Cone b-wave implicit time as an early predictor of rubeosis in central retinal vein occlusion

PURPOSE: To investigate the predictive value of the cone b-wave implicit time in the 30-Hz flicker electroretinogram for rubeosis in the acute phase of central retinal vein occlusion. METHODS: In a prospective study, 25 patients (25 eyes) with a central retinal vein occlusion of less than 14 days' duration were examined with electroretinography and followed up for a minimum of 18 months. RESULTS: The cone b-wave implicit time in the eyes that developed rubeosis (n = 11) was more than 37.1 milliseconds and in the eyes that did not develop rubeosis (n = 14), less than 37 milliseconds (P < .00001). CONCLUSION: The cone b-wave implicit time in the 30-Hz flicker electroretinogram is a good predictor of rubeosis at an early stage in eyes with central retinal vein occlusion.     

The effect of posterior vitreous detachment on the prognosis of branch retinal vein occlusion

PURPOSE: Two important complications causing visual loss in retinal branch vein occlusions are vitreous hemorrhage due to retinal neovascularization and persistent macular edema. The aim of this study was to identify the effect of the total posterior vitreous detachment on the disease prognosis. METHODS: Fifty-three patients with temporal branch vein obstruction were followed for eighteen months on average. The vitreous conditions of all patients were established, and the effect on persistent macular edema and retinal neovascularization development was statistically investigated. RESULTS: This prospective study shows that total posterior vitreous detachment has a clear preventive effect on both complications. CONCLUSION: Careful vitreous examinations of all patients with branch retinal vein occlusion give us important information about the prognosis and patient management.     

Factors that influence the increase in the electroretinogram 30-Hz flicker amplitude during light adaptation

Cone responses of the electroretinogramm (ERG) surprisingly increase during the first few minutes of light adaptation. In this study, especially the influence of rods and cones on this not yet understood phenomenon was examined. In 100 subjects a dark-adapted ERG was recorded. Afterward, two 30-Hz flicker recordings were performed, the first one after 1 min and the second one after 10 min of light adaptation. The relative flicker-amplitude increase was calculated. The influence of the ERG standard rod response and the 30-Hz flicker amplitude itself on the 30-Hz flicker-amplitude increase was estimated. The mean increase in the 30-Hz flicker amplitude was 51.7%. There was no significant correlation between the standard rod amplitude and the amplitude growth (r = 0.031). The correlation between the 30-Hz flicker amplitude itself and the increase in cone response was -0.426 (P < or = 0.001). The lower the cone flicker amplitude was after 1 min of light adaptation, the bigger was the amplitude increase. This might either be due to saturation or indicate that the flicker-amplitude increase is mainly related to cone function rather than being dependent on the rod-response amplitude.     

Spatial cone activity distribution in diseases of the posterior pole determined by multifocal electroretinography

Thirty patients with a reduced central vision due to diseases of the posterior pole were examined with the VERIS system developed by Sutter and Tran (Vis Res 1992;32:433-446) to characterize the topography of electroretinographic (ERG) changes in comparison to the results in 30 normal volunteers. Diagnoses included Stargardt's macular dystrophy (SMD, n = 10), age-related macular degeneration (AMD, n = 5), cone dystrophy (CD, n = 5), central retinal vein occlusion (CRVO, n = 5), and autosomal dominant optic atrophy (ADOA, n = 5). The 61 local responses obtained from each subjects were grouped by eccentricity to form five concentric rings. The foveal ERG, originating from a central area of 2 degrees radius, was non-recordable or markedly diminished in all patients except those with optic atrophy, where amplitudes were found to be in the normal range. In patients with advanced stages of SMD, functional defects were larger and involved more peripheral areas than in patients with early stages of SMD or with AMD. A reduction of response amplitude even in the most peripheral ring (17-30.5 degrees eccentricity) was found in cone dystrophies and--moderately--in patients with advanced SMD and central retinal vein occlusion only. Prolonged implicit times were found in all but the patients in early stages of SMD and they were maximal in patients with CRVO. This study shows that the multifocal ERG (MFERG) can contribute to differential diagnosis of retinal diseases of the posterior pole especially in cases with a normal photopic Ganzfeld ERG.     

