Glaucomatous vertical vessel density asymmetry of the temporal raphe detected with optical coherence tomography angiography

Early changes in photopic negative response in eyes with glaucoma with and without choroidal detachment after filtration surgery

BACKGROUND/AIMS

To evaluate the electroretinographic (ERG) changes in the early postoperative period following glaucoma filtration surgery, and its relationship with choroidal detachment (CD).

METHODS

This retrospective observational single-centre study included 57 consecutive patients with primary open-angle glaucoma who underwent unilateral glaucoma filtration surgery. The patients were divided into two groups according to the presence or absence of CD. ERG components, including the photopic negative response (PhNR), a-wave and b-wave were compared before and after surgery using skin electrodes.

RESULTS

There were 46 patients in the non-CD group and 11 in the CD group. ERG was recorded within 5.1 (2.1 to 8.1) (mean (95% CI)) days after surgery. In the non-CD group, the PhNR amplitude, PhNR/b-wave amplitude ratio and PhNR implicit time improved significantly after surgery (p=0.008, 0.002 and 0.039, respectively). In the CD group, the amplitude of the PhNR, a-wave and b-wave were significantly deteriorated after surgery (p=0.002, 0.001 and 0.001, respectively). Postoperative intraocular pressure (IOP) (p=0.031) and postoperative CD (p<0.001) were significantly associated with change in the PhNR amplitude in the univariate models. In the multivariate analysis, severe CD (stage 3) cases tended to be deteriorated more.

CONCLUSION

Even in the early postoperative period within several days, the PhNR amplitude increased with IOP lowering following filtration surgery in the absence of CD. The presence of CD may arrest the improvement of the retinal ganglion cell function. The present results enhance understanding the structural and functional recovery after glaucoma surgery and the role of postoperative CD.

Reduced intradisc vessel density is associated with optic disc hemorrhage in eyes with primary open-angle glaucoma

We sought to investigate the association between optic nerve head (ONH)/choroidal microvasculature perfusion and optic disc hemorrhage (ODH) in eyes with primary open-angle glaucoma (POAG) using swept-source optical coherence tomography angiography (SS-OCTA). A total of 266 POAG eyes (59 with a single instance of ODH, 40 with a history of recurrent ODH, and 167 eyes without ODH) with a mean follow-up of 5.4 years were included. Intradisc vessel density (VD), parapapillary choroidal VD, optic disc microvascular dropout (MvD), and choroidal microvascular dropout (CMvD), were evaluated on a 3 × 3 mm SS-OCTA image of ONH and compared between eyes with and without ODH. Recurrent ODH was defined as occurrence 1 year after first ODH detection during the total follow-up period. Logistic regression analyses were performed to investigate factors associated with ODH. The prevalence of CMvD, optic disc MvD, and β-parapapillary atrophy were not different among the no ODH, single ODH, and recurrent ODH groups. Eyes with ODH had lower intradisc VDs than those without ODH (P = 0.021), but no difference was found in intradisc VDs between the single and recurrent ODH groups (P = 0.977). Better VF MD at baseline (odds ratio [OR], 1.150; 95% confidence interval [CI], 1.055-1.254; P = 0.002) and lower intradisc VD (OR, 0.863; 95% CI, 0.812-0.918; P < 0.001) were associated with ODH occurrence. Among POAG eyes, those with ODH had lower intradisc VDs than those without ODH. POAG eyes in an earlier disease stage or those with lower intradisc VDs should be monitored for the possibility of ODH occurrence.

Relationship Between Deep Retinal Macular Vessel Density and Bipolar Cell Function in Glaucomatous Eyes

Purpose

To evaluate the correlation between macular retinal function and the changes in the macular retinal vascular structure in glaucomatous eyes.

Methods

The study included patients with glaucoma who visited Saitama Medical University and underwent optical coherence tomography angiography, and multifocal electroretinographic examinations at the same time between February 2020 and April 2021. Correlations among the ocular parameters, macular vessel density, and multifocal electroretinographic parameters were evaluated using a mixed model.

Results

Forty-one eyes (mean deviation, −12.4 ± 7.8 dB) of 24 subjects (mean age, 75.2 ± 8.3 years) were included in the analysis. There were no significant correlations for macular vessel density in the superficial retinal layer. However, macular vessel density in the deep retinal layer showed a significant positive correlation with P1–N1 amplitude (coefficient = 0.724; P = 0.001). There were no significant correlations between the optical coherence tomography parameters and any of the multifocal electroretinographic parameters.

