Future Prospects: Assessment of Intraoperative Optical Coherence Tomography in Ab Interno Glaucoma Surgery

Purpose: Ab interno glaucoma surgery, such as trabecular aspiration or ab interno trabeculotomy, has been introduced as an alternative, non-filtering procedure to lower intraocular pressure in glaucoma patients. The purpose of the present study was to assess the feasibility of intraoperative spectral domain optical coherence tomography (iOCT) for improving ab interno glaucoma surgery. Materials and Methods: Intraoperative optical coherence tomography was performed to visualize the anterior chamber angle, the aspiration canula during trabecular aspiration, and the trabectome device during ab interno trabeculotomy. A commercially available 840-nm iOCT was used in a clinical setting, a 1310-nm spectral-domain OCT in an experimental setting. Results: In the clinical setting using the 840-nm iOCT, visualization of the aspiration canula and the trabectome device was possible, however, with rather limited visibility of the chamber angle and the trabecular meshwork. In the experimental setting, the 1310-nm OCTenabled excellent visualization of the chamber angle and detailed evaluation of the instrument-trabecular meshwork relation. Conclusions: Intraoperative use of optical coherence tomography may be helpful for ab interno glaucoma surgery. Adjustments of the commercially available iOCT, including longer wavelengths and oblique scanning options, are necessary for the clinical use.