Study of aeroball injuries

PURPOSE: To evaluate the significance of refractive error in cases of branch retinal vein occlusion. METHODS: Of 354 patients with branch retinal vein occlusion who attended our clinic between 1989 and 1995, 75 patients with unilateral branch retinal vein occlusion were compared with an equal number of matched controls with similar inclusion and exclusion criteria. The spherical equivalents of the refractive errors of patients in both groups were compared using the chi-square test, student's t test, and multivariate logistic regression. RESULTS: Hypermetropia was present in 53 patients with branch retinal vein occlusion (70.7%) and in 33 control patients (44.0%; P = 0.0001). Myopia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 30 controls (40.0%; P = 0.0005). Emmetropia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 12 controls (16.0%; P = 0.820). The odds ratio of developing branch retinal vein occlusion among patients with hypermetropia was 3.42 (95% Confidence Interval [CI], 1.62-7.2; P = 0.001) when compared with patients with no hypermetropia and 5.3 (95% CI, 2.1-13.3; P = 0.0003) when compared with patients with myopia alone. CONCLUSION: Hypermetropia is significantly more common in patients with branch retinal vein occlusion than in the general population, whereas myopia is significantly less common in these patients.     

Evidence for photoreceptor changes in patients with diabetic retinopathy

PURPOSE: To determine whether the rod and cone photoreceptors are affected in patients with diabetic retinopathy. METHODS: Twelve patients with diabetes and varying levels of retinopathy and nine age-similar control observers participated in this study. Two-color (500 versus 650 nm) dark-adapted thresholds were measured as a function of retinal eccentricity. Full-field flash electroretinograms were obtained using brief, high-intensity flashes. Dark-adapted rod-isolated (Wratten 47B filter) and light-adapted cone-isolated (Wratten 26 filter) electroretinographic responses were measured as a function of flash intensity. The a-wave data were fitted with a model based on photopigment transduction to obtain values for the parameters of Rmax (the maximal response) and log S (sensitivity). Standard clinical 30-Hz flicker electroretinographic responses were also measured. RESULTS: Psychophysically measured dark-adapted thresholds were elevated primarily at eccentricities of 5 degrees and 10 degrees from the fovea. Analysis of rod and cone a-wave data showed that Rmax was normal in most of the patients, but log S was reduced. Analysis of b-wave and oscillatory potential parameters showed rod and cone postreceptoral abnormalities, including changes in the rod-isolated semisaturation constant (log k), cone-mediated 30-Hz flicker, and cone-isolated oscillatory potentials. The electrophysiological results were not significantly correlated with blood glucose or glycosylated hemoglobin level. CONCLUSIONS: The results provide evidence for rod and cone receptoral and postreceptoral deficits in patients with diabetic retinopathy. The photoreceptor changes are primarily in the log S (sensitivity) parameter and are attributed to transduction abnormalities.     

Menkes disease. New ocular and electroretinographic findings

OBJECTIVE: The authors describe new ocular and electroretinographic (ERG) features in Menkes disease. DESIGN: The study design is a case report. PARTICIPANTS: The authors studied two patients with Menkes disease. INTERVENTION: The authors performed complete ophthalmologic and ERG evaluations in both patients. MAIN OUTCOME MEASURES: The parameters used were slit-lamp biomicroscopy and ERG recordings. RESULTS: Aberrant lashes and anterior stromal hypoplasia of the iris are new findings, and profound delays in b-wave implicit time in well-developed photopic responses may be added as new ERG features. CONCLUSIONS: Patients with Menkes disease may have aberrant lashes, anterior stromal hypoplasia, and retinal degeneration.     

