Evaluation of early anatomical changes following canaloplasty with anterior segment spectral‐domain optical coherence tomography and ultrasound biomicroscopy

• Published in: Acta ophthalmologica (Oxford, England) England), 2016-08, Vol.94 (5), p.e287-e292
• Main Authors: Fuest, Matthias, Kuerten, David, Koch, Eva, Becker, Jakob, Hirsch, Thalia, Walter, Peter, Plange, Niklas
• Format: Article
• Language: English
• Subjects: Aged; bleb; canaloplasty; Conjunctiva - diagnostic imaging; Exfoliation Syndrome - surgery; Female; Filtering Surgery - methods; glaucoma; Glaucoma, Open-Angle - surgery; Humans; intraocular pressure; Intraocular Pressure - physiology; Limbus Corneae - diagnostic imaging; Male; Microscopy, Acoustic; Middle Aged; Ophthalmology; Prospective Studies; Sclera - diagnostic imaging; Surgical Flaps; Tomography, Optical Coherence; Tonometry, Ocular; Trabecular Meshwork - surgery
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/aos.12917

Purpose To analyse structural changes in conjunctiva, sclera and Schlemm's canal (SC) following canaloplasty with optical coherence tomography (AS‐OCT) and ultrasound biomicroscopy (UBM). Methods Fifteen patients undergoing canaloplasty were included in this prospective study. AS‐OCT images were acquired pre‐ and 1, 7, 30 and 90 days postoperatively. UBM was performed 3 months postoperatively. The surgical site was evaluated for the presence of SC, transscleral filtration, a scleral lake and the visibility of intra‐Schlemm‐sutures. The height and width of SC were measured at the 3 and 9 o'clock limbus position. Results After canaloplasty, SC was detectable with AS‐OCT in 93% of the patients on day 1. The increase in height was higher than that in width (height: +369%, p = 0.0004, width: +152%, p = 0.002). IOP was negatively correlated to SC's width 1 week postoperatively (r = −0.63, p = 0.04) and to SC's height until 3 months (r = −0.66, p = 0.02) postoperatively. Using UBM, a reflection of the traction sutures indicated SC's position in all patients. Transscleral filtration was found in all patients using AS‐OCT, demonstrating a peak 1 week postoperatively. At 3 months, a scleral lake could be visualized in 50% and 83% of patients using AS‐OCT and UBM, respectively. Conclusions AS‐OCT offers a high resolution for imaging superficial conjunctival areas and SC after canaloplasty, whereas UBM is capable of detecting deeper structures such as scleral lakes or intra‐canal‐sutures. The results imply a correlation of the dilation of SC with the IOP‐lowering effect and an early pronounced transscleral filtration following canaloplasty.