Microvasculature Dropout and Development of Normal Tension Glaucoma in Glaucoma Suspects: The Normal Tension Glaucoma Suspect Cohort Study.

PURPOSE: To investigate the contribution of vessel parameters to identify normal tension glaucoma (NTG) suspects at risk of NTG development. DESIGN: Multicenter prospective cohort study. SUBJECTS: A total of 307 eyes of 307 NTG suspects having intraocular pressure within the normal range; a suspicious optic disc, but without definite localized retinal nerve fiber layer (RNFL) defects; and a normal visual field (VF). METHODS: To measure laminar vessel density (VD), the VD was measured in the intradisc region from images of the deep vascular layers of optical coherence tomography angiography (OCT-A). Conversion to NTG was defined either by a new localized RNFL defect in the superotemporal or inferotemporal region, or the presence of a glaucomatous VF defect on 2 consecutive tests according to the pattern deviation plots. MAIN OUTCOME MEASURE: Conversion to NTG. RESULTS: In total, 73 (23.8%) of the 307 NTG suspects converted to NTG during the follow-up period of 59.84 ± 12.44 months. Detection rate of microvasculature dropout (MvD) was significantly higher in NTG suspects who progressed to NTG (50.7%) than in those who did not (6.4%; P < .001). The macular deep VD (P = .006) and laminar deep VD (P = .004) were significantly lower in NTG suspects who progressed to NTG. The presence of MvD (P < .001) and lower laminar deep VD (P = .006) were significantly associated with NTG conversion. CONCLUSIONS: NTG suspects with baseline MvD or a lower laminar deep VD on OCT-A had a higher risk of conversion.

Macular Blood Flow and Pattern Electroretinogram in Normal Tension Glaucoma.

PURPOSE: To investigate whether macular vessel density (VD) was associated with the pattern electroretinogram (PERG) in normal tension glaucoma (NTG). DESIGN: Cross-sectional study. METHODS: Seventy-six eyes from patients with NTG were included in this study. Macular VD was calculated from the superficial retinal layer, including the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL), using the built-in software provided with the optical coherence tomography angiography (OCTA) device. Functional parameters were obtained from standard automated perimetry (SAP) and PERG, using a commercial ERG stimulator. Moreover, structural parameters, such as peripapillary RNFL and macular ganglion cell/inner plexiform layer (GCIPL) thickness, were measured using OCT. RESULTS: Patients with higher VD had higher N95 amplitude (p = 0.048). Macular VD was significantly correlated with N95 amplitude, irrespective of disease severity (r = 0.352, p = 0.002 for the total subjects and r = 0.276, p = 0.043 for mild glaucoma). According to regression analyses, N95 amplitude and macular VD were bidirectional significant factors (p = 0.035 and 0.019, respectively). For patients with mild to moderate glaucoma, N95 amplitude and macular VD were also significantly associated bidirectionally, according to regression analyses (p = 0.032 and 0.040, respectively). CONCLUSIONS: Macular VD was significantly associated with N95 amplitude from PERG. The correlation was prominent in early glaucoma, in contrast to the other structural or functional parameters. When considering that PERG represents the objective function of the retinal ganglion cell (RGC), macular VD was associated with RGC dysfunction before the functional change became apparent on SAP.

Angiotensin II related glial cell activation and necroptosis of retinal ganglion cells after systemic hypotension in glaucoma.

