To evaluate the 6-month intraocular pressure (IOP) reduction achieved after canaloplasty in primary open-angle glaucoma (POAG) eyes and to assess the potential value of fluorescein channelography result as a predicting factor for the surgery outcome.
Prospective consecutive study including 82 Caucasian eyes of 75 patients aged between 39 and 89 years. All eyes had POAG and underwent canaloplasty surgery for lowering IOP in the Augencentrum Köln (Cologne, Germany). Channelography was performed to evaluate the aqueous outflow by analysing the amount of diffuse scleral staining, areas of superficial staining, the number of visible superficial connections to collector channels, the trabecular permeability and the number of micro-ruptures of the trabecular meshwork. Postoperatively, IOP was monitored during a 6-month follow-up, and the change from baseline was recorded.
Mean IOP changed from a preoperative value of 19.0 ± 5.1 mmHg to a 6-month postoperative value of 14.2 ± 4.5 mmHg (p < 0.01). A strong and statistically significant correlation of the 6-month IOP change from baseline with the preoperative IOP was found (r = − 0.70, p < 0.01). Additionally, the IOP change from baseline correlated significantly with the level of superficial staining (r = − 0.27, p = 0.02) and the number of visible superficial connections to collectors (r = − 0.37, p < 0.01) observed in channelography. Transient hyphaema was observed in 9.8 % of eyes and filtering bleb in 4.9 % of eyes. Medical treatment for lowering IOP was required at 6 months postoperatively in 12 eyes (14.6 %).
Canaloplasty is an effective surgical method for lowering IOP in POAG eyes, providing more significant IOP reduction in cases showing more superficial staining and visible superficial connections to collector channels during fluorescein channelographic examination.