Over the age-related changes in corneal astigmatism and their impact on target astigmatisms in corneorefractive surgery

Session Details

Session Title: Cornea: Surgical II

Session Date/Time: Sunday 08/10/2017 | 14:30-16:00

Paper Time: 15:24

Venue: Room 3.6

First Author: : K.Næser DENMARK

Co Author(s): :    G. Savini   J. Bregnhoj                 

Abstract Details

Purpose:

To examine the-age-related changes in corneal astigmatism

Setting:

Department of Ophthalmology, Randers Regional Hospital, Denmark

Methods:

In a retrospective, longitudinal design we used the Pentacam rotating Scheimpflug camera to measure the keratometric astigmatism (KA), posterior corneal astigmatism (PCA), and total corneal astigmatism (TCA) in normal, unoperated right eyes of 721 patients, aged from 20 to 89 years. Næser´s polar value method was used to calculate the with-the-rule (WTR) and against-the-rule (ATR) astigmatism, as well as the rotation of the steep meridian from a temporal to a nasal direction.

Results:

There was no change in average astigmatism in the age groups between 20 and 49 years. From 50 to 89 years of age considerable statistically significant average changes were noted. The KA changed from 0.92 D (±0.96 D) WTR to 0.06 D (±0.86 D) ATR. The PCA declined from 0.32 D (±0.17 D) ATR to 0.20 (±0.18) ATR. The TCA changed from 0.69 D (±1.0 D) WTR to 0.31 D (±0.91 D) ATR. Furthermore, from 70 to 89 years of age the steep meridian in KA and TCA rotated statistically significantly in a nasal direction.

Conclusions:

In this longitudinal study corneal astigmatisms were stationary in patients aged from 20 years to 49 years. From 50 to 89 years an average 1.0 D ATR drift was noted for ACA and TCA. This ATR change amounts to approximately 0.25 D for each decade. A 0.5 D WTR residual astigmatism should be targeted in corneorefractive surgery in order to avoid an excessive ATR astigmatism postoperatively. No financial or proprietary interests

Financial Disclosure:

NONE