The Effectiveness of a 5% Retinoic Acid Peel Combined with Microdermabrasion for Facial Photoaging: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Table 1

Glogau classification of photoaging.

Group	Classification	Typical age	Description	Skin characteristics
I	Mild	28–35	No wrinkles	Early photoaging: mild pigment changes, no keratosis, minimal wrinkles, minimal or no makeup
II	Moderate	35–50	Wrinkles in motion	Early to moderate photoaging: early brown spots visible, keratosis palpable but not visible, parallel smile lines begin to appear, wears some foundation
III	Advanced	50–65	Wrinkles at rest	Advanced photoaging: obvious discolorations, visible capillaries (telangiectasia), visible keratosis, wears heavier foundation always
IV	Severe	60–75	Only wrinkles	Severe photoaging: yellow-gray skin color, prior skin malignancies, wrinkles throughout: no normal skin, cannot wear makeup because it cakes and cracks