Factors affecting corneal deformation amplitude measured by Corvis ST in eyes with open-angle glaucoma.

PURPOSE: To evaluate the factors affecting corneal deformation amplitude (DA) measured using Corvis ST in eyes with open-angle glaucoma. METHODS: This prospective, longitudinal study included 48 eyes with open-angle glaucoma who required additional intraocular pressure (IOP)-lowering drops. All eyes underwent a complete eye examination at baseline, including a Corvis ST, which was repeated 4-8 weeks after the change in therapy. Factors affecting the corneal biomechanics, namely the DA, were determined using mixed effect models. RESULTS: The mean age of the cohort was 65.0 ± 7.9 years. The mean IOP reduced from 23.4 ± 5.4 mmHg to 17.9 ± 5 mmHg after the change in glaucoma treatment ( P < 0.001). The DA increased from 0.89 ± 0.16 mm to 1.00 ± 0.13 mm after IOP reduction ( P < 0.001). On mixed effect model analysis, IOP (-0.02 ± 0.001, P < 0.001) and corneal pachymetry (-0.0003 ± 0.0001, P = 0.02) affected the change in the DA. CONCLUSION: IOP and corneal pachymetry affect the DA and must be accounted for when using Corvis ST to evaluate corneal biomechanics in glaucoma.

Agreement of a Novel Artificial Intelligence Software With Optical Coherence Tomography and Manual Grading of the Optic Disc in Glaucoma.

PRCIS: The offline artificial intelligence (AI) on a smartphone-based fundus camera shows good agreement and correlation with the vertical cup-to-disc ratio (vCDR) from the spectral-domain optical coherence tomography (SD-OCT) and manual grading by experts. PURPOSE: The purpose of this study is to assess the agreement of vCDR measured by a new AI software from optic disc images obtained using a validated smartphone-based imaging device, with SD-OCT vCDR measurements, and manual grading by experts on a stereoscopic fundus camera. METHODS: In a prospective, cross-sectional study, participants above 18 years (Glaucoma and normal) underwent a dilated fundus evaluation, followed by optic disc imaging including a 42-degree monoscopic disc-centered image (Remidio NM-FOP-10), a 30-degree stereoscopic disc-centered image (Kowa nonmyd WX-3D desktop fundus camera), and disc analysis (Cirrus SD-OCT). Remidio FOP images were analyzed for vCDR using the new AI software, and Kowa stereoscopic images were manually graded by 3 fellowship-trained glaucoma specialists. RESULTS: We included 473 eyes of 244 participants. The vCDR values from the new AI software showed strong agreement with SD-OCT measurements [95% limits of agreement (LoA)=-0.13 to 0.16]. The agreement with SD-OCT was marginally better in eyes with higher vCDR (95% LoA=-0.15 to 0.12 for vCDR>0.8). Interclass correlation coefficient was 0.90 (95% CI, 0.88-0.91). The vCDR values from AI software showed a good correlation with the manual segmentation by experts (interclass correlation coefficient=0.89, 95% CI, 0.87-0.91) on stereoscopic images (95% LoA=-0.18 to 0.11) with agreement better for eyes with vCDR>0.8 (LoA=-0.12 to 0.08). CONCLUSIONS: The new AI software vCDR measurements had an excellent agreement and correlation with the SD-OCT and manual grading. The ability of the Medios AI to work offline, without requiring cloud-based inferencing, is an added advantage.

Prevalence of primary angle-closure disease in retinitis pigmentosa.

