Development of the 4-3-2-1 meibum expressibility scale

With increased interest in the assessment of meibomian gland dysfunction and evaporative dry eye, there remains a deficit in simple, clinically applicable grading scales for gland expression. A new scale to assess meibum expressibility is described.

A meibum expressibility scale was developed using a new standardized meibomian gland expression device, which provides constant pressure along the inferior lid. For the scale development, 30 patients (53.0±8.49 years; 93.33% female) with mild-to-moderate dry eye were compared with 13 normal, non-dry eye subjects (25.6±4.3 years; 46.1% female) using the meibum expression device developed by Korb and Blackie. The device was placed 4 glands lateral to the inferior punctum and 1 mm below the lash line and was held stable for 15 sec. The glands expressing meibum were counted. The weighted κ statistic was used to evaluate the extent of agreement, and a receiver operating characteristic curve was created to test the proposed scale.

The mean number of glands that expressed from the worse lid in the normal group was 3.54±1.61, whereas 1.53±1.28 glands expressed in the dry eye group. In the dry eye group, 1 subject showed 5 glands expressing, and 29 demonstrated scores of 4 or less. In the normal group, 3 or more glands were expressible in 11 of 13 subjects.

A 4-3-2-1 scoring system is proposed, whereby 4 or greater=normal expressibility, 3=mildly reduced expressibility, 2=moderately reduced expressibility, and 1 or lesser=severely reduced expressibility. Further validation of the scale is warranted.