Retinal arteriovenous shunt at the arteriovenous crossing

OBJECTIVE: The purpose of the study was to demonstrate that the arteriovenous shunt at the arteriovenous crossing could occur in major retinal vascular diseases other than Takayasu disease. DESIGN: Clinical review of consecutive case series. PARTICIPANTS: The authors studied 1885 eyes with retinal vascular diseases such as diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, central retinal artery occlusion, Leber's miliary aneurysms, Eales disease, Beh?et disease, and systemic lupus erythematosus retinopathy. INTERVENTION: Fluorescein fundus angiography using a wide-field fundus camera (60 degrees) was performed. MAIN OUTCOME MEASURES: Dye transit from artery to vein through sequential angiography. RESULTS: The arteriovenous shunt at the arteriovenous crossing was found in 8 eyes with proliferative diabetic retinopathy, 27 eyes with branch retinal vein occlusion in the chronic stage, 2 eyes with central retinal vein occlusion, 2 eyes with central retinal artery occlusion, and 2 eyes with miliary aneurysms. The arteriovenous shunt was formed by a direct inflow from artery to vein, showing vasodilation and hyperpermeability, followed by obliteration peripheral to the shunts. The pattern of initial inflow was classified into axial flow and laminar flow, and the inflow became wider and more rapid in the advanced stage. CONCLUSIONS: These findings indicate that the arteriovenous shunt at the arteriovenous crossing is not a unique phenomenon in Takayasu disease but rather is a basic pattern of retinal vascular reaction pathologic states.     

Thrombin-antithrombin III complex in acute retinal vein occlusion

PURPOSE: To determine whether quantitative differences in systemic hypercoagulable state could be identified among patients with retinal vein occlusion at various sites of occlusion. METHODS: The value of thrombin-antithrombin III complex was determined in 57 patients with retinal vein occlusion within 1 month after the subjective onset of retinal vein occlusion and in 15 age-matched normal controls. RESULTS: Levels of log thrombin-antithrombin III complex were significantly higher in the patients with proximal retinal vein occlusion in which the occlusion site is at the optic disc (mean +/- SD, 0.493 +/- 0.389) than in those with distal retinal vein occlusion in which the occlusion site is away from the optic disc (0.312 +/- 0.150, P = .025) and in the normal controls (0.294 +/- 0.151, P = .020). There was no significant difference between the distal retinal vein occlusion and the normal controls (P = .720). More patients with proximal retinal vein occlusion showed elevated thrombin-antithrombin III complex values more than 3.9 ng/ml than those with distal retinal vein occlusion (8/29 vs 1/28, P = .025). Of nine patients showing an initial value of thrombin-antithrombin III complex of more than 3.9 ng/ml, repeated measurements were obtained in eight patients, who showed reduced value of thrombin-antithrombin III complex in the normal range in several months. CONCLUSIONS: A systemic hypercoagulable state, which could be demonstrated with the elevation of thrombin-antithrombin III complex value, may contribute more to the development of retinal vein occlusion with thrombus at or near the trunk of the central retinal vein than those with thrombus at branch veins away from the optic disc in the retina.     

Role of electroretinography in the prognosis of central retinal vein occlusion

The aim of the study is to evaluate the role of electroretinography in diagnosis of central retinal vein occlusion CRVO. There are two forms of this entity, each of them having a different prognosis. While haemorrhagic form has a better outcome, with fairly good prognosis for vision, ischaemic form usually develops many complications: macular oedema, neovascularisation of the retina or optic disk, neovascular glaucoma, and possible blindness. Three months after the onset, when oedema and retinal haemorrhages are usually resolved, it is possible to perform fundus fluorescein angiography (FFA) and make differentiation between the two forms of the disease. However, neovascular glaucoma may challenge the vision even before the diagnosis of ischaemic form becomes possible by observing the fundus or by performing FFA. Trying to foresee the course of the disease, and thus to help a patient with panretinal photocoagulation, we performed electroretinography (ERG) in each patient just after the onset of the disease. The prospective study included 40 patients with CROV which lasted less than three months and without any complication. Two parameters were examined: scotopic "b" wave and photopic b/a ration. By ERG action potentials from the retina after its stimulation with light, are recorded. Scotopic "b" wave generates in bipolar layer from Muller's and bipolar cells. Photopic b/a ratio is a ration of two waves, "b" and "a" in photopic conditions and is a good indicator of saturation of the retina with blood and oxygen. Visual acuity, applanation tonometry, examination of the fundus after dilatation of pupils with Sol. Mydriacili were performed in each patient. Each patient was examined by ERG in scotopic and photopic conditions. The results were as follows: Scotopic b wave per se could not indicate potential complications, while b/a ratio was a good predictor of possible complications when its value was less than 1.25. CONCLUSION: Electroretinography, which can be performed at any time after the onset of the disease may be a good indicator of retinal perfusion and oxygen saturation, by giving the ratio of b and a waves under photopic conditions. The status of Muller's cells and bipolar cells is reflected in the scotopic b wave. In a prospective study forty patients with CRVO of less than three months duration and without neovascularisation were studied with the use of ERG, both in scotopic and photopic conditions. Our results suggest that the b/a ratio may be a good predictor of the development of retinal, disk and iris neovascularisation by showing the degree of retinal ischaemia, while the scotopic b wave cannot be used for such evaluation. Predicting the new vessel development by ERG may save the useful vision and prevent a disastrous outcome, blinding and painful neovascular glaucoma by performing panretinal photocoagulation.     

