eTAO Dry Eye Score

Clinical examination with fluorescein identifies the presence, distribution and severity of epithelial staining, ranging from a normal ocular surface to localized or diffuse epithelial damage. The eTAO classification distinguishes four clinical patterns.

The Oxford staining scale provides the clinical basis for assessing corneal epithelial damage, while eTAO reorganizes these findings into four clinically relevant categories.

The eTAO epithelial score distinguishes not only the severity of corneal staining, but also different clinical patterns of epithelial involvement.

This is particularly important because significant ocular surface dysfunction may be present even in the absence of conventional corneal staining: reflex tearing without staining (e2) is itself a sign of surface instability.

Telangiectatic changes can progressively involve different anatomical levels.

Assessing these vascular changes provides complementary information on the inflammatory and vascular component associated with meibomian gland dysfunction and ocular surface disease.

Meibography allows gland loss to be visualized and quantified according to four levels.

Structural gland loss provides important information on the severity and chronicity of meibomian gland dysfunction. This four-level grading is consistent with established meibography scales (meiboscore).

Whenever possible, both upper and lower eyelids should be evaluated to obtain a comprehensive assessment of meibomian gland structure.

Four stages are distinguished.

Unlike meibography, which assesses gland structure, the O score provides functional information about gland obstruction and secretion.

The clinical appearance of expressed meibum changes progressively from clear and easily expressed secretion to thickened meibum and, ultimately, complete gland obstruction.

Each axis is graded on a defined 1 to 4 scale, so the profile is reproducible from one examination to the next. These standardized inputs are then combined through a proprietary weighting algorithm. The resulting global eTAO Score is expressed on a 0 to 10 scale, providing an intuitive representation of overall dry eye severity.

Two patients with a similar global score may nevertheless present very different eTAO Profiles, reflecting different predominant ocular surface abnormalities.

Repeating the same four-parameter evaluation after treatment allows changes in both the global eTAO Score and the individual components of the radar profile to be visualized. Changes in the radar profile show which components improve and which abnormalities persist.

Dry eye disease can result from very different underlying mechanisms. In this example of isotretinoin-associated dry eye disease, eTAO provides a structured representation of the ocular surface profile before and after treatment.

Patients may present with several simultaneous abnormalities involving the corneal epithelium, eyelids and meibomian glands. The eTAO radar makes it possible to visualize these multidimensional patterns and monitor their evolution over time.