Kinetics of foveal cone photopigment in myopia without chorioretinal degeneration

Jpn J Ophthalmol. Jan-Feb 1999;43(1):44-7. doi: 10.1016/s0021-5155(98)00062-8.

Abstract

Purpose: To study the early changes in the outer retina of myopic eyes, we performed fundus reflection foveal cone densitometry in 45 subjects with normal visual acuity and no chorioretinal degeneration (ages: 18-47 years, refraction; +2.00-(-14.50) diopters).

Methods: After full bleaching, the density of the photopigment was measured for 7 minutes by using a test spot, 562 nm in wavelength and 1 degrees in diameter, focused on the fovea. We calculated the density difference (DD) and the time constant (TC) of photopigment regeneration.

Results: Although we found no correlation between the DD and the refractive error, there was a significant increase in TC as the refractive error increased (r = 0.50, P < 0.01).

Conclusions: These findings indicated that the kinetics of cone pigments become abnormal preceding the loss of cone cells or chorioretinal degeneration in high myopia.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cell Count
  • Choroid Diseases / complications
  • Densitometry
  • Female
  • Fovea Centralis / metabolism*
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Myopia / metabolism*
  • Prognosis
  • Retinal Cone Photoreceptor Cells / metabolism*
  • Retinal Degeneration / complications
  • Retinal Pigments / metabolism*

Substances

  • Retinal Pigments