Abstract
Purpose:
Meibomian gland dysfunction (MGD) is a common cause of the signs and symptoms of dry eye, yet a symptom survey specific for MGD has not been developed. We created a new MGD questionnaire based on the Rasch analysis of results from a previous MGD survey on MGD patients and results from several sources. We took this instrument and evaluated it in an independent sample of all patients presenting to a private clinic.
Methods:
Subjects over age 18 were recruited and classified as either MGD, aqueous deficient (AD), allergic conjunctivitis (AC), or normal based on accepted tests (i.e. meibum quality, Schirmer I, papillary conjunctivitis). The refined instrument contained 18 items targeting the frequency and intensity of 9 symptoms. Possible responses were marked from 0 (never, or not intense) to 9 (all the time, or extremely intense). Subjects were also asked to respond to three other questionnaires: Subjective Evaluation of Symptoms of Dryness (SESoD), Ocular Surface Disease Index (OSDI), and a questionnaire for AC, Total Ocular Symptom Score (TOSS). Unpaired t-test and Pearson correlation were performed to analyze the responses between groups.
Results:
108 subjects were enrolled. MGD subjects (n=27) responded with less crusting than the other 81 subjects for both frequency (p=<0.001) and intensity (p=0.004). When comparing MGD to AD, frequency of crusting approached statistical significance (p=0.058) with AD having more crusting than MGD. Responses to the nine frequency questions in the MGD questionnaire showed good correlation to the other three frequency questionnaires. TOSS > SeSOD > OSDI with the respective correlation coefficients and p-values (0.64, 0.005; 0.61, 0.008; 0.52, 0.030).
Conclusions:
MGD subjects may perceive less crusting because a vast majority of MGD is non-obvious, meaning symptomatic but without clinical signs until a clinician expresses the Meibomian glands. Further work entails the evaluation of this instrument at other centers and finding another symptom that may distinguish MGD from ATD.
Keywords: 486 cornea: tears/tear film/dry eye •
576 lacrimal gland