Utilization of lacrimal urea assay in the monitoring of hemodialysis: conditions,limitations and lacrimal arginase characterization

The lacrimal urea content was found to be proportional to that of blood, which suggested its possible utilization in the monitoring of hemodialysis as a less invasive method. On the other hand, however, arginase activity was detected in tears, which may influence the urea content independently of blood urea concentration. The feasibility of using lacrimal urea measurement to replace blood urea measurement in the monitoring hemodialysis was also investigated. Blood and tear samples of 35 healthy persons and 43 renal patients undergoing hemodialysis were tested. Tear samples were collected on Schirmer paper strips. After elution the lacrimal urea content was measured by a colorimetric method. The determination of arginase activity was based on the release of urea and ornithine. The correlation between blood and lacrimal urea and arginase was studied by multivariate regression analysis. The lacrimal arginase isoenzyme pattern was investigated by native polyacrylamide gel electrophoresis and Western blotting. The effect of partially isoform-specific inhibitors was also studied. Blood urea levels in blood were significantly higher in the renal patients before dialysis than in the control patients (12.86 +/- 0.59 vs. 6.45 +/- 0.41 mM, p < 0.0001). Blood sera arginase activity was very low. Lacrimal arginase activity was significantly higher in tears than in sera (p < 0.0001 for each group). The tear/serum ratio of urea content was significantly different between controls and renal patients, particularly in postdialytic samples (1.89 +/- 0.07 vs. 3.49 +/- 0.31, p < 0.0001). The correlation between lacrimal and blood sera urea was best in controls (r = 0.89) and was better in predialytic (r = 0.75) than in postdialytic (r = 0.52) samples, depending on the level of arginase activity. In postdialytic samples a stronger correlation (r = 0.77) between tear urea and arginase was observed. Both arginase isoforms were detected in tears, but the extrahepatic (arginase II) isoenzyme was present in higher concentration. In conclusion, the determination of lacrimal urea level as a possible less invasive replacement for blood urea determination could only be utilized in the monitoring of hemodialysis if lacrimal arginase is also measured. Blood urea levels can be correctly determined by using equations, which take into account arginase activity. The accuracy of these equations was checked on a new patient population. Both arginase isoenzymes were observed in lacrimal samples.     

Intraocular pressure fluctuations during regular hemodialysis and ultrafiltration

The effect of hemodialysis and of ultrafiltration on intraocular pressure (IOP) was studied in 30 non glaucomatous patients (58 eyes) with chronic renal failure. IOP and serum osmolality were measured before and after dialysis and every hour during the procedure. IOP showed a slight but non-significant rise when measured after hemodialysis and a significant drop for ultrafiltration. Serum osmolality decreased significantly when measured after hemodialysis, but remained stable for ultrafiltration. The variations in IOP were found to be significantly correlated with changes in osmolality during hemodialysis.     

Results of cataract surgery in renal transplantation and hemodialysis patients

AIM: To compare the effect of cataract surgery in renal transplantation and hemodialysis patients.METHODS: We evaluated 51 eyes of 31 renal transplantation patients, 41 eyes of 29 hemodialysis patients and 45 eyes of 32 normal control patients who received phacoemulsification and intraocular lens (IOL) implantation from January, 2000 to August, 2014 in the Beijing Friendship Hospital. Each individual underwent a blood routine and a kidney function examination. Routine ophthalmologic examination included best-corrected visual acuity (BCVA), a slit-lamp examination to detect cataract type, determination of intraocular pressure, a corneal endothelial count, and fundus examination. All patients received phacoemulsification and an IOL implantation.CONCLUSION: This study showed that the PSC was more in the renal transplantation patients. BCVA was better and fundus lesions were less frequent in the renal transplantation group than in the hemodialysis group after cataract surgery. The multiple linear regression was showed that the Hb was positively correlated with postoperative BCVA, while Cr was negatively correlated with postoperative BCVA. These results may act as indicators in predicting visual acuity for the renal transplantation and hemodialysis patients.     

