Relationships between clinical measures of visual function, fluorescein angiographic and optical coherence tomography features in patients with subfoveal choroidal neovascularisation

Aims:

To examine the relationships between measures of vision, optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) characteristics in patients with exudative age-related macular degeneration (AMD).

Study design:

Retrospective case note review. Inclusion criteria were: confirmed diagnosis of new exudative AMD; recorded visual function using best corrected distance visual acuity (DVA), near visual acuity (NVA) and contrast sensitivity; corresponding FFA and OCT. FFA parameters included greatest linear diameter of lesion (GLD), area of choroidal neovascularisation (CNV) and area of leakage. OCT parameters included maximum retinal thickness (Ret_max), central foveal thickness, maximum thickness of the CNV (CNV_max), and the distances from the foveal depression to Ret_max and CNV_max.

Results:

74 patients were included in this study. Correlations were highly statistically significant for both NVA and contrast sensitivity with GLD, CNV area and leakage (p<0.01 for all combinations). With DVA, modest statistically significant correlations were seen with CNV area and GLD (p<0.05). There was a statistically significant correlation between CNV leakage and the distance of CNV_max to the fovea (p<0.05). The relationships between the measures of vision and OCT parameters were weak and did not reach significance. Regression analysis showed that the combination of Ret_max, GLD, and CNV_max to fovea had the highest coefficient (r2 = 0.27).

Conclusion:

OCT measurements by themselves are not robust markers for visual function.