. 2020 Aug 26;20(1):6–17. doi: 10.1111/jocd.13475

Table 3.

Anatomical characteristics that affect the classification of the tear trough deformity and the hyaluronic acid treatment assessment

Component	Description
Pretarsal orbicularis oculi hypertrophy	This is a diffuse muscle thickening, not greater than 4 mm, along the entire length of the lower eyelid, just below and parallel to the eyelashes that causes a fold	This fold does not constitute a tear trough deformity per se. Treatment is not contraindicated, but it is very risky to improve it with HA.
Skin hyperpigmentation	Darkening or coloration that does not contribute to the depth and extension of the tear trough deformity, but can be confused or accentuate the effects of a depression.	Its presence may be due to various causes, and not all are treatable with HA. ²⁷ The use of HA is indicated only when tear trough deformity (depression) and hyperpigmentation coexist. The reduction in the concavity may help the light to reflect more homogeneously.
Laxity/ skin wrinkles	To evaluate the degree of laxity/photoaging, we can use the Glogau scale ⁴⁵	The skin should be firm and of acceptable thickness. Marked skin laxity may lead to excess product use. If fluid retention by the HA occurs, the skin will be unable to contain it and it will become more obvious
Fat pad prolapse	Anterior projection of the pad that contributes to the perception of depth of the tear trough deformity. The more pronounced the prolapse (medial and/or central), the greater this perception will be	HA treatment is not contraindicated, but there are limitations: the greater the degree of prolapse, the harder it is to achieve a good result, as a higher volume needs to be injected into a very narrow area.
Lower eyelid/malar edema	Periocular fluid retention that contributes to the tear trough deformity. It is essential to know the etiology to determine whether HA is the best approach.	Periocular edema should be addressed according to its etiology. ⁴⁶ The HA could aggravate this accumulation of fluids due to its hygroscopic potential and the compression of lymph structures that could already be damaged beforehand.
Extension of the depression		This will influence the amount of HA to inject, and therefore the limitations should be taken into account according to the quality of the skin and likelihood of lymphatic compression.