Comparison of Refractive Error Depending on the Refraction before and after Reverse Geometry Gas Permeable Contact Lens in Myopic Regressive Patients after Laser Refractive Surgery

Abstract

Purpose : To evaluate the differences of refractive error measurements depending on the methods of refraction before and after reverse geometry gas permeable (RGP) contact lens wear in myopic regressive patients after laser refractive surgery. Methods : Forty six eyes (24 patients, mean age 32.04 ± 4.74 years) with myopic regression in unilateral or bilateral eyes after laser refractive surgery were participated. Refractive errors were corrected with RGP contact lenses and measured by auto-refraction (AR), retinoscopy and subjective refraction (MR) before and after refractive correction with RGP contact lenses and refractions were compared. Results : Spherical equivalent refractive errors of myopic regression eyes measured by AR, retinoscopy and MR were -2.58 ± 1.23 D, -1.98 ± 1.14 D and -1.93 ± 1.08 D respectively, and those measurements were significantly different (p=0.013). And after wearing with RGP lens, the spherical equivalent refractive errors measured by AR, retinoscopy and MR were -0.98 ± 0.69 D, -0.26 ± 0.69 D and -0.29 ± 0.64 D respectively and those measurements were significantly different (p=0.000). And refractive errors measured by AR were significantly highest to the minus power (p=0.000). The difference between AR and MR measurements after laser corneal refractive surgery and after RGP contact lenses wear showed a greater correlation with the refractive errors in the spherical, cylindrical and spherical equivalent measurements and the differences were grater in eyes with high myopia than in those with low myopia. Conclusions : AR is useful for preliminary refraction, but for the refractive assessment of myopic regressive patients and RGP contact lenses wearers, AR can be misleading when using as a preliminary refraction that subjective refraction should be recommended for them.