Conclusions

A decrease in N1–P1 amplitude was observed in glaucomatous eyes in relation to a reduction in macular vessel density in the deep retinal layer, which suggests that ischemia-induced bipolar cell dysfunction may be involved in the intermediate retinal dysfunction associated with glaucoma.

Translational Relevance

Intermediate retinal dysfunction in glaucoma is related to the changes in deep retinal microvasculature.

Relationship between macular intercapillary area measured by optical coherence tomography angiography and central visual field sensitivity in normal tension glaucoma

PURPOSE

To investigate the relationship of macular intercapillary area (ICA) with macular ganglion cell-inner plexiform layer (GCIPL) thickness and central visual field sensitivity (CVFS) in normal tension glaucoma (NTG).

METHODS

Seventy-eight early NTG eyes, 33 moderate-to-severe NTG eyes and 75 normal control eyes were cross-sectional evaluated. All participants underwent swept-source optical coherence tomography angiography (OCT-A; DRI-OCT, Topcon, Tokyo, Japan). A customised MATLAB program was used to quantify macular OCT-A metrics at central 3×3 mm macular region including vascular density (VD), foveal avascular zone (FAZ) area, 10 largest ICA including FAZ area (ICA10_IncFAZ) and excluding FAZ area (ICA10_ExcFAZ). Generalised estimating equation regression models were performed to determine the relationships of OCT-A vascular metrics with GCIPL thickness in the macular region and CVFS.

RESULTS

NTG eyes had lower global VD, larger ICA10_IncFAZ, and larger ICA10_ExcFAZ than normal controls (all p≤0.016). In the multivariable analyses, decreased VD (β=-0.304, p=0.006) and increased ICA (β=-0.231 for ICA10_IncFAZ and β=-0.259 for ICA10_ExcFAZ, all p≤0.042) were significantly associated with decreased GCIPL thickness in early NTG eyes but not in moderate-to-severe NTG eyes. ICA enlargement was associated with CVFS in early NTG eyes (β=-0.310, p=0.009), while VD was associated with CVFS in moderate-to-severe NTG eyes (β=-0.272, p=0.038).

CONCLUSION

ICA enlargement could be a potentially important disease marker of early NTG as reflected by its association with GCIPL thinning and decrease CVFS specifically for early NTG eyes.

Macular and submacular choroidal microvasculature in patients with primary open-angle glaucoma and high myopia

AIMS

To characterise the influence of primary open-angle glaucoma (POAG) and high myopia (HM) on the macular and choroidal capillary density (CD).

METHODS

Two hundred and seven eyes were enrolled, including 80 POAG without HM, 50 POAG with HM, 31 HM without POAG and 46 normal controls. A fovea-centred 6×6 mm optical coherence tomography angiography scan was performed to obtain the CD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris. Macular and choroidal CDs were compared among the groups and the association of CDs with visual field mean deviation (MD) was determined using linear regression models.

RESULTS

Compared with normal eyes, SCP CD was decreased in the POAG without HM group (p<0.05), while DCP CD was significantly decreased in the HM without POAG group (p<0.05). Both SCP and DCP CDs were significantly decreased in the POAG with HM group (p<0.05). CD reduction occurred mainly in the outer rather than inner ring of the 6×6 mm scan size. In multivariate regression analysis, worse MD was associated with lower CD in the outer ring of the SCP in all the HM eyes (p<0.05).

CONCLUSIONS

POAG and HM reduced macular CD in different layers of the retinal capillary plexus and both particularly in the outer ring of the 6×6 mm scans. Furthermore, assessment of the CD in the outer ring of the SCP may facilitate the diagnosis of glaucoma in eyes with HM.

Longitudinal Macular Retinal and Choroidal Microvasculature Changes in High Myopia

Purpose

The purpose of this study was to determine the longitudinal changes in macular retinal and choroidal microvasculature in normal healthy and highly myopic eyes.

Methods

Seventy-one eyes, including 32 eyes with high myopia and 39 healthy control eyes, followed for at least 12 months and examined using optical coherence tomography angiography imaging in at least 3 visits, were included in this study. Fovea-centered 6 × 6 mm scans were performed to measure capillary density (CD) of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC). The rates of CD changes in both groups were estimated using a linear mixed model.

