Abstract
Purpose :
Ultra-widefield (UWF) fundus autofluorescence (AF) is helpful in diagnosis of retinitis pigmentosa (RP), and AF changes at the posterior pole are useful for monitoring the disease progression. In addition to AF changes at the posterior pole, there is a loss of AF, which usually starts at the mid peripheral fundus and expands both anteriorly and posteriorly over time.
The purpose of this retrospective study was to evaluate potential correlation between the AF loss and vascular attenuation which has been shown to be associated with disease severity in RP.
Methods :
UWF AF and dual wavelength retinal imaging were performed in 23 eyes of 16 RP patients using a commercially available scanning laser ophthalmoscope (Optos, California). UWF AF images were analyzed using ImageJ software to measure the proportion of AF loss area to total gradable area. Red-free images were analyzed using a customized image analysis software to measure the diameter of the retinal arteries and veins in a region between one and two optic disc radii from the optic disc. Linear mixed model analysis was performed to relate vessel diameter and AF loss.
Results :
The proportion of fundus AF loss ranged from 3% to 100% (mean = 19.9%, SD = 20.6%), retinal arterial diameter ranged from 39.1 μm to 69 μm (mean = 48.6 μm, SD = 7.5 μm), and retinal venous diameter ranged from 43.6 μm to 72.4 μm (mean = 57.3 μm, SD = 8.5 μm). There was no significant association between AF loss and arterial diameter (p = 0.72) nor between AF loss and venous diameter (p = 0.97).
Conclusions :
In our study, loss of fundus AF did not correlate with vascular attenuation in RP, suggesting that these phenotypical changes may be influenced by different factors. The extent of fundus AF loss was highly variable among our RP patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.