Hypertensive Eyes Research Articles

Ocular hypertension: general characteristics and estimated cerebrospinal fluid pressure. The Beijing Eye Study 2011.

PurposeTo examine characteristics of ocular hypertensive subjects and potential associations with estimated cerebrospinal fluid pressure (estCSFP).MethodsThe population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6±9.8 years. Ocular hypertension was defined as intraocular pressure (IOP) >21 mmHg, normal optic nerve head appearance and normal retinal nerve fiber layer thickness. IOP was corrected for its dependence on central corneal thickness (CCT) and corneal curvature radius. Estimated CSFP was calculated as CSFP [mmHg] = 0.44×Body Mass Index [kg/m2]+0.16×Diastolic Blood Pressure [mmHg]−0.18×Age [Years]−1.91. Estimated trans-lamina cribrosa pressure difference (estTLCPD) was IOP–estCSFP.ResultsEstCSFP (10.5±3.6 mmHg versus 9.0±3.7 mmHg; P = 0.003) and estTLCPD (12.0±4.4 mmHg versus 5.4±3.8 mmHg; P<0.001) were higher in the ocular hypertensive group than in the normotensive group. In binary regression analysis, ocular hypertension was associated with increased estCSFP (P = 0.03; odds ratio (OR): 1.08; 95% confidence interval (CI): 1.01, 1.17) after adjusting for prevalence of arterial hypertension (P = 0.07; OR: 1.79; 95%CI: 0.96, 3.34), retinal nerve fiber layer thickness (P = 0.03; OR: 0.97; 95%CI: 0.95, 0.997) and blood glucose concentration (P = 0.006; OR: 1.17; 95%CI: 1.04, 1.30).ConclusionsOcular hypertensive subjects (with IOP correction for CCT and corneal curvature) as compared to ocular normotensive subjects had a significantly higher estCSFP in univariate analysis and in multivariate analysis. Despite of a higher estCSFP, estTLCPD was still markedly higher in ocular hypertensive eyes than in ocular normotensive eyes.

Imaging the Eye in Idiopathic Intracranial Hypertension

Imaging the Eye in Idiopathic Intracranial Hypertension

FR-190997, a nonpeptide bradykinin B2-receptor partial agonist, is a potent and efficacious intraocular pressure lowering agent in ocular hypertensive cynomolgus monkeys.

Preclinical Research FR-190997 (8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl) cinnaminoacetyl]-N-methylamino]benzyloxy]-2-methyl-4- (2-pyridylmethoxy) quinoline), a nonpeptide bradykinin (BK) B2-receptor-selective agonist, represents a novel class of ocular hypotensive agents. FR-190997 exhibited a high affinity for the human cloned B2-receptor (Ki = 9.8 nM) and a relatively high potency (EC50 = 155 nM) for mobilizing intracellular Ca(2+) ([Ca(2+)]i) in human ocular cells from nonpigmented ciliary epithelium; trabecular meshwork [h-TM]; ciliary muscle [h-CM] that are involved in regulating intraocular pressure (IOP). Unlike BK, FR-190997 behaved as a partial agonist (Emax = 38-80%) in these cells and its [Ca(2+)]i-mobilizing effects were blocked by the B2-receptor-selective antagonists (HOE-140, Ki = 0.8-7 nM; WIN-64338, Ki = 157-425 nM). FR-190997 stimulated the production of prostaglandins (PGs) in h-CM and h-TM cells (EC50 = 15-19 nM; Emax = 27-33%); an effect that was reduced by the cyclooxygenase-2 inhibitor bromfenac, and by HOE-140. FR-190997 also induced pro-matrix metalloproteinase (MMP)-1 and MMP-3 release from h-CM cells. FR-190997 significantly lowered IOP (37% [P < 0.001] with 30 μg, 24 h post-topical ocular dosing) in ocular hypertensive eyes of conscious Cynomolgus monkeys. This effect was reduced by bromfenac and completely blocked by a B2-antagonist. FR-190997 primarily stimulated uveoslceral outflow (UVSO) of aqueous humor (2.6 to 3.9-fold above baseline). In conclusion, FR-190997 is a B2-receptor selective partial agonist that activates phospholipase C, mobilizes [Ca(2+)]; induces PG and pro-MMP production, and that profoundly lowers IOP by promoting UVSO in ocular hypertensive Cynomolgus monkey eyes.

