title: The progression of corrected myopia.
abstract: OBJECTIVE
  This study seeks to demonstrate the existence of a feedback loop controlling myopia by comparing the prediction of a feedback model to the actual progression of corrected myopia. In addition to theoretical results, confirming clinical data are presented.
  
  
  METHODS
  The refraction of 13 continuously corrected myopic eyes was collected over a period of time ranging from 4 to 9 years from the time of their first correction. Refractive data was collected in an optometry office from myopic young subjects from the general population in Boston. Subjects were myopes, ages 2 to 22 at the time of first correction selected randomly from a larger population. All individuals were fully corrected with lenses; new lenses were prescribed every time that their myopia increased by 0.25 diopters or more. Subjects wore their spectacle lenses during the followed period.
  
  
  RESULTS
  Subjects exhibit a linear time course of myopia progression when corrected with lenses. The observed rate of myopia increase is 0.2 to 1.0 diopters/year, with a mean correlation coefficient r  = -0.971, p < 0.005.
  
  
  CONCLUSIONS
  This report establishes that feedback control theory applies to the clinical phenomenon of progressive myopia. Continuous correction of myopia results in a linear progression that increases myopia. The Laplace transformation of temporal refractive data to the s-domain simplifies the study of myopia and emmetropia. The feedback transfer function predicts that continuous correction of myopia results in a linear progression because continuous correction opens the feedback loop. This prediction is confirmed with all subjects.
authors: Massachusetts Institute of Technology, Research Laboratory of Electronics, Cambridge, MA, 02139, USA, puerta@alum.mit.edu.
authors: Antonio
authors: A
authors: Medina
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005139:Eyeglasses; D006801:Humans; D009216:Myopia / Q000175:diagnosis* / Q000628:therapy*; D012029:Refraction, Ocular / Q000502:physiology