摘要:

Abstract.Inward and outward movement of fluorescein across the human blood‐retina barrier was studied in five healthy volunteers, using a differential spectrofluorometry method that eliminates the contribution of fluorescein glucuronide to the total fluorescence in the vitreous and in plasma. The inward permeability across the blood‐retina barrier, which is presumed to be passive, and the diffusion coefficient in the vitreous for fluorescein was calculated from data obtained 1 h after intravenous injection of fluorescein. The rate of elimination of fluorescein from the vitreous across the blood‐retina barrier was estimated from data obtained 7 to 12 h after injection of fluorescein. The calculations were based upon the free plasma fluorescein decay curve and the preretinal fluorescein gradient in the vitreous. The mean inward permeability of fluorescein was 1.39 times 10−7cm/sec (range: 0.70‐2.06 times 10−7cm/sec), whereas the mean outward permeability was 1.51 times 10−5cm/sec (range: 1.14‐1.73 times 10−5cm/sec). We have thus found that the movement of fluorescein across the blood‐retina barrier is highly asymmetric, the outward transport being more than 100 times faster than the passive inward leakage. This could indicate the presence of an active pumping mechanism in the blood‐retina barrier, responsible for fluorescein transport in the direction from the

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04675.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.The effect of probenecid on the outward transport of fluorescein from vitreous to blood was studied in 13 insulin‐dependent diabetic patients with background retinopathy in a randomised double‐masked placebo controlled cross‐over study. Fluorescein and fluorescein glucuronide were separated in the vitreous and in plasma by differential spectrofluorometry. The data for fluorescein were analysed using a simplified mathematical model of the eye. The inward permeability was estimated from data obtained 1 h after injection and the outward transport from data obtained 7 h after injection. During placebo treatment the mean inward permeability was 3.75 times 10−7cm/sec and the mean outward permeability was 2.25 times 10−5cm/sec. During probenecid treatment the mean inward permeability was 3.34 times 10−7cm/sec and the mean outward permeability was 1.44 times 10−5cm/sec. Thus, we found no significant change in inward permeability (p = 0.5879), whereas a significant decrease of 36% was found in the outward permeability of fluorescein (p = 0.0171). The demonstration that the outward permeability, which is more than 100‐fold higher than the inward permeability in the healthy eye, is significantly decreased by probenecid, demonstrates that active transport is involved in movement of fluorescein across the blood‐retina barrier from the vitre

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04676.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.We compared neurosensorial visual function by psychophysical tests (macular recovery time and contrast sensitivity) in two well matched groups of young Type 1 (insulin‐dependent) diabetic patients with micro‐and normoalbuminuria, respectively. The patients had normal visual acuity (≥ 1.0) and either no retinopathy or non‐proliferative retinopathy. Thirty patients with microalbuminuria (albumin excretion ≥ 15 μg/min in a least two out of three timed overnight urine samples) were matched (age, diabetes duration, mean one‐year HbA1c, gender) with normoalbuminuric (n = 27) patients. Retinopathy (50° colour fundus photography) was assessed by counting microaneurysms and hemorrhages as ‘red spots’. Contrast sensitivity was examined for the spatial frequencies of 1.5, 3, 6, 12 and 18 cycles per degree (cpd). Macular recovery time (nyctometry) refers to the time‐related (2 min) ability of the retina to regain visual acuity following exposure to bright light (photostress). Contrast sensitivity score was reduced in patients with microalbuminuria compared to those without; 18 cpd (mean and 95% confidence intervals): [4.2 (3.8‐4.7) vs 5.0 (4.6‐5.4), p = 0.03]. Macular recovery performance was not significantly reduced: [21.0 arbitrary units (17.5–24.6) vs 26.0 (22.6–30.7), p = 0.12]. We conclude that impaired contrast sensitivity independent of background retinopathy is shown in a group of young Type 1 (insulin‐dependent) diabetic patients with low‐grade microalbuminuria compared to a group of

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04677.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.In a population‐based cross‐sectional study of insulin‐dependent diabetes mellitus, 42 children ‐ with a median age of 11 years (range 7–15 years) and a median duration of diabetes of 4 years (range 1–12 years) ‐ underwent an ophthalmological and a biochemical examination (HbAlc). None of the children had visual loss due to diabetes, and only 4.8% had mild, non‐proliferative retinopathy. Using cycloplegic refractioning, we found low degree myopia (less than −2D) in 12% of the patients, whereas non‐mydriatic measurements increased the frequency of myopia to 29%. We therefore recommend the use of cycloplegia in refractive evaluations o

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04678.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Visual prognosis is a crucial theme in the councelling of individuals affected by a progressive retinal dystrophy. Unfortunately prognostic predictions are hampered by large interindividual differences in disease courses even within well defined nosological entities. Ten patients from 8 families affected by choroideremia were studied. The clinical signs in our patients were rather uniform. Deterioration of the peripheral visual fields typically began in the second decade of life, and progressed during the following one or two decades. Esterman transformation of peripheral visual field measurements was chosen as the best single indicator of visual impairment. Noticeable age differences in residual visual fields among patients were demonstrated. The age difference between the mildest and the severest cases amounted to 25 years. One of the expectations of the exploration of disease genes, is the potential predictive value of mutation identification with regard to phenotypic variability. Different presumed causative mutations were identified. Nevertheless, all the mutations are predicted to cause premature stops during translation, resulting in a non‐functional or missing protein. Consequently, the observed age variation in the photopic visual field degradation must be due to still unrecognized factors, either constitutional and/or environmenta

