Abstract
Purpose :
Meibomian gland dysfunction is often incorrectly diagnosed based upon the presence of eyelid vascularization without gland expression. Eyelid margin vascularization is difficult to appreciate with dark skin pigmentation. We performed an observational clinical study to test the hypothesis that MGD diagnosed using meibomian gland expression is seen with all skin pigmentations, however, reliance on eyelid margin vascularization as a primary diagnostic criterion results in under-diagnosis of MGD in individuals with dark skin.
Methods :
Following IRB approval, subjects were recruited from the Ross Eye Institute, Buffalo, NY. Subjects completed: a dry eye symptom questionnaire; digital slit lamp photographs of the eyelids; infrared images of the meibomian glands (meibography, Heidelberg Spectralis, Germany); Schirmer’s test for tear production; and evaluation of meibum quantity/quality using a Korb Meibomian Gland Evaluator (Tear Science). Eyelid pigmentation from slit lamp photos was graded using RGB pixel analysis in ImageJ software. Vascularization and gland truncation/dropout were graded visually from slit lamp and meibography images, respectively, and confirmed by a masked observer.
Results :
We recruited 47 subjects from age 15 to 79 years old. Skin pigmentation by RGB pixel analysis ranged from 231 (fair skin) to 68 (dark skin), with a mean of 160 (median 170). Dry eye symptoms ranged from 0 (no symptoms) to 100 (severe symptoms), with a mean of 24 (median 8). MGD diagnosed by abnormal meibum quality/quantity ranged from absent to severe. Dry eye symptoms, abnormal tear production, gland truncation/dropout, and abnormal meibum quality/quantity affected individuals of all skin pigmentations. However, vascularization was not seen in any darkly pigmented individuals (RGB<145, n = 13), despite the presence of MGD in this population (10/13 had abnormal meibum). Vascularization was neither sensitive (33%) nor specific (50%) for the diagnosis of MGD.
Conclusions :
Although vascularization of the eyelid margin has been used for diagnosis of MGD, vascularization is not seen in our population of darkly pigmented individuals. Because MGD affects individuals of all skin pigmentations, meibomian gland expression is central to diagnosis, especially in those with darker pigmentation.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.