Ocular biometry and open-angle glaucoma: the Los Angeles Latino Eye Study

Abstract

Purpose: To examine the associations among myopic refractive error (MRE), corneal power (CP), axial length (AL), and the prevalence of open-angle glaucoma (OAG) in an adult Latino population.

Design: Population-based, cross-sectional epidemiologic study.

Participants: A total of 5927 Latinos aged 40 years and older in the Los Angeles Latino Eye Study (LALES).

Methods: Myopic refractive error was defined as a non-cycloplegic sphero-cylindrical refractive error of < or =-1 diopter (D). Axial length was measured by A-scan ultrasound. Corneal power was measured using a Humphrey auto-refractor. Open-angle glaucoma was diagnosed by a combination of optic nerve and visual field changes. Pseudophakic and aphakic eyes were excluded from the analysis. The associations among MRE, AL, CP, and the prevalence of OAG were calculated using a logistic regression model, adjusting for age, gender, intraocular pressure, central corneal thickness, diabetes mellitus, family history of glaucoma, and lens nuclear opacification (NO).

Main outcome measures: Odds ratios (OR) for the prevalence of OAG.

Results: After adjusting for covariates, persons with greater MRE (OR 1.82; confidence interval [CI], 1.20-2.77; P = 0.005), longer AL (OR 1.25; CI, 1.03-1.50; P = 0.02), and flatter corneas (OR 1.21; CI, 1.08-1.35; P = 0.0007) were associated with a higher prevalence of OAG when compared with those with emmetropic refractive error, shorter AL, and steeper corneas.

Conclusions: Persons with an MRE, flatter corneas, and longer ALs should be considered to be at higher risk of having OAG.

Figure 1

Prevalence of Open Angle Glaucoma stratified by age groups in myopes and non-myopes in Los Angeles Latino Eye Study Participants

Figure 2

A LOWESS plot (a locally weighted polynomial regression) of the relationship between axial length and adjusted prevalence of Open Angle Glaucoma in participants in the Los Angeles Latino Eye Study. The LOWESS plot uses an iterative, locally weighted, least-squares method to plot the best-fit line and has been adjusted for age, gender, IOP (intraocular pressure), diabetes, family history, nuclear opacity, and corneal power.

Figure 3

A LOWESS plot (a locally weighted polynomial regression) of the relationship between corneal power and adjusted prevalence of Open Angle Glaucoma in the Los Angeles Latino Eye Study participants. The LOWESS plot uses an iterative, locally weighted, least-squares method to plot the best-fit line and has been adjusted for age, gender, intraocular pressure, diabetes, family history, nuclear opacity, and axial length.