Purpose To evaluate the characteristics and morphological alterations in central retinal
ischemia caused by diabetic retinopathy (DR) or retinal vein occlusion (RVO) as seen
in optical coherence tomography angiography (OCTA) and their relationship to visual
acuity. Methods Swept-source optical coherence tomography (SSOCT) and OCTA (Topcon,
Triton) data of patients with central involving retinal ischemia were analyzed in
this cross-sectional study. The following parameters were evaluated: vessel parameters,
foveal avascular zone (FAZ), intraretinal cysts (IRC), microaneurysms (MA), vascular
collaterals in the superficial (SCP) and deep plexuses (DCP), hyperreflective foci
(HRF), epiretinal membrane (ERM), external limiting membrane (ELM) and ellipsoid zone
(EZ) disruption, as well as the disorganization of retinal inner layers (DRIL). Best-corrected
visual acuity (BCVA), age, gender, disease duration and ocular history were also recorded.
Results 44 eyes of 44 patients (22 with RVO, 22 with DR) were analyzed. The mean age
was 60.55 +/- 11.38 years and mean BCVA 0.86 +/- 0.36 (Snellen, 6m). No significant
difference was found between DR subgroups (non proliferative vs. proliferative). Between
RVO subgroups (CRVO vs. BRVO) a significant difference was found in term of collateral
vessel of the DCP (p = 0.014). A pooled DR and RVO group were created and compared.
Significantly more MAs (p = 0.007) and ERM (p = 0.007) were found in the DR group.
Statistically significant negative correlation was demonstrated between FAZ and BCVA
(p = 0.45) when analyzing all patients with retinal ischemia. Conclusion This study
has shown that the best predictor of visual outcome in center involved ischemic diseases
is the size of FAZ. Besides the presence of MAs and ERM, all other OCT and OCTA parameters
were present in a similar extent in DR and RVO group despite the completely different
disease origins. Our results suggest that as soon as retinal ischemia in the macular
region is present, it has a similar appearance and visual outcome independently of
the underlying disease.
