A Laser-induced Mouse Model of Chronic Ocular Hypertension to Characterize Visual Defects

Glaucoma, frequently associated with elevated intraocular pressure (IOP), is one of the leading causes of blindness. We sought to establish a mouse model of ocular hypertension to mimic human high-tension glaucoma. Here laser illumination is applied to the corneal limbus to photocoagulate the aqueous outflow, inducing angle closure. The changes of IOP are monitored using a rebound tonometer before and after the laser treatment. An optomotor behavioral test is used to measure corresponding changes in visual capacity. The representative result from one mouse which developed sustained IOP elevation after laser illumination is shown. A decreased visual acuity and contrast sensitivity is observed in this ocular hypertensive mouse. Together, our study introduces a valuable model system to investigate neuronal degeneration and the underlying molecular mechanisms in glaucomatous mice.     

兔先天性青光眼网络膜血管改变

目的　研究青光眼对视网膜脉络膜血液循环的影响。方法　选24月龄、体重3.5～4kg的先天性青光眼大耳白兔5只(7只眼),选10只同龄大耳白兔作为对照组。另选10只2月龄、体重2kg大耳白兔前房内灌注生理盐水制成急性高眼压模型。对三组兔进行眼底照像、闪光视诱发电位(FVEP)检查,观察视网膜脉络膜血管形态和FVEP的变化。对人工急性高眼压组还进行了闪光视网膜电流图(FERG)检查。结果　先天性青光眼组与同龄对照组相比视网膜脉络膜末梢血管网明显减少;人工急性高眼压组眼压升高后首先使视网膜脉络膜末梢血管网灌流不足,随着眼压的继续升高脉络膜大血管变细,末梢血管网灌流不足加重,眼压极度升高时脉络膜大血管血流中断。同龄正常对照组的FVEP的主波P100潜伏期是(83±9)ms,先天性青光眼组则为(112±14)ms,差异有非常显著意义(P＜0.01);人工急性高眼压组高眼压前为(69±5)ms,眼压60～80mm　Hg时延长为(81±7)ms,眼压在100～130mmHg时FVEP波形低平,近似直线;眼压恢复正常后2hFVEP的P100潜伏期为(82±8)ms。人工急性高眼压前后FERG变化显著。结论　青光眼可以影响视网膜脉络膜血液循环;可使FVEP、FERG发生变化。     

两种手术方式治疗原发性闭角型青光眼疗效比较

目的:探讨治疗原发性闭角型青光眼二种手术方式的适应症和初步临床疗效观察。方法:拟订手术适应症,对临床收治的42例48眼原发性闭角型青光眼进行手术处理:单纯抗青光眼手术--小梁切除术(Trabeculectomy,Trab)、青白联合手术--超声乳化白内障吸除联合小梁切除+人工晶体植入术(Phacotrabeculectomy+IOL,PhacoTrab+IOL)。比较不同适应症下二种手术方式初步的临床疗效。包括术前术后眼压情况、前房深度、眼轴长度的变化。随访时间平均1个月。结果均经统计学处理。结果:原发性闭角型青光眼患者术后眼压有显著改变,有统计学差异,Trab组手术后平均(10.92±1.74)mmHg,Phaco Trab+IOL组手术后平均(10.86±1.73)mmHg。术后眼压明显降低(t检验,P值<0.001),Trab组和Phaco Trab+IOL组两组间术后眼压无显著差异(t检验,P值>0.05)。Trab组手术前后前房深度无统计学差异(t检验,P值>0.05),Phaco Trab+IOL组手术前后前房深度有统计学差异(t检验,P值均<0.001)。术前分别为(1.74±0.16)mm、(1.72±0.16)mm,术后分别为(1.74±0.17)mm、(2.06±0.14)mm。Trab组及Phaco Trab+IOL组手术前后眼轴长度无统计学差异(t检验,P值>0.05)。结论:青-白联合手术可以改善前房深度,明显降低眼压,不同手术方式适合不同的病人情况,但要注意适应症的选择。利用A超检查可快速、有效、准确地观察眼前节结构,有助于早期进行手术。     

The effects of cigarette smoking on intraocular pressure and arterial blood pressure of normotensive young Nigerian male adults.