Calciphylaxis and bilateral optic neuropathy

A 51-year-old woman on hemodialysis for chronic renal failure complained of visual loss in her right eye. Right optic disc edema was observed on fundus examination. An arteritic optic neuropathy was suspected. However, a first biopsy did not reveal any inflammatory cells. Two months later, the patient experienced sudden visual loss in her left eye and presented with necrotic cutaneous lesions at the distal phalanges of several fingers of the right hand. Necrotic lesions also appeared on the inner aspect of the thighs. Biopsy of the cutaneous lesions revealed calcification in the wall of a small artery. A new biopsy of the temporal artery showed large calcium deposits in the artery's tunica media. The diagnosis of optic neuropathy secondary to calciphylaxis was made. A temporal artery biopsy should be repeated if the first one is inconclusive. An early diagnosis leading to appropriate treatment may help to prevent an irreversible loss of vision in these patients.     

Corneal disease in patients with chronic renal insufficiency undergoing hemodialysis

PURPOSE: To evaluate alterations of the corneal endothelium in patients undergoing hemodialysis for renal insufficiency. METHODS: Sixty-six patients undergoing hemodialysis received a complete ophthalmologic examination. The state of the endothelium was assessed using pachymetry and specular microscopy. The group of patients undergoing dialysis was divided according to the time of dialysis, aluminum, product of calcium and phosphate in blood, and parathyroid hormone to analyze the influence of these factors. The possible presence of iron and aluminum in the aqueous humor of patients who underwent and those who did not undergo hemodialysis was also estimated. RESULTS: Patients undergoing hemodialysis did not have significant corneal edema. Cell density was significantly lower in patients undergoing dialysis than in patients not undergoing dialysis; this reduction appeared to be associated with length of dialysis and was unrelated to serum aluminum and calcium levels. Patients undergoing dialysis did not have cell polymorphism or polymegethism, although there was a tendency toward increased polymegethism with length of dialysis. Aluminum and iron were not increased in the aqueous humor of patients undergoing dialysis. CONCLUSIONS: The alteration of the endothelium that we found is not related to the elements studied. It is possibly the result of another product dissolved in the anterior chamber or to the alterations of the anterior segment that these patients are known to have.     

Changes in the ocular fundus in patients with chronic kidney failure on regular dialysis therapy

Investigation of changes of the ocular fundus by ophthalmoscopy, coloured photography and fluoroangiography confirmed assumptions that the most frequent finding is hypertonic angiopathy and angiosclerosis. Hypertonic retinopathy and neuroretinopathy were recorded only in one quarter of the cases, most frequently during the initial years of dialysation treatment. The part played by a high blood pressure in chronic renal failure before and during dialyzation treatment is important. Under the influence of many metabolic changes in dialysed patients a general affection of the blood vessels and tissues of the retina, choroid and optic nerve develops. The appearance of the ocular fundus in the patient reminded of findings in subjects by two or more decades older and supported thus the theory of hastened ageing in chronic renal failure with regular dialysation treatment.     

Papilledema Associated with Dialysis Disequilibrium Syndrome

The purpose of this paper is to report a case of dialysis disequilibrium syndrome as an unusual cause of papilledema. A 38-year-old woman with type 1 diabetes mellitus presented with decreased visual acuity and bilateral optic nerve swelling associated with systemic signs and symptoms of dialysis disequilibrium syndrome. Repeated lumbar punctures revealed elevated intracranial pressures. She was placed on acetazolamide with some improvement in symptoms. After renal transplantation, the patient had complete resolution of headaches, nausea and the papilledema. Our conclusion is that patients with visual disturbance and focal neurological symptoms during and after hemodialysis should be suspected of having dialysis disequilibrium syndrome (DDS). DDS is thought to occur as a result of a rapid reduction in plasma osmolality during dialysis. As the shift of urea from cerebral spinal fluid (CSF) is delayed, the relative increase in CSF osmolality draws fluid into the brain. The ensuing cerebral edema is responsible for the characteristic neurological symptoms. We report the association of papilledema with this syndrome, and caution as to the possible concurrent risk of permanent visual impairment.     

