Ocular Hypertension Group Research Articles

Relationships between corneal biomechanics and the structural and functional parameters of glaucoma damage.

To investigate the relationships between (i) thickness of the retinal nerve fiber layer, optic nerve head topography, and visual field parameters and (ii) corneal biomechanical properties in normal controls and patients with ocular hypertension and primary open-angle glaucoma. This observational, cross-sectional study included 68 eyes with primary open-angle glaucoma, 99 eyes with ocular hypertension and 133 control eyes. Corneal biomechanical properties, optic nerve head topographic features, retinal nerve fiber layer thickness, and visual fields were assessed in all cases. Corneal biomechanical properties, retinal nerve fiber layer thicknesses, and optic nerve head topographic features were compared among the groups. The associations between structural and functional measures of glaucomatous damage and corneal biomechanical factors were also evaluated. Significantly lower corneal hysteresis and corneal resistance factor values were observed in the primary open-angle glaucoma and ocular hypertension groups as compared with the control group, but there were no significant differences between the primary open-angle glaucoma and ocular hypertension groups. In the ocular hypertension group, no associations were observed between the corneal hysteresis and corneal resistance factor with values and the structural and functional parameters. In the primary open-angle glaucoma group, positive correlations were observed between the corneal hysteresis values and the global retinal nerve fiber layer thickness (p<0.01, r=0.27), mean retinal nerve fiber layer thickness (p<0.01, r=0.33), and mean deviation (p<0.01, r=0.26), and negative correlations were observed between the corneal resistance factor values, and the cup area (p<0.01, r=-0.39), cup-to-disk ratio (p=0.02, r=-0.28), linear cup-to-disk ratio (p=0.02, r=-0.28), and cup shape (p=0.03, r=-0.26). In the control group, weak correlations were detected between the corneal hysteresis and the cup area (p=0.03, r=0.19), cup-to-disk ratio (p=0.01, r=0.21), and linear cup-to-disk ratio (p=0.01, r=0.22). Distinct correlations were identified between the corneal hysteresis and corneal resistance factor values and the functional and structural parameters in the primary open-angle glaucoma and control groups. Corneal hysteresis and corneal resistance factor may have different roles in the pathophysiology of glaucoma.

Posttreatment Intervention With Lycium Barbarum Polysaccharides is Neuroprotective in a Rat Model of Chronic Ocular Hypertension.

To investigate the neuroprotective effects of Lycium barbarum polysaccharides (LBP) against chronic ocular hypertension (OHT) in rats and to consider if effects differed when treatment was applied before (pretreatment) or during (posttreatment) chronic IOP elevation. Sprague-Dawley rats (10-weeks old) underwent suture implantation around the limbus for 15 weeks (OHT) or 1 day (sham). Four experimental groups were studied, three OHT groups (n = 8 each) treated either with vehicle (PBS), LBP pretreatment or posttreatment, and a sham control (n = 5) received no treatment. LBP (1 mg/kg) pre- and posttreatment were commenced at 1 week before and 4 weeks after OHT induction, respectively. Treatments continued up through week 15. IOP was monitored twice weekly for 15 weeks. Optical coherence tomography and ERG were measured at baseline, week 4, 8, 12, and 15. Eyes were collected for ganglion cell layer (GCL) histologic analysis at week 15. Suture implantation successfully induced approximately 50% IOP elevation and the cumulative IOP was similar between the three OHT groups. When compared with vehicle control (week 4: -23 ± 5%, P = 0.03), LBP pretreatment delayed the onset of retinal nerve fiber layer (RNFL) thinning (week 4, 8: -2 ± 7%, -11 ± 3%, P > 0.05) and arrested further reduction up through week 15 (-10 ± 4%, P > 0.05). LBP posttreatment intervention showed no significant change in rate of loss (week 4, 15: -25 ± 4.1%, -28 ± 3%). However, both LBP treatments preserved the retinal ganglion cells (RGC) and retinal functions up to week 15, which were significantly reduced in vehicle control. LBP posttreatment arrested the subsequent neuronal degeneration after treatment commencement and preserved RGC density and retinal functions in a chronic OHT model, which was comparable with pretreatment outcomes.

Comparison of a commercial spectral-domain OCT and swept-source OCT based on an angiography scan for measuring circumpapillary retinal nerve fibre layer thickness

Background/aimsTo assess the agreement in measuring retinal nerve fibre layer (RNFL) thickness between spectral-domain (SD; Cirrus HD, Carl Zeiss Meditec, USA) optical coherence tomography (OCT) and swept-source (SS; Plex Elite...

