Abstract
Purpose:
Trabeculotomy with the Trabectome is an effective surgical procedure to lower intraocular pressure (IOP). However, in some patients it does not lead to a significant IOP reduction despite a gonioscopically well visible opening of Schlemm’s canal. This study investigated whether the size of the trabeculotomy opening and other parameters, such as anterior chamber depth and lens status, are related to the resulting IOP reduction.
Methods:
In this retrospective observational case series 73 eyes of 73 patients underwent trabeculotomy with the Trabectome either alone or combined with cataract surgery (n=32). Trabeculotomy opening and anterior chamber depth (ACD) were measured with an anterior segment spectral domain OCT (Tomey SS-1000). The IOP was taken with Goldmann applanation tonometry pre-operatively and at a single follow-up exam (follow-up time 151 ± 101 days (mean±SD)). The relationship between the IOP reduction and the OCT parameters as well as possible confounding factors was analysed using a multiple linear regression model.
Results:
The trabeculotomy opening size was not correlated with the IOP reduction (p=0.35). In contrast, ACD and pre-operative lens status (phakic / pseudophakic) were significantly correlated with the postoperative IOP reduction (p=0.037 and 0.002, respectively). Potential confounding factors such as the number of eye drops at follow-up or the follow-up time were not correlated.
Conclusions:
The fact that the trabeculotomy opening size was not correlated with IOP reduction points to the poorly understood role of the distal aqueous outflow pathway in glaucomatous IOP elevation.