Characteristics of Exudative Age-Related Macular Degeneration without Drusen in Japan Short title: Exudative AMD without Drusen

Abstract

Purpose : Although exudative age-related macular degeneration (AMD) is thought to develop with drusen formation, some patients may clinically have macular neovascularization (MNV) cases without drusen.
While the existence of pachychoroid neovasculopathy (PNV) based on choroidal abnormalities without drusen has been proposed, there are cases lacking the characteristics of PNV and also without drusen. In current study, we evaluated the characteristics of patients with exudative AMD without drusen.

Methods : Eighty-six eyes of 84 patients with MNV without drusen (62 males and 22 females, mean age 74.7 years) were included in this study. All patients were Japanese. Subfoveal choroidal thickness (SCT) was measured by optical coherence tomography (Topcon), and response to initial treatment was evaluated by the dry macula rate in patients treated three times during the loading phase with anti-VEGF therapy.

Results : The subjects consisted of 41 eyes in 40 patients with PNV (31 males, 9 females, 73.0 years old) and 45 eyes in 43 patients with MNV (30 males, 13 females, 76.4 years old) neither with features of PNV nor with drusen. Those with polypoidal lesions were 15 (36.6%) and 21 (46.7%) eyes, respectively, which did not reach the difference (P=0.39). The mean SCT tended to be thicker in PNV cases, 302 ± 98 µm and 241 ± 82 µm, respectively, however there was no significant difference (P = 0.12). The dry macula rates just after the loading phase (32 and 39 eyes, respectively) were 87.5% and 53.8%, respectively, which were significantly higher in PNV cases (P<0.01).

Conclusions : There are a certain number of MNV cases without features of PNV and without drusen, and these cases do not respond better to initial treatment with anti-VEGF therapy than PNV cases.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.