Optical Coherence Tomography of the Ex-press™ miniature glaucoma implant

Purpose: To describe the localisation of the Ex-PRESS miniature glaucoma implant with an experimental setup for optical coherence tomography (OCT) of the anterior segment of the eye. Methods: An OCT scanner, central wavelength 1,280 nm, bandwidth 60 nm, resolution of 12 μm, was built onto a slitlamp to scan the anterior segment of the eye. Five ex-vivo porcine eyes received an Ex-PRESS miniature glaucoma implant and were used as a model to visualise the position of the implant in the anterior segment. Results: In the ex-vivo porcine eyes, the OCT images showed the anatomy of the anterior segment in great detail. The anterior segment OCT was able to visualise the whole outline and position of the implant. The abrupt change in reflectivity going from tissue to the implant resulted in a clear border along the circumference of the whole device. Conclusion: In this paper, we have shown that we were able to outline the Ex-PRESS miniature glaucoma implant in the anterior segment of the ex-vivo porcine eye by using an experimental OCT setup built onto a slitlamp. The acquisition time of 0.8 s is short enough to allow for the scanning of patients, and anterior segment OCT is expected to aid in providing answers to the question regarding which parameters will determine the success or failure of such a device.