The purpose of this study was to design an animal model mimicking glaucoma with hemodynamic instability and to identify involvement of angiotensin II (AngII) and associated changes of the retina. Systemic hypotension was induced in Sprague-Dawley rats by oral hydrochlorothiazide administration. Rats were sacrificed at 4, 8, and 12-week time points. AngII and receptor levels were examined in the serum and retina. To examine the relationship between glia activation and associated RGC death, biochemical analysis of GFAP, Iba-1, and necroptosis associated factors such as TNFα, receptor-interacting protein (RIP) 1, 3, and inactive caspase 8 were explored. To investigate the difference in RGC death mechanism, JNK inhibitor or RIP3 inhibitor were given intraperitoneally to rats with ocular hypertension and systemic hypotension both to identify the pathway mainly involved. AngII and receptors were increased in the serum and retina of systemic hypotensive rat. At 4, 8, and 12 weeks after hypotension induction, glial activation was increased as indicated by GFAP and Iba-1 staining. TNFα, RIP3 were elevated. and downregulation of inactive caspase 8 was apparent in the retina of hypotensive rat. Electron microscopy revealed that necroptosis of RGC was gradually increased after systemic hypotension. Following intraperitoneal JNK inhibitor or RIP3 inhibitor administration, RGC loss was attenuated in systemic hypotensive rats but not in ocular hypertensive rats. In conclusion, AngII is involved in glial activation and associated RGC necroptosis following systemic hypotension. This pathway represents a novel and distinct cell death mechanism when compared to that involved in elevated intraocular pressure.

Parapapillary Choroidal Microvasculature Dropout in Branched Retinal Vein Occlusion and Glaucoma.

Purpose: To investigate parapapillary choroidal microvasculature dropout (MvD) in branch retinal vein occlusion (BRVO) patients and compare them with open-angle glaucoma (OAG) patients using optical coherence tomography angiography (OCT-A). Methods: In total, 85 eyes of BRVO patients and 85 eyes of OAG patients, matched by age, spherical equivalent, and baseline mean deviation (MD) of the visual field (VF), were assessed. MvD was defined as complete loss of microvasculature within the choroidal layer on OCT-A. Linear regression analysis was used to obtain the slope of the MD change of the VF. Results: The presence of MvD on OCT-A was significantly more frequent in OAG eyes (63.1%) compared to BRVO eyes (31.8%). BRVO eyes with MvD showed worse baseline MD of the VF than BRVO eyes without MvD (-10.19 ± 8.50 and -7.77 ± 6.46 dB, respectively; P = 0.045). The presence of MvD was the only factor significantly associated with MD change of the VF in OAG eyes. Lower baseline average RNFL thickness, greater MvD angle, and lower macular superficial vessel density were significantly associated with MD change of the VF in BRVO eyes. Conclusions: OCT-A of the parapapillary area showed choroidal microvasculature impairment in both BRVO and OAG patients. However, the frequency was higher in glaucoma patients with similar degrees of VF damage, which suggests that the glaucomatous process contributes to MvD development. The effect of MvD on VF change was different between BRVO and OAG, suggesting that the underlying pathogenesis may also be different.

Predicting the development of normal tension glaucoma and related risk factors in normal tension glaucoma suspects.

This study investigated the predicted risk factors for the development of normal-tension glaucoma (NTG) in NTG suspects. A total of 684 eyes of 379 NTG suspects who were followed-up for at least 5 years were included in the study. NTG suspects were those having (1) intraocular pressure within normal range, (2) suspicious optic disc (neuroretinal rim thinning) or enlarged cup-to-disc ratio (≥ 0.6), but without definite localized retinal nerve fiber layer (RNFL) defects on red-free disc/fundus photographs, and (3) normal visual field (VF). Demographic, systemic, and ocular characteristics were determined at the time of the first visit via detailed history-taking and examination of past medical records. Various ocular parameters were assess using spectral-domain optical coherence tomography and Heidelberg retinal tomography. Conversion to NTG was defined either by the presence of a new localized RNFL defect at the superotemporal or inferotemporal region on disc/fundus red-free photographs, or presence of a glaucomatous VF defect on pattern standard deviation plots on two consecutive tests. Hazard ratios were calculated with the Cox proportional hazard model. In total, 86 (12.6%) of the 684 NTG suspects converted to NTG during the follow-up period of 69.39 ± 7.77 months. Significant (P < 0.05, Cox regression) risk factors included medication for systemic hypertension, longer axial length, worse baseline VF parameters, thinner baseline peripapillary RNFL, greater disc torsion, and lamina cribrosa (LC) thickness < 180.5 µm (using a cut-off value obtained by regression analysis). Significant (P < 0.05, Cox regression) risk factors in the non-myopic NTG suspects included medication for systemic hypertension and a LC thinner than the cut-off value. Significant (P < 0.05, Cox regression) risk factors in the myopic NTG suspects included greater disc torsion. The results indicated that 12.6% of NTG suspects converted to NTG during the 5-6-year follow-up period. NTG suspects taking medication for systemic hypertension, disc torsion of the optic disc in the inferotemporal direction, and thinner LC of the optic nerve head at baseline were at greater risk of NTG conversion. Related baseline risk factors were different between myopic and non-myopic NTG suspects.