Aqueous Humor Dynamics in Uveitic Eyes

To investigate aqueous humor dynamics in uveitic eyes. Cross-sectional study. Patients with recurrent (≥3 attacks) anterior uveitis (now quiescent) and being treated for glaucoma or ocular hypertension (OHT) (Group 1), previous recurrent anterior uveitis (≥3 attacks) without glaucoma or OHT (Group 2), and normal subjects with no ocular problems and IOP < 21mm Hg at screening (control group; Group 3). Patients had one-off measurements. Group 1 patients who were on antihypertensives were washed out for a 4-week period, prior to their study measurements. Main outcome measures were tonographic outflow facility, aqueous humor flow rate, and uveoscleral outflow. One hundred and one patients were screened between February 2014 and February 2017. Nine patients did not meet the inclusion criteria. Groups 1 and 3 each included 30 patients, and Group 2 included 32 patients. The mean intraocular pressure was higher in Group 1 compared to the others (25 ± 10.2mm Hg in Group 1 vs 16 ± 2.7mm Hg in Group 2 vs 16 ±2.2mm Hg in Group 3, P < .001). The tonographic outflow facility was lower in Group 1 compared to the others (0.18 ± 0.1μL/min/mm Hg in Group 1 vs 0.25 ± 0.1μL/min/mm Hg in Group 2 vs 0.27 ± 0.1μL/min/mm Hg in Group 3, P= .005). However, aqueous humor flow rate was not statistically different (2.47 ±0.9μL/min in Group 1 vs 2.13 ± 0.9μL/min in Group 2 vs 2.25 ± 0.7μL/min in Group 3, P= .3). There was also no significant difference in calculated uveoscleral outflow. This is the first aqueous humor dynamics study in patients with uveitic glaucoma/OHT and recurrent anterior uveitis compared with age-matched controls. We have demonstrated that the elevated intraocular pressure seen in the uveitic glaucoma/OHT eyes (3-6 attacks) was due to reduced tonographic outflow facility. The aqueous humor flow rate was not detectibly different, nor did the calculated uveoscleral outflow demonstrate any discernible difference. However, the exact mechanism remains to be elucidated.

Role of Pattern Electroretinogram in Ocular Hypertension and Early Glaucoma.

To test whether pattern electroretinogram (PERG) can early detect retinal ganglion cells dysfunction in ocular hypertension. Cross-sectional observational study. The study included 3 groups: control, primary open-angle glaucoma (POAG) and ocular hypertension (OHT) groups with 30 eyes in each group. Visual fields were examined using automated perimetry with central 24-2 program. Optical coherent tomography (OCT) was done to assess the neuroretinal rim area, vertical cup/disc ratio, and average superior and inferior retinal nerve fiber layer thickness. PERG was recorded using skin electrodes. Amplitude and latency of P50 and N95 were documented. PERG data: the mean P50 and N95 latency were significantly higher in the POAG group and the OHT group compared with the control group (P<0.001, <0.001, respectively). Also, the mean P50 and N95 amplitude were significantly lower in the POAG group and the OHT group compared with the control group (P<0.001,<0.001, respectively). In the POAG group, there was a significant negative correlation between PSD on one hand and P50 amplitude (r=-0.620, P=0.001) and N95 amplitude (r=-0.61, P<0.001) on the other hand. Also, the mean deviation was positively correlated with P50 amplitude (r=0.51, P=0.007) and N95 amplitudes (r=0.50, P=0.002). However, there was no significant correlation between PERG parameters and OCT parameters. In the OHT group, PERG parameters did not correlate with visual field and OCT parameters. PERG can detect the dysfunctional, but still live retinal ganglion cells earlier than OCT in OHT cases, allowing the early start of treatment that can restore the ganglion cell function before irreversible damage occurs.

