Abstract
Purpose :
Drusen are known as the hallmark of early to intermediate age-related macular degeneration (AMD). AMD occurring without drusen is thought to be associated with pachychoroid spectrum disease (PSD). Although choroidal thickening, dilatation of choroidal vessels, and their hyperpermeability are known as signs of PSD, there are, to our knowledge, no obvious thresholds to distinguish PSD and typical AMD regarding choroidal vessel diameters. The aim of the current study is to compare choroidal vessel diameters between drusen and non-drusen type of AMD using ultra-wide-filed optical coherent tomography (OCT).
Methods :
Sixty eyes from 75 exudative AMD patients who visited Kyushu University Hospital from March 2021 to September 2022 and whose eyes were able to obtain a clear en face image of 23mm x 20 mm (1856 x 1614 pixels) by OCT-S1 Xephilio® (Canon Inc.) were analyzed. The patients who had soft drusen in the macula of either the diseased eye or the fellow eye on the fundus photography were defined as drusen group, and the others were non-drusen group. In the acquired en face ultra-wide-field OCT images, two regions of interest were set as 900×750 pixels of upper or lower area from the foveal center. Choroidal vessel diameters were automatically measured by the imaging software Image-Pro® (Media Cybernetics Inc.). Vessel diameters with 20 pixels or more were defined as “dilated choroidal vessel spots”. Differences were assessed using the paired t-test.
Results :
Mean age of 26 eyes in the drusen group was 78.0 years-old, and that of 49 eyes in the non-drusen was 70.2 years. In the drusen group, the average number of dilated choroidal vessel spots were 299 and 208 in the upper and lower area, respectively. In the non-drusen group, the average number of dilated choroidal vessel spots were 384 and 278, respectively. The number of dilated choroidal vessels spots both in the upper and lower area were significantly different between two groups (p<0.05). There were no significant difference in the vertical difference or the vertical ratio (upper spots vs lower spots) between two groups (p = 0.93, p = 0.90, respectively).
Conclusions :
Increased number of dilated choroidal vessels of dilated choroidal vessels may be the features observed in non-drusen type of AMD rather than the vertical difference in the choroidal vessel diameters.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.