title: Keratoconus Clinical Findings According to Different Classifications.
abstract: OBJECTIVE
  To demonstrate the topographic and keratometric findings in patients with keratoconus (KC), according to age, sex, and KC severity groups.
  
  
  METHODS
  A total of 2073 eyes of 1081 patients with KC were consecutively diagnosed and enrolled in this prospective cross-sectional study. All patients underwent ophthalmic examination and Pentacam (Oculus Optikgerate GmbH) measurements. The patients were divided into different groups according to their age, sex, Amsler-Krumeich classification, and keratoconus severity score classification. Keratometric (K) values (flattest, steepest, and mean), central and thinnest corneal thickness, and manifest refraction were recorded for each patient with KC and they were then compared according to the patient's age, sex, and KC severity groups.
  
  
  RESULTS
  The age (mean ± SD) of the population was 24 ± 7 years. The average central corneal thickness and mean K of all patients were 462 ± 45 μm and 48.8 ± 4.8 diopters, respectively. Female patients with KC were significantly younger and had significantly higher K values and lower anterior chamber depth than those of men. All parameters except for the pupil diameter and astigmatism were significantly associated with KC severity grades. The thinnest corneal thickness was the most important and also the most sensitive and specific parameter for distinguishing all stages of KC severity in all KC severity classifications. The Amsler-Krumeich classification had the most correlation with other severity classifications.
  
  
  CONCLUSIONS
  The results of this study enable clinicians and researchers to understand better the differences between clinical characteristics between sex, age groups, and the changes in clinical characteristics during disease progression, which may lead to further advancement in KC management.
authors.affiliation: *School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; †Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran; and ‡Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Naderan
authors.forename: Saeed
authors.initials: S
authors.lastname: Shoar
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Kamaleddin
authors.forename: Mohammad T
authors.initials: MT
authors.lastname: Rajabi
authors.forename: Morteza
authors.initials: M
authors.lastname: Naderan
authors.forename: Marjan
authors.initials: M
authors.lastname: Khodadadi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D003315:Cornea / Q000473:pathology*; D063171:Corneal Pachymetry; D019781:Corneal Topography; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000145:classification* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012720:Severity of Illness Index; D012737:Sex Factors; D055815:Young Adult