An Agreement of Two Tonometers: Goldmann Applanation and Non-Contact Scheimflug Technology in Healthy, Ocular Hypertension and Open-angle Glaucoma Patients

Objective: The primary objective was to find an agreement of intraocular pressure (IOP) assessed by Goldmann applanation tonometry (GAT) and Corvis in healthy, ocular hypertension (OHT) and primary open-angle glaucoma (POAG). The secondary objective was to find a reliability of intra-examiner and inter-examiner IOP measurement by GAT and Corvis. Methods: Fifty three eyes from 53 participants were included and were divided into healthy (N=20), OHT (N=13) and POAG group (N=20). Only right eyes were selected for further statistical analysis except one patient with only left eye eligible. The eyes with corneal pathologies, greater than 2.5 diopters astigmatism, or recent ocular surgery were excluded. Randomized examining sequence between GAT and Corvis was applied. To minimize an after measurement IOP fluctuation, five minutes and two minutes gap between measurements were strictly applied for Corvis and GAT respectively. The first ten patients had 3 measurements per measurer and two measurers were assigned per machine to evaluate intra-examiner and inter-examiner reliability. Intraclass correlation coefficient was used to analyze the reliability of the IOP measuring machine. Bland & Altman plot was used to analyze an agreement between the machines. Results: High ICCs were found in both measurers using GAT (ICC of measurer 1 = 0.954, measurer 2 = 0.977) and Corvis (ICC of measurer 1 = 0.920, measurer 2 = 0.927) which indicated excellent intra-examiner reliability. High ICCs were found when comparing IOP between 2 measurers who used the same machine (GAT ICC = 0.928, Corvis ICC = 0.915) which indicated excellent inter-examiner reliability. GAT tends to yield higher IOP reading. The mean IOP were 13.93±3.849 by GAT and 12.15±4.030 by Corvis. The mean IOP differences were 1.8, 1.7, 1.4 and 2.2 mmHg in total, healthy, OHT and POAG group respectively. POAG had highest mean difference and widest standard deviation which might result from poor agreement between 2 machines. According to Bland & Altman plot the values were scattered and no trend was found indicating higher or lower average IOP would result in higher or lower difference between the two machines. From the clinical point of view, 71.7% and 47.2% fall into IOP difference range of ±3 and ±2 mmHg respectively. Conclusion: Corvis-IOP is a good parameter with excellent intra-examiner and inter-examiner reliability. In clinical practice, the usefulness of Corvis-IOP is limited especially in POAG patients according to the poor agreement with gold standard GAT-IOP.

Evaluation of dynamic thiol-disulfide homeostasis in glaucoma patients and the correlation with retinal nerve fiber layer analysis.

The aim of this study was to evaluate thiol/disulfide homeostasis and ischemia-modified albumin levels with primary open-angle glaucoma, ocular hypertension, and control group; also to interpret the correlation between these biochemical parameters and retinal nerve fiber layer analysis. In a prospective cross-sectional study, 30 primary open-angle glaucoma cases, 30 ocular hypertension cases, and 30 control subjects were included in the study. Native thiol, total thiol, and disulfide measurements and disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were evaluated as thiol-disulfide homeostasis. Albumin and ischemia-modified albumin parameters were also evaluated. All cases underwent detailed ophthalmologic examination including visual acuity, retinal nerve fiber layer via optical coherence tomography, intraocular pressure, and central corneal thickness measurements and visual field analysis by 24-2 Swedish Interactive Threshold Algorithm (SITA) Standard visual field test. Primary open-angle glaucoma group had significantly higher ischemia-modified albumin values than ocular hypertension and control group (p < 0.001). Native thiol and total thiol values of control group were statistically higher than those of primary open-angle glaucoma and ocular hypertension groups. The correlation between the temporal retinal nerve fiber layer value and ischemia-modified albumin, disulfide/native thiol, and disulfide/total thiol values of the primary open-angle glaucoma patients included in the study was moderate correlation in negative direction (r = -0.46, r = -0.39, r = -0.39, respectively), whereas there was a statistically significant moderate correlation in positive direction between the native thiol/total thiol values (r = 0.39) (p < 0.05). These findings have reinforced the role of oxidative stress in the etiopathogenesis of primary open-angle glaucoma, suggesting that the thinning retinal nerve fiber layer may be associated with oxidative stress in favor of prooxidant shift.

Optical Coherence Tomography Angiography of Optic Disc in Eyes With Primary Open-angle Glaucoma and Normal-tension Glaucoma.

