Ethnicity may have role in IOP stability among myopic children, study suggests

Among children with myopia, black children appear to have higher IOPs compared with Hispanic, white and non-black children, according to a new analysis of data from the Correction of Myopia Evaluation Trial.

However, IOP does not appear to be associated with gender, baseline refractive error, baseline axial length, myopic progression or changes in axial length over the long term, the study authors noted.

“Additional measures of IOP and corneal thickness on the entire ethnically diverse [Correction of Myopia Evaluation Trial] cohort would be useful in further exploring these ethnic differences,” they said.

Ruth E. Manny, OD, PhD, and colleagues at the University of Houston and New England College of Optometry, Boston, obtained annual cycloplegic and axial length measurements of the right eye for 104 children with myopia over 5 consecutive years. Of these children, 17 participants were black, 50 were Hispanic, 25 were white, seven were Asian and five were of mixed ethnicity, according to the study.

IOP averaged 15.92 mm Hg at baseline in the whole group and significantly decreased by an average of 0.125 mm Hg yearly over the 5 years of follow-up (P = .05). “The small but statistically significant decrease in IOP ... could be related to age,” the authors said.

Among black participants, IOP averaged 19.88 mm Hg, which was significantly higher than the average IOP in Hispanic, white and non-black children.

IOPs averaged 15.77 mm Hg in Hispanic children (P = .006), 14.51 mm Hg in white children (P = .0001) and 15.38 mm Hg in non-black children (P = .0006), according to the study.

Overall, mean IOPs did not differ by gender. Also, there was no significant association between baseline IOP, baseline myopia, myopia progression or change in axial length, the authors noted.

The study is published in the February issue of Optometry and Vision Science.