This study was designed to determine the effects of cigarette Smoking on intra ocular pressure and arterial blood pressure of normotensive young male adults. Fifty male students (who met the screening conditions and devoid of obvious ocular pathology and systemic diseases and non-smokers) had their intra ocular pressure (IOP) measured with a schiotz tonometer and blood pressure(BP) measured with standard syphgmomanometer respectively prior to smoking of two sticks of cigarette each day for one month and thereafter. The result showed a significant [P < 0.01] effect on the intra ocular pressure with a mean control of 37.76 +/- 0.98 for both eyes and test of 41.93 +/-0.98. Cigarette smoking increased the blood pressure from mean control of 197.24 +/-0.88 to 208.46 +/-0.82. The increase of both intra ocular pressure and arterial blood pressure was due to nicotine, the principal constituent of cigarette. It is recommended that health care workers should check regularly the IOP and BP of their cigarette smoking patients for early diagnoses of ocular hypertension (glaucoma) and hypertension.     

The Short-Term Effects of Exercise on Intraocular Pressure,Choroidal Thickness and Axial Length

Purpose

To explore ocular changes in healthy people after exercise.

Methods

Twenty five volunteers underwent exercise for 15 minutes on a treadmill. Measurements of choroidal thickness, intraocular pressure (IOP), ocular biometry, and blood pressure were taken before and after exercise. Enhanced Depth Imaging optical coherence tomography (EDI-OCT) was used to measure choroidal thickness at the fovea. Intraocular pressure (IOP) was measured by Goldmann applanation tonometry. Ocular biometric measures were collected using A scan ultrasound. Blood pressure was measured concurrently with the acquisition of the scans.

Results

Twenty five volunteers (25 eyes) with a mean age of 25.44±3.25 years were measured. There was a significant increase in systolic and diastolic pressure after exercise (P<0.05). The IOP showed a significant decrease after exercise (P<0.05). However there was no significant difference in the mean choroidal thickness, ocular axial length, anterior chamber depth, lens thickness, or vitreous length before and after exercise measurements (P>0.05).

Conclusion

There was a significant decrease in IOP from exercise without a change in choroidal thickness and ocular biometric measures. IOP and choroidal thickness were not correlated, suggesting that the IOP decrease from exercise is not due to changes in choridal thickness.     

超声乳化手术治疗慢性闭角型青光眼合并白内障的临床疗效分析

目的:探讨超声乳化手术治疗慢性闭角型青光眼合并白内障的临床效果。方法:慢性闭角型青光眼合并白内障64例(64眼)根据治疗方法的不同分为治疗组与对照组各32例,对照组采用传统小梁切除手术,治疗组采用超声乳化手术。结果:(1)两组术前视力对比无明显差异,治疗后视力情况都明显改善,同时组间对比有明显差异(P0.05)。(2)两组术前眼压比较无显著性差异,术后两组组间与组内对比都有明显差异(P0.05)。(3)两组术前前房深度比较无显著性差异,治疗后都有明显上升(P0.05),同时组间对比差异明显(P0.05)。(4)两组患者术中与术后都无严重并发症发生。结论:对于慢性闭角型青光眼合并白内障患者行超声乳化手术具备加深前房、控制眼压、提高视力的作用,同时安全性好,可作为标准治疗选择。     

DBA/2J Mice Are Susceptible to Diabetic Nephropathy and Diabetic Exacerbation of IOP Elevation

Some pathological manifestations of diabetes in the eye include retinopathy, cataracts and elevated intraocular pressure (IOP). Loss of retinal ganglion cells (RGCs) in non-proliferative stages of diabetic retinopathy and small increases in IOP in diabetic patients has raised the possibility that diabetes affects the development and progression of ocular hypertension and glaucoma. The Ins2^Akita mutation is known to cause diabetes and retinopathy on a C57BL/6J (B6) background by as early as 3 months of age. Here, the impact of the Akita mutation on glaucoma was assessed using DBA/2J (D2) mice, a widely used mouse model of ocular hypertension induced glaucoma. In D2.Ins2^Akita/+ mice, the contribution of diabetes to vascular permeability, IOP elevation, RGC loss, and glaucoma development was assessed. D2.Ins2^Akita/+ mice developed a severe diabetic nephropathy and early mortality between 6–8 months of age. This agrees with previous reports showing that the D2 background is more susceptible to diabetes than the B6 background. In addition, D2.Ins2^Akita/+ mice had vascular leakage, astrocyte reactivity and a significant increase in IOP. However no RGC loss and no anterograde axonal transport dysfunction were found at 8.5 months of age. Therefore, our data show that despite severe diabetes and an increased IOP compared to controls, RGCs do not lose axon transport or degenerate. This may be due to a DBA/2J-specific genetic modifier(s) that could provide novel and important avenues for developing new therapies for diabetic retinopathy and possibly glaucoma.     