Purpose: To determine the prevalence of primary angle-closure disease (PACD) in patients with retinitis pigmentosa (RP). Methods: This was a retrospective review of the electronic medical records of all RP patients over the age of 10 years attending the Genetics Eye Clinic of a tertiary-care hospital during a 7-year period. Information regarding age, gender, vision, refraction, lens, intraocular pressure (IOP), type of RP, and inheritance pattern using pedigree charts for all patients were obtained. Patients with a shallow anterior chamber, high IOP, or glaucomatous optic discs were referred to the glaucoma department where they underwent additional IOP measurements, a gonioscopy, and disc evaluation by a glaucoma specialist. The prevalence of PACD was determined. Results: A total of 618 RP patients were examined during the study period, of which 95.1% had typical RP. The prevalence of primary angle-closure suspects was 2.9%, primary angle closure was 0.65%, and primary angle-closure glaucoma (PACG) was 2.27%. In contrast, the prevalence of primary open-angle glaucoma was 1.29%. The prevalence of PACG in those older than 40 years was 3.8% (95% confidence interval: 1.6-6.0). Conclusion: The prevalence of PACG in RP patients over 40 years was higher than that found in the general population of a similar age (3.8% vs. 0.8%). In our cohort of RP patients, 5.9% had PACD. Hence, gonioscopy is warranted in all RP patients to identify this condition and treat it appropriately.

Upregulated NOTCH Signaling in the Lens of Patients With Pseudoexfoliation Syndrome Compared With Pseudoexfoliation Glaucoma Suggests Protective Role.

PRCIS: NOTCH signaling is significantly upregulated in the lens capsules of eyes with pseudoexfoliation syndrome (PXF) but not in those with pseudoexfoliation glaucoma (PXG) when compared with healthy controls. PURPOSE: NOTCH signaling has neuroprotective functions and altered NOTCH signaling is associated with neurodegenerative diseases with protein aggregation such as Alzheimer disease. As PXG is also a protein aggregate disease associated with neural degeneration, NOTCH molecular expression was explored in the lens capsules of patients with PXF, PXG, primary open-angle glaucoma (POAG), and healthy controls. METHODS: Anterior lens capsules were collected from 106 patients (27 PXF, 24 PXG, 22 POAG, and 33 controls) undergoing cataract surgery. Gene expression profiling for NOTCH pathway molecules (ligands, receptors, and downstream target genes) was performed on the tissue using a quantitative reverse transcription-polymerase chain reaction. The results were confirmed by protein analysis using dot-blot or immunostaining techniques. RESULTS: There was no difference in the demographic characteristics between the groups. There was an increase in NOTCH4 receptor expression (>14-fold) in the PXF group as compared with the controls. Similarly, the Delta-like 3 and Delta-like 4 ligands were significantly elevated in the PXF group compared with controls (P<0.05). Downstream targets HES3, HES5, and HEY1 expression were significantly elevated (P<0.005) in PXF lens capsules, confirming a higher activity of NOTCH signaling in this cohort. Immunostaining also corroborated the gene expression profile. CONCLUSION: The finding that NOTCH signaling is significantly upregulated in the lens capsule of eyes with PXF and not in PXG or POAG patients suggests a possible protective role in the development of glaucoma.

Optical Microangiography and Progressive Retinal Nerve Fiber Layer Loss in Primary Open Angle Glaucoma.

PURPOSE: To evaluate the association between optical microangiography (OMAG) measurements and progressive retinal nerve fiber layer (RNFL) loss in primary open angle glaucoma (POAG). DESIGN: Prospective case series. METHODS: Sixty-four eyes of 40 patients with POAG (108 quadrants) with mild to moderate functional damage were longitudinally studied for at least 2 years and with a minimum of 3 optical coherence tomography examinations. OMAG imaging was performed at the baseline visit. Effect of clinical parameters (age, sex, presence of systemic diseases, central corneal thickness, presence of disc hemorrhage, and mean and fluctuation of intraocular pressure during follow-up), baseline hemifield mean deviation, baseline quadrant optical coherence tomography RNFL and ganglion cell inner plexiform layer thickness), and OMAG (peripapillary and macular perfusion density [PD] and vessel density [VD]) on the rate of RNFL change was evaluated using linear mixed models. RESULTS: Average (±SD) mean deviation, RNFL, and ganglion cell inner plexiform layer thickness of the analyzed quadrants at baseline were -5.5 ± 2.9 dB, 96.5 ± 17.9 µm, and 73.8 ± 8.6 µm, respectively. Peripapillary PD and VD in the quadrant were 44.6% ± 5.9% and 17.5 ± 2.2 mm/mm2, respectively. Rate of quadrant RNFL change was -1.8 ± 0.6 µm/y. Multivariate mixed models showed that lower peripapillary PD (coefficient = 0.08, P = .01) and lower VD (coefficient = 0.21, P = .02) were significantly associated with a faster rate of RNFL loss. CONCLUSIONS: Lower baseline peripapillary PD and VD measured using OMAG were significantly associated with a faster rate of RNFL loss in POAG. OMAG imaging provides useful information about the risk of glaucoma progression and the rate of disease worsening.

