Abstract
Abstract: :
Purpose: To test the feasibility of Zywave aberrometry to evaluate quality of vision with and without rigid gas-permeable contact lenses (RGPs) in patients with myopic-astigmatism (MA), keratoconus (KC), or penetrating keratoplasty (PK) through the identification and analysis of higher-order aberrations and evaluate the effect of rigid gas-permeable contact lenses (RGPs) on these higher-order aberrations. Methods: Wavefront analysis with the Zywave aberrometer was performed on 14 patients/28 eyes from the Ohio State University Department of Ophthalmology: 5 keratoconus, 6 myopic/astigmatism and 3 penetrating keratoplasty. RGPs were then placed and wavefront analysis was repeated in these eyes. Results: In their native state, 6 of the 10 eyes with keratoconus and 4 of the 6 eyes post-penetrating keratoplasty could be analyzed by Zywave, while all 12 eyes of the patients with myopic-astigmatism were analyzed successfully. With the use of rigid gas-permeable contact lenses, 27 of the 28 subject eyes were successfully analyzed. Mean total wavefront error of KC group was significantly higher than that of MA group (P < 0.0001). The use of RGPs led to a significantly greater decrease in total wavefront error in KC compared to MA (24.32% vs 7.39%, respectively; P = 0.0593). Conclusion: Significant corneal surface irregularity can prevent the extraction and analysis of higher-order aberrations in patients with keratoconus or a corneal graft. Correcting these surface irregularities with a properly fit, rigid gas-permeable contact lens enables successful wavefront analysis to be performed in these populations. Corneal conditions that lead to surface irregularities/irregular astigmatism appear to increase wavefront error. RGPs can not only improve a patient's visual acuity, but can also improve quality of vision by decreasing total wavefront error.
Keywords: cornea: clinical science • keratoconus • contact lens