title: Corneal spherical aberration in Saudi population.
abstract: OBJECTIVE
  To find out the mean corneal spherical aberration and its changes with age in Saudi population.
  
  
  METHODS
  AlHokama Eye Specialist Center, Riyadh, Saudi Arabia.
  
  
  METHODS
  Three hundred (300) eyes of 185 Saudi subjects (97 men and 88 women), whose age ranged from 15 to 85 years old, with matched refractive errors, were divided into three groups according to their age, 100 for each. All the subjects were included in measuring the spherical aberration (SA) using pentacam HR (OCULUS, Germany) at the 6-mm optical zone.
  
  
  RESULTS
  The mean corneal spherical aberration (CSA) of the fourth order (Z4 (0)) of the whole groups was 0.252 ± 0.1154 μm. Patients from 15 to 35 years old have root mean square (RMS) of CSA of 0.2068 ± 0.07151 μm, 0.2370 ± 0.08023 μm was the RMS of CSA of the patients from 35 to 50 years old, while those from 50 to 85 years old have a CSA-RMS of 0.31511 ± 0.1503 μm (P < 0.0001). A positive correlation was found between the spherical aberration (Z4 (0)) and the progress of age (r = 0.3429, P < 0.0001). The high order aberration (HOA) presented 28.1% of the total corneal aberrations. While the fourth order corneal spherical aberration constituted 57% of the HOA and 16% of the total aberration. The pupil diameter shows a negative correlation with the increase in age (P = 0.0012).
  
  
  CONCLUSIONS
  Our results showed a CSA (Z4 (0)) that is varied among the population, comparable to other studies, and significantly correlates to the progress of age.
authors.affiliation: Optometrist, Riyadh, Saudi Arabia.
authors.forename: Tarfah M
authors.initials: TM
authors.lastname: Al-Sayyari
authors.affiliation: Consultant ophthalmologist, Ophthalmology Department, Ain Shams University, Cairo, Egypt.
authors.forename: Samah M
authors.initials: SM
authors.lastname: Fawzy
authors.affiliation: Consultant ophthalmologist, AlHokama Eye Specialist Center, Riyadh, Saudi Arabia.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Al-Saleh
keywords: Cataract; Corneal aberration; Fourth order spherical aberration; High order aberration; IOL; Saudi population; Spherical aberration; Z(4,0); Z(6,0)