Progressive Vessel Density Reduction on OCT Angiography in Glaucoma Eyes with Disc Hemorrhages.

PURPOSE: To identify longitudinal changes in peripapillary and parafoveal vessel density (VD) measured by OCT angiography (OCTA) in primary open-angle glaucoma (POAG) eyes with disc hemorrhages (DHs). DESIGN: Prospective cohort study conducted from August 2016 through August 2020 PARTICIPANTS: Eighteen Asian-Indian participants with POAG (18 eyes) who sought treatment at the clinic with a single DH in the peripapillary region were recruited consecutively. METHODS: The study was conducted at a tertiary eye care center. All participants who were recruited underwent a baseline OCT and OCTA, which were repeated every 4 to 6 months. MAIN OUTCOME MEASURES: Peripapillary VD and retinal nerve fiber layer (RNFL) thickness, parafoveal VD and ganglion cell-inner plexiform layer (GCIPL) thickness in the DH sector, and the corresponding mirror-image sector across the horizontal meridian (control) were evaluated over time using linear mixed-effects models. RESULTS: The baseline average RNFL thickness was 79 ± 9 µm. Mean duration of follow-up was 2.6 ± 0.7 years. In the DH sector, all VD and structural parameters showed a significant negative slope (P < 0.01). In the control sector, the slopes of the structural parameters (RNFL and GCIPL thickness) were not significant (P > 0.05), but the rate of change of the peripapillary and parafoveal VDs were significant (P < 0.01). The rate of change of peripapillary VD was greater in the DH sector compared with the non-DH sector (-2.86 ± 0.6%/year vs. -1.71 ± 0.7%/year; P < 0.01). However, the parafoveal VD slopes did not differ significantly between DH and control sectors (-2.9 ± 0.17%/year vs. -2.8 ± 0.8%/year; P = 0.51). CONCLUSIONS: Eyes with POAG harboring a DH showed not only progressive RNFL and GCIPL loss in the DH sector, but also progressive peripapillary and parafoveal VD reduction in the DH and non-DH regions as documented on OCTA.

Optical Microangiography and Progressive Ganglion Cell-Inner Plexiform Layer Loss in Primary Open-Angle Glaucoma.

PURPOSE: To evaluate the association between optical microangiography (OMAG) measurements and progressive ganglion cell-inner plexiform layer (GCIPL) loss in patients with primary open-angle glaucoma (POAG). DESIGN: Prospective case series. METHODS: Sixty-three eyes of 38 patients with POAG were studied for ≥2 years and with ≥ 3 optical coherence tomography examinations. Only those hemifields with mild to moderate functional damage at baseline (106 hemifields) were included in the analysis. OMAG imaging was performed at the baseline visit. The effects of clinical parameters (age, gender, central corneal thickness, presence of disc hemorrhage, and mean and fluctuation of intraocular pressure), baseline mean deviation, retinal nerve fiber layer, and GCIPL thickness and baseline OMAG measurements (peripapillary and macular perfusion density [PD] and vessel density [VD]) on the rate of change of GCIPL thickness were evaluated using linear mixed models. RESULTS: Average (± standard deviation) mean deviation, quadrant retinal nerve fiber layer, and sector GCIPL thickness of the analyzed hemifields respectively at baseline were -5.2 ± 2.8 dB, 94.5 ± 20.0 µm, and 72.4 ± 8.7 µm, respectively. Peripapillary PD and VD in the quadrant were 43.1% ± 7.0% and 17.0 ± 2.6 mm/mm2, respectively. Macular PD and VD in the quadrant were 37.2% ± 6.9% and 15.1 ± 2.6 mm/mm2, respectively. Rate of sector GCIPL change was -0.97 ± 0.15 µm per year. Multivariate mixed models showed that lower peripapillary PD (coefficient 0.04, P = .01) and VD (coefficient 0.09, P = .05) were significantly associated with a faster rate of GCIPL loss. CONCLUSIONS: Lower baseline peripapillary OMAG measurements were significantly associated with a faster rate of GCIPL loss in patients with mild to moderate POAG.