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.

Evaluation of Systemic Renin and Angiotensin II Levels in Normal Tension Glaucoma.

The purpose of this study was to investigate the function of the renin-angiotensin-aldosterone system (RAAS) in normal tension glaucoma (NTG) patients by measuring the level of renin and angiotensin II (AngII) in the plasma. Twenty-four patients with NTG and 38 control subjects were included in this study. Renin and AngII were measured in the blood samples of all subjects by enzyme-linked immunosorbent assay (ELISA). No significant differences were found in the complete blood count, fasting glucose, low-density lipoprotein (LDL), and high-sensitivity C-reactive protein (hs-CRP) levels between the control and NTG groups. The systemic concentration and variability of the renin concentration in the blood was significantly higher in the NTG group (p = 0.005 and 0.005, respectively). According to multivariate logistic regression analysis, the variability of the renin concentration was associated with NTG (p = 0.006). In conclusion, the systemic concentration and variability of renin levels were elevated in NTG patients. An altered renin concentration could represent a difference in RAAS function in NTG patients.

Association of Scleral Deformation Around the Optic Nerve Head With Central Visual Function in Normal-Tension Glaucoma and Myopia.

PURPOSE: To investigate the structural characteristics of the posterior sclera around the optic nerve head (ONH) in patients with normal-tension glaucoma (NTG) and myopia with central visual field (VF) defect. DESIGN: Cross-sectional study. METHODS: Ninety-seven eyes of 97 NTG patients with myopia were included in this study. Swedish interactive thresholding algorithm (SITA) 24-2 and 10-2 were both performed to compare the central VF with peripheral VF. Optic disc torsion, tilt, and peripapillary atrophy area were calculated in 2-dimensional disc photographs. The most posterior point-that is, the deepest point of the eye (DPE)-was identified in 3-dimensional en face optical coherence tomography results and related measurements were calculated using built-in software. RESULTS: Forty-two eyes had worse SITA 10-2 mean deviation (MD) than SITA 24-2 MD and they were assigned to the central dominant VF defect group. The central dominant VF defect group had larger disc torsion and ONH tilt angle and shallower disc-DPE depth than the peripheral dominant VF defect group. According to logistic regression analysis, large ONH tilt angle and shallow disc-DPE depth were significant factors associated with central visual function impairment. CONCLUSIONS: Subjects with worse central VF than peripheral showed greater peripapillary scleral deformation, such as in torsion and tilt. Their posterior scleral deformation appeared to be closer to the ONH. Scleral deformation around the ONH may be associated with papillomacular bundle and central VF defects.

Posterior scleral deformation and autonomic dysfunction in normal tension glaucoma.

In meta-analyses, it has been reported that myopia is a risk factor for glaucoma and there is increasing evidence that autonomic dysfunction causing vascular dysregulation or perfusion dysfunction is considered an important factor in the progression of glaucoma. There have been experimental studies to find out the association between autonomic nervous system and ocular growth, but no clinical study yet has evaluated the relationship between them. Therefore, we enrolled 208 open angle glaucoma patients and measured heart-rate-variability(HRV). We used the standard deviation value of the qualified normal to normal intervals (SDNN) parameter of HRV, which is considered an autonomic influence index and characterized the total effect of the regulation of autonomic blood circulation. Patients were classified into the two groups according to SDNN: those with low possibility of autonomic dysfunction (LoAD group) and those with high possibility of autonomic dysfunction (HiAD group). We evaluated myopic features employing a 'posterior scleral profile' identified by the disc tilt ratio, disc torsion, fovea-BMO center (FoBMO) angle and peripapapillary area(PPA) to disc ratio. HiAD group showed higher values than LoAD group in posterior scleral deformation profile such like axial length, disc tilt, torsion degree. We suggest the possibility of association between myopic deformation and autonomic dysfunction.

