Evaporative dry eye disease due to meibomian gland dysfunction: Preferred practice pattern guidelines for diagnosis and treatment

Abstract

Evaporative dry eye (EDE) due to meibomian gland dysfunction (MGD) is one of the common clinical problems encountered in ophthalmology. It is a major cause of dry eye disease (DED) and of ocular morbidity. In EDE, inadequate quantity or quality of lipids produced by the meibomian glands leads to faster evaporation of the preocular tear film and symptoms and signs of DED. Although the diagnosis is made using a combination of clinical features and special diagnostic test results, the management of the disease might be challenging as it is often difficult to distinguish EDE from other subtypes of DED. This is critical because the approach to the treatment of DED is guided by identifying the underlying subtype and cause. The traditional treatment of MGD consists of warm compresses, lid massage, and improving lid hygiene, all measures aimed at relieving glandular obstruction and facilitating meibum outflow. In recent years, newer diagnostic imaging modalities and therapies for EDE like vectored thermal pulsation and intense pulsed light therapy have emerged. However, the multitude of management options may confuse the treating ophthalmologist, and a customized rather than a generalized approach is necessary for these patients. This review aims to provide a simplified approach to diagnose EDE due to MGD and to individualize treatment for each patient. The review also emphasizes the role of lifestyle modifications and appropriate counseling so that patients can have realistic expectations and enjoy a better quality of life.

Keywords: Dry eye disease; evaporative dry eye; meibography; meibomian gland; meibomian gland dysfunction.

Figure 1

(a) Typical pattern of corneal fluorescein staining seen under cobalt blue illumination on slit-lamp biomicroscopy in the inferior quadrant adjacent to the lid margin in a case of evaporative dry eye due to meibomian gland dysfunction. (b) Pouting and blocked meibomian gland orifices along the lower lid margin. (c) Reduced tear meniscus height (TMH) as measured by the Keratograph. (d) Infrared imaging of the lids shows areas of meibomian gland dropouts, gland distortion or tortuosity, and gland shortening. (e) Non-invasive-Keratograph-break-up time (NIKBUT) showing abnormal value and pattern

Figure 2

Representative photographs of progressive degrees of meibomian gland loss (a- f), as seen in decreasing number of glands and increase in areas of gland dropouts

Figure 3

Presence of telangiectatic vessels over the lid margin surrounding the meibomian gland orifices of the upper eyelid and blocked and capped orifices of the lower lid. Meibography showing areas of blocked meibomian glands and their loss or dropouts (marked in the oval)