Augmented Reality in Oculoplastic Surgery: First iPhone Application
Paolo Mezzana, Fabio Scarinci, Nazareno Marabottini · Plastic & Reconstructive Surgery · 2011
Sir: Augmented reality is a growing area in virtual reality research. An augmented reality system generates a composite view for the user.1 It is a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information. The users enhance their performance and their perception of the world. Because imaging technology is so pervasive throughout the medical field, it is not surprising that this domain is viewed as one of the most important for augmented reality systems.1–3 In this article, the authors describe one of the first applications of augmented reality in oculoplastic surgery: the evaluation of the position of the lateral canthal ligament. The postoperative results are generally good, and the complications are mostly attributable to vertical and horizontal dystopia of the lateral canthal ligament.4,5 The purpose of this study was to introduce augmented reality in oculoplastic and orbit surgery through a simple iPhone (Apple, Inc., Cupertino, Calif.) application, and to stimulate research in this direction. This investigation was conducted on nine patients, all of whom were undergoing lateral canthal detachment for inferior and lateral orbit exposure (all male patients). The lateral canthal ligament position and alignment were evaluated in real time with an iPhone-based augmented reality system. The software used for this purpose was Video Laser Level by Robert Szeleney. This unique application uses the iPhone 3.1 Video Overlay support to position virtual red horizontal lines over the live video. These lines can be used to correctly align points or measure inclination (Fig. 1). In this application, the lateral canthal angle position of the two eyes, their possible misalignment, and the degree of this dystopia were assessed before canthal surgery. Two other points were marked on the skin after their alignment by means of the iPhone application. These points were marked on the patient's face to obtain a calibration system for the iPhone software to be used in the operating room (Fig. 2). During surgery, the alignment was assessed rapidly using the two marked points for calibration purposes. The lateral canthal alignment was verified after surgery with the same procedure. A manual level was used to confirm the results of this augmented reality test. Two different investigators assessed the procedure before, during, and after canthal surgery.Fig. 1.: The augmented reality iPhone application during canthal ligament alignment evaluation. Two digital horizontal lines were superimposed onto the real-time image of the patient. Red lines indicate misalignment and the green line indicates alignment. The degree of inclination is shown under the bars.Fig. 2.: The two calibration points drawn on the patient's face before surgery.The new iPhone-based application of augmented reality in oculoplastic surgery is rapid, inexpensive, and reproducible. The interobserver agreement was 100 percent. All of the patients had perfect alignment of the lateral canthal position after surgery verified by manual level assessment. The detachment of the lateral canthal tendon may result in an asymmetric repositioning of the canthus as compared with the contralateral side.4,5 This new application of augmented reality is simple, reproducible, and inexpensive. It allows the surgeon to evaluate canthal position, especially alignment or misalignment in all phases of surgical planning, execution, and follow-up on a live image–based system. This is probably the beginning of the rapid development of new applications. Augmented reality is a growing area in virtual reality research. An augmented reality system generates a composite view for the user. It is a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information. In this article, the authors describe one of the first applications of augmented reality in oculoplastic surgery: the evaluation of the position of the lateral canthal ligament. Paolo Mezzana, M.D. Fabio Scarinci M.D. G. B. Bietti Eye Foundation Nazareno Marabottini, M.D. Ophthalmic Department S. Giovanni Addolorata Hospital Rome, Italy DISCLOSURE The authors have no financial interest in any of the products or devices mentioned in this article.