Study on treatment of retinitis pigmentosa with traditional Chinese medicine by Flicker electroretinogram

Study on treatment of 54 patients (106 eyes) of retinitis pigmentosa (RP) with traditional Chinese medicine was conducted by using modified method of electroretinography. Results showed: (1) Flicker response of electroretinogram was the most sensitive-criterion in examination, it was more effective when combined with infrared spectrogram. (2) The 30 Hz flicker index, response time were improved after TCM therapy in different hereditary types of RP, the improvement was significant in patients with Yang-Deficiency of Spleen-Kidney Syndrome and those of autosomal dominant inheritance type (P < 0.01). (3) Decrease of phase angle (phi) under different frequency of flicker after treatment was also significant statistically. The results suggested that flicker responses, which represents mainly retinal cone activity of patients, could be improved to a certain extent by TCM treatment, even in those with advanced retinal degeneration. TCM treatment could also enhance the bioactivity of nerve network and therefore have a definite significance in retarding the progression of disease and keeping the central vision. The flicker ERG, especially its flicker index, is an effective, sensitive and useful parameter for detection of visual function in patient with retinitis pigmentosa.     

Pharmacokinetics of once-daily amikacin dosing in patients with cystic fibrosis

PURPOSE: To report the injection of tissue plasminogen activator into a retinal vein to treat central retinal vein occlusion. METHODS: An 81-year-old woman with visual loss of the right eye secondary to central retinal vein occlusion developed central retinal vein occlusion and visual loss in her left eye. Treatment of her left eye with topical ocular hypotensive medications, pentoxifylline, and laser chorioretinal anastomosis was without benefit. Thereafter, she underwent vitreoretinal surgery, including tissue plasminogen activator injection into a branch retinal vein of her left eye. RESULTS: The patient reported subjective improvement in the vision of her left eye. Ophthalmoscopic and fluorescein angiographic improvement were also noted. CONCLUSION: The feasibility of cannulating a retinal vein for treatment has been demonstrated.     

Degranulation of human basophils by picomolar concentrations of IL-3, IL-5, or granulocyte-macrophage colony-stimulating factor

PURPOSE: To determine capillary blood flow measurements in eyes with branch retinal vein occlusion using a scanning laser Doppler flowmeter. METHODS: Retinal capillary blood flow in branch retinal vein occlusion areas and corresponding ipsilateral nonbranch retinal vein occlusion areas, 11 equivalent areas of the contralateral fellow eye of 12 consecutive untreated branch retinal vein occlusion patients, and 16 eyes of 11 age-matched normal control subjects were measured with scanning laser Doppler flowmetry. A template consisting of eight squares, each with a field of 100 x 100 microm (10 x 10 pixel) with space interval of 500 microm equidistant horizontally and vertically was used to obtain blood flow measurements in all subjects. Mean blood volume, flow, and velocity were obtained by averaging the mean values measured in each field. We avoided measurement over large retinal vessels to prevent the aliasing artifact of blood cells from moving faster than the sampling frequency. RESULTS: Branch retinal vein occlusion areas have significantly decreased microvascular blood volume (P = .0009), flow (P = .02), and velocity (P = .016) compared with ipsilateral nonbranch retinal vein occlusion areas in the same eye. Branch retinal vein occlusion areas also have decreased blood volume (P = .001), flow (P = .0042), and velocity (P = .0044) compared with areas of contralateral fellow eyes of branch retinal vein occlusion subjects. Branch retinal vein occlusion areas have significantly decreased blood volume (P = .0012), flow (P = .008), and velocity (P = .02) compared with age-matched normal areas. CONCLUSION: Average retinal blood volume, flow, and velocity in areas of branch retinal vein occlusion are significantly lower than in healthy retinas. The ability to noninvasively measure hemodynamic changes in the retinal capillary bed may be relevant to development of new therapies for retinovascular disease.     