In vivo assessment of aqueous humor dynamics upon chronic ocular hypertension and hypotensive drug treatment using gadolinium-enhanced MRI.

Although glaucoma treatments alter aqueous humor (AH) dynamics to lower intraocular pressure, the regulatory mechanisms of AH circulation and their contributions to the pathogenesis of ocular hypertension and glaucoma remain unclear. We hypothesized that gadolinium-enhanced magnetic resonance imaging (Gd-MRI) can visualize and assess AH dynamics upon sustained intraocular pressure elevation and pharmacologic interventions. Gadolinium contrast agent was systemically administered to adult rats to mimic soluble AH components entering the anterior chamber (AC) via blood-aqueous barrier. Dynamic Gd-MRI was applied to examine the signal enhancement in AC and vitreous body upon microbead-induced ocular hypertension and unilateral topical applications of latanoprost, timolol maleate, and brimonidine tartrate to healthy eyes. Gadolinium signal time courses in microbead-induced hypertensive eyes possessed faster initial gadolinium uptake and higher peak signals in AC than control eyes, reflective of reduced gadolinium clearance upon microbead occlusion. Opposite trends were observed in latanoprost- and timolol-treated eyes, indicative of their respective drug actions on increased uveoscleral outflow and reduced AH production. The slowest initial gadolinium uptake but strongest peak signals were found in AC of both brimonidine-treated and untreated fellow eyes. These findings drew attention to the systemic effects of topical hypotensive drug treatment. Gadolinium leaked into the vitreous of microbead-induced hypertensive eyes and brimonidine-treated and untreated fellow eyes, suggestive of a compromise of aqueous-vitreous or blood-ocular barrier integrity. Gadolinium-enhanced MRI allows spatiotemporal and quantitative evaluation of altered AH dynamics and ocular tissue permeability for better understanding the physiological mechanisms of ocular hypertension and the efficacy of antiglaucoma drug treatments.

Physical Activity as a Risk Factor for Hypertension and Target Hypertensive Eye Damage in Two Ethnic Groups in Macedonia

Abstract Introduction. Hypertension is one of the most common chronic, noncommunicable diseases, and it is strongly associated with cardiovascular disease incidence. Lifestyle modifications are most important in HTA management, and physical activity (PA) is crucial among them. It is very difficult to give general recommendation for intensity and duration of the PA, because of the needs to make complete patient evaluation before PA is advised. The general recommendation in most of the national guidelines is to start with moderate PA, 40 min/per day, several times a week. The objectives of our study were: comparison of the physical activity, as a risk factor for hypertension in two ethnic groups in Macedonia, and comparison of the intensity of the target eye damage in the hypertensive subjects in two ethnic communities in Macedonia. Methods. We performed a cross-sectional study with hypertensive Roma patients as a target group, and an equal number of subjects of Macedonian nationality as controls. For both groups we completed a questionnaire where we evaluated the PA. The target eye damage was analyzed according to the Keith-Wagener-Barker categorisation. Results. Hypertensive patients exercised significantly less, or had no physical activity compared with the controls. Conclusions. Physical inactivity is a potential risk for HTA in Roma population. This is a possible cause for the early development, and more severe stage of HTA in Roma ethnic groups, and more intensive target eye damage caused by HTA.

Frequency-Doubling Technology Perimetry for Detection of the Development of Visual Field Defects in Glaucoma Suspect Eyes