马来酸噻吗洛尔联合拉坦前列腺素治疗高眼压型开角型青光眼的效果

目的:探讨马来酸噻吗洛尔联合拉坦前列腺素治疗高眼压型开角型青光眼的临床效果。方法:选取高眼压型开角型青光眼患者210例,随机分为治疗组和对照组,每组各105例。对照组患者给予马来酸噻吗洛尔治疗,治疗组患者给予马来酸噻吗洛尔联合拉坦前列腺素治疗。观察并比较两组患者治疗前后视力改善情况,眼压、视乳头杯盘比值变化情况,眼结膜充血、眼内干涩、角膜点状浸润以及一过性视觉模糊等不良反应的发生情况等。结果:治疗组患者视力改善率为85.7%,对照组为71.4%,治疗组高于对照组,差异具有统计学意义(P0.05);治疗后两组患者眼压、视乳头杯盘比值均明显下降,且治疗组明显低于对照组,差异具有统计学意义(P0.05)。治疗组患者眼结膜充血、眼内干涩、角膜点状浸润以及一过性视觉模糊等不良反应明显低于对照组,差异具有统计学意义(P0.05)。结论:马来酸噻吗洛尔联合拉坦前列腺素治疗高眼压型开角型青光眼能够改善患者视力水平,值得临床推广应用。此外,我们分析其作用可能与降低视乳头杯盘比值有关。     

Up-regulated Endogenous Erythropoietin/Erythropoietin Receptor System and Exogenous Erythropoietin Rescue Retinal Ganglion Cells after Chronic Ocular Hypertension

Aims Recent studies have showed that erythropoietin (EPO) is a neuroprotectant for central nerve system neurons in addition to being a hematopoietic cytokine in response to hypoxia. In this study, we investigate the role of the EPO/EPO receptor (EPOR) system in the rat retina after ocular hypertension injury that mimics glaucoma. Methods Elevated intraocular pressure was induced by laser coagulation of the episcleral and limbal veins. Expression of EPO and EPOR in the normal and glaucomous retinas was investigated by immunohistochemistry and Western blot. To examine the effects of endogenous EPO on the survival of retinal ganglion cells (RGCs) subjected to hypertensive injury, soluble EPOR was directly injected into the vitreous body. Recombinant human EPO was both intravitreally and systemically administrated to study the effect of exogenous EPO on the survival of RGCs after ocular hypertension injury. Results Immunohistochemistry studies identified Müller cells as the main source of EPO in the normal retina. Expression of EPO and EPOR proteins was increased significantly 2 weeks after ocular hypertension. RGCs, amacrine and bipolar cells all demonstrated an increased expression of EPOR after ocular hypertension. Neutralization of endogenous EPO with soluble EPOR exacerbated ocular hypertensive injury, suggesting a role of the EPO/EPOR system in the survival of RGCs after injury. Similarly, topical and systemic administration of recombinant human EPO rescues RGCs after chronic ocular hypertension. Conclusions These results indicate that an endogenous EPO/EPOR system participates in intrinsic recovery mechanisms after retina injury and RGCs might be rescued by exogenous administration of EPO.     

Effects of intravitreous sodium hydrosulfide on intraocular pressure and retinopathy in ocular hypertensive rats

We investigated the possible neuroprotectant and intraocular pressure (IOP) lowering effects of intravitreous injection of sodium hydrosulfide (NaSH) in a rodent model of experimental glaucoma. Glaucoma currently is treated by controlling IOP using medications and/or surgery. These methods are not entirely adequate for all patients. We divided 24 rats into three groups. For the control group, the right eye was treated with intravitreous saline. For the glaucoma group, ocular hypertension was induced by photocoagulating three episcleral veins and the limbal plexus of the right eye using an argon laser, then saline was injected into the vitreous of these eyes during the third week. For the NaSH group, rats were treated with intravenous NaSH 3 weeks after photocoagulation. IOP was measured each week during the 6 week experimental period. Coagulating the episcleral veins rapidly increased the IOP of rat eyes. Intravitreous injection of NaSH significantly reduced IOP. Intravitreous NaSH prevented degeneration of the retina and decreased the number of apoptotic cells. Intravitreous NaSH appeared to reduce IOP and to prevent IOP induced retinopathy in rats.     