Comparison of the Performance of a Novel, Smartphone-based, Head-mounted Perimeter (GearVision) With the Humphrey Field Analyzer.

PRECIS: The agreement between a head-mounted perimeter [GearVision (GV)] and Humphrey field analyzer (HFA) for total threshold sensitivity was a mean difference of -1.9 dB (95% limits of agreement -5 to 1). GV was the preferred perimeter in 68.2% of participants. PURPOSE: The purpose of this study was to compare reliability indices and threshold sensitivities obtained using a novel, smartphone-based, head-mounted perimeter (GV) with the HFA in normal, glaucoma suspect and glaucoma patients. A secondary objective was to evaluate the subjective experience participants had with both perimeters using a questionnaire. METHODS: In a prospective, cross-sectional study; 107 eyes (34 glaucoma, 18 glaucoma suspect, and 55 normal) of 54 participants underwent HFA and GV in random order. The main outcome measure was the agreement of threshold sensitivities using Bland and Altman analysis. Participants also completed a questionnaire about their experience with the devices. RESULTS: Median false-positive response rate for GV was 7% (4% to 12%), while for HFA it was 0% (0% to 6%, P<0.001). Median false-negative response rate was similar for both tests. In all, 84 eyes with reliable HFA and GV results were included in the final analysis. Median threshold sensitivity of all 52 points on HFA was 29.1 dB (26.5 to 30.7 dB) and for GV was 30.6 dB (29.1 to 32.6 dB; P<0.001). Mean difference (95% limits of agreement) in total threshold sensitivity between HFA and GV was -1.9 dB (-5 to 1 dB). The 95% limits of agreement were fairly narrow (-8 to 2 dB) across the 6 Garway-Heath sectors. Most participants preferred to perform GV (68.2%) if required to repeat perimetry compared with HFA (20.6%, P<0.001). CONCLUSIONS: There was fairly good agreement between the threshold sensitivities of GV and HFA. GV was also preferred by most patients and could potentially supplement HFA as a portable or home perimeter.

Optical Coherence Tomography Angiography and Visual Field Progression in Primary Angle Closure Glaucoma.

PRECIS: Lower whole enface disc (coefficient: 0.02, P=0.03) and macular vessel densities (coefficient: 0.04, P=0.02) on optical coherence tomography angiography (OCTA) were significantly associated with faster rate of mean deviation (MD) decline. PURPOSE: To evaluate the association between OCTA features and prior visual field (VF) progression in primary angle closure glaucoma (PACG). METHODS: In a cross-sectional study, 46 eyes of 31 PACG patients with 5 reliable VF examinations performed over ≥3 years of follow-up underwent OCTA imaging. Effect of clinical (age, sex, number of antiglaucoma medications, mean, and SD of intraocular pressure during follow-up), optical coherence tomography (average retinal nerve fiber layer and ganglion cell complex thickness) and OCTA (whole enface vessel density of disc and macular scan, deep-layer microvascular dropout) parameters on the rate of MD change was evaluated using linear mixed models. RESULTS: Average (±SD) MD of the baseline VF was -7.4±7.3 dB, and rate of MD change was -0.32±0.29 dB/y. Whole enface vessel density of disc and macular scans was 39.5%±8.1% and 38.7%±4.4%, respectively. Microvascular dropout was noted in 33.3% of the eyes. Multivariate mixed models showed that lower whole enface disc (coefficient: 0.02, P=0.03) and macular vessel densities (coefficient: 0.04, P=0.02) were significantly associated with faster rate of MD decline. Other factors significantly associated with faster progression in multivariate models were older age (coefficient: -0.02, P<0.05) and the presence of systemic hypertension (coefficient: -0.37, P=0.01) and diabetes (coefficient: -0.28, P=0.05). CONCLUSIONS: Lower superficial vessel density measured using OCTA was significantly associated with faster VF progression in PACG. In these eyes, OCTA parameters can serve as biomarker suggestive of past VF progression.

