Abstract
Purpose:
Previous studies found reduced choroidal and retinal blood flow in retinitis pigmentosa (RP) patients compared to normals, as well as decreased velocities in the central retinal artery (CRA) and short posterior ciliary arteries (PCA) in RP patients. However, less is known about their correlation with measured loss of visual field (VF) or night vision, and duration or onset of RP.
Methods:
Retrobulbar ocular haemodynamics in six RP patients with visual acuity better than 20/60 and Goldmann V4e VF diameters 20°-125° were assessed by measuring the peak systolic (PSV) and end diastolic velocities (EDV) of the CRA and PCA using the color Doppler imaging (Philips iU-22 xMATRIX). We analyzed the relationship between blood velocity measures with the eye positioned in primary gaze or directed nasally, and history of night vision and VF loss, as well as dark-adapted Full-field Stimulus Thresholds (FST) and Goldmann VF retinal areas determined with V4e and III4e targets.
Results:
Patients with earlier onset age of night vision loss showed statistically significantly reduced PSV in the CRA in primary gaze and temporal PCA in nasal gaze, after adjusting for night vision loss duration (95% CI: 0.36, 0.98; p=0.01; R2=0.96) (95% CI: 0.08, 1.72; p=0.04; R2=0.93). Longer duration of VF loss was statistically significantly correlated with reduced EDV in nasal PCA in primary gaze, after adjusting for onset age of VF loss (95% CI: -1.4, -0.54; p=0.02; R2=0.997). There was a non-statistically significant trend for reduced III4e retinal area with reduced PSV in the CRA (p=0.08; R2=0.69) and reduced V4e retinal area with reduced PSV and EDV in the nasal PCA in primary gaze (p=0.07; R2=0.86) (p=0.08; R2=0.84). Reduced retinal area with the III4e and V4e targets was statistically significantly related to reduced EDV in the CRA and temporal PCA in nasal gaze, respectively (p=0.02; R2=0.96). PSV and EDV in the CRA were not statistically significantly related to FST (p>0.05). Reduced FST sensitivity was significantly related to reduced PSV in the nasal PCA in primary gaze and reduced EDV in the temporal PCA in nasal gaze (p≤0.03).
Conclusions:
Reduced blood velocities in retrobulbar arteries supplying the retinas of RP patients correlate with earlier onset of RP and longer duration of RP, and to a lesser extent, with decreased visual function. Further studies should examine correlations with visual function changes in RP patients.
Keywords: 702 retinitis •
436 blood supply •
584 low vision