Dermatology Research Centre, The University of Queensland, Brisbane, Qld, Australia.
Br J Dermatol. 2012 Aug;167(2):270-9. doi: 10.1111/j.1365-2133.2012.10943.x. Epub 2012 Jun 20.
Skin ageing is a complex process due to intrinsic chronological factors (chronoageing) and extrinsic environmental factors. The primary extrinsic factor is cumulative ultraviolet (UV) exposure, and is therefore termed photoageing. The current standards for measuring cumulative sun damage are biopsy histology and skin microtopography. However, skin biopsies are too invasive for population studies and skin replicas render only superficial skin architecture data. Reflectance confocal microscopy (RCM) is a noninvasive imaging tool that allows for in vivo imaging of the skin at quasihistological resolution.
To define and identify RCM features associated with chronological ageing and photoageing on the forearm in two age groups with different skin phototypes and to assess whether these results agree with previous findings.
We obtained RCM images of dorsal and volar nonlesional skin of the lower forearm of 75 individuals with skin Fitzpatrick phototypes I-III in two age groups (20-30 years and 50-60 years). From each participant and body site, 21 RCM features were assessed and statistically significant differences between the two age groups and different forearm sites determined.
RCM enabled identification of changes in architecture, cell morphology and extracellular matrix (collagen) at the level of the epidermis, dermoepidermal junction and papillary dermis. Changes that were correlated with chronological ageing and which were aggravated on the UV-exposed dorsal forearm were: loss of small skin furrows resulting in wider and less intersecting furrows; irregularity of the epidermal honeycomb pattern; irregularly distributed (mottled) pigmented keratinocytes/melanocytes; irregularity of the papillary rings and/or effacement of the rete ridges; and loss of thin collagen fibres and presence of collagen clods.
We have tested previously reported and new parameters for skin ageing evaluation by RCM, and identified 15 statistically significant RCM features that can be used to quantify ageing and photoageing in forearm skin noninvasively.
皮肤老化是一个复杂的过程，由内在的时间因素（老化）和外在的环境因素引起。主要的外在因素是累积的紫外线（UV）暴露，因此称为光老化。目前衡量累积太阳损伤的标准是活检组织学和皮肤微观结构。然而，皮肤活检对于人群研究来说过于侵入性，皮肤复制品只能提供浅层皮肤结构数据。反射共聚焦显微镜（RCM）是一种非侵入性成像工具，可在近乎组织学分辨率下对皮肤进行体内成像。
在两个不同皮肤光型的年龄组中，定义和识别与前臂时间老化和光老化相关的 RCM 特征，并评估这些结果是否与以前的发现一致。
我们对 75 名皮肤 Fitzpatrick 光型 I-III 的前臂下背部和下腹部非病变皮肤进行了 RCM 图像采集，这些人分为两个年龄组（20-30 岁和 50-60 岁）。从每个参与者和身体部位评估了 21 个 RCM 特征，并确定了两个年龄组和不同前臂部位之间的统计学显著差异。
RCM 能够识别表皮、真表皮交界处和乳头真皮层水平的结构、细胞形态和细胞外基质（胶原）的变化。与时间老化相关且在 UV 暴露的背部前臂加重的变化是：小皮肤皱纹的丧失导致更宽且更少交叉的皱纹；表皮蜂巢模式不规则；不规则分布（斑驳）的色素角质形成细胞/黑素细胞；不规则的乳头环和/或网嵴消失；以及薄胶原纤维的丧失和胶原团块的存在。
我们已经测试了 RCM 评估皮肤老化的先前报道和新参数，并确定了 15 个具有统计学意义的 RCM 特征，可用于非侵入性定量评估前臂皮肤的老化和光老化。
