Changes in Corneal Astigmatism and High Order Aberrations After Clear Corneal Tunnel Phacoemulsification Guided by Corneal Topography

ABSTRACT Keratoconus is the most common primary corneal ectasia, involving a thinning of the central cornea, leading to irregular corneal astigmatism. Wavefront analysis is an evolving field in the area of corneal surgery, initially designed for laser refractive treatments, but today is growing in importance and application in the diagnosis and treatment of corneal disorders such as keratoconus. In this article we will review the theoretical background of high order aberrations and the wavefront analysis as a tool for the diagnosis of keratoconus. How to cite this article Castillo JH, Hanna R, Berkowitz E, Tiosano B. Wavefront Analysis for Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):76-83.

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Eyes of Aniso-Axial Length Individuals Share Generally Similar Corneal Biometrics with Normal Eyes in Cataract Population

Journal of Ophthalmology ◽

10.1155/2020/4760978 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Min Zhang ◽

Tianhui Chen ◽

Michael Deng ◽

Jiahui Chen ◽

Qinghe Jing ◽

...

Keyword(s):

Axial Length ◽

Case Series ◽

High Order ◽

Corneal Astigmatism ◽

Retrospective Case ◽

Corneal Aberrations ◽

Length Group ◽

Cataract Patients ◽

High Order Aberrations ◽

Anterior Corneal Astigmatism

Aims. To determine the characteristics of corneal biometrics in eyes from aniso-axial length cataract patients compared with eyes from non-aniso-axial length individuals. Methods. This is a retrospective case series. Cataract patients with preoperative binocular measurements were recruited. A binocular axial difference of ≥1 mm was considered to indicate aniso-axial length. The anterior segmental biometrics were measured using Pentacam HR (Oculus, Wetzlar, Germany) and IOLMaster 500 (Carl Zeiss Meditec, Jena, Germany). Comparisons of biometrics were made among 4 eye conditions: the longer eyes from aniso-axial length patients, the shorter eyes from aniso-axial length patients, the longer eyes from non-aniso-axial length patients, and the shorter eyes from non-aniso-axial length patients. The aniso-axial length eyes were also stratified into 8 subgroups with axial length (AL) increments of 1 mm, and the biometrics of the subgroups were compared. Results. There was smaller anterior corneal astigmatism in the shorter aniso-axial length group than those in the longer aniso-axial length group (1.01 ± 0.70 D vs 1.12 ± 0.76 D, P = 0.031 ). The longer aniso-axial length eyes had greater anterior corneal steep curvature (44.13 ± 1.69 D vs 43.87 ± 1.69 D, P = 0.009 ) and anterior corneal astigmatism (1.12 ± 0.76 D vs 1.02 ± 0.69 D, P = 0.023 ) compared with longer non-aniso-axial length subjects. Other corneal biometrics were similar between the aniso-axial length eyes and the non-aniso-axial length eyes. In the longer aniso-axial length group, the posterior corneal aberrations of eyes in the ≥5 mm subgroups were greater than those in the <5 mm subgroups (0.879 ± 0.183 μm vs 0.768 ± 0.178 μm for total aberrations, P < 0.001 ; 0.228 ± 0.086 μm vs 0.196 ± 0.043 μm for high-order aberrations, P = 0.036 ; 0.847 ± 0.173 μm vs 0.741 ± 0.179 μm for low-order aberrations, P = 0.001 ). Conclusion. Eyes of aniso-axial length individuals share generally similar corneal biometrics with normal eyes in cataract population. Anterior corneal astigmatism of the longer eyes from the aniso-axial length cataract patients was higher than that of the longer eyes from the non-aniso-axial length individuals. Total posterior corneal aberrations of the longer aniso-axial length eyes increased when the binocular axial difference was over 5 mm.

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