A very interesting debate at the recent International Symposium of Ophthalmology in Hong Kong.
Toric lenses implanted to replace the cataract have the ability to reduce a patient’s astigmatism. The main benefit for the patient is that it reduces their dependence on glasses for day to day vision and need for image distorting astigmatism correcting glasses. I recently attended the International Symposium of Ophthalmology where there was significant discussion on techniques to achieve the best outcomes with these lenses.
There are two steps to the lens being implanted at the correct orientation.
The first step is determining what is the correct orientation for the lens. Traditionally, measures of astigmatism have considered only the front corneal surface, ignoring the back surface as a contributor to astigmatism. Newer techniques now take this into account.
The next step is to facilitate the lens being implanted as close as possible to the advised orientation. There are currently two systems available facilitate implantation at the advised axis. The Verion system (Alcon) and Callisto (Carl Zeissi). There was much discussion on this. It will be very interesting to see what contribution, if any, these make to reducing patient’s final astigmatism and consequent glasses dependence.