Abstract
Purpose :
To compare the rates of disease progression in retinitis pigmentosa (RP) patients obtained from two imaging modalities, near-infrared autofluorescence (NIR-AF) and short-wave autofluorescence (SW-AF), using the progressive constriction of the hyperautofluorescent ring as a measure of disease progression.
Methods :
NIR-AF and SW-AF images were acquired from 22 patients (44 eyes) with RP at two visits separated by an average of 27 months. The clinical diagnosis of RP was confirmed by electrophysiology. For both NIR-AF and SW-AF, the area and horizontal diameter enclosed by the outer border of the hyperautofluorescent ring were measured by the first author twice, two weeks apart.
Results :
All eyes presented a hyperautofluorescent ring on both NIR-AF and SW-AF. At the first visit, the mean horizontal diameter of the ring exhibited by SW-AF and NIR-AF was 3135.25 µm and 2951.82 µm, while the mean area was 7.63 mm2 and 6.96 mm2, respectively. At the second visit, the mean horizontal diameter was 2811.50 µm and 2675.36 µm, while the mean area was 6.24 mm2 and 5.71 mm2, respectively. There was a significant difference between SW-AF and NIR-AF area values obtained at both the first and second visits (P= 0.0014 and P= 0.0423). A significant difference was also observed in the horizontal diameter at the first visit (P=0.0004), with the greater values always observed in SW-AF. For NIR-AF and SW-AF, the horizontal diameter decreased at a rate of 12.61 µm/month and 19.65 µm/month, while the area decreased at a rate of 0.06 mm2/month and of 0.07 mm2/month, respectively. There was no significant difference between these rates (horizontal diameter P= 0.216; area P=0.298) in NIR-AF and SW-AF. Similar results were observed in the left eye.
Conclusions :
SW-AF and NIR-AF demonstrate similar disease progression rates in terms of both the horizontal diameter and area enclosed by the hyperautofluorescent ring. Given that there is no significant difference in progression rate as measured by the two modalities, our data suggests that NIR-AF may ultimately be more advantageous when monitoring disease progression in RP patients, as concerns have been raised regarding (1) the effects of long-term short-wavelength light exposure in patients with retinal disorders and (2) decreased patient comfort and cooperation—two crucial considerations for pediatric and photophobic patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.