To examine vessel density (VD) properties of the optic nerve head in eyes with ocular hypertension (OHT), high-tension glaucoma (HTG), and normal-tension glaucoma (NTG) and to evaluate associations on structural parameters of retinal nerve fiber layer (RNFL). Three groups of patients with OHT (n=15), HTG (n=36), and NTG (n=22), and a healthy control group (n=23) were included in this study. Peripapillary VD and optic disc flow area were measured using optical coherence tomography angiography, and peripapillary RNFL (pRNFL) thickness was determined. Global and sectoral analysis of optic nerve head vasculature and pRNFL thickness were measured. Glaucomatous eyes had lower global peripapillary VD (HTG: 54.04±5.11, NTG: 54.74±6.37) compared with nonglaucomatous eyes (OHT: 59.72±1.63, controls: 61.35±2.47). VD parameters of the optic disc were comparable between the control and OHT group and between the HTG and NTG group. In the HTG and NTG groups we found significant correlations between average peripapillary VD and global pRNFL thickness (HTG ρ=0.71, P<0.001; NTG ρ=0.65, P=0.001). This was true for all sectors except for the temporal position. Overall, glaucomatous eyes had lower peripapillary VD compared with normal and OHT eyes. There is a strong relationship between the peripapillary structure of RNFL and its vasculature.

Early Macular Angiography among Patients with Glaucoma, Ocular Hypertension, and Normal Subjects.

Purpose To evaluate early macular circulation in open-angle glaucoma (OAG), normal-tension glaucoma (NTG), ocular hypertension (OHT), and healthy subjects via optical coherence tomography angiography (OCTA). Methods A retrospective cross-sectional study was conducted. Medical records were reviewed, and the patients who received OCTA examinations were divided into the OAG, NTG, OHT, and normal groups. The ophthalmic data including best-corrected visual acuity, spherical equivalent, intraocular pressure, central corneal thickness, central foveal thickness, visual field deviation, retinal nerve fiber layers thickness, and ganglion cell complex thickness were obtained from medical documents. For the macular area, the superficial vessel density (VD), deep VD, foveal avascular zone (FAZ), flow area of the outer retina, and flow area of the choriocapillaris were measured via OCTA and analyzed using the default vascular density analysis program in the same OCTA device. Results A total of 70 eyes from 70 patients were analyzed in the current study. Significant differences in the intraocular pressure, central corneal thickness, visual field deviation, retinal fiber layer thickness, and ganglion cell complex thickness were observed in the patients in the glaucoma group at their last visits. The OAG and NTG groups evinced a lower superficial VD than did the control group, while the NTG group had a lower deep VD than the control group. The NTG group also had a larger FAZ than did the OHT group. The flow area of the outer retina in the OAG group was low relative to those of the OHT and control groups. No difference in choriocapillaris perfusion was observed among the groups. Conclusion The OAG and NTG patients demonstrated impaired vasculature before significant disease development could be observed. Furthermore, the differences in macular circulation may be associated with differences in the courses of disease between the glaucoma and OHT patients.

Macular Choroidal Thickness in Patients with Ocular Hypertension as Assessed Using Enhanced Depth Imaging Optical Coherence Tomography.

Objectives:The aim of this study was to evaluate the macular choroidal thickness (CT) in patients with ocular hypertension (OHT) using spectral domain optical coherence tomography (SD-OCT) and compare the results with healthy individuals.Methods:Thirty eyes of 30 patients newly diagnosed with OHT and 24 eyes of 24 healthy controls were included in this cross-sectional study. After a detailed ophthalmological examination, macular CT was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) (Cirrus HD-OCT, Carl Zeiss Meditec AG, Jena, Germany) at the fovea and at positions 500 μ, 1000 μ, 1500 μ nasal and temporal to the fovea. The Mann-Whitney U test was used to compare the CT measurements between groups. The correlation between the mean deviation, pattern standard deviation, and retinal nerve fiber layer thickness (RNFL) and CT was evaluated with the Spearman correlation coefficient. Statistical significance was accepted as p<0.05.Results:The mean CT in the OHT group was significantly thinner than that of the controls at locations 1000 μ (250.13±69.53μ vs 275.92±47.34μ; p=0.02) and 1500μ (236.03±65.44μ vs 265.46±47.56μ; p=0.009) temporal to the fovea. The CT at the other measurement points was also thinner in eyes with OHT, but the difference failed to reach statistical significance. A moderately negative correlation was detected between the mean deviation and CT at locations 1000μ (r=-0.42; p=0.03) and 1500μ (r=-0.44; p=0.02) temporal to the fovea There was a moderate correlation between the average RNFL thickness and CT at locations 500μ (r=0.44; p=0.03), 1000μ (r=0.42; p=0.04) and 1500μ (r=0.56; p=0.005) temporal to the fovea.Conclusion:In the present study, the macular CT was thinner in patients with OHT and this thinning was statistically significant at the temporal macula. A longitudinal, prospective study involving multiple EDI-OCT measurements is required to further understand the relationship.

The ganglion cell complex as an useful tool in glaucoma assessment

Glaucoma is known as an optic neuropathy prone to progression that determines characteristic not only structural (loss of the ganglion cells as well as their axons) but also functional defects (visual field loss). Objective: To evaluate the possibility of applying ganglion cell complex analysis (GCC) in patients who associate ocular hypertension with tilted disc and marked peripapillary atrophy. Methods: In order to evaluate its components, GCC can be investigated using the Optical Coherence Tomography (OCT) revealing: ganglion cell layer (cells bodies), inner plexiform layer (dendrites and synapses), and nerve fiber layer (axons). Our study included 196 eyes divided into 3 groups: 52 diagnosed with primary open angle glaucoma (POAG), 63 with ocular hypertension (OH), and 81 healthy (normal) eyes (NE). All eyes were submitted to a complete ophthalmologic checkup that involved advanced optic nerve and GCC evaluation. Results: A positive statistically significant correlation was identified between the GCC thickness and the RNFL in all three categories taken into account: R=0,6, p<0,0001 for glaucoma group, R=0,66, p<0,0001 for OH group and R=0,46, p<0,0001 for normal group. Conclusions: GCC has been proved useful for the assessment of the retinal nerve fiber layer (RNFL) in eyes with OH that associate tilted disc or peripapillary atrophy where the optic disc edges might not be certainly determined by the OCT.

Evaluation of RETICs Glaucoma Diagnostic Calculators in Preperimetric Glaucoma.

PurposeTo evaluate two glaucoma diagnostic calculators (GDC) in a group of eyes with preperimetric glaucoma (PPG).MethodsAll eyes (n = 265) included in this study had ocular hypertension with normal visual fields (VFs) on repeated VF tests. PPG was defined as progression in the Guided Progression Analysis software from Cirrus-optical coherence tomography (GPA-OCT). Three PPG types were defined according to the GPA-OCT software as follows: (1) GPA-OCT with one or more red boxes in two or more columns; (2) GPA-OCT with two or more red boxes in two or more columns; and (3) GPA-OCT with two or more red boxes in two or more columns (definition 2), and in the last scan one or more red box in the RNFL average or quadrants. Nonparametric tests, areas under the receiver operating characteristic curve (AUC), and Bland-Altman tests were assessed.ResultsDefinitions one, two, and three were met by 44 (16.6%), 29 (10.9%), and 11 (4.2%) eyes, respectively. The GDC indices (means ± standard deviations) were, respectively, 14.49 ± 21.55% and 26.06 ± 22.50% using the combined and quantitative GDC (P < 0.001) in all eyes. Both GDC showed higher glaucoma probability in the PPG group (P < 0.04; combined GDC AUCs, 0.720–0.833; quantitative GDC AUCs, 0.700–0.839). GDC values were higher (P < 0.01) with greater GPA progression.ConclusionsThe values of both GDC were higher in the PPG group than the ocular hypertension group. The GDC were higher when more columns in the GPA software indicated progression. Both GDC showed a similar ability to detect PPG.Translational RelevanceThese calculators facilitate diagnosis of PPG in ocular hypertensive eyes.

Noninvasive evaluation of cerebrospinal fluid pressure in ocular hypertension: a preliminary study

To compare the orbital cerebral spinal fluid pressure (CSFP) and trans-lamina cribrosa pressure difference (TLCPD) determined noninvasively in ocular hypertensive (OH) subjects and controls. Cross-sectional observational study. Magnetic resonance imaging was used to measure orbital subarachnoid space width (OSASW). The CSFP (mmHg) was estimated from a published formula as 17.54×MRI derived OSASW at 15mm behind the globe+0.47×body mass index+0.13×mean arterial blood pressure -21.52. Estimated TLCPD was calculated as IOP- CSFP. The orbital subarachnoid space width was significantly wider (p=0.01) in the OH group than in the control group at all three measurement locations. The MRI derived CSFP value in OH (14.9±2.9mmHg) was significantly higher than in the normal group (12.0±2.8mmHg; p<0.01). The estimated TLCPD value in OH (9.0±4.2mmHg) was significantly higher than in controls (3.6±3.0mmHg; p<0.01). The wider OSASW and higher estimated CSFP in OH subjects suggest a higher orbital CSFP. Despite a higher orbital CSFP that could be protective, the higher TLCPD in OH may play a significant role in the risk of developing glaucoma.