While standard automated perimetry (SAP) remains the reference standard for evaluation of visual field (VF) defects in glaucoma, this study demonstrates that frequency-doubling technology (FDT) perimetry is effective in monitoring visual field progression and may detect the onset of visual field defects earlier than SAP. To compare detection of the development of VF defects, rate of change of VF loss, and risk factors for progression between SAP and matrix FDT perimetry in glaucoma suspect and ocular hypertensive eyes. A total of 113 glaucoma suspect and ocular hypertensive eyes from 76 patients with normal SAP and FDT perimetry results at baseline were prospectively followed up for SAP and FDT perimetry testing at approximately 4-month intervals for 30 months or longer. Patients were consecutively enrolled and followed up from January 2, 2008, to February 28, 2012, at the Hong Kong Eye Hospital, Chinese University of Hong Kong. Visual field progression was defined by the development of VF defects confirmed by 3 or more consecutive examinations at a cluster of 3 or more (less conservative) or 4 or more (more conservative) locations. The rates of change of mean deviation and pattern standard deviation were evaluated with linear mixed models and the risk factors for VF progression were computed with Cox proportional hazard models. During a median study period of 3.4 years, 8.0% of eyes developed VF defects detected by FDT perimetry, 6.2% by SAP, and 4.4% by both using the less-conservative criteria. The detection dropped to 6.2%, 4.4%, and 2.7%, respectively, when the more-conservative criteria were applied. The rate of change of pattern standard deviation was significantly faster for FDT perimetry than SAP (P < .001). Baseline average retinal nerve fiber layer thickness and the number of clock hours of abnormal retinal nerve fiber layer measurement were associated with increased risk for VF progression for both SAP and FDT perimetry. Frequency-doubling technology perimetry would be useful to monitor the onset of VF defects in glaucoma and may detect VF defects not evident in SAP.

The Dynamic Response of Intraocular Pressure and Ocular Pulse Amplitude to Acute Hemodynamic Changes in Normal and Glaucomatous Eyes

To evaluate the effects of acute arterial blood pressure (ABP) and venous pressure changes on IOP in rats with experimental glaucoma. Unilateral experimental ocular hypertension was established in Sprague-Dawley rats by weekly intracameral injection of microbeads. Ocular pulse amplitude (OPA) and IOP were recorded from the anterior chamber using 1.2-Fr microsensors under urethane anesthesia. The effects on IOP during hemodynamic challenges using phenylephrine (PE) (50 μg/kg/min intravenous [IV]) and rapid saline loading (20 mL/kg/min IV) were studied. Over an 8-week period, IOP was significantly elevated by 60% in the unilateral ocular hypertensive eyes. Both ABP and IOP were significantly increased by PE infusion. A significantly greater IOP increase was found in the experimental eyes compared with control eyes (1.32 ± 0.18 mm Hg vs. 0.90 ± 0.09 mm Hg). Correspondingly, higher OPAs and an amplification of the OPA during arterial hypertension were found in the experimental eyes. A sustained rise in IOP secondary to IV saline loading was observed, with a greater rise observed among experimental eyes (0.74 ± 0.13 mm Hg vs. 0.37 ± 0.005 mm Hg). Sympathetic acceleration of ABP using PE resulted in surges in IOP and OPA. In contrast, increased venous pressure resulted in a more sustained rise in IOP but to a lesser extent. These responses were more pronounced in eyes with experimental glaucoma compared with control eyes, which may reflect the higher starting IOP contributing to a reduced ocular compliance. Our results suggest that eyes with ocular hypertension are more susceptible to IOP variability induced by hemodynamic fluctuations.

Meta analysis about the efficacy and safety of anti-ocular hypertension eye drops without benzalkonium chloride

ObjectiveTo explore the safety and efficacy of eye drops without benzalkonium chloride (BAK) in treating glaucoma and ocular hypertension. MethodsThe clinical case-control literatures about eye drops without BAK treating glaucoma and ocular hypertension were retrieved in PubMed, EMBASE, Cochrane and Chinese Biological and Medical database. Meta 5.0 software was used to analyze the literatures. ResultsFive clinical control studies were included. The results indicated both eye drops could lower the intraocular pressure, and the intraocular pressure-lowering difference between two eye drops was 0.07 mmHg (95% CI: 0.04, 0.19) (P>0.05). Two adverse reactions occurred more were conjunctival injection (10.78%) and allergic conjunctivitis (4.78%). The odd ratio of two eye drops occurring conjunctival injection and allergic conjunctivitis was 0.67 (95% CI, 0.25, 1.10) and 0.82 (95% CI, 0.09, 1.54), respectively (P<0.05) in fixed effect model. ConclusionsThere is no difference between the eye drops with or without BAK in lowering intraocular pressure, but the latter is of higher safety. In consideration of the relatively small sample size of this research, more high-quality clinical research contrasts are needed as evidence.

