Assessment of peripapillary vessel density in acute non-arteritic anterior ischemic optic neuropathy

A case-control study of peripapillary microvascular structure by OCT-angiography in non-arteritic ischaemic optic neuropathy at early and resolutive stages

OBJECTIVES

To analyse peripapillary and papillary superficial microvascularization using OCT-angiography (OCT-A) in patients with non-arteritic ischaemic optic neuropathy (NAION) at the acute and resolutive stages.

METHODS

This retrospective case-control study conducted between October 2018 and November 2019 included 23 NAION subjects at the acute stage (onset <1 month) and 20 patients at the resolutive stage (onset >3 months). NAION and contralateral eyes were compared to control eyes of patients (n = 50) matched 1:1 for refractive error, sex, age, systemic hypertension, diabetes, and sleep apnoea syndrome. The acquisition of OCT-A (OCTA-SD Cirrus 5000, Carl Zeiss) in 6 × 6 mm format centred on the papilla allowed measurement of the radial peripapillary plexus. A commercialized algorithm was used to obtain maps of density and microvascular retinal and papillary retinal perfusion, by positioning an ETDRS grid centred on the optic nerve head.

RESULTS

There was significant decrease in peripapillary density and microvascular perfusion values for NAION eyes both at the acute and resolutive stages compared to the contralateral and control eyes, mainly in the temporal sectors. Papillary vascular density and perfusion were significantly increased in NAION and contralateral eyes compared to control eyes. There was no significant difference in peripapillary density or peripapillary vascular perfusion between contralateral and control eyes.

CONCLUSION

Eyes in the acute and resolutive phases of NAION exhibit decreased microvascular density and peripapillary capillary perfusion. Increased papillary vascular density and perfusion seem to be an intrinsic characteristic of the optic nerves of both eyes in patients who develop NAION.

Longitudinal evaluation of circumpapillary structure-function and vasculature-function relationships in acute and sub-acute nonarteritic anterior ischemic optic neuropathy

PURPOSE

To investigate the global and regional correlations between longitudinal structure-function (S-F) and vasculature-function (V-F) using circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements, circumpapillary vessel density (cpVD) and the corresponding/final visual outcomes at different stages of nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

Thirty eyes of 30 patients with acute NAION were included. LogMAR best-corrected visual acuity(BCVA), mean deviation (MD) and visual field index (VFI), cpRNFL thickness and cpVD across different retinal layers were examined at baseline, 2 weeks and 1 month after diagnosis. Potential correlations between the Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) parameters and visual outcomes were investigated in both acute and sub-acute NAION.

RESULTS

Significant global and regional correlations in S-F relationship were identified exclusively in sub-acute stage (p < 0.05). However, among the OCTA parameters for the acute NAION, the temporal cpVD in superficial vessel complex (SVC) and inner retinal layer (IRL) exhibited positive correlations with corresponding and final visual acuity and visual field outcomes. In the sub-acute stage of NAION, the cpVD of global or temporal section in radial peripapillary capillary (RPC), SVC and IRL were positively correlated with visual outcomes.

CONCLUSION

Significant longitudinal V-F relationships exist both globally and regionally, in acute and sub-acute NAION. The cpVD parameters of the SVC and IRL are potentially valuable for evaluating corresponding and final visual outcomes and highlights the importance of monitoring cpVD over cpRNFL thickness in acute NAION.

Evaluation of optical coherence tomography angiography changes in nonarteritic anterior ischemic optic neuropathy

Purpose

To study the long-term microvasculature changes at the macula and the optic disk in eyes with nonarteritic anterior ischemic optic neuropathy (NAION).

Methods

Patients with acute NAION of less than 6 weeks duration were included. Optical coherence tomography angiography (OCTA) of the macula and the optic disk was performed at baseline, 3 and 6 months and compared with the controls.

Results

The mean age of 15 patients was 52.25 (±9.06) years. The whole image superficial peripapillary density (42.49 ± 5.28) was significantly low when compared to that of control eyes (46.36 ± 2.09); similarly, radial peripapillary capillary density (49.35 ± 5.64) was also significantly reduced when compared to controls (53.45 ± 1.96, P < 0.05). These parameters showed significant progressive decrease at 3 and 6 months (P < 0.05). At the macula, both superficial (41.83 ± 3.64) and deep macular vasculature densities (47.30 ± 2.04) were significantly reduced when compared to control eyes (52.15 ± 4.84 and 55.13 ± 1.81, respectively). The vascular density at the macula remained stable at 3- and 6-months period.