Analysis of choroidal thickness in ocular hypertensive patients using enhanced depth imaging optical coherence tomography.

This study aimed to compare choroidal thickness between subjects with ocular hypertension (OHT) and normal individuals and explore factors affecting choroidal thickness. This study included 60 untreated newly diagnosed OHT eyes and 60 normal eyes. Choroidal thickness obtained from Cirrus HD-OCT was measured at different locations in the macular and peripapillary regions and compared between the two groups before and after adjusting for potential confounding variables. Regression analysis was performed to figure out factors influencing choroidal thickness. The macular choroidal thickness did not vary significantly between OHT patients and normal controls regardless of locations (all P>0.05). The average peripapillary choroidal thickness was 167±53μm in OHT eyes and 185±63μm in the normal eyes; no significant differences were identified (P=0.107). Only one of the locations in the temporal area in the OHT group demonstrated significantly thinner peripapillary choroidal thickness as compared to the normal group (P=0.033). Age was the only significant factor affecting choroidal thickness on multivariate analysis regardless of locations (all P<0.001). Choroidal thickness of the macular and peripapillary regions in OHT patients is not decreased significantly except one location in the temporal area of the optic disc when comparing with the normal subjects. Anatomic peripapillary choroidal thickness measurements with SD-OCT might be one more tool to track changes in OHT patients.

Pilot study of the pulsatile neuro-peripapillary retinal deformation in glaucoma and its relationship with glaucoma risk factors

ABSTRACTPurpose: To perform a pilot study of the neuro-peripapillary retinal tissue deformation during the cardiac cycle among healthy eyes, ocular hypertensive (OHT), open angle glaucoma suspect (OAG-S), and early open angle glaucoma (EOAG) patients using video rate optical coherence tomography (OCT) image series.Methods: OCT line scan sequences of the same region of the optic nerve head (ONH) were obtained from 15 EOAG, 6 OHT, 10 OAG-S, and 10 healthy age-matched eyes. One eye per patient was studied. Changes in the axial distance between the inferotemporal peripapillary retina and the prelaminar tissue, in time, were determined using an automated custom made algorithm. Linear correlations between this neuro-peripapillary retinal (N-PP) deformation and variables measured during the full ophthalmic examination are analyzed.Results: Healthy eyes showed larger N-PP deformation (4.8 ± 1 µm) than the OHT (3.5 ± 0.3 µm, p = 0.015), OAG-S (3.8 ± 0.8 µm, p = 0.045), and EOAG (3.2 ± 0.7 µm, p < 0.001) groups. Eyes with lower ocular pulse amplitude, thinner RNFL’s, or worse visual fields showed smaller N-PP deformation, depending on the diagnosis. A linear model to explain deformation within the EOAG group with intraocular pressure and systolic perfusion pressure as predictors was found to be significant (R2 = 0.767, p < 0.001).Conclusions: Smaller mean N-PP deformation was observed in the EOAG, OAG-S, and OHT groups compared to healthy eyes in this pilot study. The measured deformation correlated with risk factors for the glaucomatous optic neuropathy, but these correlations varied depending on the diagnosis. The role of pulsatile neuro-peripapillary retinal deformation in the pathophysiology of OAG remains to be determined.

Relationship Between OCT Angiography Temporal Peripapillary Vessel-Density and Octopus Perimeter Paracentral Cluster Mean Defect.