The Incidence of Vitamin, Mineral, Herbal, and Other Supplement Use in Facial Cosmetic Patients

Dietary supplement use is common in the United States. Some herbal supplements may cause coagulopathy, hypertension, or dry eyes. The goal of this study is to reveal the incidence of herbal supplement use in the cosmetic surgery population. A retrospective chart review of 200 patients undergoing facial cosmetic surgery performed by a single surgeon was performed. Variables studied included patient age, sex, surgical procedure, herbal medication use, and intraoperative variables. Exclusion criteria were age younger than 15 years, noncosmetic procedures such as trauma, and incomplete preoperative medication form. Patients were subdivided into the supplement user group (herbal) and the supplement nonuser group (nonherbal). Statistical analysis included descriptive statistics, t test, and chi-square analysis. The incidence of supplement use was 49 percent in the 200 patients; 24.5 percent of patients used only vitamins or minerals, 2.5 percent of patients used only animal- and plant-based (nonvitamin/mineral) supplements, and 22 percent of patients used both types of supplements. In the herbal group, patients used an average of 2.8 supplements. The herbal and nonherbal groups differed significantly in sex (herbal, 89.8 percent female; nonherbal, 77.5 percent; p < 0.04) and age (herbal, 51.4 years; nonherbal, 38.5 years; p < 0.001). Herbal supplement use is prevalent in the facial cosmetic surgery population, especially in the older female population. Considering the potential ill effects of these products on surgery and recovery, awareness and careful documentation and prohibiting the patients from the consumption of these products will increase the safety and reduce the recovery following cosmetic procedures.

Functional and structural evaluation of lamotrigine treatment in rat models of acute and chronic ocular hypertension

Voltage gated sodium channels (Nav), are proposed mediators of neuronal damage in ischemic and excitotoxicity disease models. We evaluated the neuroprotective effects of lamotrigine, a Nav blocker, in the acute and chronic rat ocular hypertension models. Additionally, expression of the main Nav subtypes in the optic nerve (ON) was assessed to test whether their upregulation plays a role in the pathogenesis of ocular hypertension induced optic neuropathy. Unilateral intraocular pressure (IOP) elevation was induced for 60 min (80 mmHg) and 14–21 days (670–859 mmHg*day) in the acute and chronic models, respectively. Lamotrigine was administered at dosages of 10 mg/kg twice daily and 12.5 mg/kg once daily in the acute (n = 9) and chronic (n = 11) trials, respectively. Treatment began 2 days prior to IOP elevation until sacrifice. Outer and inner retinal function was evaluated with dark- and light-adapted flash electroretinography and pattern electroretinography, respectively, 6 and 14 days post acute IOP elevation and 13, 28 and 48 days post chronic IOP elevation. Retinal ganglion cell and axon densities and inflammatory reaction were evaluated through Fluorogold, Bielschowsky's silver impregnation and ED1 labeling respectively. Immunohistochemistry for Nav1.1, 1.2 and 1.6 was performed in ONs of untreated rats 7 and 15 days post IOP elevation in the acute model and after 7, 28 and 50 days in the chronic model. In the acute model, no differences were found in the a-wave amplitudes between lamotrigine-treated and vehicle-treated rats. B-wave amplitudes decreased by 40–66% in both treatment groups 6 days post IOP elevation, with no significant difference between groups (p = 0.38). However, a partial recovery of b-wave amplitudes was found in lamotrigine-treated rats between day 6 and day 14 post procedure (p < 0.05). No differences were found in any other parameter tested in this model. Similarly, lamotrigine treatment did not result in any beneficial effect in structural parameters of the chronic model. Functional evaluation of this model was inconclusive due to super-normal values in the hypertensive eyes. Up-regulation of Nav1.1 and 1.2 expression was found in both models, beginning by day 7; an increase of the former continued in a time-dependent manner in the chronic model. Nav1.6 labeling was inconclusive. In conclusion we found lamotrigine treatment to be mostly ineffective in both acute and chronic ocular hypertension models.