Tele-consultations in the wake of COVID-19 - Suggested guidelines for clinical ophthalmology.

While telemedicine has been around for a few decades, it has taken great importance and prominence in recent times. With the fear of the virus being transmitted, patients and physicians across specialties are using consultation via a telephone call or video from the safety of their homes. Though tele-ophthalmology has been popular for screening, there are no clear guidelines on how to comprehensively manage patients seeking advice and treatment for a particular eye condition. Some major barriers to diagnosis and management are compromised detailed examination, no measurement of the visual acuity or intraocular pressure and a retinal evaluation not being feasible. Despite these limitations, we do need to help those patients who need immediate care or attention. Hence, this article has put together some guidelines to follow during such consultations. They are important and timely due to the medicolegal and financial implications.

A Comparison of the Visual Field Parameters of SITA Faster and SITA Standard Strategies in Glaucoma.

PURPOSE: To compare the visual field (VF) parameters of the new Swedish Interactive Thresholding Algorithm (SITA), SITA Faster (SFR) with that of SITA Standard (SS) on the Humphrey Field Analyzer. METHODS: Ninety-seven eyes of 97 subjects (63 glaucoma, 26 glaucoma suspects, and 8 normal eyes) underwent VF examination with SFR and SS strategies on the same day in random order. Agreement in VF parameters between SFR and SS strategies was assessed by Bland and Altman plots. In addition, some subjects underwent a second VF examination with SFR strategy to evaluate its test-retest variability. RESULTS: The median test duration of SS strategy was 6 minutes 14 seconds, whereas SFR was 2 minutes 49 seconds (55% shorter, P<0.001). Median mean deviation (-7.3 vs. -7.6 dB, P=0.73) and VF index (88 vs. 88%, P=0.32) were similar between the 2 strategies, whereas pattern standard deviation was significantly higher (4.8 vs. 4.7 dB, P=0.01) with SS strategy. Overall average threshold sensitivity and Garway-Heath sector-wise threshold sensitivities were similar between the 2 strategies except for the nasal sector where SFR strategy had higher sensitivity (26 vs. 25 dB, P=0.02). Bland-Altman plots showed the mean difference in all VF parameters between the SS and SFR strategies were small (ranging from -1.0 dB for the nasal sector to -0.01 dB for superotemporal sector sensitivity). The test-retest variability of VF parameters with SFR strategy was low. CONCLUSIONS: VF parameters with SFR showed good agreement with that of SS strategy. This, combined with low test-retest variability, suggests that SFR can be considered for diagnosis and monitoring of glaucoma.

A comparison of the corneal biomechanics in pseudoexfoliation syndrome, pseudoexfoliation glaucoma, and healthy controls using Corvis® Scheimpflug Technology.

Purpose: To compare the corneal biomechanical parameters among pseudoexfoliation syndrome (PXF), pseudoexfoliation glaucoma (PXG), and healthy controls using Corvis Scheimpflug Technology (ST). Methods: A prospective, cross-sectional study of 141 treatment-naïve eyes that underwent Corvis ST was conducted. These included 42 eyes with PXF, 17 eyes of PXF with ocular hypertension (PXF + OHT) defined as intraocular pressure (IOP)> 21 mmHg without disc/field changes, 37 eyes with PXG, and 45 healthy controls. Corneal biomechanical parameters, which included corneal velocities, length of corneal applanated surface, deformation amplitude (DA), peak distance, and radius of curvature, were compared among the groups using analysis of variance models. Results: The four groups were demographically similar. The mean IOP was lower in the controls (15.6 ± 3 mmHg) and PXF group (16.0 ± 3 mmHg) compared to the other two groups (>24 mmHg). Corneal pachymetry was similar across the four groups. Mean DA was significantly lower (P < 0.0001) in the PXG group (0.91 ± 0.18 mm) and the PXF + OHT group (0.94 ± 0.13 mm) when compared to the PXF (1.10 ± 0.11 mm) and control groups (1.12 ± 0.14 mm). Corneal velocities were also found to be statistically significantly lower in PXG and PXF + OHT compared to the PXF and control groups. However, after adjusting for age and IOP, there was no difference in any of the biomechanical parameters among the four groups. Conclusion: Corneal biomechanical parameters measured on Corvis ST are not different between healthy controls and eyes with PXF and PXG. Since PXG is a high-pressure glaucoma, corneal biomechanics may not play an important role in its diagnosis and pathogenesis.