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04679.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.A reliable bedside test for screening of visual field defects is a valuable tool in the examination of patients with a putative disease affecting the sensory visual pathways. Conventional methods such as Donders' confrontation method, counting fingers in the visual field periphery, ot two‐hand confrontation are not sufficiently sensitive to detect minor but nevertheless serious visual field defects. More sensitive methods requiring only simple tools are also described. In this study, a test card with four red squares surrounding a fixation target, a black dot, with a total test area of about 11 times 12.5° at a distance of 30 cm, was designed for testing experience of red colour saturation in four quadrants, red square test. The Goldmann visual field was used as reference. 125 consecutive patients with pituitary adenoma (159 eyes), cranio‐pharyngeoma (9 eyes), meningeoma (21 eyes), vascular hemisphere lesion (40 eyes), hemisphere tumour (10 eyes) and hemisphere abscess (2 eyes) were examined. The Goldmann visual field and red square test were pathological in pituitary adenomas in 35%, in craniopharyngeomas in 44%, in meningeomas in 52% and in hemisphere tumours or abscess in 100% of the eyes. Among these, no false‐normal or false‐pathological tests were found. However, in vascular hemisphere disease the corresponding figures were Goldmann visual field 90% and red square test 85%. The 5% difference (4 eyes) was due to Goldmann visual field defects strictly peripheral to the central 15°. These defects were easily diagnosed with two‐hand confrontation and were due to anterior occipital lobe infarction. The red square test is a sensitive and quick method for visual field screening. And, hitherto it seems to be the most simple of reliable visual field screening bedside test

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04680.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.To investigate the distribution and elimination of carteolol in pigmented rabbits,14C‐carteolol eye drops were instilled singly and repeatedly. After single ocular instillation, the radioactivity in the iris and ciliary body reached maximum levels at 24 h. The elimination rate of pigmented tissues decreased at a half‐life of approximately 15 days. The concentration of radioacitivy in pigmented tissues increased markedly by repeating the ocular instillation and reached a maximum after the 8oth repeated instillation. The concentration of radioactivity at 1 h after 80th instillation was 63.7 times that in the iris, 61.1 times that in the ciliary body and 17.2 times that in the retina&choroid after single instillation. No accumulation of radioactivity was found in other ocular tiss

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04681.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.The precise behavior of the anterior chamber depth after intraocular lens implantation is uncertain. To ascertain variations in the values at different time points, we measured the anterior chamber depth in 38 eyes that had undergone extracapsular cataract extraction and posterior chamber intraocular lens implantation. Measurements were performed by ultrasonography preoperatively and at 2 days, 1 and 2 weeks postoperatively, and at 1‐month intervals thereafter up to 10 months (mean follow‐up period, 9 months). Results showed that two peaks of the anterior chamber depth occurred at 1 week and 3 months postoperatively (means ±sd, 3.54 ± 0.39 and 3.59 ± 0.43 mm, respectively). A significant difference was found between the values measured preoperatively (3.29 ± 0.57) and at 2 days postoperatively (3.33 ± 0.39) and the 1‐week postoperative value (p<0.05, using the one‐way analysis of variance test). A significant difference also was found between the preoperative and the monthly measurements and the 3‐month postoperative measurement (p<0.05). We also calculated the refractive error and found that during the second postoperative week, the refraction tended toward higher myopia that became more hyperopic 3 months postoperatively. This anterior chamber depth variation may cause variations in vision after cataract surgery with intraocular len

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04682.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Ocular effects and plasma concentrations of cyclopentolate were studied in 8 volunteers after eyedrop application with two methods. While recumbent two 30 μl drops of 1% cyclopentolate hydrochloride were instilled in randomized order either conventionally to the lower conjunctival cul‐de‐sac or on the inner canthus with eyes closed, followed by immediate opening of the eyes. The cycloplegic responses as well as the extent and time of maximal mydriasis did not differ significantly between the two methods. None of the parameters describing the systemic absorption of the drug differed between the treatment groups. Conventionally applied drops caused slightly longer subjective discomfort. Instilling eyedrops on the inner canthus with eyes closed is an alternative method to deliver ocular cyclopentolate with similar efficacy and safety as the conventional technique. This method could be useful especially when treating non‐cooperative ch

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04683.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.A preliminary series of endonasal dacryocystorhinostomy was carried out on 12 patients with nasolacrimal obstruction using a recently developed combined CO2‐Nd: YAG laser that was guided by a fiberoptic light pipe inserted into the lacrimal sac through lacrimal canaliculi. The lacrimal passages were stented using silicone tubing that was kept in place for 6 months postoperatively. At an average follow‐up time of 14.3 months the success rate was 83%. The advantages of the operation include a relatively short operation time, quick rehabilitation, absence of a skin wound, good hemostasis, and preservation of canthal anat

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1994.tb04684.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY