Predicting the position of pIOLs

March 1, 2014

Predicting the position of an iris-fixated pIOL is important to ensure intraocular structure health is maintained. In this article, Dr Soltani Moghadam describes his recent study that found AS-OCT imaging technique to be particularly useful as a preoperative simulation technique.

Regarding endothelial cell health, an endothelial cell count of more than 2000 cells/mm2 and internal anterior chamber depth (ACD) of more than 2.8 mm have been reported to be criteria for implantation of iris-fixated pIOLs. However, for implantation of any prosthesis in the anterior chamber, the critical distance between endothelium and prosthesis, known as endothelial clearance, would be better for evaluation than just the ACD.

In the case of the myopic Artisan pIOLs (Ophtec, Groningen, The Netherlands), the peripheral endothelial clearance (distance from endothelium to peripheral edge of the Artisan) seems to be more important than the ACD, and it has been suggested that it should be more than 1.5 mm. So, it seems to be important that we are able to predict this distance preoperatively.

Scheimpflug photography

Scheimpflug photography has been used preoperatively to simulate the position of pIOLs in the anterior chamber. Tehrani et al.1 used Scheimpflug photography for preoperative simulation of the pIOL position in the anterior chamber and reported the results in 1 case.

AS-OCT

Anterior segment optical coherence tomography (AS-OCT) is a useful imaging technique for internal biometry of the anterior chamber. The Visante AS-OCT system (Carl Zeiss Meditec, Jena, Germany) also has a software tool (pIOL template) to simulate the postoperative position of iris-fixated pIOLs and can be useful in evaluating its position preoperatively.