Conclusion

The study shows that the microvasculature in case of NAION is significantly reduced both in peripapillary area and in macular area.

Optical coherence tomography angiography (OCT angiography) in anterior ischemic optic neuropathy (AION): A systematic review and meta-analysis

PURPOSE

To summarize the evidence available on optical coherence tomography angiography (OCTA) in patients with anterior ischemic optic neuropathy (AION).

METHODS

Systematic searches were conducted on PubMed, Embase, Web of Science, Scopus, Cochrane, and Google Scholar Databases. The quality assessment of the included studies was performed using Newcastle -Ottawa Scale. The data were extracted to an Excel sheet. Vessel density (VD) data were pooled by random effects model, presented as pooled percentage change (PPC), and weighted mean differences (WMD). Additional subgroup analysis was also conducted.

RESULTS

In initial searches in online databases, we found 3535 citations, and after screening and checking the titles and abstracts, 26 articles were ultimately eligible for our meta-analysis. The overall PPC of Intra-optic-disc (IOD) VD (-10.73%; p = 0.017, I² = 0.0%; p = 0.898) was lower than that of radial peripapillary (RP) VD (-17.57%; p < 0.001, I² = 44.3%; p = 0.002). The overall PPC of peripapillary choroid VD (-6.99%; p < 0.001, I² = 0.0%; p = 0.766) was significant, but noticeably lower than the pooled percentage change of RPVD and IOD VD. The WMD of RPVD was significant when non-affected fellow eyes were compared to the healthy subjects' eyes (-36.26; p < 0.001, I² = 0.0%; p = 0.706).

CONCLUSIONS

The central retinal artery and its branches might be the main vessels which are affected in AION. The superficial retina was more affected than choroid layer in AION. Also, radial peripapillary retinal nerve fibre layer was more affected than the IOD area. OCTA might be a suitable tool for prediction of AION in susceptible eyes.

Analysis of Vessel Density Using OCTA in Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose: To investigate the intraocular vessel density in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).Methods: Medical records of patients with NAION were retrospectively analyzed. Their age, sex, best corrected visual acuity, color vision results, mean deviation of visual field test were analyzed. Using results of OCT and OCTA that was performed at first visit within 3 weeks of symptom onset, vessel densities in eyes with NAION were evaluated by comparing contralateral unaffected eyes. Furthermore, in only affected eyes, the correlation between visual acuity at the time of diagnosis and anatomical factors such as mean vessel density and retinal nerve fiber layer (RNFL) thickness was investigated.Results: Twenty-five patients (11 males and 14 females) were enrolled in this study and the mean age was 65.92 ± 9.37 years. Whole RNFL thickness in affected eye was significantly lower than that in unaffected eye (<i>p</i> < 0.001). The average peripapillary vessel density was also significantly lower in affected eyes, 45.63% ± 7.60% compared to that in the contralateral eyes, 51.44% ± 3.40% (<i>p</i> = 0.004). In analysis of only 25 affected eyes, there was no significant correlation between each sectoral peripapillary RNFL thickness and vessel density. There was also no significant correlation between the visual acuity and the vessel density and retinal nerve fiber layer thickness in the ischemic peripapillary hemisphere. However, there was a significant negative correlation between the visual acuity and the un-ischemic peripapillary hemisphere with a coefficient of -0.608 (<i>p</i> = 0.001).Conclusions: The higher vessel density of nonaffected sector, the better visual acuity at the time of diagnosis in patients with NAION. Patency of blood supply in the preserved peripapillary intraretinal vessel density sector may affect the visual function.

Microvascular alterations detected by optical coherence tomography angiography in non-arteritic anterior ischaemic optic neuropathy: a meta-analysis

PURPOSE

To evaluate microvascular alterations with optical coherence tomography angiography (OCTA) in eyes with non-arteritic anterior ischaemic optic neuropathy (NAION) and the unaffected fellow eyes.

DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive literature search was conducted in the PubMed and Embase databases through 6 September 2020, to identify the studies on NAION and the unaffected fellow eyes using OCTA. Eligible studies and data of interest were extracted and analysed by RevMan Software v. 5.4 and Stata Software v.14.0. The weighted mean differences and 95% confidence intervals were used to assess the strength of the association.

RESULTS

Seventeen observational comparative studies, including 379 eyes with NAION, 175 unaffected contralateral eyes and 470 eyes of healthy controls, were identified. Compared to those of the healthy controls, the perfusion density (PD) of radial peripapillary capillary (RPC) and peripapillary superficial capillary plexus (ppSCP) of NAION were significantly lower. Moreover, the PD of the macular SCP (mSCP) in NAION was significantly reduced in the whole image, superior quadrant and temporal quadrant, while the macular deep capillary plexus (mDCP) showed a decreasing PD only within the whole image. Between unaffected fellow eyes and healthy eyes, significant differences of PD were demonstrated in the whole image and some peripapillary regions of the RPC and ppSCP.