Rescue of Retinal Function by BDNF in a Mouse Model of Glaucoma

Vision loss in glaucoma is caused by progressive dysfunction of retinal ganglion cells (RGCs) and optic nerve atrophy. Here, we investigated the effectiveness of BDNF treatment to preserve vision in a glaucoma experimental model. As an established experimental model, we used the DBA/2J mouse, which develops chronic intraocular pressure (IOP) elevation that mimics primary open-angle glaucoma (POAG). IOP was measured at different ages in DBA/2J mice. Visual function was monitored using the steady-state Pattern Electroretinogram (P-ERG) and visual cortical evoked potentials (VEP). RGC alterations were assessed using Brn3 immunolabeling, and confocal microscope analysis. Human recombinant BDNF was dissolved in physiological solution (0.9% NaCl); the effects of repeated intravitreal injections and topical eye BDNF applications were independently evaluated in DBA/2J mice with ocular hypertension. BDNF level was measured in retinal homogenate by ELISA and western blot. We found a progressive decline of P-ERG and VEP responses in DBA/2J mice between 4 and 7 months of age, in relationship with the development of ocular hypertension and the reduction of Brn3 immunopositive RGCs. Conversely, repeated intravitreal injections (BDNF concentration = 2 µg/µl, volume = 1 µl, for each injection; 1 injection every four days, three injections over two weeks) and topical eye application of BDNF eye-drops (12 µg/µl, 5 µl eye-drop every 48 h for two weeks) were able to rescue visual responses in 7 month DBA/2J mice. In particular, BDNF topical eye treatment recovered P-ERG and VEP impairment increasing the number of Brn3 immunopositive RGCs. We showed that BDNF effects were independent of IOP reduction. Thus, topical eye treatment with BDNF represents a promisingly safe and feasible strategy to preserve visual function and diminish RGC vulnerability to ocular hypertension.     

Pregnenolone sulfate decreases intraocular pressure and changes expression of sigma receptor in a model of chronic ocular hypertension

Sigma receptors are Ca²⁺-sensitive, ligand-operated receptor chaperones at the mitochondrion-associated endoplasmic reticulum membrane. This study describes the effect of the sigma receptor 1 agonist pregnenolone sulfate on intraocular pressure (IOP) and sigma receptor 1 expression in rat retinas after chronic ocular hypertension. Chronic ocular hypertension was induced by occlusion of episcleral veins. Retinal histological sections were obtained to determine inner plexiform layer thickness and the number of cell bodies in the ganglion cell layer. Sigma receptor expression in rat retinas was analyzed by RT-PCR and Western blotting. Cauterization caused IOP to increase >73%, and the pressure was maintained for 2 months. A time-dependent loss of ganglion cells and retinal thickness occurred at elevated IOP. High IOP decreased sigma receptor 1 expression during the first week, but expression was increased at 8 weeks. Injected pregnenolone significantly decreased IOP, prevented ganglion cell loss, protected inner plexiform layer thickness, and increased sigma receptor 1 expression in episcleral vein-cauterized rats. Sigma receptors appear to be neuroprotective and potential targets for glaucoma therapeutics.     

Effect of Age-Stiffening Tissues and Intraocular Pressure on Optic Nerve Damages

Age-stiffening of ocular tissues is statistically linked to glaucoma in the elderly. In this study, the effects of age-stiffening on the lamina cribrosa, the primary site of glaucomatous nerve damages, were modeled using computational finite element analysis. We showed that glaucomatous nerve damages and peripheral vision loss behavior can be phenomenologically modeled by shear-based damage criterion. Using this damage criterion, the potential vision loss for 30 years old with mild hypertension of 25mmHg intraocular pressure (IOP) was estimated to be 4%. When the IOP was elevated to 35mmHg, the potential vision loss rose to 45%; and age-stiffening from 35 to 60 years old increased the potential vision loss to 52%. These results showed that while IOP plays a central role in glaucomatous damages, age-stiffening facilitates glaucomatous damages and may be the principal factor that resulted in a higher rate of glaucoma in the elderly than the general population.     

