Changes in iris color have been noted anecdotally after cataract surgery in infants, but they have not been studied systematically. The mechanism for these iris color changes has not previously been reported in the biomedical literature.
Photographs were taken of both eyes of 15 children and 11 rhesus monkeys who had undergone unilateral cataract surgery. Masked examiners reviewed the photographs and compared the iris color of the eyes that were operated on with the eyes that were not operated on. Between 4 and 6 weeks postoperatively, the level of prostaglandin F(2alpha) in the aqueous humor (n = 4) and vitreous humor (n = 2) was measured in both the operated and nonoperated eyes of 4 monkeys that had undergone a neonatal lensectomy during the first 5 days of life.
Thirteen of 15 children had a darker iris color in the operated eye in relation to the nonoperated (control) eye. Four of 11 monkeys had a uniformly darker iris in the operated eye; the other 7 monkeys had regional darkening or patches of darker iris in the eye that was operated on. The prostaglandin F(2alpha) levels in neonatal monkeys were higher in the aqueous humor and in the vitreous humor of the operated eye in relation to the nonoperated eye.
In some children, cataract surgery is associated with a darkening of the iris color in the operated eye. We speculate that this darkening results from an exuberant prostaglandin release stimulated by the cataract surgery and may occur through the same or a similar mechanism by which latanoprost causes the darkening of iris color.
Heterochromia after pediatric cataract surgery.