Intraocular Pressure Lowering Is Associated with an Increase in the Photopic Negative Response (PhNR) Amplitude in Glaucoma and Ocular Hypertensive Eyes

The aim of our study was to determine whether IOP lowering in glaucomatous and ocular hypertensive (OHT) eyes leads to an improvement in the full-field photopic negative response (PhNR) of the electroretinogram. A prospective nonrandomized interventional cohort study was conducted. Patients with OHT or glaucomatous optic neuropathy were recruited, and photopic full-field electroretinograms (ERG) were performed at baseline and then repeated 1 to 2 months later. The change in PhNR amplitude was compared between those eyes that had a significant lowering in IOP (defined as >25% decrease from baseline or to a predetermined target IOP) during follow-up and those that did not. From a cohort of 30 eyes, 18 eyes had a significant reduction in IOP during follow-up (n = 18) and 12 eyes had no significant change in IOP (<25% reduction in IOP, n = 12). A significant increase in PhNR amplitude and the PhNR/b-wave amplitude ratios was observed in the reduced IOP group, but not in the IOP stable group for the two flash intensities used (2.25 and 3.00 cd.s/m(2)). The full-field PhNR amplitude provides a potentially reversible measure of inner retinal function that improves after IOP lowering. Further study now is required to assess its use as a measure of optic nerve health in glaucoma patients.

The Rate of Structural Change: The Confocal Scanning Laser Ophthalmoscopy Ancillary Study to the Ocular Hypertension Treatment Study

To compare rates of topographic change in ocular hypertensive eyes that develop primary open-angle glaucoma (POAG) compared to eyes that do not, and to identify factors that influence the rate of change. Longitudinal, randomized clinical trial. Four hundred forty-one participants (832 eyes) in the Confocal Scanning Laser Ophthalmoscopy Ancillary Study to the Ocular Hypertension Treatment Study were included. POAG was defined as repeatable visual field, photography-based optic disc changes, or both. The rate of topographic change in the 52 participants (66 eyes) who developed POAG was compared with that of participants who did not develop POAG using multivariable mixed effects models. In both univariate and multivariate analyses,the rate of rim area loss was significantly faster in eyes in which POAG developed than in eyes in whichitdidnot(univariate mean,-0.0131mm(2)/year and-0.0026mm(2)/year, respectively). The significantly faster rate of rim area loss in black persons found in the univariate analysis did not remain significant when baseline disc area was included in the model. In multivariate analyses, the rate of rim area loss and other topographic parameters also was significantly faster in eyes with worse baseline visual field pattern standard deviation and higher intraocular pressure during follow-up. Moreover, a significant rate of rim area loss was detected in eyes in which POAG did not develop (P < .0001). The rate of rim area loss in eyes with an optic disc POAG endpoint was significantly faster than in those with a visual field POAG endpoint. The rate of rim area loss is approximately 5 times faster in eyes in which POAG developed compared with eyes in which it did not. These results suggest that measuring the rate of structural change can provide important information for the clinical management of ocular hypertensive patients. Additional follow-up is needed to determine whether the statisticallysignificant change in the eyes in which POAG did notdevelop represents normal aging or glaucomatous change not detected by conventional methods.

Delta-Opioid Agonist SNC-121 Protects Retinal Ganglion Cell Function in a Chronic Ocular Hypertensive Rat Model

This study examined if the delta-opioid (δ-opioid) receptor agonist, SNC-121, can improve retinal function and retinal ganglion cell (RGC) survival during glaucomatous injury in a chronic ocular hypertensive rat model. IOP was raised in brown Norway rats by injecting hypertonic saline into the limbal venous system. Rats were treated with 1 mg/kg SNC-121 (intraperitoneally [IP]) once daily for 7 days. Pattern-electroretinograms (PERGs) were obtained in response to contrast reversal of patterned visual stimuli. RGCs were visualized by fluorogold retrograde labeling. Expression of TNF-α and p38 mitogen-activated protein (MAP) kinase was measured by immunohistochemistry and Western blotting. PERG amplitudes in ocular hypertensive eyes were significantly reduced (14.3 ± 0.60 μvolts) when compared with healthy eyes (18.0 ± 0.62 μvolts). PERG loss in hypertensive eyes was inhibited by SNC-121 treatment (17.20 ± 0.1.3 μvolts; P < 0.05). There was a 29% loss of RGCs in the ocular hypertensive eye, which was inhibited in the presence of SNC-121. TNF-α production and activation of p38 MAP kinase in retinal sections and optic nerve samples were upregulated in ocular hypertensive eyes and inhibited in the presence of SNC-121. Furthermore, TNF-α induced increase in p38 MAP kinase activation in astrocytes was inhibited in the presence of SNC-121. These data provide evidence that activation of δ-opioid receptors inhibited the loss of PERG amplitudes and rate of RGC loss during glaucomatous injury. Mechanistic data provided clues that TNF-α is mainly produced from glial cells and activates p38 MAP kinase, which was significantly inhibited by SNC-121 treatment. Overall, data indicate that enhancement of δ-opioidergic activity in the eye may provide retina neuroprotection against glaucoma.

Correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes

BackgroundThe purpose of this study was to investigate the correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes.MethodsNinety eyes from 90 patients were included. Thirty patients had been recently diagnosed with glaucoma and had no previous history of treatment for ocular hypotension, 30 had elevated intraocular pressure (IOP) without evidence of glaucoma, and 30 had normal IOP (<21 mmHg) with no detectable glaucomatous damage. Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), blood pressure measurement, pachymetry, Humphrey visual field, and routine ophthalmic examination was performed in each patient. Ocular perfusion pressure was calculated as the difference between mean arterial pressure and IOP. The ocular pulse amplitude was given by DCT. The Pearson correlation coefficient was used to compare the glaucomatous and ocular hypertensive groups, and comparisons with the normal IOP group were done using the Spearman’s rank correlation coefficient.ResultsMean IOP by DCT was 22.7 ± 4.3 mmHg in the glaucoma group, 22.3 ± 2.8 mmHg in the ocular hypertension group, and 14.3 ± 1.6 mmHg in the control group. Mean IOP by GAT was 19.0 ± 5.1 mmHg for glaucoma, 22.4 ± 2.1 mmHg for ocular hypertension, and 12.9 ± 2.2 mmHg for controls. Mean ocular pulse amplitude was 3.4 ± 1.2 mmHg in the glaucoma group, 3.5 ± 1.2 mmHg in the ocular hypertension group, and 2.6 ± 0.9 mmHg in the control group. Mean ocular perfusion pressure was 46.3 ± 7.9 mmHg in the glaucoma group, 46.3 ± 7.9 mmHg in the ocular hypertension group, and 50.2 ± 7.0 mmHg in controls. No significant correlation between ocular perfusion pressure and ocular pulse amplitude was found in any of the groups (P = 0.865 and r = −0.032, P = 0.403 and r = −0.156, P = 0.082 and ρ = −0.307 for glaucoma, ocular hypertension, and normal eyes, respectively).ConclusionThere is no significant correlation between ocular perfusion pressure and ocular pulse amplitude values in glaucoma, ocular hypertension, or normal eyes. IOP values measured by GAT correlate with those measured by DCT.

The relationship between measurement method and corneal structure on apparent intraocular pressure in glaucoma and ocular hypertension

To analyse the relationship between measured intraocular pressure (IOP) and central corneal thickness (CCT), corneal hysteresis (CH) and corneal resistance factor (CRF) in ocular hypertension (OHT), primary open-angle (POAG) and normal tension glaucoma (NTG) eyes using multiple tonometry devices. Right eyes of patients diagnosed with OHT (n=47), normal tension glaucoma (n=17) and POAG (n=50) were assessed. IOP was measured in random order with four devices: Goldmann applanation tonometry (GAT); Pascal dynamic contour tonometer (DCT); Reichert ocular response analyser (ORA); and Tono-Pen XL. CCT was then measured using a hand-held ultrasonic pachymeter. CH and CRF were derived from the air pressure to corneal reflectance relationship of the ORA data. Compared to the GAT, the Tonopen and ORA Goldmann equivalent (IOPg) and corneal compensated (IOPcc) measured higher IOP readings (F=19.351, p<0.001), particularly in NTG (F=12.604, p<0.001). DCT was closest to Goldmann IOP and had the lowest variance. CCT was significantly different (F=8.305, p<0.001) between the 3 conditions as was CH (F=6.854, p=0.002) and CRF (F=19.653, p<0.001). IOPcc measures were not affected by CCT. The DCT was generally not affected by corneal biomechanical factors. This study suggests that as the true pressure of the eye cannot be determined non-invasively, measurements from any tonometer should be interpreted with care, particularly when alterations in the corneal tissue are suspected.

