Optic Disc Vascular Density in Normal-Tension Glaucoma Eyes with or without Branch Retinal Vessel Occlusion.

We analyzed the vascular densities (VDs) of the optic disc areas in eyes with normal-tension glaucoma (NTG) according to their branch retinal vessel occlusion (BRVO) status. The VDs of the optic discs and peripapillary areas of 68 NTG patients with BRVO (BRVO group; BRVO eyes and fellow eyes) and 37 patients with NTG alone (control eyes) were measured on angiographic images obtained via swept-source optical coherence tomography angiography. VDs were compared among groups and correlations were assessed. The VD of the optic disc large vessel was the highest in BRVO eyes, followed by the fellow eyes and controls (all P < 0.05). Conversely, small and medium vessel VD was in the opposite order (all P < 0.05). Large vessel VD was negatively correlated with small and medium vessel VD (r = -0.697, P < 0.001). Peripapillary VD was lower in the BRVO eyes than in the control and fellow eyes (P < 0.001 and P = 0.861, respectively). In conclusion, significant changes in the distribution of VDs for optic disc larger vessel and small and medium vessels were observed in both eyes of NTG patients with BRVO, compared to NTG patients without BRVO.

Vessel Density Loss of the Deep Peripapillary Area in Glaucoma Suspects and Its Association with Features of the Lamina Cribrosa.

PURPOSE: To investigate the association of decreased vessel density (VD) in the deep peripapillary region and structural features of the lamina cribrosa (LC). MATERIALS AND METHODS: 70 eyes of glaucoma suspects with enlarged cup-to-disc ratio were scanned and 51 eyes with adequate image quality were included in this study. All subjects had localized VD defects in the deep layer but intact VD in the superficial layer around the peripapillary region using optical coherence tomography angiography (OCTA). Only single-hemizone OCTA results from one eye of each subject had to fulfill the distinctive feature mentioned above to perform inter-eye and inter-hemizone comparisons. The thickness and depth of the LC, and prelaminar thickness were measured using enhanced depth imaging OCT (EDI-OCT). Paired t-tests were performed to evaluate differences in measurements of the LC and prelaminar thickness within each individual. p-values lower than 0.05 was considered to be statistically significant. RESULTS: Eyes with deep VD defects in the peripapillary region in OCTA had thinner LC than the fellow eyes. The hemizone with the deep VD defects in the peripapillary region had a thinner LC and a deeper depth of LC than the other hemizone in the same eye. According to logistic regression analysis, a thin LC was a significant factor associated with deep VD defect in the peripapillary region. CONCLUSIONS: Glaucoma suspect eyes with deep VD defects in the peripapillary area exhibited structural differences in the LC. The structural changes of the LC was associated with the vessel density in the deep peripapillary layer at the stage of suspected glaucoma.

Pattern Electroretinograms in Preperimetric and Perimetric Glaucoma.

PURPOSE: To investigate whether visual function can be graded in detail using pattern electroretinogram (PERG) in preperimetric to perimetric glaucoma. DESIGN: Cross-sectional observational study. METHODS: Twenty-six normal subjects, 113 preperimetric glaucoma patients (which included glaucoma suspect patients), and 52 early perimetric glaucoma patients with a mean deviation (MD) >-10 dB were included. Structural and functional measurements were performed using spectral-domain optical coherence tomography and a commercial ERG stimulator, respectively. RESULTS: The average retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness were thinnest in the perimetric group, followed by the preperimetric group and the control group (P < .001). PERG N95 amplitude was the largest in the control group, followed by the preperimetric group and the perimetric group (P < .001). Among the preperimetric glaucoma patients, presence of the RNFL defect was associated with lower PERG N95 amplitude (P = .013). The N95 amplitude showed a significant relationship with average RNFL thickness (r = 0.336, P < .001) and GCIPL thickness (r = 0.376, P < .001). In the preperimetric group with the RNFL defect, the N95 amplitude showed larger areas under the receiver operating characteristic curve (0.779) than the MD (0.533, P = .005). CONCLUSIONS: PERG N95 amplitudes decreased from the control to preperimetric glaucoma group and were reduced more in perimetric glaucoma. The functional assessment for detecting early glaucomatous damage could be complemented by PERG N95 amplitude. Usefulness of PERG parameters except N95 amplitude seemed to be limited in a clinical setting because of relatively low diagnostic performance in preperimetric glaucoma.

Comparison of pattern electroretinograms of glaucoma patients with parafoveal scotoma versus peripheral nasal step.