CONCLUSION

Our results suggested that compared to those of healthy controls, the eyes affected by NAION and unaffected fellow eyes demonstrated significant microvascular impairments in different regions. Between acute and non-acute NAION, macular OCTA parameters showed different characteristic patterns.

Retinal and Optic Disc Vascular Changes in Patients Using Long-Term Tadalafil: A Prospective Non-Randomized Matched-Pair Study

Retinal, choroidal and optic disc vascularity has never been evaluated in patients taking PDE5is long-term. The aim of our study was to evaluate the neurostructural and vascular changes after long-term use of tadalafil, using spectral domain (SD)-optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). In the present clinical trial, 27 patients who have been taking tadalafil 20 mg on alternate days (OAD) for at least 6 months (Group A) were enrolled. The matched group consisted of 27 healthy men (Group B). Both groups of patients underwent SD-OCT to study ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) and choroidal thickness and OCTA for the evaluation of superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC) and radial peripapillary capillary (RPC). A reduction in SCP, DCP and RPC vessel density was found in patients using tadalafil long-term. Retinal and optic disc toxicity may be detected using modifications of capillary vessel density. Further studies are needed to investigate the possibility of a causal association.

Optical coherence tomography angiography in neuro-ophthalmology: Current clinical role and future perspectives

Optical coherence tomography angiography (OCTA) is a noninvasive, depth-resolved imaging tool for the appraisement of retinal vascular changes. Since its introduction, the understanding of diabetic retinopathy, age-related macular degeneration, central serous retinopathy, and other diseases has been enriched on many fronts. Its dyeless imaging property maps retinal as well as deeper choroidal vasculature in quick succession with good reproducibility. Hence, it can play an important role in the diagnosis and management of optic nerve-related diseases as well. A detailed literature review for its role in nonarteritic anterior ischemic optic neuropathy, papilledema, optic disc drusen, papillitis, hereditary optic neuropathies, central nervous system diseases, and others highlights its role. The whole spectrum of neuro-ophthalmological diseases shows consistent peripapillary and macular capillary changes with structural and functional correlation. The superficial and deeper retinal and choroidal vasculatures are affected depending on the nature of the disease process. Hence, OCTA positions itself as a useful, noninvasive tool in the armamentarium of a neuro-ophthalmologist in future; however, there are several limitations of the OCTA with respect to its technical abilities in challenging neuro-ophthalmic cases. Therefore, future research should be directed to enhance the technical capabilities of OCTA and to determine the more precise role of it in the prognosis of neuro-ophthalmic diseases.

Optical Coherence Tomography Angiography Assessment of the Peripapillary Vessel Density and Structure in Patients with Nonarteritic Anterior Ischemic Optic Neuropathy: A Meta-Analysis

Background

This meta-analysis is aimed at assessing the peripapillary vessel density (VD) and structural outcomes using optical coherence tomography angiography (OCTA) in patients with nonarteritic anterior ischemic optic neuropathy (NAION).

Methods

A comprehensive search of PubMed, Embase, Cochrane Library, and Web of Science databases for literature comparing VD and structural outcomes in patients with NAION and controls was performed. Mean differences (MDs) and its 95% confidence interval (CI) were calculated for continuous estimates. Review Manager (V5.30) was used for analysis.

Results

Fourteen published studies met the requirement. The radial peripapillary capillary (RPC) whole enface VD measured by OCTA was significantly lower in patients with NAION compared to that of the controls (MD = −10.51, P < 0.00001). The RPC inside disc VD was significantly decreased in the NAION group than that in the control group (MD = −8.47, P < 0.00001). For RPC peripapillary VD, there was a statistically significant difference between patients with NAION and the controls (MD = −12.48, P < 0.00001). The peripapillary retinal nerve fibre layer (p-RNFL) thickness was significantly lower in patients with NAION in comparison to the controls (MD = −22.18, P = 0.004). The ganglion cell complex (GCC) thickness in the macular zone of NAION patients was remarkably reduced compared to that in the controls (MD = −17.18, P = 0.0002).

Conclusions

The findings suggested that the peripapillary VD and RNFL thickness were attenuated, and the macular GCC thickness was reduced in patients with NAION. OCTA, in the future, may facilitate the diagnosis and monitoring of patients with NAION.