Visual function evaluation for low vision patients with advanced glaucoma.

This study aimed to compare various visual function parameters for evaluating the quality of life (QOL) of patients with advanced glaucoma with low vision.In total, 44 eyes of advanced glaucoma patients with low vision were included in this cross-sectional study. A moving pattern edge band program was used to assess edge detection ability and the low vision quality-of-life (LVQOL) questionnaire was used for evaluating QOL scores of subjects. Correlation analyses between QOL scores and visual functional parameters including pattern edge band unit, visual acuity (VA), and Mean deviation (MD) of perimetry were performed. The areas under receiver operating characteristic curves (AUROCs) of diverse visual functional parameters were calculated.VA and pattern edge band unit were related to LVQOL score in all subjects. For patients with a decimal VA lower than 0.1, only the pattern edge band showed a significant correlation with the QOL associated with distant activities (P = .031). However, the MD of perimetry was not related to the QOL score. After sorting subjects into 2 groups according to the LVQOL score, VA and pattern edge band unit were significantly different (P < .01 and P = .029, respectively). The AUROC for edge detection ability using pattern edge band was higher than MD of perimetry.Assessment of edge detection ability using pattern edge band was meaningful for predicting QOL associated with visual performance in patients with far-advanced glaucoma. For these patients, edge detection could be used as an additional parameter for visual function with traditional VA and perimetry.

Association between peripapillary scleral deformation and choroidal microvascular circulation in glaucoma.

Peripapillary vessel density, which is reduced in eyes with glaucoma, has been proposed as a diagnostic tool for the desease and peripapillary choroidal microvasculature dropout(MvD) is considered one of pathophysiological manifestation of glaucomatous damage. However, little is known about the underlying pathogenic mechanism of dropout. According to recent studies, MvD is associated with structural changes in ONH structures. Therefore, we investigated the association between peripapillary scleral deformation and MvD. Data from 62 open-angle glaucoma (OAG) eyes with MvD and 36 eyes without MvD were analyzed in this study. And eyes with MvD were classified into two groups based on location: a juxtapapillary group and a non-juxtapapillary group for further analysis. More eyes with MvD had focal scleral deformation than did those without MvD (64.5% versus 2.8%; P < 0.001). Peripapillary choroidal thickness and focal scleral deformation were significantly associated with MvD. And juxtapapillary group was more associated with focal scleral deformation and coincidental RNFL defects than non-juxtapapillary groups. Peripapillary choroidal MvD was associated with the presence of scleral deformation, especially with juxtapapillary MvD, which was related to corresponding RNFL defects.

Relationship between pattern electroretinogram and optic disc morphology in glaucoma.

PURPOSE: To evaluate the relationship between pattern electroretinogram (PERG) and optic disc morphology in glaucoma suspect and glaucoma. METHODS: Eighty-six eyes of glaucoma suspect and 145 eyes of manifest glaucoma subjects were included in this study. Average peripapillary retinal nerve fiber layer (RNFL) thickness was obtained with spectral-domain optical coherence tomography, and optic disc imaging was performed using the Heidelberg Retinal Tomograph (HRT). Visual function was evaluated with perimetry (SITA and frequency doubling technology) and PERG. Scatter plots and correlation coefficients were evaluated between visual function and RNFL thickness or optic disc structure. RESULTS: Scatter plots of PERG and perimetry according to RNFL thickness change showed that PERG started to decrease earlier than did perimetry. The differences between linear and logarithmic R2 were largest for the scatter plot of SITA 24-2 (linear R2 = 0.415; logarithmic R2 = 0.443) and the smallest for P50 amplitude of PERG (linear R2 = 0.136, logarithmic R2 = 0.138). In glaucoma suspect, HRT parameters such as cup shape measure (CSM) and linear cup-disc ratio (CDR) had significant correlations with PERG amplitudes (P = 0.016 for P50 and 0.049 for N95 in CSM, P = 0.012 for P50 in CDR). However, in glaucoma patients, mean RNFL thickness was associated with PERG amplitude (P = 0.011 for P50 and 0.002 for N95). CONCLUSIONS: PERG deterioration occurred earlier than did perimetry according to RNFL thickness decrease. PERG amplitudes were significantly correlated with disc morphology in glaucoma suspect. These results suggest that PERG can detect ganglion cell dysfunction before the cells die.