Optical Coherence Tomography Angiography in Glaucoma.

Optical coherence tomography angiography (OCTA) is a relatively new, noninvasive, dye-free imaging modality that provides a qualitative and quantitative assessment of the vasculature in the retina and optic nerve head. OCTA also enables visualization of the choriocapillaris, but only in areas of parapapillary atrophy. With OCTA, the movement of red blood cells is used as a contrast to delineate blood vessels from static tissues. The features seen with OCTA in eyes with glaucoma are reduction in the superficial vessel density in the peripapillary and macular areas, and complete loss of choriocapillaris in localized regions of parapapillary atrophy (called deep-layer microvascular dropout). These OCTA changes correlate well topographically with the functional changes seen on visual field examination and structural changes seen on optical coherence tomography (OCT) (ie, parapapillary retinal nerve fiber layer changes and inner retinal layer thickness changes at macula). The OCTA measurements also have acceptable test-retest variability and well differentiate glaucomatous from normal eyes. OCTA measurements can be affected by various subject-related, eye-related, and disease-related factors. Vessel density reduction on OCTA reaches a base level (floor) at a more advanced disease stage than the structural changes on OCT and therefore has the potential to monitor progression in eyes with advanced glaucomatous damage. OCTA also adds information about glaucoma patients at risk of faster progression. OCTA, therefore, complements visual field and OCT examinations to diagnose glaucoma, detect progression, and assess risk of progression.

Choroidal Microvascular Dropout in Pseudoexfoliation Glaucoma.

Purpose: To compare the prevalence of choroidal microvasculature dropout (CMvD) in pseudoexfoliation glaucoma (PXG) and disease severity-matched primary open-angle glaucoma (POAG) eyes. Methods: In a cross-sectional study, 39 eyes with PXG (33 patients) and 39 glaucoma severity-matched POAG eyes (34 patients) underwent visual fields, optical coherence tomography and optical coherence tomography angiography examination. Peripapillary vessel density (VD) was evaluated from the radial peripapillary capillary slab, parafoveal VD was measured on the superficial vascular plexus slab of the macula, and CMvD was evaluated on the choroidal slabs of the optic disc scan. Results: The PXG and POAG groups were similar with respect to average mean deviation on visual fields (-12.1 vs. -12.0 decibel, P = 0.96) and average peripapillary retinal nerve fiber layer thickness on optical coherence tomography (71 vs. 74 µ, P = 0.29). Average peripapillary superficial VD (49.7% vs. 51.3%, P = 0.35) and parafoveal VD (44.8% vs. 45.8%, P = 0.33) were similar between the PXG and POAG groups. CMvD was seen in 18 PXG and 31 POAG eyes (46.2% vs. 79.5%, P = 0.002). On multivariate analysis that accounted for the severity of glaucoma, the odds of CMvD was significantly lower in the PXG group when compared with the POAG group (odds ratio: 0.18-0.21, P < 0.01). Conclusions: The prevalence of CMvD was significantly lower in the PXG eyes when compared with the POAG eyes.

Choroidal Microvascular Dropout in Primary Open-angle Glaucoma Eyes With Disc Hemorrhage.

