[Canaloplasty and transient anterior chamber haemorrhage: a prognostic factor?]

An attempt has been made to evaluate transient anterior chamber haemorrhage after canaloplasty.

In the period from November 2008 to October 2009 a total of 21 eyes in 17 patients underwent canaloplasty for primary open angle glaucoma in our clinic. At the end of surgery all eyes left the surgical table with an intraocular pressure (IOP) of 5 - 10 mmHg and a deep anterior chamber without any bleeding.

The IOP on day 1 after surgery was 9.6 mmHg in average. By that time 15 of 21 eyes showed anterior chamber haemorrhage with a hyphaema between 0.5 - 2 mm in height. Eyes without hyphaema showed an IOP of > 15 mmHg at the same time. In no case was there further haemorrhage, the blood was absorbed in all cases within a maximum of 1 week without further complications.

In contrast to trabeculectomy, where the natural anterior chamber water outflow is by-passed via an artificial fistula, canaloplasty attempts to re-establish the physiological anterior chamber water draining system by means of a 360 degree viscocanalostomy and a thread mediated dilation of Schlemm's canal and its collector channels. If the anterior chamber pressure temporarily lowers the level of the venous capillary pressure, it is consistent with a patent piping system when a reverse flow with blood reflux into the anterior chamber can be observed as long as a minimal physiological pressure gradient from the anterior chamber in the direction of channel Schlemm's canal has been restored. Thus, in the authors opinion, anterior chamber haemorrhage shows the desired consistency of the water draining system and should therefore logically be expected after each successful operation in all cases where hypotony in the postoperative period occurs.