Association of Retinal Blood Flow with Progression of Visual Field in Glaucoma.

In the glaucoma clinic, patients with normal intraocular pressure (IOP) can sometimes show visual field (VF) progression. Therefore, clarification of relationship between vascular status and glaucomatous VF deterioration is a focus of interest. We used optical coherence tomography angiography (OCTA), with the aim of evaluating the relationship between vessel density (VD) and VF progression in glaucoma patients. We included 104 eyes with open angle glaucoma who were followed up for at least 5 years in this retrospective case-control study. Superficial and deep VD of macula were assessed by OCTA. Regression analysis and Cox proportional hazards model were used to identify factors significantly associated with VF progression. In logistic regression analysis determining VF progression from Guided Progression Analysis (GPA) program, initial IOP and deep macular VD were significantly associated with VF progression in multivariate analysis (P = 0.019 and 0.004). Cox proportional hazards model also identified deep macular VD as significantly related to VF progression (P = 0.035). In conclusion, initial IOP and deep VD were related to VF deterioration in glaucoma. Deep VD might be used as a surrogate of glaucomatous VF progression related with vascular incompetence.

Association Between Parapapillary Choroidal Vessel Density Measured With Optical Coherence Tomography Angiography and Future Visual Field Progression in Patients With Glaucoma.

Importance: Investigating the vascular risk factors of glaucoma progression is important to individualize treatment; however, few studies have investigated these factors because the available methods have proven insufficient to evaluate the vascular features of patients with glaucoma. Recently, the advent of optical coherence tomography angiography (OCT-A) allowed both qualitative and quantitative microvascular data to be obtained, to in turn evaluate the perfusion status of different retinal layers. Objective: To determine whether baseline parapapillary choroidal vessel density (VD) as measured by OCT-A was associated with future glaucoma progression. Design, Setting, and Participants: A prospective, observational, comparative study was conducted at Seoul St Mary's Hospital of The Catholic University of Korea from March 1, 2016, to December 31, 2018, for 108 glaucomatous eyes in which the retinal nerve fiber layer thickness and mean deviation were measured by at least 5 serial OCT and visual field (VF) examinations. The participants underwent OCT-A at baseline. Vessel density was measured using the en face image of the choroidal map of OCT-A within the ß-zone parapapillary atrophy region. Main Outcomes and Measures: Parapapillary choroidal VD, retinal nerve fiber layer thinning rate, mean deviation rate, and progression of glaucoma as measured by OCT and VF. Results: Among 108 patients (74 women and 34 men; mean [SD] age, 59.2 [13.1] years), 38 (35.2%) showed progression of glaucoma as measured by OCT and 34 (31.5%) showed progression of glaucoma as measured by VF at the last follow-up. The mean (SD) follow-up duration was 2.6 [2.3] years. The presence of disc hemorrhage (odds ratio, 5.57; 95% CI, 3.18-8.29; P = .001), baseline mean deviation (odds ratio, 0.83; 95% CI, 0.71-0.97; P = .02), and parapapillary choroidal VD (odds ratio, 1.18; 95% CI, 1.09-1.28; P = .01) were associated with progression of glaucoma as measured by VF, but not with progression of glaucoma as measured by OCT. Baseline parapapillary choroidal VD (ß, 1.08; 95% CI, 1.02-1.13; P < .001) was associated with progression of glaucoma as measured by VF using Cox proportional hazards regression analysis. Conclusions and Relevance: These data suggest that lower parapapillary choroidal VD within the ß-zone parapapillary atrophy at baseline among individuals with glaucoma could play some role in the risk of progression of glaucoma as measured by VF. The findings suggest that patients with glaucoma with lower parapapillary choroidal VD within the ß-zone parapapillary atrophy at baseline warrant careful monitoring for progression of glaucoma as measured by VF.

