If you have undergone PRK or LASIK Surgery and now require cataract surgery, very critical data must be obtained to determine the power of the intraocular lens that will be implanted in your eye. Mathematical formulae have been developed, IOL Nomograms, that require information about the curvature of the cornea in addition to other data about the pre-surgical eye. However, these Nomograms assume that the cornea has not been altered by refractive surgery. If the cornea is incorrectly measured, the incorrect intraocular lens will be implanted. To assure that the correct corneal curvature is measured, Jack Holladay, MD of Houston, Texas, has developed a special corneal map, the Holladay Report, using the unique capability of the Pentacam corneal measuring device.

The IOL Nomogram that has achieved universal approval for its accuracy is the one developed by Dr. Haigis of Germany. Besides the cornea curvature of the Holladay Report, the Nomogram uses the Pentacam's Anterior Chamber Depth Measurement (ACD) as well. The ACD is the distance between the cornea and the anterior surface of the cataract. Requiring this information is intuitively desirable since this distance is approximately where the implanted IOL will be ultimately located. The final measurement introduced into the Haigis Nomogram is the axial length of the eye, measured extremely accurately by the Zeiss IOL Master.    

 

The Pentacam is used to analyze the corneal curvature and the distance between the cornea and the front surface of the lens, the Anterior Chamber Depth (ACD)

The Holladay Report generates the critical corneal curvature measurement of an eye that has undergone refractive surgery