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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ERGs (electroretinogram) of dense mature cataractous eyes were compared with those of the fellow eyes with good visual acuity in 22 senile patients who showed normal preoperative ERG. The mean amplitudes of the a- and b-waves were slightly reduced in the cataractous eyes as compared to those of the fellow eyes, but the difference was not significant. The light-absorbing effect of the cataract based on the a- and b-wave amplitudes was 0.5 log units. Another group of 13 eyes with senile mature cataract showed abnormal preoperative ERG. Chorioretinal atrophy was the most common cause of the subnormal ERG. Postoperative visual acuity was lower in cataractous eyes with subnormal ERGs than in eyes with normal ERGs. Despite the fact that it does not always reflect the macular function and the visual pathway, the ERG still remains a reliable guide in evaluating the visual prognosis before cataract surgery.
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PMID:Quantitative evaluation of electroretinogram before cataract surgery. 262 79

A case is described in which the patient had been struck by lightning, with involvement of one eye and the visual pathways. Ophthalmological examination revealed a posterior capsule cataract in the right eye and peripheral constriction of the visual field of the left eye, although central vision in the left eye was not affected. The peak latency of the pattern reversal-evoked potentials in the left eye was longer and their amplitude lower. The skin ERG was normal. The CT scan revealed a thickening of the left optic nerve. The importance of electrophysiological and CT scan examination in the diagnosis and etiology of abnormalities caused in the eye by lightning is emphasized.
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PMID:[Optic nerve neuropathy following a lightning accident--electrophysiologic and computerized tomography findings]. 357 57

The toxic effects on rabbit eyes of 2 intravitreally injected fibrinolytic substances at different concentrations were studied with repeated clinical observations and registrations of the DC ERG. The fellow, control eye of each animal was injected with saline. Urokinase (Ukidan, Serono) (13 rabbits) initially produced aqueous flare (64%), iris hyperaemia (36%) vitreous opacities (27%) and small retinal haemorrhages (18%). 2-3 months after the injection cataract (50%), vitreous opacities (25%) and retinal changes (13%) were observed. The highest dose (10 000 Ploug units) caused reduction of the ERG b-wave, as a sign of retinal toxicity. Tissue activator (D-44, Centre d'immunologie et de biologie Pierre Fabre) (10 rabbits) produced marked aqueous flare (initially 100%, after 2 weeks 50%) and pronounced, persistent vitreous opacities (25% after 2-3 months). At the late stage corneal blood vessels (38%) and cataract (38%) were also found, but only in eyes injected with the highest dose (1000 units), which was retinotoxic as judged by the ERG (reduced b- and c-waves).
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PMID:Toxic ocular effects of two fibrinolytic drugs. An experimental electroretinographic study on albino rabbits. 634 35

The effects of visual field changes and ocular hypertension on visual evoked potentials were investigated by photopic ERG and by luminance and pattern-reversal EPs on 116 glaucomatous and on 7 normal eyes. The problem was approached by way of four investigations: Firstly, which nerve structures are affected by glaucoma and how do visual field defects caused by glaucoma influence the EP? The results show a functional diminution of all intraocular nerve structures in which the prelaminary part of the optic nerve is most affected. The EPs, especially the pattern-reversal EPs, are markedly diminished if the visual field defects extend inside the 10 degree boundary. Differences in the visual field defects of both eyes and the course of the sickness can be well observed by the EPs. Secondly, which preoperative prognosis for visual acuity produced by the EP can be given to patients who have a dense cataract in addition to glaucoma? A postoperative improvement of the visual acuity can be expected if the L-EPs are within the standard deviation. If the EP is distinctly diminished and does not increase with increasing stimulus intensity, then there is no hope for an improvement of the visual acuity after the operation. Thirdly, does a decrease of intraocular pressure in chronic and acute glaucoma influence the EP? In acute glaucoma with pressure levels of 50 mmHg or more, and sometimes in chronic glaucoma with pressure levels of about 30 mmHg, an increase of the amplitude of the EP and an improvement of the visual field could be noticed after pressure regulation. Fourthly, what is the behaviour of the EP in normal and glaucomatous eyes at experimentally elevated intraocular pressure? The amplitudes of the ERG components show a gradual decrease in normal as well as in glaucomatous eyes when intraocular pressure is increased and are maintained when intraocular pressure reaches systolic ophthalmic blood pressure. On the other hand, the EPs show a strong decrease in amplitude when intraocular pressure exceeds the mean ophthalmic blood pressure, particularly in the case of glaucomatous eyes.
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PMID:The effects of visual field changes and ocular hypertension on the visual evoked potential. 695 70

