Simple technique using phone to measure postop toric IOL axis

The authors present a simple, inexpensive technique for measuring postoperative toric IOL axis using a camera-enabled cellular phone (in this case an iPhone 5S) and computer software.

They have used this technique for measuring the postoperative IOL axis for more than a year. They say the results have been reproducible, and the image-capture technique is simple, fast and cost effective.

Their technique involves affixing a camera-enabled cell phone to a slitlamp using a special adapter.

The authors note that the factory-installed camera application on the iPhone does not provide a way to determine whether the phone is level when a photo is being taken. Therefore, they use a photo application that concurrently uses the iPhone’s internal accelerometer and displays a level (Camera Awesome, Smugmug, Inc.).

Computer software (they recommend ImageJ) is then used to import and analyze the image. A line is drawn using ImageJ between the IOL markings on opposite sides of the optic. If the phone was level when the image was captured, the IOL axis can be read directly from the screen without further processing.