Effect of Macular Vascular Density on Central Visual Function and Macular Structure in Glaucoma Patients.

In patients with glaucomatous parafoveal scotoma, evidence of compromised vascular circulation was commonly seen. The purpose of this study is to evaluate the relationship between macular vascular density (VD) and central visual function and structure in glaucoma patients. We enrolled 46 eyes of normal tension glaucoma (NTG) patients with parafoveal scotoma. All subjects underwent measurement of segmented macular thickness in each layer and optical coherence tomography angiography (OCTA) to assess VD of macula. Correlation coefficients of VD with structural parameters were identified and multivariate regression analyses were performed to verify factors affecting the MD of SITA 10-2. Superficial VD in NFL, GCL and IPL showed significant correlation with thickness of those layers, but deep VD in INL did not show meaningful correlation with any structural parameters. However, deep VD showed significant correlations with central visual field parameters such as MD of SITA 10-2. By multivariate regression analysis, the significant factors affecting central visual function were deep VD. Different multivariate regression models including segmented macular thicknesses were compared and R2 value was best for the model with deep VD, not containing superficial VD (R2 = 0.326, p = 0.001). Assigning subjects as worse or better visual functional group using regression line, deep VD of worse functional group was significantly lower than that of better group. In couclusion, decreased deep VD was an independent risk factor for central scotoma in addition to structural thinning. Taking both macular thickness and vascular circulation into acount, the deterioration of central visual function could be predicted more precisely.

Relationship between Systemic Vascular Characteristics and Retinal Nerve Fiber Layer Loss in Patients with Type 2 Diabetes.

Retinal nerve fiber layer (RNFL) loss in diabetic patients is especially common regardless of diabetic retinopathy (DR). The correlations between nonglaucomatous RNFL loss and systemic characteristics in diabetic patients have aroused interests in many aspects. 167 subjects with type 2 diabetes who underwent evaluation for arterial stiffness and cardiovascular autonomic function using heart rate variability (HRV) were included in this study. Arterial stiffness was measured using cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI). Multivariate regression analysis was performed to determine factors influencing the presence of RNFL loss according to age. Factors determining the superior location of diabetic RNFL loss were also investigated. CAVI were worse in patients with RNFL loss, especially in those with old age (≥50 yrs) (p = 0.037). Influential factor of RNFL defect in old group was ABI (p = 0.007). However, in young group (<50 yrs), HRV parameter (low-frequency/high-frequency ratio) determined the presence of RNFL loss (p = 0.040). Significant determinants of superior RNFL defect in old subjects were CAVI and ABI (p = 0.032 and p = 0.024). For young diabetic patients, autonomic dysfunction may have relationship with RNFL loss, but as patients get older, arterial stiffness could aggravate vascular autoregulation and diabetic RNFL loss. RNFL loss in diabetes may be correlated with systemic vascular conditions.

Features of the Choroidal Microvasculature in Peripapillary Atrophy Are Associated With Visual Field Damage in Myopic Patients.

