Abstract
Purpose :
To investigate the relationship between spectral domain optical coherence tomography (SD-OCT) ganglion cell layer (GCL) probability plot “step” patterns and visual field sensitivity near the nasal horizontal raphe.
Methods :
Glaucoma and glaucoma suspect patients were randomly selected using ICD-9-CM codes from the first visits of all patients seen at an academic eye care center during 2012-2017. Record reviews were performed to identify subjects who met the following inclusion criteria: 1) confirmed diagnoses of glaucoma, ocular hypertension (IOP>21 mm Hg), or glaucoma suspect; 2) Cirrus SD-OCT imaging with retinal nerve fiber layer (RNFL) and GCL (signal strength >7) and Humphrey Visual Field (HVF) 24-2 SITA Standard or Fast testing (fixation<20%, FP<15%, FN<30%) within one year of each other. Exclusion criteria were: 1) <18 years old, refractive error >6D sphere or astigmatism >2D, and 2) ocular/systemic abnormality that may significantly affect SD-OCT or HVF testing. Using reference images (no step, trace, 1-4+), right eye GCL step grades were classified by masked reviewers and step presence was compared with other parameters and to HVF sensitivity in the nasal step region.
Results :
The study group included 137 subjects (mean age, 62.4 +/- 13.5 years, 25.5-90.9 years; 51.1% male, 91.2% African American; 55.5% with glaucoma, 13.9% with ocular hypertension, and 30.7% glaucoma suspects). Prevalence of any grade GCL step was 68.4% among glaucoma eyes, 52.5% among ocular hypertension eyes, and 54.8% among suspect eyes. Respectively, prevalence of a grade 3-4+ GCL step was 21.1%, 5.3%, and 4.8%. Eyes with any grade GCL step pattern were more likely than eyes without a step to have thinner average RNFL thickness (P=0.001), thinner average GCL-IPL thickness (P=0.004), larger average (P=0.001) and vertical cup-to-disc ratios (P=0.003), but did not show HVF differences directly above and below the nasal horizontal raphe (P>0.5). Eyes with grade 3-4+ GCL step patterns did show HVF sensitivity differences in the nasal step region (P<0.01).
Conclusions :
Eyes with SD-OCT GCL step patterns tend to have lower average GCL and RNFL thicknesses and larger cup-to-disc ratios. Only eyes with more pronounced GCL step patterns tend to have significant relative sensitivity differences in the nasal step region on HVF threshold automated perimetry.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.