Purpose: To characterize higher-order aberrations (HOAs) from the anterior and posterior corneal surfaces and whole eye using an integrated Scheimpflug corneal tomographer/Hartmann-Shack wavefront aberrometer in borderline cases of suspected keratoconus (KC) without bilateral clinical and topographic signs.
Methods: In this prospective case-control study, the inclusion criteria for suspected KC were patients 1) referred to a university hospital for close examination on the eyecare provider's suspicion that KC may be present and 2) without clinical and topographic KC signs bilaterally. Corneal and ocular wavefront aberrations were obtained using an integrated Scheimpflug tomographer/Hartmann-Shack wavefront aberrometer at Osaka University Hospital. Age-matched healthy eyes were evaluated as controls. The magnitudes of coma, spherical aberration, and total HOAs for 4-mm pupils from the anterior and posterior corneal surfaces and whole eye were calculated and compared in two groups.
Results: This study included 14 suspected KC cases (mean age: 20.4±5.3 years) and 14 controls (mean age: 22.0±2.2 years). The suspected KC group had significantly greater total HOAs from the posterior corneal surfaces and whole eye (0.07±0.02 μm and 0.15±0.06 μm, respectively) than did the control group (0.06±0.01 μm and 0.11±0.04 μm, respectively) (p<0.05 for all). Similarly, coma from the posterior corneal surfaces and whole eye were significantly greater in the suspected KC group (0.03±0.01 μm and 0.09±0.05 μm, respectively) than in the control group (0.02±0.01 μm and 0.06±0.03 μm, respectively) (p<0.05 for all). No significant difference was observed in other wavefront parameters between the two groups.
Conclusions: Based on a comprehensive wavefront assessment, wavefront characteristics differed from healthy eyes in suspected KC cases without bilateral clinical and topographic signs. Future studies with a longer follow-up period are required to expound on this.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 127: 1063-1068, 2023.