Papilledema associated with dialysis disequilibrium syndrome

The purpose of this paper is to report a case of dialysis disequilibrium syndrome as an unusual cause of papilledema. A 38-year-old woman with type 1 diabetes mellitus presented with decreased visual acuity and bilateral optic nerve swelling associated with systemic signs and symptoms of dialysis disequilibrium syndrome. Repeated lumbar punctures revealed elevated intracranial pressures. She was placed on acetazolamide with some improvement in symptoms. After renal transplantation, the patient had complete resolution of headaches, nausea and the papilledema. Our conclusion is that patients with visual disturbance and focal neurological symptoms during and after hemodialysis should be suspected of having dialysis disequilibrium syndrome (DDS). DDS is thought to occur as a result of a rapid reduction in plasma osmolality during dialysis. As the shift of urea from cerebral spinal fluid (CSF) is delayed, the relative increase in CSF osmolality draws fluid into the brain. The ensuing cerebral edema is responsible for the characteristic neurological symptoms. We report the association of papilledema with this syndrome, and caution as to the possible concurrent risk of permanent visual impairment.     

Renal coloboma syndrome

OBJECTIVE: To characterize the ocular features of renal coloboma syndrome. DESIGN: Prospective, observational case series. PARTICIPANTS: Twelve patients referred by the pediatric nephrology clinic and the ophthalmic records of five additional patients. METHODS: For each patient, age at the time of examination, gender, renal function, and presence of a mutation in the PAX2 gene were noted. All patients underwent measurement of visual acuity and anterior and posterior segment examination with fundus photography. Goldmann visual fields were tested in four cases. MAIN OUTCOME MEASURES: Visual acuity, optic disc abnormalities, and mutation in the PAX2 gene. RESULTS: Mean age was 21.5 years. Renal failure was mild in 6 patients and severe in 11 patients. A mutation in the PAX2 gene was identified in nine patients, without correlation to the ocular phenotype. Ocular features could be divided into five groups: optic disc dysplasia limited to an unusual pattern of retinal vessels without functional consequence; optic disc pit with normal visual acuity and blind spot enlargement; large optic disc coloboma; large coloboma of the optic disc and adjacent retina; morning glory anomaly (these last three conditions were accompanied by poor visual acuity). Fundus abnormalities were symmetrical in most cases and unrelated to renal status. CONCLUSIONS: Ophthalmic and renal characteristics of the renal coloboma syndrome are highly variable. The need for dialysis or renal transplantation can occur early in life or several years later. A wide range of ocular abnormalities located in the posterior segment can be observed. Mild optic disc dysplasia or pit have no functional consequence and can be underdiagnosed. More severe colobomas or related abnormalities, such as morning glory anomaly, often lead to poor visual acuity. Molecular biology allows detection of the mutations in the PAX2 gene, but can be negative in approximately 50% of cases. The observation of an optic disc coloboma or related abnormality stimulates the ophthalmologist to propose simple nephrologic investigations to check for renal hypoplasia, a potentially life-threatening disease. Conversely, renal hypoplasia stimulates the nephrologist to ask for a fundus examination to confirm the diagnosis and check for complications such as retinal detachment.     

Changes in optic disc drusen. Demonstration by stereophotographs and electronic subtraction

As a part of more comprehensive examination of 180 patients with optic disc drusen, fundus photographs of 159 cases were evaluated. There were 70 patients whose optic discs were photographed two or more times during the years from 1967 to 1981. Four patients were selected to present the changes which can take place in optic discs with drusen and the alterations are demonstrated by autofluorescence pictures, stereophotographs, and electronic subtraction method.     

放射状视神经切开术治疗视网膜中央静脉 阻塞的初步观察

目的观察放射状视神经切开术（RON）治疗视网膜中央静脉阻塞（CRVO）的临床效果。方法回顾分析 5例经平坦部玻璃体途径行RON治疗的CRVO患者的临床资料。其中，2例患者手术前确诊为CRVO，手术前后分别进行视力、眼底照相、荧光素眼底血管造影（FFA）、彩色超声多谱勒（CDI）血流扫描、电脑视野及光相干断层扫描（OCT）等检查；3例患者因玻璃体积血接受手术治疗，手术中确诊为CRVO所致。5例均有明显黄斑水肿。对比观察患者手术前后视力、眼底检查及手术后眼底照相和OCT检查结果。手术后随访12个月。结果除1例患者视力下降外，其余4例患者视力均有不同程度提高。 眼底照相和（或）FFA、OCT检查显示手术后1个月时黄斑水肿均明显消退，手术后2个月时眼底出血基本吸收， 1例行视野检查者显示手术后视野改善。1例手术后出现玻璃体积血，2例手术中穿刺视盘时出血。结论RON可有助于CRVO患者改善患眼黄斑水肿，减少眼底出血，防止新生血管形成，并能一定程度地提高视力，对治疗CRVO具有一定可行性及临床价值。但尚需要较大规模、多中心的随机临床对照观察来进一步研究证实。(中华眼底病杂志,2005,21:6-9)     