PURPOSE: Optical coherence tomography angiography (OCT-A) was used to investigate the features of choroidal microcirculation within the ß-zone peripapillary atrophy (PPA) and its association with visual field (VF) defects in myopic patients. DESIGN: Cross-sectional study. METHODS: Participants: Eighty-four myopic patients with a unilateral glaucomatous VF defect. OBSERVATION PROCEDURES: Comparison was performed between VF-affected eyes and contralateral normal eyes. Area of ß-zone PPA was measured on disc photographs and the choroidal map of OCT-A. The presence of regional microvasculature dropout (MvD) was defined as a complete loss of microvasculature in OCT-A images. Analyses were performed to investigate factors associated with the presence of VF defects or central VF defects within the 10-degree region. MAIN OUTCOME MEASURES: The ß-zone PPA area, OCT-A PPA area, and MvD detection percentage. RESULTS: The PPA area was greater in myopic eyes with VF defects compared to myopic eyes without VF defects (P = .039 and P = .027, respectively) on both disc photographs and OCT-A images. MvD was found significantly more frequently (77.4%) in glaucomatous eyes with central scotoma than in eyes without central scotoma (36.4%; P = .019). Larger PPA area on OCT-A than on disc photographs was independently associated with the presence of glaucomatous VF damage in myopic eyes. The presence of MvD was significantly associated with the presence of central scotoma in myopic eyes. CONCLUSIONS: Glaucomatous VF damage, especially central VF damage, was present in myopic eyes with a larger PPA or with the presence of MvD on the choroidal map of OCT-A.

Characteristics of Retinal Nerve Fiber Layer Defect in Nonglaucomatous Eyes With Type II Diabetes.

PURPOSE: To investigate the characteristics of retinal nerve fiber layer (RNFL) defects associated with type II diabetes. METHODS: Forty nonglaucomatous eyes with type II diabetes and 54 eyes with early open angle glaucoma that exhibited a localized RNFL defect and 42 eyes from age- and sex-matched nondiabetic, nonglaucomatous controls were imaged with red-free fundus photography and optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec). The area under the receiver operating characteristic curves of eyes with diabetes was compared with that of eyes with glaucoma. When an RNFL defect on fundus photographs was identified in the quadrant, clock-hour, temporal-superior-nasal-inferior-temporal (TSNIT), deviation, and thickness maps, it was considered a true detection. RESULTS: In eyes with diabetes, the RNFL defects were located more frequently in the superior hemisphere than they were in those with glaucoma (P < 0.001). The angular locations of RNFL defects in eyes with diabetes (56.1 ± 12.7°) were significantly farther from the fovea compared with those in glaucoma (44.3 ± 17.3°; P < 0.001); in addition, the width of RNFL defects in diabetes (5.1 ± 2.3°) was significantly narrower than those in glaucoma (20.8 ± 12.3°; P < 0.001). The best parameter discriminating RNFL defects in diabetes from those in glaucoma was width of RNFL defect (0.955), followed by rim area (0.844), and average RNFL (0.791). The thickness map showed a sensitivity (70%) and specificity (69.1%), superior to those of all other maps in eyes with diabetes. CONCLUSIONS: The narrow width and identification of RNFL defect in thickness map obtained with Cirrus HD-OCT seems to be an effective tool for detecting RNFL defects in diabetes.

Stop-Chop versus Retro-Chop Nucleotomy During Phacoemulsification.

PURPOSE: To compare the outcomes of two nuclear fracture techniques used in phacoemulsification (stop-chop vs. retro-chop). METHODS: A total of 131 eyes from 111 patients with severe cataracts and nucleosclerosis (of grades 4-5) were included. The patients were randomly assigned to undergo stop-chop or retro-chop nucleotomy during phacoemulsification. The Drysdale manipulator was used as the chopping instrument in both groups. The intraocular phacoemulsification parameters including phacoemulsification power and phacoemulsification time were compared across the two groups. The following parameters were compared postoperatively at 1, 2, 5, and 8 weeks using unpaired t test: corrected distance visual acuity (CDVA), corneal endothelial cell density (CD), central corneal thickness (CT). RESULTS: There were significant differences in the phacoemulsification parameters between the groups. Retro-chop group showed less phacoemulsification time (p < 0.05) and less phacoemulsification power (p < 0.05) than stop-chop group. There was also a significant difference in the rate of corneal endothelial cell loss between the two groups (p < 0.05). In contrast, there were no significant differences in the postoperative change of CT or CDVA between the groups. CONCLUSION: Retro-chop nucleotomy with a Drysdale nucleus manipulator is an effective and safe method. It reduces both the use of intraoperative ultrasound energy, and early postoperative corneal endothelial cell loss compared to other nucleotomy techniques.