Age and refraction in 46,000 patients as a potential predictor of refractive stability after refractive surgery

To analyze the process of emmetropization and determine the potential for progression of refractive error following refractive surgery.

The prevalence of refractive error was retrospectively examined in 46,384 consecutive patients (77,124 eyes) at an outpatient clinic in Amman, Jordan. Biometry was also obtained in 4240 eyes. Correlation of axial length and corneal power as a function of age was determined based on these data.

Patients were distributed into four distinct groups: emmetropia, hyperopia, low to moderate myopia, and high (> 6.00 diopters [D]) myopia. The prevalence of myopia was found to be 23.8%. High myopia occurred in 3.8% of patients, and 17.5% of patients were hyperopic. Patients with < 1.00 D of myopia at age 10 and < 3.00 D of myopia at the time of refractive surgery had a stable refraction at age 18. In patients with high myopia, 7.4% demonstrated a progression of corneal power and axial length that does not stabilize until age 30. Finally, the refractive error of hyperopic patients tended to progress from age 30 to age 50.

Myopes with < 1.00 D of myopia at age 10 and < 3.00 D of myopia at the time of refractive surgery are unlikely to progress. High myopes and hyperopes have potential to progress. Patients in which the axial length of the eye exceeds 26 mm in conjunction with higher corneal powers are likely in a state of decomposition and are at risk of marked progression of refractive error following refractive surgery. The likelihood of progression should be determined prior to surgery and explained to the patient.