Association between genetic polymorphisms of adrenergic receptor and diurnal intraocular pressure in Japanese normal-tension glaucoma.

Purpose

To evaluate the relationship between genetic polymorphisms of the adrenergic receptor (ADR) and diurnal intraocular pressure (IOP) in Japanese normal-tension glaucoma (NTG) patients.

Design

Prospective, comparative case series.

Participants

Ninety-two untreated NTG patients.

Methods

The IOP of both eyes was measured at 3-hour intervals from 0600 to 2400 hours over 2 consecutive days. We used IOP data from the eye with the greater visual field defect for statistical analysis. The mean IOP over 2 days was used for each time point. Genetic polymorphisms in α1A-, α2A-, α2B-, α2C-, β1-, β2-, and β3-ADR were determined mainly by direct DNA sequencing. The relationship between IOP and genetic polymorphisms was analyzed.

Main outcome measures

The IOP and genotypes of genetic polymorphisms.

Results

Diurnal mean IOP of the subjects was 14.8 ± 2.1 mmHg (mean value ± standard deviation). For Del 301-303 in α2B-ADR, insertion/insertion (I/I) had a significantly higher diurnal mean IOP (P = 0.017), peak IOP (P = 0.038), and trough IOP (P = 0.046) than deletion (D) carriers. For Del 322-325 in α2C-ADR, I/I had a significantly lower diurnal mean IOP (P = 0.037) and peak IOP (P = 0.029) than D carriers. For S49G (A/G) in β1-ADR, A/A had a significantly higher diurnal mean IOP (P = 0.023), peak IOP (P = 0.019), and trough IOP (P = 0.014) than G carriers. For these 3 polymorphisms, repeated measures analysis of variance showed that the major homozygotes and minor carriers had parallel diurnal IOP curves, but significantly different diurnal IOP levels.

Conclusions

Polymorphisms of the ADR gene may alter the untreated IOP level of patients with NTG.