Related Experiment Video
Updated: Feb 5, 2026

Author Spotlight: Assessment of Visual Acuity in Central Vision Loss Through Motion-Based Peripheral Vision Testing
Published on: February 23, 2024
Correlations between Spectral Domain Optical Coherence Tomography Measurements and Visual Acuity in Patients with
Emma Carpenter1, Khushi Saigal1, Elizabeth Slaney1
1University of Florida College of Medicine, Gainesville, Florida, USA.
Introduction:
This study aimed to investigate the relationship between spectral domain optical coherence tomography (SD-OCT) structural findings and visual acuity in patients with retinitis pigmentosa (RP), with and without cystoid macular edema (CME), at baseline and 1-year follow-up.
Methods:
This retrospective chart review included 30 patients with RP treated at the University of Florida Health Eye Center from 2014 to 2020. Patient records were analyzed for SD-OCT structural features and visual acuity outcomes. Statistical analyses included descriptive statistics, χ2 tests, independent t tests, and Pearson's correlation tests. Main outcome measures were best corrected visual acuity (BCVA), presence of the ellipsoid zone (EZ) in the fovea and macula, central retinal thickness (CRT), total macular volume (TMV), and presence of an epiretinal membrane (ERM).
Results:
The study included 30 patients (21 female, 9 male) with an average age of 46.83 ± 18.86 years (range, 10-80 years). The average follow-up period between visits was 11.9 ± 1.6 months (range, 9-15 months). Among the 60 eyes analyzed, 50% had CME. Eyes with CME had a greater CRT at the follow-up visit (p = 0.029). No significant differences were found in BCVA or TMV between RP patients with and without CME. Correlation analyses revealed a significant relationship between CRT and BCVA at both visits (p = 0.001, p = 0.004) in RP patients without CME, but not in RP patients with CME. EZ foveal sparing consistently predicted BCVA outcomes (p < 0.001) and CRT (p ≤ 0.001) at both visits in RP patients with and without CME. Greater TMV at both visits (p = 0.009, p = 0.012) and the presence of an ERM at the follow-up visit (p = 0.046) were significantly associated with a decline in BCVA between visits in RP patients without CME.
Conclusions:
EZ foveal sparing is a significant predictor of visual acuity in RP patients regardless of the presence of CME. While CRT correlates with visual acuity in patients without CME, it does not predict outcomes in those with CME. TMV may serve as a marker for preclinical CME, and both increased TMV and ERM presence may predict visual decline in RP patients with undetectable CME on SD-OCT.
Related Concept Videos
Correlations
Correlation and Causation
Correlation versus Causation
If the dependent variable increases or decreases when the independent variable increases, there is a positive or negative...
Correlation
Two variables, for example, a and b, are said to be positively correlated if both variables move in the same direction. In other words, a positive correlation exists between two variables, a and b, if:
Correlation and Regression
Coefficient of Correlation
If you suspect a linear relationship between x and y, then r can measure how strong the linear relationship is.
What the VALUE of r tells us:
The value of r is always between –1 and +1: –1 ≤ r ≤ 1.
The size of the correlation r indicates the...
Spearman's Rank Correlation Test
Spearman's test calculates correlation by...

