The relationship between patient age and residual refractive error after uneventful laser in situ keratomileusis for moderate-to-high hyperopia

Abstract

Purpose: To determine if the manifest sphero-cylindrical residual refractive error, at various time points over a 12-month postop period after laser in situ keratomileusis (LASIK) was associated with patient age at time of surgery. Methods: Patients with moderate to high hyperopia (3.00–7.00 DS) and astigmatism ⩽2 DC underwent LASIK using Wavelight Allegretto Eye Q (400 Hz). Treatments were centered on corneal vertex, flaps were made with Moria M2 mechanical microkeratome. Pre-and postoperative uncorrected and corrected distant visual acuity, best corrected spherical equivalent (SEQ) were measured. Measurements were taken at 1 week, 1, 3, 6, and 12 months after the surgery. Target refraction was emmetropia. Total of 161 patients were treated. In binocular cases, data from the right eyes were included for analysis. In this article, we report on refraction data only. Raw data were subjected to several permutations to elicit any links between refractive outcomes and patient age. Results: The key findings were as follows y = postop SEQ (diopters), x = patient age (years), ln(x) = natural logarithm of patient age: At 1 month, y = x[0.049 −0.011.ln(x)] (R = −0.205, p = 0.001, n = 161). At 3 months, y = x[0.077 −0.017.ln(x)] (R = −0.355, p < 0.001, n = 161). At 6 months, y = x[0.088 −0.020.ln(x)] (R = −0.382, p < 0.001, n = 161). At 12 months, y = x[0.093 −0.021.ln(x)] (R = −0.409, p < 0.001, n = 161). There was no significant association between x and y at 1 week (p > 0.05). Conclusion: Residual postop refractive error after LASIK for hyperopia has a logarithmic association with patient age at time of surgery. In younger patients there is tendency toward undercorrection, the opposite occurs in older patients and this persists 1 year after treatment.