Increased Tear Fluid Production as a Compensatory Response to Meibomian Gland Loss A Multicenter Cross-sectional Study

Purpose: To compare tear film parameters as well as meibomian gland morphologic features and function among patients with meibomian gland dysfunction (MGD), those with non-Sjogren syndrome aqueous-deficient dry eye (non-SS ADDE), those with non-SS ADDE and MGD, and normal subjects. Design: Multicenter, cross-sectional, observational case series. Participants: Forty-one eyes of 41 patients (all women; mean age +/- standard deviation, 62.1 +/- 9.9 years) with non-SS ADDE, 70 eyes of 70 patients (all women; 66.0 +/- 8.7 years) with MGD, 17 eyes of 17 patients (all women; 72.4 +/- 7.8 years) with non-SS ADDE and MGD, and 70 eyes of 70 normal control subjects (all women; 65.0 +/- 7.1 years). Methods: Ocular symptoms were scored from 0 to 14 and lid margin abnormalities from 0 to 4 according to their respective number. Meibomian gland changes were scored from 0 to 6 (meiboscore) on the basis of noncontact meibography findings, and meibum was graded from 0 to 3 depending on its volume and quality. Conjunctival and corneal epithelial damage were scored from 0 to 9 (fluorescein score). Tear film break-up time (TBUT) was measured as an index of tear film stability, and tear fluid production was evaluated with Schirmer's test. Main Outcome Measures: Ocular symptom score, lid margin abnormality score, meiboscore, meibum grade, fluorescein score, TBUT, and Schirmer's test value. Results: The ocular symptom score did not differ significantly between the MGD and non-SS ADDE groups (P = 0.762). The lid margin abnormality score, meiboscore, and meibum grade were significantly higher in the MGD group than in the non-SS ADDE group (P = 0.0012, P < 0.0001, and P < 0.0001, respectively). The fluorescein score, TBUT, and Schirmer's test value were significantly worse in the non-SS ADDE group than in the MGD group (P < 0.0001, P = 0.0061, and P < 0.0001, respectively). The meiboscore correlated significantly with Schirmer's test value only in the MGD group (rho = 0.508, P = 8.3x10(-6)). Conclusions: An increase in tear fluid production likely compensates for loss of meibomian glands in individuals with MGD. (C) 2015 by the American Academy of Ophthalmology.