Ocular changes in dialysis patients

The study analyzes the ocular aspects in patients receiving hemodialysis, in order to define the importance of the ophthalmological exam as prognosis and follow-up parameter. The prospective study includes 84 patients with renal insufficiency who received hemodialysis between 1994-1998. The ocular aspects and their connection with the dialysis and the basic disease are described and analyzed. The most important were the retinal vascular complications: hypertensive retinopathy, anterior optic ischaemic neuropathy, central retinal artery occlusion, diabetic retinopathy.     

Ocular findings in hemodialysis and following kidney transplantation in childhood and adolescence

Between August 1980 and January 1987, 23 patients undergoing treatment for chronic renal failure underwent eye examinations. Hemodialysis and subsequent kidney transplants were performed in 18 patients; in two patients a kidney transplant was performed alone, and in three others hemodialysis without transplant. The interval between dialysis and transplantation averaged 23.1 months, the mean follow-up after transplantation 20 months. Patients who underwent hemodialysis alone were followed up for periods of two, three and 85 months. The patients' ages when hemodialysis treatment was first instituted ranged from six to 17 years (average 11.8 years). The mean age at the time kidney transplants were performed was 13.6 years (ranging from one to 17 years). Seventeen patients had conjunctival and corneal infiltrations in the area of the palpebral fissure. In two cases infiltrations were confined to the conjunctiva. Four patients had no pathologic changes, in either the cornea or the conjunctiva. Slitlamp examination revealed subcapsular losses of lens transparency in eight patients; these losses were manifested by delicate punctiform and patchy configurations. In nine cases fundus ophthalmoscopy revealed constricted retinal arteries. Within the period of observation all but one of the patients had unchanged vision. The one exception (cystinosis) had reduced visual acuity due to an accumulation of crystalline inclusions in the cornea.     

慢性肾衰患者血液透析前后眼前段结构和眼压变化的量化分析

目的 探讨慢性肾衰患者血液透析（简称血透）前后前房角宽度（鼻侧、颞侧、上方、下方）、中央前房深度、晶状体厚度和眼压的变化,以及这些改变与患者血透过程中各项血液指标改变的关系.方法 回顾性系列病例研究.选取因慢性肾衰长期在浙江省人民医院进行血透治疗的35名患者（70眼）,分别在血透前及血透后测量眼压、眼部A超（品状体厚度）以及应用索维全景超声生物显微镜进行眼前段结构扫描（中央前房深度、小梁虹膜角、房角开放距离）.根据血透前的前房角镜检查分为窄角组及宽角组,并测量其血透前后的眼压.测量血透前后上述患者尿素氮、肌酐、血浆渗透压、白蛋白及脱水量.采用配对t检验对各项结果进行分析.结果 35名（70跟）慢性肾衰患者血透后的眼压较血透前升高（t=-3.389,P＜0.05）.血透后中央前房深度较血透前显著变浅（t=8.043,P＜0.01）.血透后眼鼻侧、颞侧、上方、下方的小梁虹膜角及房角开放距离均较血透前变小（小梁虹膜角：t＝4.637、8.893、3.575、3.436,房角开放距离：t=3.122、5.372、3.838、2.915,P均＜0.01）,晶状体厚度变厚（t＝-9.132,P＜0.01）.窄角组（14眼）血透后眼压显著增高（t＝-0.045,P＜0.01）,而宽角组（56眼）血透后跟压较血透前差异无统计学意义（t＝-9.515,P＞0.05）.血透后的血尿素氮、肌酐、血浆渗透压较血透前显著降低（t=16.075、13.676、113.063,P均＜0.01）,白蛋白较血透前增高（t＝-7.756,P＜0.01）.结论 由于血透治疗后液体顺渗透压梯度移动至眼内,慢性肾衰患者血透后前房深度较血透前变浅,前房角变窄,晶状体变厚,具有窄房角的患者血透后眼压显著增高.故建议对慢性肾衰患者在血透治疗前进行前房状态评估,并进行相应的处理.     

