Longitudinal structure-function relationships with scanning laser ophthalmoscopy and standard achromatic perimetry

Abstract

Objective: To explore longitudinal correlations between structural and functional rates of glaucoma progression with confocal scanning laser ophthalmoscopy and standard achromatic perimetry.

Methods: In this retrospective longitudinal study, 108 eyes with suspected or established glaucoma and 5 or more good-quality scanning laser ophthalmoscopy examinations (global pixel SD<50 μm) and 6 or more reliable visual field (VF) examinations were included. Global and regional rates of progression for VF sensitivity and rim area (RA) were calculated with linear regression analysis. Correlations of global and regional rates of progression were calculated with bivariate correlation analyses. Linear mixed models were built to determine predictive factors for functional and structural changes over time.

Results: The mean (SD) baseline mean deviation was -4.6 (4.9) decibels. The inferotemporal and superotemporal RAs had the highest overall rates of decay (0.0018 mm2/y). Glaucoma progressed in 38 (35.2%) and 20 (18.5%) eyes based on event and trend mean deviation criteria, respectively. The highest correlations of rates were observed between the superonasal or superotemporal RA and inferior VF clusters (ρ=0.25-0.39; P≤.03). Follow-up time, baseline RA, and their interaction were the only significant predictors for RA change; belonging to the group with progression was not associated with higher rates of RA progression.

Conclusions: Longitudinal structure-function relationships are fair at best in eyes with suspected or established glaucoma. Eyes with progressing disease according to VF criteria do not show significantly higher rates of RA progression. Both structural and functional outcomes need to be monitored to detect glaucoma progression in a timely manner.