Surgeons must carefully consider the etiology of any irregular astigmatism when deciding on treatments, according to Thomas Kohnen, MD.
"Irregular astigmatism can pose a significant challenge for all of us," said Dr. Kohnen, professor and chairman, Department of Ophthalmology, Goethe University, Frankfurt, Germany.
The most widely used premium intraocular lens (IOL) is a toric lens for treating astigmatism, Dr. Kohnen said. However, the way these lenses can be used depends on whether the patient's astigmatism is regular or irregular.
"Against the rule, with the rule, and oblique astigmatism can be very easily corrected with toric lenses," he said.