Tear urea nitrogen and creatinine levels in renal patients

Tear and blood urea nitrogen, creatinine, and glucose levels were quantitatively analyzed by an enzymatic method in 30 normal patients and in 10 patients with end stage renal disease. The tear and blood samples collected from the end stage renal patients before and after hemodialysis showed that the change in urea nitrogen and creatinine levels in the tears correlated with the change in blood urea nitrogen and creatinine. Tear samples may serve as an alternative, less invasive indicator of serum metabolites in renal patients.     

Ethambutol-induced optic neuropathy in renal disorder: a clinico-electrophysiological study

ObjectiveTo report the spectrum of ethambutol induced optic neuropathy in a group of renal patients with tuberculosis and the role of visual evoked response (VER) in evaluating this disorder.MethodsTwenty-three renal patients who were started on ethambutol as a part of anti-tubercular treatment for tuberculosis in India, were divided into 4 groups based on glomerular filtration rate (GFR): group 1—chronic kidney disease (CKD) with GFR < 10 mL/min; group 2—CKD with GFR 10-30 mL/min; group 3—GFR > 30 ≤ 60 mL/min; and group 4—GFR > 60 < 90 mL/min. Detailed clinical and electrophysiological (VER) examinations were carried out in all patients before starting the treatment with ethambutol and at a 3-month interval. Twenty healthy subjects formed the control group.ResultsEthambutol optic neuropathy developed in 6 (26%) patients with higher incidence (40%) in end-stage renal disease (group 1: CKD on dialysis). Vision was recovered in 4 cases on stoppage of ethambutol, whereas 2 patients (group 1: CKD on dialysis) developed bilateral severe irreversible visual loss and also had associated hepatic dysfunction. Three patients of ethambutol optic neuropathy showed increased latency in VER recording prior to visual loss and 1 patient showed demyelinating lesions in both optic nerves and optic radiation.ConclusionsEthambutol should be avoided in renal disorder patients in view of the high incidence of toxic optic neuropathy. Follow-up VER can detect sub-clinical ethambutol toxicity and would be useful for early diagnosis of optic neuropathy.     

埋藏性视盘玻璃疣OCT检查的临床表现

目的:探讨埋藏性视盘玻璃疣在OCT检查中的特异性表现。方法:回顾性分析经FFA和B超检查确诊为埋藏性视盘玻璃疣6例6眼患者的临床资料,对其OCT检查结果进行分析讨论。结果:患者6例在由视盘玻璃膜疣引起的视盘的高荧光区(造影检查结果),由OCT进行高分辨率成像,在视盘玻璃膜疣处均显示出特异的宽大的条带样的光反射增强的钙质沉积区,这些沉积区能投下阴影,并且之间显示出空隙样的结构。结论:埋藏性视盘玻璃疣在OCT检查时可以见到特异的影像学表现。所以,OCT可以作为诊断埋藏性视盘玻璃膜疣特异性较强的一种辅助检查,可提高埋藏性视盘玻璃膜疣的检出率。     

The impact of hemodialysis on retinal circulation

In patients with chronic renal failure undergoing hemodialysis were recorded and studied by various authors multiple eye damage with time. Studying the literature we conducted a study to assess the impact of intradialitic-interdialitic and postdialitic volemic game above the retinal circulation. By measuring diameters of retinal circulation after processing the digital fundus, we found that, 30 minutes after hemodialysis session takes a degree of dilatation of retinal vessels, permanent vascular insult that can be responsible for stroke and ischamic eye and coronary diseases of these patients.     

Effect of hemodialysis in retinal circulations

In patients with chronic renal failure undergoing hemodialysis were recorded and studied by various authors multiple eye damage with time. Studying the literature we conducted a study to assess the impact of intradialitic-interdialitic and postdialitic volemic game above the retinal circulation. By measuring diameters of retinal circulation after processing the digital fundus, we found that, 30 minutes after hemodialysis session takes a degree of dilatation of retinal vessels, permanent vascular insult that can be responsible for stroke and ischamic eye and coronary diseases of these patients.