Association between Macular Blood Flow and Choroidal Structure and their Relationships to Visual Function in Retinitis Pigmentosa

Abstract

Purpose : To investigate the relationships between macular blood flow as measured by laser speckle flowgraphy (LSFG), the choroidal structure in the enhanced depth imaging optical coherence tomography (EDI-OCT), and central visual function in patients with retinitis pigmentosa (RP).

Methods : We studied 52 consecutive typical RP patients ≤50 years old and 21 age- and gender-matched controls. The mean blur rate (MBR), that represents blood flow volume, was calculated in a 2.4 x 2.4 mm area centered on the fovea by LSFG. Subfoveal horizontal EDI-OCT images were recorded, and the choroidal area, choroidal hypo-reflective area, and choroidal hyper-reflective area were analyzed in the central 2.4 mm width region. Visual acuity (VA), mean deviation (MD) and averaged macular sensitivity of static perimetry tests (Humphrey Filed Analyzer, the central 10-2 program) were measured in RP patients.

Results : MBR, choroidal area, choroidal hypo-reflective area, and choroidal hyper-reflective area were significantly decreased in RP patients (all P < 0.001, vs. controls). Spearman’s rank testing demonstrated no significant correlation between MBR and the choroidal structural parameters in RP patients. Decreased MBR was associated with reduction in VA, MD, and macular sensitivity (all P < 0.05), while the choroidal structural parameters did not correlate with central visual function.

Conclusions : These results demonstrated the divergence between the choroidal structure and blood function, and suggest that decreased blood flow, rather than the alteration of choroidal structure, was better associated with central visual function in RP patients.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.