The purpose of the study was to investigate the relationship between optical coherence tomography angiography angioflow vessel-density (PAFD) measured in the retinal nerve fiber layer in the temporal peripapillary sector and the average of the spatially corresponding superior and inferior paracentral cluster mean defect values (mean paracentral MD) measured with Octopus perimetry. Spaerman's correlation between temporal peripapillary PAFD acquired with the Angiovue OCT and mean paracentral MD measured with the Normal and tendency-oriented perimetry strategy of Octopus G2 perimetry, respectively, was determined on 1 eye of 13 healthy participants, 22 medically controlled ocular hypertensive, and 27 stable early to moderate glaucoma patients. Octopus perimetry was made within 3 months from optical coherence tomography angiography imaging. Strong negative relationship was found irrespective to Octopus test strategy between temporal sector peripapillary PAFD and mean paracentral MD for the total population (r-values: -0.5525 and -0.4496, respectively, P≤0.002), the glaucoma group (r-values: -0.4901 and -0.4936, respectively, P<0.01) and the ocular hypertensive group (r-values: -0.4445 and -0.4496, P≤0.0382). For the healthy eyes, and for all groups when correction for the diffuse defect component of global MD was made using the perimeter's software, no significant relationship was found. Strong negative relationship exists between the temporal peripapillary sector PAFD measured with Angiovue OCT angiography in the retinal nerve fiber layer and mean paracentral cluster MD determined with uncorrected Normal and tendency-oriented perimetry strategies of Octopus perimetry. This relationship may be usefully applied in research when eyes with paracentral scotomas are investigated.

Evaluation of Central Macular Thickness and Perifoveal Ganglion Cell Complex Thickness with Optical Coherence Tomography in Cases with Primary Open Angle Glaucoma and Ocular Hypertension

Objective: Evaluation of central macular thickness (CMT) and perifoveal ganglion cell complex thickness (GCC) through spectral-domain optical coherence tomography (SD-OCT) in cases with primary open angle glaucoma (POAG) and ocular hypertension (OHT). Material and Methods: In this study, 150 eyes of 75 patients with POAG, 144 eyes of 72 patients with OHT and 142 eyes of 71 healthy cases were included. All cases undergone a complete ophthalmologic examination, visual field examination with standard automated perimetry, and CMT and GCC thickness measurements with RTVue-100 SD-OCT device. In CMT and GCC analysis, average, inferior-half and superior-half thickness values were evaluated. Results: No statistically significant difference was detected between the groups in terms of age and gender (p>0.05). CMT was found as 227.4±21.6 ìm, 235.7±20.3 ìm, 238.5±17.8 ìm, GCC average thickness was found as 91.6±9.6 ìm, 98.1±6.5 ìm, 98.2±6.8 ìm, GCC superior-half thickness as 91.2±9.6 ìm, 97.4±6.6 ìm, 97.4±6.8 ìm and GCC inferior-half thickness as 92.1±10.3 ìm, 98.9±6.8 ìm, 99.0±7.3 ìm in POAG, OHT and control groups, respectively. In the POAG group, the GCC average, superior-half and inferior-half thickness and CMT values were significantly lower than those of the OHT and control groups. No significant difference was detected between the OHT and control groups. GCC and CMT analyses are correlated. Conclusions: In distinguishing POAG cases from OHT and healthy cases, GCC and CMT analyses are rather effective and reliable. GCC and CMT analyses may be used as adjuvant methods to visual field testing in the diagnosis and treatment follow-up of patients with POAG. GCC and CMT analyses are not reliable in distinguishing OHT cases from normal cases.

Non-invasive Evaluation of Cerebrospinal Fluid Pressure in Ocular Hypertension: The Beijing Intracranial and Intraocular Pressure Study

Objective: To compare the orbital CSFP and trans-lamina cribrosa pressure difference (TLCPD) determined noninvasively in Ocular Hypertension (OH) and controls, and study its association with the estimated risk of conversion to glaucoma. Design: Cross-sectional observational study. Participants: 19 subjects with OH recruited from the Tongren Eye Center and 23 controls enrolled in the Beijing Intracranial and Intraocular Pressure Study between June 2010 to December 2013. Methods: Magnetic resonance imaging was used to measure orbital subarachnoid space width (OSASW) at 3, 9 and 15 mm posterior to the globe. The CSFP (mmHg) was estimated from a published formula as 17.54 × MRI derived OSASW at 15 mm behind the globe +0.47 × body mass index +0.13 × mean arterial blood pressure -21.52. Estimated TLCPD was calculated as IOP- CSFP. The values of CSFP and TLCPD were compared between OH and controls. The estimated risk of progression to glaucoma in OH was calculated and its correlation with CSFP determined. Main outcome measures: Orbital subarachnoid space width; MRI derived CSFP value; TLCPD value. Association of risk of progression with CSFP. Results: The orbital subarachnoid space width was significantly wider (P=0.01) in the OH group than in the control groups at all three measurement locations. The MRI derived CSFP value in OH (14.9 ± 2.9 mmHg) was significantly higher than in the normal group (12.0 ± 2.8 mmHg; P<0.01). The estimated TLCPD value in OH (9.0 ± 4.2 mmHg) was significantly higher than in controls (3.6 ± 3.0 mmHg; P<0.01). The estimated risk of conversion to glaucoma in OH (15.2 ± 8.7%) was negatively correlated with the MRI derived CSFP value (r=-0.51, r2=-0.26, P<0.01). Conclusions: The wider OSASW and higher estimated CSFP in OH subjects suggest a higher orbital CSFP. Despite a higher orbital CSFP that could be protective, the higher TLCPD in OH may play a significant role in the risk of developing glaucoma.

