Abstract
Abstract: :
Purpose: Direct examination of subjects is not always feasible in large–scale epidemiological studies. Thus, various questionnaires have been used to assess the status of dry eye, although it is not known how well the questionnaire instruments identify subjects with clinical signs of dry eye syndrome (DES). The aim of this study was to estimate the sensitivity and specificity of a short dry eye questionnaire in ascertaining dry eye status, using clinical data to define the "true" status of the eyes. Method: A short questionnaire consisting of three questions (1. How often are your eyes dry?; 2. How often are your eyes irritated?; and 3. Have you ever been diagnosed by a clinician as having DES?) was administered to 53 subjects. We then conducted a standardized clinical ophthalmologic examination including the Schirmer test, Rose Bengal staining, tear breakup time (TBUT), fluorescein staining and meibomian gland assessment. We estimated the sensitivity and specificity of the questionnaire versus objective signs of DES. Based on the questionnaire, we defined dry eye syndrome as the presence of either a previous clinical diagnosis of DES or severe symptoms (both dryness and irritation either constantly or often). In the absence of a gold standard for diagnosis of DES based on the clinical exam, for our primary analysis we considered a subject to have DES if a finding of either a Schirmer I (without anesthesia) ≤10 mm or a TBUT <10 seconds was noted. In further analyses, we also considered alternative definitions of DES. Results: Subjects were 44 females and 9 males with a mean age of 56 years. Compared with the clinical exam, the short questionnaire had a sensitivity of 76% and specificity of 83% in diagnosing dry eye. If criteria for a clinical diagnosis of DES were Schirmer I ≤ 10 mm or Rose Bengal staining of ≥ 3, the questionnaire had a sensitivity of 82% with a specificity of 69%. Conclusion: These data indicate that a short questionnaire–based assessment of dry eye can achieve a good balance of sensitivity and specificity versus commonly used clinical tests in the diagnosis of DES.
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical research methodology • cornea: tears/tear film/dry eye