and chronicity of ocular disease were described and recorded as outlined by the Standardization of Uveitis Nomenclature criteria. Anatomic location of inflammation was noted as anterior, intermediate, posterior/panuveitis, scleritis, cicatrizing conjunctivitis, or orbital inflammation. The type of uveitis was noted as acute (new onset and singular event), recurrent (multiple episodes of inflammation marked by medication-free inactive periods of greater than 3 months), or chronic (persistent inflammation and inability to remain free of inflammation for at least 3 months without medications). History of changing immunomodulatory therapy for any reason was recorded. Immunomodulatory medications are typically prescribed to patients with ocular inflammation using a stepladder approach, starting with antimetabolites and adding T-cell inhibitors and biologics for refractory cases. Alkylating agents are also used in particularly severe cases. The necessity to change therapies may result from poorly controlled inflammation, inability to taper concomitant corticosteroids, intolerance to an agent because of undesirable side effects or safety concerns, discontinuation secondary to cost, or reduced effectiveness of an agent over time, as can happen with tumor necrosis factor α (TNF-α) inhibitors. Socioeconomic status, approximated by median household income, was determined by using geocodes ( http://www.ffiec.gov/Geocode/default.aspx , accessed July 20, 2010).

The Beck Depression Inventory II (BDI-II), a validated 21-item self-administered questionnaire, was used to measure depression in this study. Each question has 4 choices, ranging in point value from 0 to 3. Total scores of 0 to 13 represent no depression, 14 to 19 mild depression, 20 to 28 moderate depression, and 29 to 63 severe depression. Using a cutoff value of > 13 as a positive screen for depression yields 90% sensitivity and 99% specificity.

Vision-related quality of life was determined using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25), a self-administered 25-question survey. An overall composite score is generated with the lowest score of 0 to the highest score of 100, along with 12 subscales each with scores from 0 to 100 relating to general health, general vision, ocular pain, near activities, distance activities, social functioning, mental health, role difficulties, dependency, driving, color vision, and peripheral vision.

An additional supplementary questionnaire was created to capture information regarding past history of depression, level of perceived emotional support, knowledge about uveitis and participation in uveitis support groups, and smoking history.

Statistical Considerations

Conservatively assuming that 10% of incoming patients would be classified as depressed, a sample size of 100 patients was chosen to give us 80% power to detect a 20-point difference in composite NEI-VFQ score using a 2-sided t test. This estimate assumes a 95% confidence level and a pooled standard deviation of 21.6 points. If as many as 25% were classified as depressed, as seen in another study of chronic eye disease, we would be able to detect a somewhat smaller difference of 14 points.

Statistical analyses were conducted using R statistical software (The R Foundation for Statistical Computing, Vienna, Austria). The Fisher’ exact test was used to determine differences in categorical variables between the depressed and not-depressed groups, while continuous variables were analyzed using a 2-sided t test; all tests were performed at a 95% confidence level. Pearson correlations were included where appropriate. A backward stepwise linear regression model using all variables was used to determine significant predictors of BDI-II score. A backward stepwise logistic regression model using all variables was used to determine significant predictors of whether a subject screened positive or negative for depression according to BDI-II. Visual acuity using a Snellen eye chart was recorded individually for each eye and then converted into logarithm of the minimal angle of resolution (logMAR) scale. Low vision of count fingers, hand motion, light perception, and no light perception was recorded as logMAR 1.7, 1.8, 1.9, and 2.0, respectively.