Laser Resurfacing for the Management of Periorbital Scarring.

Laser (light amplification by the stimulated emission of radiation) skin resurfacing is currently one of the most widely adopted technologies in facial rejuvenation. While most often used for aesthetic purposes, lasers also have applications in the management of scars. Since the introduction of the CO2 laser for skin rejuvenation in the 1990s, the last three decades have seen significant growth in the number of laser devices available to the physician. More recently, promising alternatives to light-based resurfacing technologies have emerged that include radiofrequency and intense focused ultrasound. To help the physician navigate the most current laser technologies as they apply to periocular scars, this review discusses the available treatment modalities, pre-treatment assessment of periorbital scars, treatment selection, and reported outcomes and complications. The recommendations described herein are based on published literature and the authors' experience in an academic oculoplastics practice.

Ptosis repair in aesthetic blepharoplasty.

A straightforward approach to ptosis in a patient interested in aesthetic blepharoplasty is presented. Beginning with an explanation of how ptosis often becomes apparent after an aesthetic surgery of the upper lid, this article describes functional anatomy of the eyelid relevant to ptosis, and discusses the various causes of ptosis, examination of the patient presenting with a drooping lid, aspects the surgeon should be aware of from the patient's perspective of this problem, and surgical options and techniques. The author describes in step-by-step detail external levator aponeurosis resection, pretarsal aponeurosis resection, Müller muscle-conjunctival resection, the complications that can arise with these procedures, and aftercare required.

Statistical procedures for determination and verification of minimum reporting levels for drinking water methods.

The United States Environmental Protection Agency's Office of Ground Water and Drinking Water has developed a single-laboratory quantitation procedure: the lowest concentration minimum reporting level (LCMRL). The LCMRL is the lowest true concentration for which future recovery is predicted to fall, with high confidence (99%), between 50% and 150%. The procedure takes into account precision and accuracy. Multiple concentration replicates are processed through the entire analytical method and the data are plotted as measured sample concentration (y-axis) versus true concentration (x-axis). If the data support an assumption of constant variance over the concentration range, an ordinary least-squares regression line is drawn; otherwise, a variance-weighted least-squares regression is used. Prediction interval lines of 99% confidence are drawn about the regression. At the points where the prediction interval lines intersect with data quality objective lines of 50% and 150% recovery, lines are dropped to the x-axis. The higher of the two values is the LCMRL. The LCMRL procedure is flexible because the data quality objectives (50-150%) and the prediction interval confidence (99%) can be varied to suit program needs. The LCMRL determination is performed during method development only. A simpler procedure for verification of data quality objectives at a given minimum reporting level (MRL) is also presented. The verification procedure requires a single set of seven samples taken through the entire method procedure. If the calculated prediction interval is contained within data quality recovery limits (50-150%), the laboratory performance at the MRL is verified.