To analyze the prevalence and presentation patterns of corneal astigmatism in cataract
University of Valencia, Valencia, Spain.
Refractive and keratometric values were measured before surgery in patients having
cataract extraction. Descriptive statistics of refractive and keratometric cylinder
data were analyzed and correlated by age ranges.
Refractive and keratometric data from 4,540 eyes of 2,415 patients (mean age 60.59
years +/- 9.87 [SD]; range 32 to 87 years) differed significantly when the patients
were divided into 10-year subsets. There was a trend toward less negative corneal
astigmatism values, except the steepest corneal radius and the J(45) vector component,
in older groups (Kruskal-Wallis, P<.01). In 13.2% of eyes, no corneal astigmatism
was present; in 64.4%, corneal astigmatism was between 0.25 and 1.25 diopters (D)
and in 22.2%, it was 1.50 D or higher.
Corneal astigmatism less than 1.25 D was present in most cataract surgery candidates;
it was higher in about 22%, with slight differences between the various age ranges.
This information is useful for intraocular lens (IOL) manufacturers to evaluate which
age ranges concentrate the parameters most frequently needed in sphere and cylinder
powers and for surgeons to evaluate which IOLs provide the most effective power range.