Measurements in wound healing : effects of topical agents on full thickness dermal incised wounds in an animal model

Bibliography: leaves 55-59.Inert topical agents in the form of creams, lotions and ointments are often applied to wounds to create an environment conducive to wound healing. These agents, although not pharmacologically active on the intact skin, have activity when applied to wounds where the stratum comeum barrier to penetration is absent. From measurements of simple parameters like the rate of re-epitheliasation. it is known that some topical agents enhance wound healing while others retard the healing process. There is data available on the antiseptic and anti-microbial properties of most of the topical agents in use today, but ail the effects of these products on the micro-environment of wounds and their influence on the process of healing is not known. Central to the study of wounds and wound healing is the need for accurate methods to evaluate wounds. Parameters used for measuring outcome should be unambiguous and measurements should be accurate and reproducible. At present, no universally accepted methods of assessing wounds exist. Clinical evaluation is usually subjective and not quantitative, resulting in unacceptable levels of inter- and intra-observer variation. Similarly lacking are clear histological correlates of what we consider good healing characteristics of a wound. As our knowledge increase about the complex process of wound healing, in particular the hormones and peptide growth factors that regulate the process, possibilities arise for therapeutic intervention to enhance or improve clinical outcome. At the same time, the need for objective measurements becomes more urgent, as we need to evaluate and compare treatment options. Previous measurement systems were developed, ranging from visual scoring systems to measurement of biological and chemical wound constituents. Physical characteristics of healing wounds can also be measured by properties such as the tensile strength. The structural and ultra- structural elements of healing wounds remain difficult to measure, although immuno-histochemistry and scanning electron microscopy allows some quantification and simple morphometric measurements. With current advances in computer technology however, rapid, automatic measurements can be made from tissue sections for a variety of practical applications in the pathology laboratory. Image analysis offers dynamic functional imaging, linking multiple data sources to provide composite quantitative systems. Further correlation of detailed histologic examination of wounds to a detailed clinical assessment of the same wounds is important, not only to add credibility to clinical scoring schemes, but also to understand which structural features of the dermis are important for the severity of scarring (and therefore which should be the object of future therapeutic or preventative strategies)