Validating three-dimensional imaging for volumetric assessment of periorbital soft tissue.

Purpose: To evaluate the accuracy and interobserver variability of three-dimensional (3D) stereophotogrammetric imaging for volumetric assessment in the periorbital region and to propose a protocol for measurement. Methods: A cross-sectional study was performed. Fifty-eight normal adult subjects had photographs taken using the VECTRA M3 imaging system on two separate occasions at a single center teaching hospital. The primary study outcome measurement was mean volume change in the periorbital region, using different methods of image analysis with the following variables: registration method, eyes open or closed, eyelids measured separately or together, extension of area measured to include mid-face. Accuracy was defined as the agreement between paired images with no measured change in volume (0 mL). The agreement between two independent observers was assessed using Bland-Altman plots. Results: There was a statistically significant difference (P < .0001) between the different methods of measurement, with registration of images having the most effect (partial eta squared 0.229). A mean change in volume of 0.11 ± 0.13 mL was reported for the most accurate method. Agreement between observers was confirmed (highest Intraclass Correlation Coefficient 0.63). Conclusions: Assessment of volumetric change in the periorbital region using 3D image reconstruction is accurate with good interobserver repeatability and is suitable for clinical use. A protocol for data acquisition using the VECTRA M3 is proposed. 3D image reconstruction holds promise to enable diagnosis, treatment monitoring, and surgical outcome evaluation in ocular adnexal disease.

The use of prophylactic Nunchaku stents to reduce the risk of nasolacrimal duct obstruction in patients with midfacial tumours undergoing radiotherapy.

The treatment of midfacial tumours with radiotherapy, chemotherapy and radio-iodine can cause nasolacrimal duct fibrosis resulting in epiphora. Nasolacrimal patency can be maintained by stenting. We report our experience of prophylatic Nunchaku stent insertion in 5 patients prior to midfacial radiotherapy. Four out of 5 patients (80%) had patent nasolacrimal ducts without any symptoms of epiphora following removal of the stents. One patient was initially asymptomatic with patent nasolacrimal duct, but subsequently developed epiphora. Nunchaku stents may provide a simple and effective way of preventing epiphora, obviate the need for nasal retrieval that is required for other nasolacrimal stents, and reduce the risk of requiring further lacrimal surgery.