Iatrogenic central retinal vein occlusion and hyperviscosity associated with high-dose intravenous immunoglobulin administration

PURPOSE: To describe a patient with iatrogenically induced central retinal vein occlusions secondary to serum hyperviscosity from intravenous immunoglobulin administration. METHOD: Case report. RESULTS: The patient developed bilateral central retinal vein occlusions in association with high-dose intravenous immunoglobulins. The central retinal vein occlusions resolved when the immunoglobulins were withheld and serum hyperviscosity decreased. CONCLUSION: Administration of high-dose intravenous immunoglobulins can be associated with hyperviscosity syndrome manifested by central retinal vein occlusion.     

Ureteral replacement by jejunoplasty. New concepts, new techniques (author''s transl)

Whole-blood and plasma viscosity with haematological and biochemical investigations were measured in 44 patients with retinal vein occlusion. The patients were subdivided on the basis of fluorescein angiographic findings into: 1. Those with large areas of capillary non-perfusion. 2. Those with small areas of capillary non-perfusion. 3. Those with an intact capillary pattern. Capillary non-perfusion in retinal vein occlusion is associated with a higher morbidity owing to the complications of retinal neovascularization. Significantly higher values of whole-blood viscosity, packed cell volume, and yield stress have been found in patients with capillary non-perfusion than in those without. These differences may be of critical importance during the episode of retinal vein occlusion and suggest an aetiological factor in the development of capillary non-perfusion. Higher whole-blood and plasma viscosity values and plasma fibrinogen levels have also been shown in the whole retinal vein occlusion group compared with a control group of 30 individuals. These differences may be a factor in the development of retinal vein occlusion but their precise role is difficult to evaluate. Further biochemical investigations in the vein occlusion group supported the strong association with arterial disease and suggested a higher incidence of biochemical abnormalities in those patients with capillary non-perfusion.     

Regression of advanced refractory ovarian cancer treated with iodine-131-labeled anti-CEA monoclonal antibody

PURPOSE: To report a 24-year-old man with bilateral central retinal vein occlusions who had preceding episodes of prolonged transient monocular visual loss during which ophthalmoscopic findings were not suggestive of vein occlusion. METHOD: Case report. RESULT: Extensive hematologic studies for causes of vein occlusion were unremarkable with the exception of increased plasma homocysteine in the patient and in his asymptomatic father. CONCLUSIONS: Impending vein occlusion should be considered in the differential diagnosis of transient monocular visual loss regardless of ophthalmoscopic appearance, and hyperhomocystinemia should be considered as a possible cause of retinal vein occlusion.     

