Mid-infrared laser orbital septal tightening: ex vivo dosimetry study and pilot clinical study

Abstract

Importance: Blepharoplasty is one of the most commonly performed facial aesthetic surgeries. While myriad techniques exist to improve the appearance of the lower eyelids, there is no clear consensus on the optimal management of the orbital septum.

Objectives: To evaluate the safety and feasibility of the use of the holmium:yttrium aluminum garnet (Ho:YAG) laser for orbital septal tightening, and to determine whether modest use of this laser would provide some degree of clinical efficacy.

Design, setting, and participants: Direct laser irradiation of ex vivo bovine tissue was used to determine appropriate laser dosimetry using infrared thermal imaging and optical coherence tomography before conducting a pilot clinical study in 5 patients. Laser irradiation of the lower eyelid orbital septum was performed through a transconjunctival approach. Standardized preoperative and postoperative photographs were taken for each patient and evaluated by 6 unbiased aesthetic surgeons.

Exposure: Use of the Ho:YAG laser for orbital septal tightening.

Main outcome and measure: To determine appropriate laser dosimetry, infrared thermal imaging and optical coherence tomography were used to monitor temperature and tissue shape changes of ex vivo bovine tissue that was subjected to direct laser irradiation. For the clinical study, preoperative and postoperative photographs were evaluated by 6 surgeons on a 10-point Likert scale.

Results: Optical coherence tomography demonstrated that laser irradiation of bovine tissue to a temperature range of 60°C to 80°C resulted in an increase in thickness of up to 2-fold. There were no complications or adverse cosmetic outcomes in the patient study. Patient satisfaction with the results of surgery averaged 7 on a 10-point Likert scale. For 3 patients, 3 (50%) of the evaluators believed there was a mild improvement in appearance of the lower eyelids after surgery. The remaining patients were thought to have no significant changes.

Conclusions and relevance: Transconjunctival Ho:YAG laser blepharoplasty is a safe procedure that may ameliorate mild pseudoherniation of lower eyelid orbital fat and is a first step toward the development of percutaneous techniques.

Figure 1. Schematic of Direct Laser Irradiation (IR) Setup

Schematic of setup for direct laser irradiation of ex vivo bovine tissue. Ho:YAG indicates holmium:yttrium aluminum garnet.

Figure 2. Intraoperative Exposure of the Orbital Septum

Intraoperative photograph demonstrating exposure of orbital septum through a transconjunctival approach. Black circles indicate the typical pattern of laser irradiation.

Figure 3. Number of Pulses vs Temperature

Bar graph of number of pulses vs temperature at (A) 1.5 W, (B) 2.5 W, and 3.5 W. Arrowheads denote the minimum number of pulses required to cross the critical 60°C threshold.

Figure 4. Optical Coherence Tomographic Images of Bovine Diaphragmatic Tissues Before and After Holmium:Yttrium Aluminum Garnet (Ho:YAG) Laser Irradiation

Optical coherence tomographic images of bovine diaphragmatic tissues (A) before and (B) after irradiation with the Ho:YAG laser to a temperature range of 60° to 80°C and a setting of 3.5 W at 8 Hz using 6 pulses.

Figure 5. Preoperative and Postoperative Photographs

Preoperative (A, C, E, G, I, K) and 2-month (B, D, F, H, J, K) postoperative photographs of patient 2 after lower eyelid holmium:yttrium aluminum garnet (Ho:YAG) laser septal tightening.