Optical coherence tomography and optical coherence tomography angiography in glaucoma: diagnosis, progression, and correlation with functional tests

Non-invasive electrophysiology in glaucoma, structure and function-a review

Glaucoma, its early diagnosis, and monitoring of interventions remain an ongoing challenge. We here review developments in functional assessment and its relation to morphology, evaluating recent insights in electrophysiology in glaucoma and highlighting how glaucoma research and diagnostics benefit from combined approaches of OCT and electrophysiological investigations. After concise overviews of OCT and non-invasive electrophysiology in glaucoma, we evaluate commonalities and complementarities of OCT and electrophysiology for our understanding of glaucoma. As a specific topic, the dynamic range (floor effects) of the various techniques is discussed.

Retinal Vessel Density Changes on Optical Coherence Tomography Angiography and Predictive Factors in Normal-Tension Glaucoma Treated with Topical Beta-Blocker

(1) Background: Topical antiglaucoma medications may alter the microcirculation in the optic nerve head. We aimed to evaluate the changes in retinal vessel density (VD) on optical coherence tomography angiography (OCTA) in patients with newly diagnosed normal-tension glaucoma (NTG) treated with a topical beta-blocker. (2) Methods: This study included 80 patients diagnosed with NTG not using systemic medication, who received topical carteolol treatment between December 2019 and November 2020. We studied the changes in the OCTA VD/signal strength index (SSI) after the 6-month treatment period and determined the predictive factors affecting the changes in VD/SSI. (3) Results: After the 6-month treatment period, the peripapillary VD increased in 40 patients but decreased in the other 40 patients. The univariate and multivariate analyses revealed that old age and hypertension were significant factors associated with a VD/SSI decrease after carteolol treatment. Moreover, high baseline peripapillary, superficial, and deep macular VDs were significantly associated with the VD decrease after carteolol treatment. (4) Conclusions: Carteolol treatment could increase or decrease the VD in patients with NTG. The baseline VD, age, and hypertension could affect these VD changes. Patients with NTG and higher baseline peripapillary or macular VD, older age, and hypertension are more likely to have a decreased VD after carteolol treatment.

The role of pattern electroretinograms and optical coherence tomography angiography in the diagnosis of normal-tension glaucoma

In this study, we investigated the correlation between pattern electroretinogram (PERG) and optical coherence tomography angiography (OCTA) parameters for diagnosis in patients with normal-tension glaucoma (NTG). Forty-nine normal individuals (49 eyes) and 60 patients with NTG (60 eyes) were enrolled. OCTA and PERG parameters, such as macular vessel density (VD) and the amplitude of N35–P50 and P50–N95, were measured. Correlation analyses were performed between the parameters, and the area under the curve (AUC) was used to identify their diagnostic ability for NTG. Macular VD and the amplitude of N35–P50 and P50–N95 showed significant differences between the normal individuals and patients with NTG. Correlation between P50 and N95 amplitude and macular VD was significant in the normal and early glaucoma groups. Macular VD showed a higher AUC value (0.730) than that of P50–N95 amplitude (0.645) in the early glaucoma group. In the moderate to severe glaucoma group, the AUC value of the amplitude of P50–N95 (0.907) was higher than that of macular VD (0.876). The results indicate that PERG and OCTA parameters may identify glaucoma in its early stage, based on the severity of glaucomatous damage in patients with NTG.

Evaluation of the optic nerve head vessel density in patients with limited scleroderma

Objectives:

To investigate the optical coherence tomography angiography (OCTA) parameters of the optic nerve head and peripapillary retina and to assess macular and peripapillary retinal nerve fiber layer (RNFL) thickness by using spectral-domain optical coherence tomography (SD-OCT) in patients with limited scleroderma and to compare these results with those of healthy control subjects.

Materials and Methods:

42 patients with a confirmed diagnosis of limited scleroderma and 32 age- and sex-matched healthy control subjects were included in the study. OCTA was performed for the radial peripapillary capillary plexus (RPCP) whole image, inside disc, and peripapillary vessel densities in all participants with XR Avanti AngioVue OCTA (Optovue, Fremont, California, USA). OCT images were obtained with Spectralis OCT with eye-tracking dual-beam technology (Heidelberg Engineering GmbH, Heidelberg, Germany), and peripapillary RNFL thickness was evaluated with circle program. The data from the right eyes of all participants were used for statistical analysis.

Results:

No significant difference was found between the radial RPCP whole image, inside disc, and peripapillary vessel density values or the RNFL parameters of the scleroderma patients when compared with the controls (p > 0.05 for all).

Conclusion:

Decreased peripapillary vessel density on OCTA, which can be an early sign of glaucoma, could not be observed in scleroderma patients in this study. However, further long-term studies are still needed to identify glaucoma tendency in patients with scleroderma before clinically detectable glaucoma.