Rate of Visual Field Progression in Eyes With Optic Disc Hemorrhages in the Ocular Hypertension Treatment Study

Objective To compare rates of visual field (VF) change in ocular hypertensive eyes with and without optic disc hemorrhage (DH). Methods Ocular Hypertension Treatment Study subjects (minimum 10 reliable VF tests, followed up ≥5 years) were included. Trend analyses of VF sequences over time of DH and non-DH eyes were assessed by regression of mean deviation (MDR) and pointwise linear regression (PLR). The main outcome measures were rates of VF change in DH and non-DH eyes. Results Two thousand six hundred seven eyes (1378 participants) were included. The mean (SD) number of VF tests per eye was 23.7 (4.9) spanning a mean (SD) of 12.2 (2.0) years. At least 1 DH was detected in 187 eyes (7.2%), of which 52 eyes had recurrent DH. Mean deviation rate of change was significantly worse in DH compared with non-DH eyes (mean [SD], −0.17 [0.27] vs −0.07 [0.19] dB/y; P Conclusions Eyes with DH had more rapid VF deterioration when assessed by global (MDR) or local (PLR) trend analysis than eyes without DH. Eyes with recurrent DH had similar rates of global VF change (MDR) when compared with eyes with a single DH but reached criteria for rapid PLR change more often. Intraocular pressure reduction in ocular hypertension reduces the risk of developing a DH. Ocular hypertensive eyes with DH should be monitored closely and may need more aggressive therapy. Trial Registration clinicaltrials.gov Identifier: NC0125

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To compare rates of visual field (VF) change in ocular hypertensive eyes with and without optic dischemorrhage (DH). Ocular Hypertension Treatment Study subjects(minimum 10 reliable VF tests, followed up 5 years) were included. Trend analyses of VF sequences over time of DH and non-DH eyes were assessed by regression of mean deviation (MDR) and pointwise linear regression (PLR). The main outcome measures were rates of VF change in DH and non-DH eyes. Two thousand six hundred seven eyes (1378 participants) were included. The mean (SD) number of VF tests per eye was 23.7 (4.9) spanning a mean (SD) of 12.2 (2.0) years. At least 1 DH was detected in 187 eyes(7.2%), of which 52 eyes had recurrent DH. Mean deviation rate of change was significantly worse in DH compared with non-DH eyes (mean [SD], −0.17 [0.27] vs−0.07 [0.19] dB/y; P<.01). Significant PLR progression occurred more frequently in eyes with DH (odds ratio,3.6; P<.01), which increased when 2 or more DHs were present (odds ratio, 4.2; P=.01). Eyes initially randomized to treatment were less likely to have a DH during follow-up. Eyes with DH had more rapid VF deterioration when assessed by global (MDR) or local (PLR)trend analysis than eyes without DH. Eyes with recurrent DH had similar rates of global VF change (MDR)when compared with eyes with a single DH but reached criteria for rapid PLR change more often. Intraocular pressure reduction in ocular hypertension reduces the risk of developing a DH. Ocular hypertensive eyes with DH should be monitored closely and may need more aggressive therapy. clinicaltrials.gov Identifier: NCT00000125

Assessment of Corneal Biomechanical Properties in Normal Tension Glaucoma and Comparison With Open-angle Glaucoma, Ocular Hypertension, and Normal Eyes

To assess the biomechanical properties of corneas in patients with normal tension glaucoma (NTG) and to compare them with those of patients with primary open-angle glaucoma (POAG), ocular hypertension (OHT), and normal controls (N). Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann intraocular pressure (IOPg), and corneal compensated IOP (IOPcc) were obtained using an ocular response analyzer for 28 eyes in 14 patients with NTG, 75 eyes in 38 patients with chronic POAG, 53 eyes of 27 patients with OHT, and 44 eyes of 22 N controls. IOP using Goldmann applanation tonometry (IOPGA) and ultrasonic central corneal thickness (CCT) were also measured for each eye. Analysis of variance test was used for statistical analysis. CH was significantly lower in the NTG group (9.88±2.02 mm Hg) compared with the N group (11.05±1.53 mm Hg; P<0.01). CRF was significantly lower in the NTG group (9.5±1.89 mm Hg) compared with the POAG group (11.15±2.35 mm Hg; P<0.01) and to the N group (11.00±1.75 mm Hg; P<0.01). CCT was not considered significantly different between the 4 groups. However, IOPcc was found to be significantly lower in NTG group compared with the POAG group and OHT group (P<0.001). NTG was associated with significantly lower CRF than chronic POAG and N patients. CH and CRF could be a useful tool in early diagnosis of NTG.

Pattern ERG and RNFL thickness in hypertensive eyes with normal blue-yellow visual field

To evaluate the transient pattern electroretinogram (t-PERG) and the retinal nerve fiber layer (RNFL) thickness in eyes with ocular hypertension (OH) and normal short-wavelength automated perimetry (SWAP). In 26 patients with bilateral OH with normal SWAP, and in 26 age and sex matched healthy controls, t-PERG recording and RNFL thickness measurement were performed. Mean deviation (MD) and pattern standard deviation (PSD) of a reliable full threshold 24-2 SWAP were considered. RNFL thickness was determined by OCT3. Monocular PERG were recorded by using a black and white checkerboard pattern (check size 0.9°, contrast 100 %, mean luminance 80 cd/m2) generated on a monitor and reversed in contrast (four reversals per second, 2 Hz) at a distance of 70 cm. Patients had optimal correction at viewing distance; no mydriatic or miotic eye drops were used. Silver/silver chloride skin electrodes were placed over the lower eyelids in the stimulated eye (active electrode) and in the patched eye (reference electrode); ground electrode was in the Fpz scalp. Peak-to peak amplitude of P50 (N35-P50) and N95 (P50-N95) waves, and implicit time of P50, were considered. Compared to controls, in OH eyes, a reduction of N35-P50 amplitude (2.86 ± 1.49 vs. 3.77 ± 1.08 microvolts, -24.1 %, t-test p = 0.015), of average RNFL thickness (88 ± 11 vs. 96 ± 10 μm, -9.5 %, t-test p = 0.002), and of RNFL thickness in superior (p = 0.015) and inferior quadrant (p < 0.001), were found. Multivariate analysis showed that in OH eyes, N35-P50 amplitude was inversely related to intraocular pressure (IOP) (p = 0.001); no correlation was found between N35-P50 amplitude and MD, PSD, CCT or RNFL thickness. In OH eyes, both PERG and RNFL thickness changes occur in hypertensive eyes with undamaged SWAP; the correlation of PERG amplitude with IOP, but not with RNFL thickness, suggests that such PERG changes are an effect of the IOP on retinal ganglion cells, rather than a sign of their loss.

IOP lowering effect of low intensity ultrasound on experimental glaucoma model using microbeads in rats

AbstractPurpose To report the intraocular pressure (IOP) lowering effect of low intensity ultrasound (LIUS) on eyes of ocular hypertensive rats.Methods Continuous radiation of LIUS on ocular hypertensive eyes induced by unilateral microbeads injection was performed. A round plane ultrasound transducer operating at a frequency of 1MHz was utilized to deliver a sonication of 240mW/cm2 in acoustic intensity. LIUS was treated on both eyes of rats (n=5) simultaneously and the IOP measurements of treated group were compared with those of untreated group (n=5).Results The mean IOPs of LIUS‐treated eyes and un‐treated eyes were 9.4 ± 0.55 mmHg and 9.6 ± 0.55 mmHg, respectively at baseline. After an intracameral injection of microbeads, IOPs were reached to 18.6 ± 4.037 mmHg and 22.8 ± 3.493 mmHg (p=0.580) at 3 days after microbeads injection. Then the IOPs were decreased by 39.47 % and 9.68 % at 1 day after a single sonication.Conclusion These results showed that continuous low intensity ultrasound suppresses the IOP elevation in experimental glaucoma model using microbeads injection into anterior chamber. By the reason of its non‐invasiveness and repeatability, LIUS could be an alternative method for glaucoma treatment in near future.