Clinical and electrophysiological records are of particular importance in tapetoretinal degenerations. In the absence of therapy they are at least a help in establishing a differential diagnosis and a scale of progression of the disease; these in turn lead to improved counselling possibilities. In a retrospective study of 289 patients a great variability of ophthalmoscopic, functional and electrophysiologic findings was observed. The variability was seen both in individual examination of patients of all ages at one point in time, and in genetic pattern, penetrance and expressivity, Criteria for autosomal recessive inheritance were established in 21.3% and for simplex cases in 51.6%. Constriction the retinal vessels was the most reliable ophthalmoscopic finding, seen in 74% of the cases of RP. In 68% of the cases the onset of symptoms started before the age of 20. In 62% of RP patients the visual acuity remained 0.4 or better up to the sixth decade of life. In 40% of the cases the dark adaptation threshold was normal or raised only by up to 1.5 log units. The ERG was absent in 70%, residual in 10%, and subnormal in 20% of RP patients. The residual and subnormal ERGs showed predominantly rod involvement in 77%, equal rod and cone involvement in 17%, and chiefly cone involvement in 6% of 95 cases. The most common associated abnormalities were found to be cataract in 33% and myopia in 22%. (Detailed data on impairment of visual fields and on ERG analysis are published elsewhere: Gurewitsch, K., G. Niemeyer: Rod/cone separation by electroretinography, fundus changes and visual fields in retinitis pigmentosa. In: Techniques in Clinical Electrophysiology of Vision. G. Niemeyer and C. Huber (eds). Docum. Ophthal. Proc. Ser., in press).
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PMID:[Variability of visual acuity, dark adaptation and electroretinogram in retinitis pigmentosa]. 710 86

A cataract changes pattern-evoked contrast responses to a mostly unknown extent by a blurred retinal image. Pattern electroretinograms (P-ERG), evoked by a reversing checkerboard pattern, were measured (a) in 12 healthy volunteers with a cataract simulated by Bangerter foils; (b) pre- and postoperatively in 44 cataract eyes without retinal damage; and (c) in 13 healthy contralateral eyes. Slight media opacities (visual acuity 1.0 to 0.8) already diminished the amplitudes of the pattern ERG significantly, whereas the latencies did not react significantly. This can be explained by a decrease more in contrast than in luminance. Postoperatively, the amplitudes continued to increase during the first 10 weeks, when the visual acuity remained stable. The postoperative amplitudes did not reach the amplitudes of comparable healthy contralateral eyes. It is recommended that eyes be checked for cataracts before an interpretation is made.
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PMID:[Effect of cataracts on contrast pattern reversal stimuli exemplified by the pattern electroretinogram]. 896 48

The effects of two commercially available intraocular irrigating solutions, Opeguard MA and BSS Plus, were studied during extracapsular cataract surgery in 45 eyes of 35 patients. After irrigation and aspiration of the residual cortex with Opeguard MA or BSS-Plus, the ERG amplitude increased, respectively, to 111.2+/-5.8% and 109.5+/-5.3% of the preirrigation amplitudes. The increases reached significance (116.9+/-7.0% and 115.7+/-6.5%; both P < .05) at the end of surgery compared with pre-irrigation ERG amplitudes. After irrigation with Opeguard MA or BSS-Plus, the ERG peak times were significantly prolonged to 103.9+/-0.8% and 104.2+/-1.2%, respectively, of the preirrigation peak times (both P < .01). The ERG peak times significantly shortened to 101.5+/-0.9% and 101.3+/-1.22%, respectively, at the end of surgery (P < .001 and P < .05) compared with just after irrigation. Although we have previously shown that Opeguard MA maintained amplitude and implicit time of 30 Hz flicker ERG during vitrectomy better than BSS-Plus, there were no statistically significant differences between the changes in amplitude and peak time with Opeguard MA and BSS-Plus during cataract surgery. We speculate that a drop in the retinal temperature during irrigation and aspiration in the anterior chamber and an increase in the photopic ERG amplitude during light adaptation with the operating microscope caused these ERG changes.
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PMID:Effect of intraocular irrigating solution on flicker electroretinogram during cataract surgery in human eye. 974 67