The Association of Central Corneal Thickness with Ocular and General Parameters in a Community Setting: The Yazd Eye Study.

Purpose:To assess central corneal thickness (CCT) and its associations in an adult Iranian population.Methods:This was a population-based cross-sectional study of adults aged 40–80 years. Eyes with corneal disorders, previous ocular surgery, or trauma were excluded. All subjects underwent complete ophthalmic examination, general health assessment, laboratory tests, and a detailed interview. CCT was measured with an ultrasonic pachymeter. Intraocular pressure (IOP) was measured with Goldmann applanation tonometry. Except for the report on interocular differences in CCT, only one eye of each subject was used for the rest of statistical analyses.Results:The mean age (±SD) of the 1203 participants, who had CCT measurements and met inclusion criteria, was 51.8 ± 8.5 years. The mean CCT was 544 ± 35, 564 ± 28, and 544 ± 36 μm in the eyes of the normal, ocular hypertension, and glaucoma groups, respectively (P = 0.025). In participants without glaucoma, the mean interocular difference in CCT was 9 ± 12 μm. CCT was not significantly associated with age, sex, or some select systemic factors (body mass index, diabetes, hypertension, and renal failure). While controlling for age and sex, CCT was greater in individuals with higher IOPs (P < 0.001), larger vertical or horizontal cup-to-disc ratios (P = 0.044, and P = 0.025, respectively), and hyperopia (P = 0.009).Conclusion:In this adult Iranian population, CCT was significantly associated with IOP, cup-to-disc ratio, and the refractive status of eye. CCT outside the normal range of 475–613 μm or with interocular asymmetry greater than 33 μm (6%) should prompt evaluation for potential ocular disorders.

Central corneal thickness in newly diagnosed glaucoma patients in South West Ethiopia: a cross-sectional study

BackgroundReports of central corneal thickness (CCT) among glaucoma patients, particularly for pseudoexfoliative glaucoma (PXG) and Primary Angle Closure Glaucoma (PACG) are scarce in the Sub-Saharan African (SSA) population. The aim of this study is to evaluate CCT in black patients with newly diagnosed glaucoma and ocular hypertension (OHT) in South West Ethiopia.MethodsThis was a prospective study undertaken with an ultrasonic pachymeter from June 2014 to February 2015 in Jimma University Specialized Hospital. Patients aged 18 years and older newly diagnosed with glaucoma or OHT were included.ResultsA total of 162 eyes of 162 subjects were included. Hundred and fifty five subjects were glaucomatous: (67 PXG, 42 Primary Open Angle Glaucoma (POAG), 28 PACG, 14 Normal Tension Glaucoma (NTG), 5 Juvenile Open Angle Glaucoma (JOAG) and 6 (OHT). The mean age was 59.3 ± 12.8 years.For the whole sample, CCT was 518.67 (±39.97) μm. OHT group had significantly greater CCT (576.33 ± 49.32 μm) than the glaucomatous groups (p = 0.004). POAG (506.69 ± 35.08 μm) and NTG (510.79 ± 44.37 μm) groups had thinner CCT than PXG (520.48 ± 38.95 μm), PACG (524.00 ± 37.16 μm), and JOAG (518.00 ± 30.82 μm) groups, but this was not statistically significant (p = 0. 296). There was a statistically significant decline of CCT with advanced age (P = 0.02). There wasn’t significant difference of average CCT between the ethnic groups (P = 0.3) and gender (P = 0.064).ConclusionThe mean CCT of Ethiopian glaucoma patients is thinner than Caucasians and similar to those reported from previous studies in Sub Saharan Africa. OHT patients had thicker CCT; there was no statistically significant difference observed in average CCT amongst glaucoma subtypes.