Results

Over a mean 14-month follow-up period, highly myopic eyes exhibited a faster rate of whole image CD (wiCD) loss (−1.44%/year vs. −0.11%/year, P = 0.001) and CD loss in the outer ring of the DCP (−1.67%/year vs. –0.14%/year, P < 0.001) than healthy eyes. In multivariate regression analysis, baseline axial length (AL) was negatively correlated with the rate of wiCD loss (estimate = −0.27, 95% confidence interval [CI] = −0.48 to −0.06, P = 0.012) and CD loss in the outer ring (estimate = −0.33, 95% CI = −0.56 to −0.11, P = 0.005), of the DCP. The CD reduction rates in the SCP and CC were comparable in both groups (all P values > 0.05).

Conclusions

The rate of CD loss in the DCP is significantly faster in highly myopic eyes than in healthy eyes and is related to baseline AL. The CD in the outer ring reduces faster in eyes with longer baseline AL.

Longitudinal Changes in Macular Optical Coherence Tomography Angiography Metrics in Primary Open-Angle Glaucoma With High Myopia: A Prospective Study

Purpose

To characterize longitudinal changes in macular microvasculature as quantified from optical coherence tomography angiography (OCTA) metrics in primary open-angle glaucoma (POAG) eyes with and without high myopia.

Methods

In total, 63 and 61 POAG eyes with and without high myopia, respectively, underwent swept-source OCTA imaging in at least four follow-up visits at an ophthalmic center, with a scanning protocol of 3- × 3-mm centered at the fovea. The foveal avascular zone (FAZ) area, FAZ circularity, and vessel density (VD) in both the superficial (SCP) and deep capillary plexuses (DCP) were measured. The rate of change in macular OCTA metrics over time was estimated using linear mixed-effects models in both groups of POAG eyes.

Results

The mean follow-up time and number of visits were 27.72 ± 8.57 months and 8.5 (8 to 13) times, and 30.95 ± 10.19 months and 10 (8‒13) times in POAG eyes with and without high myopia, respectively. VD in the DCP reduced significantly more quickly in POAG eyes with high myopia than in those without high myopia (−5.14%/year vs. −3.71%/year, P = 0.008). Moreover, lower baseline VD in the DCP was significantly associated with faster VD reduction in POAG with high myopia eyes (P < 0.001). Conversely, the VD reduction rate in the SCP, FAZ area, and FAZ circularity in both the SCP and DCP were similar in both groups (all Ps > 0.05).

Conclusions

VD in DCP reduced significantly more quickly in POAG eyes with high myopia over time. Density in the DCP reduced more quickly when baseline VD was low.

Glaucoma diagnostic capabilities of macular vessel density on optical coherence tomography angiography: superficial versus deep layers

BACKGROUND/AIMS

To compare glaucoma diagnostic capabilities of superficial and deep macular vessel density (mVD) parameters in a series of healthy and open-angle glaucoma (OAG) eyes with central visual field (CVF) loss.

METHODS

We consecutively enrolled 113 eyes of 113 patients with OAG and 47 eyes of 47 healthy participants in a retrospective manner. Superficial and deep mVDs were measured at foveal, parafoveal and perifoveal locations on optical coherence tomography (OCT) angiography. The macular ganglion cell-inner plexiform layer thickness (mGCIPLT) was measured on OCT as a reference standard. Glaucoma diagnostic capabilities of superficial and deep mVD parameters were assessed according to the glaucoma stage. Factors associated with the CVF mean sensitivity (MS) were evaluated using linear regression analyses in the OAG eyes.

RESULTS

Glaucoma diagnostic capabilities of superficial perifoveal and parafoveal mVDs were significantly better than those of deep perifoveal and parafoveal mVDs, regardless of the glaucoma stage (both p<0.05). Both mGCIPLT and superficial parafoveal mVD were significantly associated with CVF MS (β-coefficients=10.567 and 21.147, respectively, both p<0.05), independent of age and glaucoma severity.

CONCLUSION

Superficial mVD parameters showed significantly greater glaucoma diagnostic capabilities and better correlation with CVF MS compared with deep mVD parameters.