Endogenous ocular lipids as potential modulators of intraocular pressure

Elevated intraocular pressure (IOP) is a risk factor in glaucoma, a group of irreversible blinding diseases. Endogenous lipids may be involved in regulation of IOP homeostasis. We present comparative fold analysis of phospholipids and sphingolipids of aqueous humour and trabecular meshwork from human control vs primary open-angle glaucoma and mouse control (normotensive) vs ocular hypertensive state. The fold analysis in control vs disease state was based on ratiometric mass spectrometric data for above classes of lipids. We standardized in vitro assays for rapid characterization of lipids undergoing significant diminishment in disease state. Evaluation of lipids using in vitro assays helped select a finite number of lipids that may potentially expand cellular interstitial space embedded in an artificial matrix or increase fluid flow across a layer of cells. These assays reduced a number of lipids for initial evaluation using a mouse model, DBA/2J with spontaneous IOP elevation. These lipids were then used in other mouse models for confirmation of IOP lowering potential of a few lipids that were found promising in previous assessments. Our results provide selected lipid molecules that can be pursued for further evaluation and studies that may provide insight into their function.     

Nocturnal Headache-Hypertension Syndrome: A Chronobiologic Disorder

The study of blood pressure (BP) monitoring in essential hypertensive patients recurrently suffering from nocturnal headache revealed a rhythmic elevation of sphygmomanometric values during the night. Such a finding was not detected in essential hypertensive patients suffering from occasional headache. The nocturnal elevation of BP was seen to be paralleled by the circadian peak of heart rate, suggesting that the disorder is a systemic phenomenon. Importantly, the headache episodes were seen to disappear after antihypertensive therapy that was adjusted to lower the nocturnal increase of BP. The therapeutic results suggested that the nocturnal headache was dependent on the phasic elevation of BP. The beneficial effects further suggested that the nocturnal headache and the nocturnal elevation of BP may represent a particular syndrome with a cause-effect relationship. The term “nocturnal headache-hypertension syndrome” is proposed.     

Pathophysiology of Glaucoma and Continuous Measurements of Intraocular Pressure

Glaucoma is a leading cause of visual impairment and blindness worldwide. The main risk factor for glaucoma is an elevated intraocular pressure (IOP), which is also the only currently treatable risk factor. Despite its importance, our understanding of IOP is incomplete and our ability to measure IOP is limited. IOP is known to undergo both random fluctuations as well as variations following a circadian pattern. In humans, IOP is highest at night and lower during the daytime, largely due to changes in body position, although other factors appear to contribute. In rabbits, IOP is also highest at night and lower during the day, likely due to circadian variations in sympathetic nervous system activity. Random and circadian IOP variations may be important to glaucoma pathogenesis, independent of the diurnal IOP level. However, due to limitations with current IOP measurement technology, clinical practice typically involves only a few IOP measurements per year. As well, current technology does not allow 24-hour monitoring of pressure without the use of sleep laboratories or hospital admission. Two strategies for automating IOP measurement are temporary (non-invasive) monitoring and permanent (implantable) monitoring. Efforts at developing devices to allow continuous IOP monitoring have occurred for over 40 years without producing a clinical device. Current technological progress would seem to suggest that such devices are possible at this time, and a review of previous attempts provides guidelines for their development.     

A new approach to antiglaucoma drugs: carbonic anhydrase inhibitors with or without NO donating moieties. Mechanism of action and preliminary pharmacology

The clinically used sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor dorzolamide (DRZ), a new sulfonamide CA inhibitor also incorporating NO-donating moieties, NCX250, and isosorbide mononitrate (ISMN) (an NO-donating compound with no CA inhibitory properties) were investigated for their intraocular pressure (IOP) lowering effects in rabbits with carbomer-induced glaucoma. NCX250 was more effective than DRZ or ISMN on lowering IOP, increasing ocular hemodynamics, decreasing the inflammatory processes and ocular apoptosis in this animal model of glaucoma. NO participate to the regulation of IOP in glaucoma, having also antiapoptotic and anti-inflammatory effects. The ophthalmic artery, both systolic and diastolic velocities, were significantly reduced in NCX250-treated eyes in comparison to DRZ treated ones, suggesting thus a beneficial effect of NCX250 on the blood supply to the optic nerve. Combining CA inhibition with NO-donating moieties in the same compound offers an excellent approach for the management of glaucoma.     

Impact of a Glaucoma Severity Index on Results of Trabectome Surgery: Larger Pressure Reduction in More Severe Glaucoma

Purpose

To stratify outcomes of trabectome-mediated ab interno trabeculectomy (AIT) by glaucoma severity using a simple and clinically useful glaucoma index. Based on prior data of trabectome after failed trabeculectomy, we hypothesized that more severe glaucoma might have a relatively more reduced facility compared to mild glaucoma and respond with a larger IOP reduction to trabecular meshwork ablation.

