Planned Undercorrection With Laser in situ Keratomileusis and Photorefractive Keratectomy for Myopes Over Age 40

To evaluate the effectiveness of planned undercorrection in myopic patients over 40 years of age.

Two hundred eight eyes of 104 patients aged 40 to 60 years had photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). Full corrections were done for the dominant eye and undercorrection of -1.50 or -2.50 D for non-dominant eye. Planned undercorrection of -1.50 D was done for patients aged 40 to 50 years, and -2.50 D for patients aged 51 to 60 years.

In eyes with planned undercorrection of -1.50 D, the achieved refraction was a mean -1.67 ± 0.40 D after PRK and a mean -1.54 ± 0.30 D after LASIK. In eyes with planned undercorrection of -2.50 D, the achieved refraction was after PRK was a mean -1.82 ± 0.50 D and after LASIK, -2.31 ± 0.60 D. Estimation of the achieved refraction was made according to the condition of the lens: in the group with clear lenses, mean achieved refraction was -1.60 ± 0.30 D (planned -1.50 D, 52 patients) and -2.10 ± 0.40 D (planned -2.50 D, 19 patients). In the group with initial opacification of the lens, mean achieved refraction was -1.00 ± 0.40 D (planned -1.50 D, 9 patients), and -1.40 ± 0.20 D (planned -2.50 D, 24 patients).

According to analysis of the achieved results, nomograms for planned undercorrection in patients aged 40 to 60 years were refined for PRK and LASIK. [J Refract Surg 2000;16(suppl):S261-S263].