Age-related changes in with-the-rule and oblique corneal astigmatism

Acta Ophthalmol. 2018 Sep;96(6):600-606. doi: 10.1111/aos.13683. Epub 2018 Jan 25.

Abstract

Purpose: To describe the age-related changes in with-the-rule (WTR) and oblique keratometric astigmatism (KA), posterior corneal astigmatism (PCA) and total corneal astigmatism (TCA).

Methods: We used a Pentacam HR (high-resolution) rotating Scheimpflug camera to determine the KA, PCA and TCA in the right eyes of 710 patients, aged from 20 to 88 years. The age-related changes along the vertical, horizontal and oblique meridians were analyzed with Naeser's polar value method in a cross-sectional study.

Results: In the whole group, all meridional astigmatic powers and polar values were stable in the age groups from 20 to 49 years, followed by a 1.0 dioptre (D) against-the-rule (ATR) change in KA and TCA, and a 0.12 D reduction in against-the-rule PCA. A nasal rotation of the steep meridian in KA and TCA was noted in the 70-88 years old. The PCA averaged approximately 0.25 D ATR in all age groups. Females displayed the same early astigmatic stability as in the whole group, while male eyes demonstrated a linear decay from 1.5 D WTR at 20 years to 0.5 D ATR astigmatism for the oldest patients.

Conclusion: Corneal astigmatism is stable until the age of 50 years; thereafter both keratometric and total corneal astigmatism show a 0.25 D ATR change per 10 years. The average 0.25 D ATR PCA compensates the predominant keratometric WTR astigmatism in the younger patients and increases the TCA in the elderly with keratometric ATR astigmatism. The gender-based differences in age-related astigmatism require further studies.

Keywords: age; keratometry; polar values; posterior corneal astigmatism; total corneal astigmatism.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Aging*
  • Astigmatism / diagnosis*
  • Astigmatism / epidemiology
  • Astigmatism / physiopathology
  • Cornea / pathology*
  • Cornea / physiopathology
  • Corneal Topography / methods*
  • Cross-Sectional Studies
  • Denmark / epidemiology
  • Disease Progression
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Refraction, Ocular / physiology*
  • Retrospective Studies
  • Young Adult