Purpose Assessment and a direct comparison of retinal vessel density with the thickness of inner retinal layer (IRL) and outer retinal layer (ORL) in the same regions of the macula in subjects with Alzheimer’s disease (AD) and primary open-angle glaucoma (POAG). Methods We analyzed data from 48 eyes of healthy control (HC) participants, 71 eyes with POAG, and 49 eyes of AD patients. Ophthalmic examination included optical coherence tomography (OCT) imaging to measure IRL and ORL thickness and OCT angiography (OCTA) in the same region for the imaging of vessel density in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) of the retina. A direct comparison of vessel density and retinal layers thickness, which different dynamic ranges, was obtained by normalizing values as percentage losses. Results Patients with AD presented significantly greater losses of vascular density in the DVP and ORL thickness compared to POAG (p <0.001), but percentage losses of vessel density in SVP and IRL thickness were considerable in POAG compared to AD eyes (p<0.001). Positive associations among presence of AD were observed primarily in outer retina where a 1% decrease of ORL thickness was associated with about 24–29% increase in odds of the presence of AD. According to OCTA measurements, a 1% decrease of vessel density in DVP was positively associated with a 4–9% increase in odds of the presence of AD. In POAG positive associations among presence of disease were observed only in inner retina where 1% loss of IRL thickness and a 1% loss of vessel density in the SVP were positively associated with a 13–23% increase in risk of presence of the disease. Conclusions Analysis of ORL thickness and vessel density in DVP could potentially improve diagnostic capabilities and may provide a valuable approach for predicting of AD.

The aim of this study was to determine whether primary open-angle glaucoma (POAG) is associated with changes in fixation stability parameters assessed by microperimetry (MP) and whether the severity of glaucoma is related to a deterioration in these indicators. This study analyzed fixation stability using MP macular analyzer integrity assessment (MAIA) in patients with mild and moderate/severe POAG and healthy controls. The resulting fixation indices were correlated with parameters used to assess retinal function with MP and standard automated perimetry (SAP) and retinal structure with optical coherence tomography (OCT) and OCT angiography (OCTA). We enrolled 54 eyes in the POAG groups (32 eyes with mild POAG and 22 eyes with moderate/severe POAG) and 24 eyes in the healthy group. It was shown that fixation stability in POAG eyes deteriorated with increasing disease severity, and significant differences in bivariate contour ellipse area (BCEA) including 95% of fixation points were observed among groups (p = 0.042). Quantitative analysis of structural and functional retinal parameters also showed significant deterioration with the progression of glaucoma (p < 0.001). Correlations among fixation parameters and abnormalities in the retinal structure and function were confirmed. We concluded that POAG is associated with disturbances in the fixation pattern, which worsen as the disease progresses and can be effectively assessed by performing a MP test.

Purpose: To examine the relationship between retinal sensitivity and the area of internal limiting membrane (ILM) peeling during pars plana vitrectomy for a full-thickness macular hole.Methods: Twenty-four eyes a minimum of 6 months after temporal inverted flap pars plana vitrectomy for a full-thickness macular hole were included in the study. En face spectral-domain optical coherence tomography images were used to assess margins of the peeled ILM area. Microperimetry was performed to examine retinal sensitivity within the central 10°. Areas of peeled ILM in en face optical coherence tomography images were correlated with the average sensitivity threshold. Retinal sensitivities at the location of each measurement point were compared with structural abnormalities observed in en face spectral-domain optical coherence tomography images.Results: The mean retinal sensitivity in the area of ILM removal was significantly lower compared with the area of preserved ILM (24.29 ± 3.96 dB vs. 26.19 ± 2.10 dB, P , 0.0001, respectively). The peeled ILM area showed a negative correlation with the average sensitivity threshold (r = 20.56, P , 0.01).Conclusion: A larger area of ILM peeling during temporal inverted flap pars plana vitrectomy for a full-thickness macular hole is related to lower retinal sensitivity in the central macula.

To evaluate the correlation between retinal sensitivity in microperimetry (MP) with vessel density (VD) using optical coherence tomography angiography (OCTA) in primary openangle glaucoma (POAG). Methods We enrolled 30 participants (52 eyes) with POAG and 15 participants (23 eyes) in the healthy control group. All participants were examined for retinal structure using OCTA to assess VD and Spectral domain OCT (SD-OCT) to assess ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) thickness. Retinal sensitivity was tested with MP and standard automatic perimetry (SAP). Results The VD in moderate/severe POAG was lower than that in mild POAG and healthy control in the macular superficial vascular plexus (SVP) (38.7±6.3% vs. 42.9±5.2%, 49.7±2.6% respectively, P<0.001) and peripapillary radial peripapillary capillaries (pRPC) (36.4±5.7% vs. 43.6±6.6%, 49.1±2.4% respectively, P<0.001). The Pearson's correlations between function-structure parameters were strongest with MP average sensitivity threshold and SVP VD in the area of whole macula (r = 0.68); followed by SAP mean deviation (MD) and pRNFL thickness (r = 0.63); SAP MD and pRPC VD (r = 0.59) and MP average threshold and GCC thickness (r = 0.54). We found the AUROCs for discriminating between glaucomatous and healthy eyes were highest for structural parameters as follows: pRNFL (0.94),

Background Retinal imaging using optical coherence tomography (OCT) and OCT angiography (OCTA) may serve as an alternative approach to monitoring and diagnosing neurodegenerative diseases such as Alzheimer's disease (AD) and primary open-angle glaucoma (POAG). In this study, we performed direct comparisons of retinal vessel density with the thickness of inner retinal layer (IRL) and outer retinal layer (ORL) in patients with AD and POAG. Methods In this cross-sectional study, we analyzed data from 48 eyes of healthy control (HC) participants, 71 eyes of POAG patients, and 49 eyes of AD patients with confirmed presence of fibrillar brain amyloid on positron emission tomography (PET) imaging with florbetapir F 18. Ophthalmic examination included OCT imaging to measure IRL and ORL thickness in the macula and OCTA in the same region for the imaging of vessel density in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) of the retina. A direct comparison of vessels density and retinal layers thickness, which different dynamic ranges, was obtained by normalizing values as percentage losses. Values were adjusted for inter-eye correlation, age, gender, and scan quality, where applicable. Results Patients with AD presented significantly greater losses of vascular density in the DVP and ORL thickness compared to POAG (p < 0.001), but percentage losses of vessel density in SVP and IRL thickness were considerable in POAG compared to AD eyes (p < 0.001). Positive associations among presence of AD were observed primarily in outer retina where a 1% decrease of ORL thickness was associated with about 24–29% increase in odds of the presence of AD. According to OCTA measurements, a 1% decrease of vessel density in DVP was positively associated with a 4–9% increase in odds of the presence of AD. In POAG positive associations among presence of disease were observed only in inner retina where 1% loss of IRL thickness and a 1% loss of vessel density in the SVP were positively associated with a 13–23% increase in risk of presence of the disease. Conclusions Analysis of ORL thickness and vessel density in DVP could potentially improve diagnostic capabilities and may provide a valuable approach for predicting of AD.