PURPOSE: The main purpose of this study was to compare the prevalence of choroidal microvascular dropout (CMvD) in primary open-angle glaucoma (POAG) eyes with and without disc hemorrhage (DH). METHODS: In a cross-sectional study, 44 eyes of 44 control subjects, 32 eyes of 32 POAG patients with DH, and 41 eyes of 41 POAG patients without DH underwent visual fields (VFs), optical coherence tomography (OCT) and OCT angiography (OCTA). Presence of CMvD was evaluated on the choroidal OCTA slab. VF defect in the glaucoma eyes were classified into initial nasal defect, initial parafoveal scotoma, and combined nasal and parafoveal defect. RESULTS: CMvD was detected in 17 POAG eyes with DH (53.1%) and 13 POAG eyes without DH (31.7%; P=0.06). On univariate analysis, CMvD in POAG eyes was associated with DH [odds ratio (OR): 2.44, P=0.06] and measures of glaucoma severity: VF mean deviation (OR: 0.85, P=0.02), retinal nerve fiber layer thickness (OR: 0.95, P=0.03), and peripapillary vessel density (OR: 0.94, P=0.09). On multivariate models that accounted for the measures of glaucoma severity, CMvD in POAG eyes was statistically significantly associated with DH (OR≥3, P<0.05). CMvD was more frequently seen in eyes with initial parafoveal scotoma than initial nasal defect both in POAG eyes with DH (P=0.06) and POAG eyes without DH (P<0.001). CONCLUSIONS: Prevalence of CMvD was significantly greater in POAG eyes with DH compared with POAG eyes without DH. CMvD in POAG eyes was also significantly associated with central VF defects and greater severity of glaucomatous damage.

Choroidal Microvascular Dropout in Primary Angle Closure Glaucoma.

PURPOSE: To determine the prevalence and factors associated with the presence of choroidal microvascular dropout (CMvD) in primary angle-closure glaucoma (PACG) eyes compared to primary open-angle glaucoma (POAG) eyes. DESIGN: Cross-sectional study. METHODS: Thirty-six POAG eyes (36 patients) and 28 PACG eyes (28 patients) underwent optical coherence tomography angiography (OCTA). Presence of CMvD was evaluated on choroidal OCTA slabs. Visual field (VF) defects in the glaucoma eyes were classified into initial nasal defect (IND), initial parafoveal scotoma (IPFS), and combined nasal and parafoveal defect, and the association between type of VF defect and CMvD was evaluated. RESULTS: CMvD was detected in 21 POAG (58.3%) and 10 PACG (35.7%) eyes (P = .07). CMvD in POAG eyes was associated with pretreatment intraocular pressure (odds ratio [OR] = 0.91/mm Hg higher intraocular pressure, P = .06), VF mean deviation (MD, OR = 0.75/dB higher MD, P = .007), retinal nerve fiber layer thickness (OR = 0.92/µm increase in thickness, P = .02), and peripapillary vessel density (OR = 0.80/unit increase in density, P = .01). CMvD in PACG eyes was associated only with VF MD (OR = 0.90/dB higher MD, P = .05). When analyzed in the entire cohort of glaucoma patients (64 eyes), CMvD was significantly associated with POAG (OR > 3.5, P < .05) after accounting for glaucoma severity. CMvD was seen in 6 of 7 eyes with IPFS and 1 of 13 with IND in the POAG group (P < .05) and 1 of 2 eyes with IPFS and 0 of 10 with IND in the PACG group (P < .05). CONCLUSIONS: Prevalence of CMvD was significantly lower in PACG compared to POAG. As in POAG, CMvD in PACG was associated with advanced VF damage and with IPFS on VF.

Diagnostic Abilities of the Optical Microangiography Parameters of the 3×3 mm and 6×6 mm Macular Scans in Glaucoma.

