Intentional anisometropia creation treats diplopia

Key Points

Chicago-Planned anisometropia in patients with long-standing diplopia who are undergoing bilateral cataract surgery can be a triple-win situation, providing clear uncorrected vision at both distance and near while simultaneously eliminating or reducing awareness of pre-existing double vision, according to Robert H. Osher, MD.

The approach, which aims for a plano outcome in the distance eye and myopia between –3 and –3.5 D in the near eye, creates an amount of anisometropia incompatible with binocular vision. Although such an outcome is considered a disaster after conventional cataract surgery, experience with it in a series of 12 patients demonstrates it is a safe and consistently successful strategy when used in carefully selected patients with long-standing acquired diplopia.

"When patients with diplopia undergo cataract surgery, even if they have two perfect operations, they may be unhappier postoperatively . . . because they will become more acutely aware of the now-clear second image, which may be impossible to suppress," he said. "Leaving pseudophakic patients with too much anisometropia is also a huge problem because these individuals will be bothered by aniseikonia."

However, several years ago, Dr. Osher was spontaneously struck with the idea that leaving a patient unable to fuse by deliberately creating anisometropia could have positive consequences in a person with diplopia.