title: Presbyopia and its anatomical and physiological variants.
abstract: OBJECTIVE
  To study the various ocular anatomical and physiological parameters in presbyopia.
  
  
  METHODS
  We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 ± 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry.
  
  
  RESULTS
  The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p less than 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age.
  
  
  CONCLUSIONS
  The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age.
authors.affiliation: Department of Physiology, Aligarh Muslim University, Aligarh, India. meenakshi3190@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Gupta
authors.forename: R R
authors.initials: RR
authors.lastname: Sukul
authors.forename: Y
authors.initials: Y
authors.lastname: Gupta
authors.forename: M
authors.initials: M
authors.lastname: Dey
authors.forename: A
authors.initials: A
authors.lastname: Phougat
authors.forename: U
authors.initials: U
authors.lastname: Bhardwaj
authors.forename: S
authors.initials: S
authors.lastname: Dixit
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging / Q000473:pathology; D000867:Anterior Chamber / Q000473:pathology*; D058452:Axial Length, Eye / Q000473:pathology*; D003315:Cornea / Q000473:pathology*; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000473:pathology* / Q000503:physiopathology*