Using a large incision to your advantage

ByUday Devgan, MD

For extremely myopic patients, a phakic IOL can be the best option to surgically correct the refractive error. These patients with more than 10 D of myopia often have a significant degree of astigmatism, typically corneal in nature. The currently available phakic IOLs in the U.S. don't offer a toric correction, but we can achieve one by varying the placement of our surgical incision. Incisions can have an astigmatic effect, which can be used to treat the patient's pre-existing corneal astigmatism.

A phakic IOL combined with a carefully placed surgical incision is used to successfully correct large degrees of myopia and astigmatism.

When I first learned phaco surgery as a resident more than a decade ago, my attendings stressed the importance of incision architecture. Scleral tunnels could be created at different positions and with different dimensions and shapes in order to modulate or minimize the induced astigmatism. We have since switched to small-incision temporal clear corneal incisions for phaco surgery, so these techniques weren't commonly used in my practice. But within the last few years, with the use of the Verisyse iris-secured anterior chamber phakic IOL (Advanced Medical Optics), I have returned to these techniques. Because the Verisyse is a non-foldable design, it requires approximately a 6-mm incision for insertion.

A patient with 16 D of myopia and 2.5 D of astigmatism underwent successful implantation of the Verisyse phakic IOL. Because the astigmatism was steep at 90° (with the rule), the surgical incision was placed at that meridian. After the initial healing when the sutures were removed, the refraction stabilized, and the patient's vision was superb. All of her myopia was successfully addressed, and her astigmatism was reduced from 2.5 D to 0.5 D.

My attendings were right: Every surgical technique that you learn should be placed into your mental "toolbox" because you never know when it will come in handy.