Background/Objectives: The purpose of this study was to analyze relevant areas in acute-stage fluorescein angiography (FA) images, predicting the long-term visual prognosis of branch retinal vein occlusion (BRVO) based on gradient-weighted class activation mapping (Grad-CAM). Methods: This retrospective observational study included 136 eyes with BRVO that were followed up for more than a year post-FA. Cropped grayscale images centered on the fovea (200 × 200 pixels) were manually pre-processed from early-phase FA at the acute phase. Pairs of the cropped FA images and the best-corrected visual acuity (BCVA) in remission at least one year post-FA were used to train a 38-layer ResNet with five-fold cross-validation. Correlations between the ResNet-predicted and true (actually measured) logMAR BCVAs in remission, and between the foveal avascular zone (FAZ) area measured by ImageJ (version 1.52r) from FA images and true logMAR BCVA in remission were evaluated. The heat maps generated by Grad-CAM were evaluated to determine which areas were consumed as computational resources for BCVA prediction. Results: The correlation coefficient between the predicted and true logMAR BCVAs in remission was 0.47, and that between the acute-stage FAZ area and true logMAR BCVA in remission was 0.42 (p < 0.0001 for both). The Grad-CAM-generated heat maps showed that retinal vessels adjacent to the FAZ and the FAZ per se had high selectivity (95.7% and 62.2%, respectively). Conclusions: The Grad-CAM-based analysis demonstrated FAZ-neighboring vessels as the most relevant predictor for the long-term visual prognosis of BRVO.

To quantify the choroidal structures of normal eyes by optical coherence tomography (OCT)-based binarization and evaluate the relationships among age, refractive power, and ocular axial length. This was a retrospective observational study. One hundred and eighty nine eyes of 189 subjects without ocular diseases were examined by enhanced depth imaging (EDI)-OCT. A choroidal OCT horizontal image with a width of 1500 μm centered on the fovea was binarized. The lumen, stroma, and total choroidal area in the choriocapillaris (CC), Sattler’s layer (SL), and Haller's layer (HL) were measured, and the ratio of the luminal area to total choroidal area (L/C ratio) was calculated. Multiple regression analysis was performed for choroidal parameters in each choroidal layer and for age, refractive power, and ocular axial length. Multiple regression analysis showed that an older age was significantly correlated with a lower choroidal area and the L/C ratio in all choroidal layers (each P < 0.05). A Long axial length was significantly associated with lower SL and HL (P < 0.05), but not with refractive power. In the choroid of normal eyes, age-related decreases in the choroidal area and L/C ratio were associated with all choroidal layers, and elongation of the axial length was associated with thinning of SL and HL.

Background/Objectives: To investigate the impact of pachychoroid on the clinical features of neovascular age-related macular degeneration (nAMD) in Japan using the deep learning-based Hokkaido University pachychoroid index (HUPI), which has a high discriminative ability for pachychoroid. Methods: This retrospective observational study examined 124 eyes of 111 treatment-naïve nAMD patients, including 44 eyes with type 1 macular neovascularization (MNV), 26 eyes with type 2 MNV, and 54 eyes with polypoidal choroidal vasculopathy (PCV). HUPI was calculated for each eye from EDI-OCT choroidal images using our modified LeNet that had learned the image patterns of pachychoroid. Differences in HUPI between nAMD types and inter-relationships between nAMD parameters, including HUPI, were evaluated. Results: The mean HUPI was 0.53 ± 0.30 for type 1 MNV, 0.33 ± 0.23 for type 2 MNV, and 0.61 ± 0.3 for PCV, with significant differences between any two of the three groups (p < 0.05, for each). Round-robin multiple regression analysis for nAMD parameters showed the close associations of the HUPI with choroidal vascular hyperpermeability (CVH) and subretinal fluid (SRF) (p = 0.017 and p < 0.001 for each) and the clear division of nAMD parameters into the following two groups: one including intraretinal fluid and type 1 and type 2 MNV and the other including SRF, CVH, polypoidal lesions, and HUPI. Conclusions: HUPI revealed that eyes with type 1 MNV and PCV had more pachychoroid-like features than eyes with type 2 MNV. HUPI was tightly associated with CVH and SRF but not MNV per se in nAMD parameters, reinforcing the pathoetiological concept of differentiating pachychoroid from typical nAMD.

This study aimed to investigate how age, sex, refractive error, and axial length are related to macular structure and perfusion in normal eyes. This retrospective, cross-sectional study included 297 eyes of 297 patients without ocular diseases other than cataract who presented to Teine Keijinkai Hospital. All subjects underwent optical coherence tomography (OCT) and OCT angiography. Multiple regression analysis was performed with retinal thickness and perfusion density in the 9 Early Treatment Diabetic Retinopathy Study subfields as dependent variables, and age, sex, refractive error, and axial length as independent variables. Results showed that older age was associated with decreased retinal thickness in most regions excluding the central region, and decreased perfusion density in all regions ( P < .05). Females had significantly thinner retinas in all regions ( P < .05) but showed no significant difference in perfusion density. Longer axial length was associated with increased retinal thickness in the central region ( P < .05), whereas it was linked to decreased values for both thickness and perfusion density in the outer regions ( P < .05). Refractive error was not correlated with either parameter. In conclusion, retinal thickness and perfusion density in normal eyes are significantly associated with age, sex, and axial length. Considering these physiological factors is essential for the accurate interpretation of OCT and OCT angiography data in clinical practice.

Objectives: To investigate the association between the hole border morphology and choroidal structure in idiopathic macular hole (IMH) patients and its impact on visual outcomes. Methods: A retrospective case–control study of 34 IMH eyes and 34 control eyes was conducted. Spectral-domain optical coherence tomography (SD-OCT) was used to categorize the patients into groups with smooth or bumpy hole borders. Based on this classification, a further evaluation was conducted of MH morphology and choroidal structure, both before a vitrectomy and at 1 and 2 months post-surgery. The choriocapillaris, Sattler’s layer, and Haller’s layer were the divisions of each choroidal vascular layer. Then, binarization techniques were employed to calculate the choroidal area (CA), luminal area (LA), stromal area (SA), and central choroidal thickness (CCT). The L/C ratio was established as the ratio of LA to CA. Results: In the patients with IMH, the choroidal structure was associated with the morphology of the hole border. In particular, the eyes with bumpy hole borders were significantly correlated with reduced choroidal thickness and total choroidal area, as well as a reduced L/C ratio in the choriocapillaris. After surgery, visual acuity improved in both groups, but the patients with smooth hole borders achieved earlier and higher levels of visual recovery. The multivariate analysis suggested that a bumpy hole border and the basal hole diameter were independent predictors of postoperative choriocapillaris recovery. Conclusions: Bumpy idiopathic macular hole borders are associated with impaired choroidal vasculatures, particularly in the choriocapillaris, which may be a contributing factor to delayed visual acuity recovery post-surgery.