Retinal ganglion cells are distributed disproportionately with retinal eccentricity. Pattern electroretinogram (PERG) stimuli resulted in reduced responses with more eccentric stimuli. Therefore, we investigated whether PERG amplitude is associated with the location of visual field (VF) defect in primary open-angle glaucoma. Data from Twenty-nine glaucoma patients with a parafoveal scotoma (PFS) within the central 10° of fixation, 23 glaucoma patients with a peripheral nasal step (PNS), and 27 normal control subjects were analyzed in this study. Electroretinograms (ERGs) were obtained using a commercial ERG stimulator (Neuro-ERG). The thickness of the ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. A lower N95 amplitude was observed in both PFS and PNS compared to the normal control (Both P < 0.001). The N95 amplitude of the PFS group was significantly lower than that of the PNS group (P = 0.034). Average GCIPL thickness correlated positively with N95 amplitude (r = 0.368, P = 0.002), but did not correlate significantly with global mean sensitivity (r = 0.228, P = 0.073) or mean deviation on 24-2 standard automated perimetry (r = 0.173, P = 0.176). In conclusion, parafoveal VF defects were associated with the lower PERG amplitude. Therefore, it is necessary to take into account the location of VF defects in evaluating PERGs of glaucoma patients.

Glaucoma Progression in the Unaffected Fellow Eye of Glaucoma Patients Who Developed Unilateral Branch Retinal Vein Occlusion.

PURPOSE: To investigate glaucoma progression in eyes with glaucoma that developed unilateral branch retinal vein occlusion (BRVO) in the contralateral eye. DESIGN: Retrospective, case-control study. METHODS: Participants: Forty glaucoma patients with unilateral BRVO and 40 age- and baseline mean deviation (MD) of the visual field (VF)-matched glaucoma patients were evaluated during at least 4 years of follow-up. OBSERVATION PROCEDURES: Glaucoma progression was defined as VF progression using the modified Anderson criteria of the MD of the VF. Kaplan-Meier life table analyses were performed to compare times to confirmed VF progression, and related risk factors were evaluated using the Cox proportional hazards model. MAIN OUTCOME MEASURES: VF progression. RESULTS: Comparison of the baseline characteristics between the glaucomatous eyes that developed BRVO and the contralateral glaucomatous eyes that did not develop BRVO showed that BRVO occurred in the more advanced-stage eyes. Patients with glaucoma with BRVO in the fellow eyes had significant and frequent detection of disc hemorrhage (35.0%), which was 7.5% in patients with glaucoma without BRVO (P = .003). Four (10%) patients from the glaucoma group without BRVO and 22 (55.0%) patients from the glaucoma group with BRVO in the fellow eye showed progression according to the modified Anderson criteria (P < .001). Disc hemorrhage and the presence of BRVO in the fellow eye were found to be significantly predictive of VF progression using the Cox proportional hazards model. CONCLUSIONS: More advanced glaucomatous eyes develop BRVO. Patients who developed BRVO showed more rapid glaucoma progression in the contralateral eyes without BRVO compared with glaucoma patients who did not develop BRVO.

Lamina Cribrosa Depth is Associated With the Cup-to-Disc Ratio in Eyes With Large Optic Disc Cupping and Cup-to-Disc Ratio Asymmetry.

PURPOSE: To investigate the lamina cribrosa (LC) depth and its relationship with the cup-to-disc ratio (CDR) in the eyes with generalized increased optic disc cupping and CDR asymmetry. METHODS: Glaucoma suspect subjects with a CDR≥0.7, CDR asymmetry ≥0.2 in the absence of visual field (VF) loss, and normal control subjects were enrolled. The optic nerve head was imaged using the enhanced depth imaging modes of Spectralis optical coherence tomography. The LC depth was determined at the mid-horizontal, and the superior and inferior mid-peripheral regions of the optic nerve head. RESULTS: Disc area and CDRs were larger in the glaucoma suspect group compared with the control group (P<0.001). The mean LC depth was significantly greater in the disc area-matched glaucoma suspect group compared with the normal control group (P<0.001). The mean LC depth was positively correlated with the average and vertical CDRs (r=0.755 and 0.664, respectively; both P<0.001), which was maintained after controlling for the disc area (r=0.756 and 0.645, respectively; both P<0.001). In eyes with CDR asymmetry, the LC was located more posteriorly in eyes with a higher CDR compared with fellow eyes with a lower CDR (P<0.001). CONCLUSIONS: The LC depth was greater in eyes with generalized increased cupping, as well as in eyes with a higher CDR than fellow eyes, and was significantly related to the CDR. These results suggest that the clinical appearance of cup enlargement or cupping has LC displacement components.