PURPOSE: To evaluate the diagnostic abilities of macular vessel length and perfusion densities measured with optical microangiography (OMAG) over a 3×3 mm and a 6×6 mm region, and to compare these with macular ganglion cell-inner plexiform layer (GCIPL) thickness in eyes with primary open-angle glaucoma (POAG). METHODS: In a cross-sectional study, 96 eyes of 57 control subjects and 88 eyes of 57 POAG patients underwent macular imaging with optical coherence tomography. Area under receiver operating characteristic curves (AUC) and sensitivities at 90% specificity of OMAG and GCIPL parameters were evaluated. RESULTS: Most OMAG parameters of the 3×3 mm macular scan and all inner sector parameters of the 6×6 mm scan were similar (P>0.05) in the POAG and control eyes. All outer sector OMAG parameters of the 6×6 mm scan were significantly less (P<0.05) in the POAG eyes. AUC and sensitivity at 90% specificity of the best parameter of the 3×3 mm OMAG scan (inner temporal vessel length density; 0.65% and 26%, respectively) were statistically similar (P>0.05) to that of the 6×6 mm scan (outer inferior vessel length density; 0.72% and 30%, respectively). AUC and sensitivity of the best GCIPL thickness parameter (inferotemporal GCIPL thickness, 0.84% and 67%) were significantly better (P<0.05) than that of the vessel length densities. CONCLUSIONS: The outer sector measurements of the 6×6 mm macular OMAG scans seem to be better than the inner sector measurements in diagnosing glaucoma. The GCIPL thickness measurements were significantly better than all macular OMAG parameters in diagnosing glaucoma.

A Sectoral Analysis of Vessel Density Measurements in Perimetrically Intact Regions of Glaucomatous Eyes: An Optical Coherence Tomography Angiography Study.

PURPOSE: To study sectoral vessel density (VD) and structural alterations in the peripapillary and parafoveal hemiretina corresponding to perimetrically intact regions of glaucomatous eyes with hemifield defects and to compare these with healthy eyes using optical coherence tomography. METHODS: This cross-sectional study included 37 eyes with open-angle glaucoma having visual fields defects restricted to 1 hemifield and 45 age-matched controls. Peripapillary VD and retinal nerve fiber layer (RNFL) thickness were measured in 8 sectors. Parafoveal VD and ganglion cell complex thickness were measured in the superior and inferior hemispheres of the macula. These parameters were compared between the intact hemiretinae of glaucomatous eyes and corresponding sectors of healthy eyes using the t test. RESULTS: Within the perimetrically intact regions of glaucomatous eyes, the mean VD and RNFL thickness were significantly reduced in inferotemporal, superonasal, and nasal upper peripapillary sectors as compared with healthy eyes (P<0.008). The temporal upper sector had reduced mean VD (60.3% vs. 62.9%, P=0.04) despite similar mean RNFL thickness (P=0.18). The superotemporal sector had decreased mean RNFL thickness (121 vs. 138 µm, P=0.0001) despite similar VD (P=0.06). At the macula, ganglion cell complex thickness was reduced in the superior and inferior hemispheres, but mean VD was reduced in the superior parafoveal region only. CONCLUSIONS: Peripapillary and parafoveal vascular changes precede functional decline. The extent of VD reduction and RNFL thinning varies in different peripapillary sectors and longitudinal studies are required to better understand the temporal relationship of vascular and RNFL loss.

Relationship of Macular Thickness and Function to Optical Microangiography Measurements in Glaucoma.

PURPOSE: The purpose of this article was to evaluate the relationship between macular optical microangiography (OMAG), ganglion cell-inner plexiform layer (GCIPL) thickness, and visual sensitivity measurements of different macular sectors in primary open-angle glaucoma. METHODS: In a cross-sectional study, 39 eyes of 26 primary open-angle glaucoma patients underwent optical coherence tomography imaging and 10-2 visual field examination of the macula in the same session. Linear regression models were used to evaluate the relationships between OMAG, GCIPL thickness, and visual sensitivity measurements in different macular sectors. Strength of relationship was reported as coefficient of determination (R). RESULTS: R values for the associations between OMAG and GCIPL thickness measurements ranged from 0.37 in the temporal sector to 0.56 in the inferior macular sector. R values for the association between OMAG and visual sensitivity measurements ranged from 0.23 in the superior to 0.53 in the inferior macular sector. R values for the association between GCIPL thickness and visual sensitivity measurements ranged from 0.15 in the superior to 0.62 in the temporal sector. CONCLUSIONS: The strongest associations between OMAG, GCIPL thickness, and visual sensitivity measurements were found in the inferior macular sector. The association of OMAG with GCIPL thickness measurements was as strong as the association between OMAG and visual sensitivity measurements in the inferior macular sector.