Corneal Spherical Aberration Changes With Age

It is well known that age-related changes take place in the eye. However, little is known about the changes of corneal spherical aberration (SA) over lifetime. This topic is of particular interest when it comes to removing the crystalline lens and implanting an IOL. Then a careful selection of an adequate IOL is required. There is an enormous amount of IOLs with a broad spectrum of characteristics available, amongst others IOLs with aberration-neutral designs and such that correct for SA. For an informed decision, the surgeon should know the amount of the corneal SA and have on mind how this may change over time. The aim of this study was to establish normative data for spherical aberration for a clinical population.

International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Germany

I.R.C.C.S.-G.B. Bietti Foundation, Rome, Italy

QVision Vithas Hospital Almería, Almería, Spain

In this three-centre retrospective study, phakic eyes without any known pathologies or previous refractive surgery were measured with the Pentacam AXL Wave (only measurements with good quality scores were included). Corneal spherical aberrations (Z₄⁰) of the 6mm zone and its correlation with age, gender and SEQ was analysed.

For statistical analysis SPSS for Windows version 26.0 (IBM, Armonk, NY, USA) was used. Simple correlation was performed using Pearson correlation coefficient, T-test was used to detect statistically significant differences between gender and with respect to the amount of data, normal distribution was assumed.

The study included 1074 eyes and their distribution with respect to gender, age and SEQ was as follows: 628 females with an average age of 51 ±19 years (rang: 10 to 91 years) and an average SEQ of -1,88 ±3,89D; 446 males with an average age of 55 ±20 years (range: 11 to 89 years) and an average SEQ of -1,72 ±3,57D.

The overall spherical aberration was 0,278 ±0,13µm. There was no statistically significant difference between gender (p=0,5); Z₄⁰ _Female= 0,276µm and Z₄⁰ _Male= 0,281µm. The spherical aberration showed a rather strong correlation (r = 0,55, p < 0.001) with age and a weak correlation (r = 0,21, p < 0.001) with SEQ.

It has been shown that corneal spherical aberration is subject to changes over lifetime, the amount of SA increases with increasing age. This process seems to affect males and females likewise however, differences between individuals can be large.