Prostaglandin-induced iris color darkening. An experimental model

Arch Ophthalmol. 1998 Aug;116(8):1065-8. doi: 10.1001/archopht.116.8.1065.


Objectives: To determine the role of sympathetic innervation and the effect of topical prostaglandin therapy on iris color in pigmented rabbits.

Methods: Twelve Dutch-belted rabbits underwent unilateral superior cervical ganglionectomy (SCGx) at age 1 to 3 months. A second group of 11 rabbits underwent bilateral SCGx at age 1 month and were treated once or twice daily for 6 to 9 months with 1 drop (about 20 microL) of latanoprost, 0.005%, to one eye and its vehicle to the contralateral eye. Standardized color photographs of the iris of each eye were taken at 1- to 2-month intervals for 6 to 10 months and evaluated by 4 to 6 observers in a masked fashion.

Results: At 8 to 10 months after unilateral SCGx, 11 of 12 rabbits showed definite heterochromia, with the lighter-colored iris on the SCGx side. Of the 11 rabbits that underwent bilateral SCGx and unilateral latanoprost treatment, 9 showed heterochromia at 6 to 9 months, with the darker-colored iris on the latanoprost-treated side.

Conclusions: These results demonstrate that sympathetic innervation is required for age-related, physiologic darkening of iris color in rabbits, that prostaglandins may compensate for sympathetic denervation to produce darkening in SCGx eyes, and that this model may be useful to study prostaglandin-induced iris color change.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Animals
  • Eye Color / drug effects
  • Eye Color / physiology*
  • Female
  • Ganglia, Sympathetic / physiology*
  • Ganglionectomy
  • Hyperpigmentation / chemically induced*
  • Hyperpigmentation / physiopathology
  • Iris / drug effects
  • Iris / innervation*
  • Latanoprost
  • Models, Biological
  • Ophthalmic Solutions
  • Photography
  • Prostaglandins F, Synthetic / administration & dosage
  • Prostaglandins F, Synthetic / pharmacology*
  • Rabbits


  • Ophthalmic Solutions
  • Prostaglandins F, Synthetic
  • Latanoprost