Immunocytochemical analysis of the laminin alpha-2 (merosin) chain in the muscle of patients with Classic Congenital Muscular Dystrophy (Cl-CMD) differentiates the types of the disease associated with a merosin deficit from those that are merosin positive. Patients with Central Nervous System involvement in merosin negative Cl-CMD always present alterations of the white matter at RMI, but usually these are not clinically significant. While ocular malformations (microphthalmia, alterations of the anterior chamber, of the retina, or of the angle and cataract) and damage to the Central Nervous System are described in some subtypes of CMD (Muscle Eye Brain disease, Walker Warburg Syndrome), ocular involvement and retino-cortical conduction in merosin negative Cl-CMD are not well known. This study reports on four patients affected by merosin negative Cl-CMD. All these patients presented important alterations of the white matter associated with ventricular enlargement and, in one case, with pachygyria and micropolygyria. Refraction, visual acuity, ocular motility, anterior segment and fundus were examined. ERG Maximal, Cone and Rod response, VEP transient pattern reversal was carried out as well. Significant alterations at the standard ophthalmologic examination or of the electroretinogram responses were not registered while, in all cases, important modifications in retino cortical conduction (reduction in amplitude, increase in latency, reduction in amplitude on the lateral derivations) were observed, demonstrating involvement of the optic pathway at different levels during the course of this disease.
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PMID:Alterations of the retino-cortical conduction in patients affected by classical congenital muscular dystrophy (CI-CMD) with merosin deficiency. 1094 99

The aim of this review is to introduce the reader to the world of clinical veterinary electroretinography. An important indication for ERG recordings in the dog is the early diagnosis of progressive retinal atrophy, an inherited form of photoreceptor degeneration, analogous to retinitis pigmentosa in humans. In most of the 20 canine breeds in which the disease has been studied electrophysiologically, changes in the ERG appear long before the appearance of clinical signs. This early diagnosis is a vital tool in efforts to eradicate the disease through preventive breeding. Pre-operative screening of canine cataract patients is another common indication for electroretinography in the dog. The ERG is also used to diagnose inherited and nutritional photoreceptor degenerations in the cat, and retinal disorders in a number of other animal species. The abundance of animal species (and breeds) seen by the veterinary ophthalmologist lends additional importance to the problem of a harmonized ERG recording protocol. The European College of Veterinary Ophthalmologists has set up a special committee to formulate guidelines for such a protocol. International meetings and wetlabs are also being organized as part of an effort to improve the quality of electrophysiological diagnosis that veterinary ophthalmologists provide their patients.
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PMID:Clinical electrophysiology in veterinary ophthalmology--the past, present and future. 1194 8

Hereditary vitreoretinopathies are potentially blinding inherited disorders characterized by an abnormal-appearing vitreous gel and associated retinal changes. Four of these disorders, Stickler's syndrome, Wagner's disease, erosive vitreoretinopathy, and Goldmann-Favre syndrome, exhibit marked syneresis of the vitreous gel. Erosive vitreoretinopathy has associated retinal pigment epithelial changes, poor night vision, visual field defects, and abnormal electroretinographic findings; symptoms not found in Stickler's syndrome. A 36-year-old man with progressive visual loss and a visual field defect had no systemic disease. His vitreous cavity was liquefied. Vitreous strands and a cataract were found in both eyes. Pronounced RPE degeneration was found superotemporally in both eyes and a bullous rhegmatogenous retinal detachment in the left eye accompanied two retinal tears. His visual field showed a ring scotoma in both eyes and the ERG finding was abnormal. We report one case of erosive vitreoretinopathy with retinal pigment epithelial changes, rhegmatogenous retinal detachment, visual field defects, abnormal electroretinographic findings, marked vitreous syneresis and cataract. These symptoms are distinct from previously described entities.
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PMID:A case of erosive vitreoretinopathy. 1216 18


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