Abstract
Purpose :
Static and dynamic bivariate contour ellipse area (BCEA) differ mainly in pathologic eyes. This study analyzes factor influencing dynamic BCEA and which kind of method of BCEA recording significantly predict advanced age-related macular degeneration.
Methods :
A total of 136 eyes were retrospectively reviewed, 85 eyes without ophthalmic disorders (logMAR acuity ≦ 0.0) and 51 eyes with maculopathy were enrolled. All patients underwent two consecutive examinations, fixation test before and during microperimetry, using MP1 microperimeter (Nidek Technologies, NAVIS software version 1.7.6). Fixation stability was quantified by calculating the BCEA. A 2°red cross was used as fixation target. After a 30 second fixation test, all patients underwent a brief training before microperimetric examination. Fixation target was the same used in the fixation test, Humphrey 10 to 2 grid of 68 loci grid, stimuli Goldmann III with a projection time of 200 ms, white background illumination of 4 asb (1.27 cd/m2), and a 4-2 staircase strategy were used to perform microperimetric test. BCEA (deg2) was normalized by logarithmic transformation (Shapiro- Wilk test, p<0.05). Statistical analysis was performed using paired t test and logistic regression analysis. Pearson's correlation was also used. Statistical significance was set at P < 0.05.
Results :
The mean BCEA was 0.48±0.62 deg2 at microperimetry test and 0.20± 0.21 deg2 at fixation test (P<0.001) in healthy subjects. In AMD group, dynamic BCEA was 2.97± 3.57 deg2 and static was 2.01 ± 2 deg2 (P=0.001). Dynamic BCEA is significantly correlated with age (r=0.38), total (r=0.43) and tracking time (r=3.86, P<.001 overall) in controls, instead no significant relationship was found in AMD group. Logistic regression analysis showed that static fixation stability significantly predict advanced AMD (ExpB 4.52, P=0.02) but not dynamic BCEA (ExpB 2.46, P=0.18).
Conclusions :
Static and dynamic BCEA are considered both useful to record the fixation stability in pathological eyes. BCEA dynamic is significantly influenced by age and time of recording. In addition, our results show that static BCEA is a significant predictor of advanced AMD, so it’s important to study it before the microperimetry for monitoring purposes and visual rehabilitation.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.