Spontaneous and traumatic vitreous hemorrhage

PURPOSE: The authors sought to provide relevant data regarding the demographic and clinical aspects of spontaneous and traumatic vitreous hemorrhages to guide clinicians in better delineating the expected etiologic patterns of these hemorrhages in an urban environment. METHODS: The records of 253 consecutive patients with newly diagnosed vitreous hemorrhage seen in a general eye clinic were selected for retrospective analysis. To minimize selection bias of a tertiary care center, patients who were referred to the clinic by outside ophthalmologists for vitreoretinal consultation or those with a history of recent intraocular surgery, postoperative complications, or loss to follow-up were excluded from study. Demographic, ocular, and general medical variables were tabulated for the 200 patients (230 eyes) who met our inclusion criteria. RESULTS: Fifty percent of the patients were black, 26% were white, 23% were Hispanic, and 1% was Oriental. The causes of vitreous hemorrhage were proliferative diabetic retinopathy (PDR) (35.2%), trauma (18.3%), retinal vein occlusion (7.4%), retinal tear without a detachment (7.0%), posterior vitreous detachment (6.5%), proliferative sickle retinopathy (5.7%), retinal tear with a detachment (4.8%), subretinal neovascularization from macular degeneration (2.2%), hypertensive retinopathy (1.7%), unknown (2.5%), and other causes (8.7%). Among black patients with spontaneous vitreous hemorrhage, sickle cell retinopathy and retinal vein occlusion were major causes, each accounting for more than 15% of the cases. Systemic hypertension was associated with vitreous hemorrhage from retinal vein occlusion. CONCLUSION: The authors propose that despite the wide array of causative factors of vitreous hemorrhage, the evaluation of demographic, ocular, and medical variables can significantly aid clinicians in identifying its etiologic patterns.     

Nodular cutaneous lupus mucinosis: report of a case and review of previously reported cases

OBJECTIVE: The study was designed for the analysis on data of 51 patients with macular branch retinal vein occlusion (McBRVO) and the comparison between them and 210 patients (214 eyes) with major branch retinal vein occlusion (MjBRVO). METHODS: Fluorescein angiography, ophthalmoscope and slit-lamp were used for the examination of the venous obstructive site and the locations of artery and vein. RESULTS: (1) The incidence of McBRVO was 19.5% (51/261) in branch retinal vein occlusion. (2) The site of occlusion: the incidence of McBRVO at supero-temporal branches was 72.5% (37/51) and the incidence of MjBRVO was 73.4% (157/214). (3) The involved branch at the first macular branch accounted for 39.6%, the second branch 58.3%, and the third branch 2.1%. The artery anterior to the vein at arteriovenous crossing at the obstructive site accounted for 93.0% in the McBRVO group and 95.0% in the MjBRVO group. (4) The complications and visual prognosis: The incidence of cystoid macular edema was 20.0% in McBRVO group and that was 28.5% in the MjBRVO group. No neovascularization was found in the McBRVO group, while 37.9% neovascular formation was found in the MjBRVO group. The visual acuity recovered to 0.5 or better was in 88.2% in the McBRVO group, while 57.0% in the MjBRVO group (P < 0.005). CONCLUSION: There are no significant differences in sex, age, laterality, pathogenesis as well as occlusion site between the McBRVO and MjBRVO groups, but the visual prognosis is better in the former than that in the latter group.     

Digital fluorescein angiography in follow-up of the clinical course in therapy of patients with central vein occlusion and cystoid macular edema

BACKGROUND: Fluorescein angiography with a scanning laser ophthalmoscope allows the quantification of morphologic and dynamic changes in the retina. In two patients with central retinal vein occlusion we monitored the progression of the cystoid macular edema (CME) and changes of microcirculation with a follow up of 4 to 6 months. MATERIALS AND METHODS: Two patients with central retinal vein occlusion and CME were examined by means of digital fluorescein angiography. Arteriovenous passage times and macular capillary blood velocities in combination with quantifications of the macular angioarchitecture and the extent of the CME were evaluated. RESULTS: Hemodilution therapy improved retinal circulation, whereas macular circulation and the severity of the CME remained unchanged. With persisting CME oral acetazolamid therapy was initiated. Oral Acetazolamide led to resorption of the cystoid edema in tandem with improved macular circulation. The capillary density was altered but remained unchanged over time. CONCLUSIONS: By means of digital analysis of fluorescein angiograms a detailed monitoring and retinal and macular dynamics, macular morphology is possible. In these two cases CME improved after Acetazolamide and moreover retinal circulation returned to normal conditions.     

Central retinal vein occlusion complicating systemic lupus erythematosus

Retinal lesions occur in 25 to 30% of patients with systemic lupus erythematosus (SLE). Visual loss, however, is rare. A patient who developed central retinal vein occlusion and blindness during the course of active SLE is described. The pertinent literature is reviewed with attention to possible pathophysiologic mechanisms.