ObjectiveWe aimed to evaluate the accuracy of three-dimensional laser scanning as an objective method for detecting facial changes.
MethodsFacial laser scanning was performed at baseline and repeated after a median of 10 months in 24 HIVinfected patients, 12 with ongoing lipodystrophy, five with 410% weight loss and seven with 410% weight gain. Surface volume change was estimated using a standardized technique, and compared with change in cheek fat measured by magnetic resonance imaging (MRI).
ResultsThe median laser scanning surface volume changes were À 2.1 (range À 4.6 to À 0.8) mL in the lipoatrophy group, À1.5 (range À6.8 to À1.3) mL in the weight loss group and 13.1 (range À 0.2 to 1 5.4) mL in the weight gain group (the median MRI cheek fat changes were À 4.6, À 3.7 and 1 7.0 mL in the three groups, respectively). Laser scanning and MRI measurements were not significantly associated in lipoatrophy patients (r 5 0.34, P 5 0.28), but there was a good association in patients who changed weight (r 5 0.71, P 5 0.01).
ConclusionsLaser scanning detects changes in the appropriate direction, although it underestimates MRImeasured cheek fat changes. Laser scanning may be useful as an objective measure of cheek surface volume changes, but needs further validation in larger clinical cohorts.Keywords: accuracy, fat, HIV, laser scanning, lipoatrophy, magnetic resonance imaging, reproducibility
IntroductionChanges in facial appearance are one of the most distressing aspects of the lipodystrophy syndrome for patients with HIV disease. The resulting stigma and psychological morbidity may adversely affect quality of life and result in compromised adherence to antiretroviral therapy (ART) [1][2][3][4]. Consideration of lipoatrophy risk influences the selection of drugs for new antiretroviral regimens [5].A number of research studies have evaluated potential interventions for facial lipoatrophy, including switching to regimens without thymidine analogues [6][7][8] and injection of facial fillers such as polylactic acid [9][10][11] and silicone [12]. However, there is currently no accepted objective method for measuring the onset and progress of lipodystrophy or for assessing the reversibility of the changes that occur as a result of therapeutic interventions. Evaluation of lipodystrophy in clinical trials is currently based on patient self-assessment and/or physician assessments, although these are subjective and have been shown to be insensitive for detecting changes over time [13]. Although dual-energy X-ray absorptiometry is often used to measure changes in peripheral lipoatrophy in clinical research, this method is not suitable for detecting facial fat changes. Facial magnetic resonance imaging (MRI) and computerized tomography (CT) have been used successfully in measuring facial soft tissue volumes, but these techniques Three-dimensional laser scanning has been used in research and clinical practice to generate images of facial contour that may be used for planning maxillofacial surgery, measuring craniofacial deformit...