Generation of a Normative Database for Optic Nerve Head Analysis by Stratus OCT

Abstract

Purpose: : To establish a normative database for Optic Nerve Head (ONH) analysis parameters as determined by the Stratus Optical Coherence Tomographer (Stratus OCT).

Methods: : In a prospective cross sectional study at five centers in the U.S.A., ONH measurements were obtained from normal volunteers using the Stratus OCT. Volunteers underwent a complete eye examination including assessment of visual acuity, IOP, anterior and posterior segment, and Humphrey visual field exam. Only participants with no evidence of ocular disease were included in this study. A Fast Optic Disc protocol, consisting of 6 mm long radial line scans centered on the optic nerve head, was performed with the Stratus OCT on each participant. Individual scans were qualified for study inclusion considering criteria such as central placement of the line scans across the ONH, appropriate recognition of ONH anatomic structures by the automated analysis algorithm, and sufficient scan signal intensity. Topographic ONH analysis was performed using the Stratus OCT ONH analysis protocol (software version 3.0). The automated ONH recognition algorithm was used, with a cup offset of 150 microns, to determine ONH boundaries for all scans, and in all cases a cup offset of 150 microns was used.

Results: : 183 of 322 ONH scans (99 OD, 84 OS) qualified for inclusion into the normative database. Mean age of study volunteers was 48(±16) years, including 81 males, 101 females, and 1 unknown gender. 128 of 139 disqualified scans were excluded due to insufficient signal intensity and inappropriate recognition of ONH structures by the automated detection algorithm. 5^th/95^th percentiles were determined for vertical integrated rim area 0.137/1.006 (mean 0.427/±0.283), horizontal integrated rim width 1.282/2.136 (1.674/±0.256), disk area 1.595/2.983 (2.225/±0.419), cup area 0.156/1.570 (0.729/±0.493), rim area 0.907/2.135 (1.496/±0.473), and cup/disk area ratio 0.074/0.597 (0.321/±0.199).

Conclusions: : Normative data for ONH parameters were established by Stratus OCT ONH analysis. Comparison of individual ONH OCT measurements to normative data could become a valuable clinical tool in patients with glaucoma and/or other optic neuropathies.

Keywords: optic disc • imaging/image analysis: clinical