Methods

Patients with primary open angle glaucoma who had undergone AIT without any other same session surgery and without any second eye surgery during the following 12 months were analyzed. Eyes of patients that had less than 12 months follow up or were diagnosed with neovascular glaucoma were excluded. A glaucoma index (GI) was created to capture glaucoma severity based on visual field, number of preoperative medications, and preoperative IOP. Visual field (VF) was separated into 3 categories: mild, moderate, and advanced (assigned 1, 2, and 3 points, respectively). Preoperative number of medications (meds) was divided into 4 categories: ≤1, 2, 3 or ≥4, and assigned with a value of 1 to 4. Baseline IOP (IOP) was divided into 3 categories: <20 mmHg, 20–29 mmHg, and greater than 30 mmHg and assigned with 1 to 3 points. GI was defined as IOP × meds × VF and separated into 4 groups: <6 (Group 1), 6–12 (Group 2), >12–18 (Group 3) and >18 (Group 4). Linear regression was used to determine if there was an association between GI group and IOP reduction after one year or age, gender, race, diagnosis, cup to disc (C/D) ratio, and Shaffer grade.

Results

Out of 1340 patients, 843 were included in the analysis. The GI group distribution was GI1 = 164, GI2 = 202, GI3 = 260, and GI4 = 216. Mean IOP reduction after one year was 4.0±5.4, 6.4±5.8, 9.0±7.6, 12.0±8.0 mmHg for GI groups 1 to 4, respectively. Linear regression showed that IOP reduction was associated with GI group after adjusting for age, gender, race, diagnosis, cup to disc ratio, and Shaffer grade. Each GI group increase of 1 was associated with incremental IOP reductions of 2.95±0.29 mmHg. Success rate at 12 months was 90%, 77%, 77%, and 71% for GI groups 1 to 4. The log-rank test suggested significant differences between GI groups.

Conclusion

A simple glaucoma index, GI, was created to capture glaucoma severity and a relative resistance to treatment. A higher GI was associated with a larger IOP reduction in trabectome surgery. This indicates that there is a role for AIT beyond mild glaucoma and ocular hypertension.     

Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle-closure glaucoma maps to chromosome 11.

Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye, as indicated by short axial length, high hyperopia (severe farsightedness), high lens/eye volume ratio, and a high incidence of angle-closure glaucoma. We performed clinical and genetic evaluations of members of a large family in which nanophthalmos is transmitted in an autosomal dominant manner. Ocular examinations of 22 affected family members revealed high hyperopia (range +7.25-+13.00 diopters; mean +9.88 diopters) and short axial length (range 17.55-19.28 mm; mean 18.13 mm). Twelve affected family members had angle-closure glaucoma or occludable anterior-chamber angles. Linkage analysis of a genome scan demonstrated highly significant evidence that nanophthalmos in this family is the result of a defect in a previously unidentified locus (NNO1) on chromosome 11. The gene was localized to a 14.7-cM interval between D11S905 and D11S987, with a maximum LOD score of 5. 92 at a recombination fraction of .00 for marker D11S903 and a multipoint maximum LOD score of 6.31 for marker D11S1313. NNO1 is the first human locus associated with nanophthalmos or with an angle-closure glaucoma phenotype, and the identification of the NNO1 locus is the first step toward the cloning of the gene. A cloned copy of the gene will enable examination of the relationship, if any, between nanophthalmos and less severe forms of hyperopia and between nanophthalmos and other conditions in which angle-closure glaucoma is a feature.     

Nocturnal Headache-Hypertension Syndrome: A Chronobiologic Disorder

The study of blood pressure (BP) monitoring in essential hypertensive patients recurrently suffering from nocturnal headache revealed a rhythmic elevation of sphygmomanometric values during the night. Such a finding was not detected in essential hypertensive patients suffering from occasional headache. The nocturnal elevation of BP was seen to be paralleled by the circadian peak of heart rate, suggesting that the disorder is a systemic phenomenon. Importantly, the headache episodes were seen to disappear after antihypertensive therapy that was adjusted to lower the nocturnal increase of BP. The therapeutic results suggested that the nocturnal headache was dependent on the phasic elevation of BP. The beneficial effects further suggested that the nocturnal headache and the nocturnal elevation of BP may represent a particular syndrome with a cause-effect relationship. The term “nocturnal headache-hypertension syndrome” is proposed.