1,536 research outputs found
Age effect on retina and optic disc normal values
Purpose:
To investigate retinal thickness and optic disc parameters by the Retinal Thickness Analyzer (RTA) glaucoma program in older normal subjects and to determine any age effect.
Methods:
Subjects over 40 years of age without any prior history of eye diseases were recruited. Only subjects completely normal on clinical ophthalmologic examination and on visual field testing by Humphrey Field Analyzer (HFA) using the SITA 24-2 program were included. A total of 74 eyes from 74 subjects with even age distribution over the decades were enrolled and underwent topographic measurements of the posterior pole and of the optic disc by RTA. The `glaucoma full' program in software version 4.11B was applied.
Results:
Mean patient age was 59.9 +/- 10.3 years with a range from 40 to 80 years. The only parameter intraocular pressure (IOP) correlated with was retinal posterior pole asymmetry (r=0.27, p=0.02). IOP itself increased significantly with age (r=0.341, p=0.003). Mean defect and pattern standard deviation of the HFA did not correlate with any of the retinal or optic disc measurements. Increasing age correlated significantly with some of the morphologic measurements of the RTA: decreasing perifoveal minimum thickness (r=-0.258, p=0.026), increased cup-to-disc area ratio (r=0.302, p=0.016) and increased cup area (r=0.338 p=0.007).
Conclusions:
An age effect exists for some of the retina and optic disc measurements obtained by the RTA. Copyright (C) 2005 S. Karger AG, Basel
Meta-Analysis of the Effect of Intravitreal Bevacizumab Versus Intravitreal Triamcinolone Acetonide in Central Retinal Vein Occlusion
published_or_final_versio
Glutathione accelerates sodium channel inactivation in excised rat axonal membrane patches
The effects of glutathione were studied on the gating behaviour of sodium channels in membrane patches of rat axons. Depolarizing pulses from –120 to –40 mV elicited sodium currents of up to 500 pA, indicating the simultaneous activation of up to 250 sodium channels. Inactivation of these channels in the excised, inside-out configuration was fitted by two time constants ( h1=0.81 ms; h2= 5.03 ms) and open time histograms at 0 mV revealed a biexponential distribution of channel openings ( short=0.28 ms; long=3.68 ms). Both, the slow time constant of inactivation and the long lasting single channel openings disappeared after addition of the reducing agent glutathione (2–5 mM) to the bathing solution. Sodium channels of excised patches with glutathione present on the cytoplasmatic face of the membrane had inactivation kinetics similar to channels recorded in the cell-attached configuration. These observations indicate that redox processes may contribute to the gating of axonal sodium channels
Intravitreal triamcinolone acetonide as an adjunct in the treatment of severe ocular toxoplasmosis
Universidade Federal de São Paulo, Vis Inst, São Paulo, BrazilUniversidade Federal de São Paulo, Vis Inst, São Paulo, BrazilWeb of Scienc
Scleral Thickness in Human Eyes
Purpose: To obtain information about scleral thickness in different ocular regions and its associations. Methods: The histomorphometric study included 238 human globes which had been enucleated because of choroidal melanomas or due to secondary angle-closure glaucoma. Using light microscopy, anterior-posterior pupil-optic nerve sections were measured. Results: In the non-axially elongated group (axial length #26 mm), scleral thickness decreased from the limbus (0.5060.11 mm) to the ora serrata (0.4360.14 mm) and the equator (0.4260.15 mm), and then increased to the midpoint between posterior pole and equator (0.6560.15 mm) and to the posterior pole (0.9460.18 mm), from where it decreased to the peri-optic nerve region (0.8660.21 mm) and finally the peripapillary scleral flange (0.3960.09 mm). Scleral thickness was significantly lower in the axially elongated group (axial length.26 mm) than in the non-axially elongated group for measurements taken at and posterior to the equator. Scleral thickness measurements of the posterior pole and of the peripapillary scleral flange were correlated with lamina cribrosa thickness measurements. Scleral thickness measurements at any location of examination were not significantly (all P.0.10) correlated with corneal thickness measurements. Scleral thickness was statistically independent of age, gender and presence of glaucoma. Conclusions: In non-axially elongated eyes, the sclera was thickest at the posterior pole, followed by the peri-optic nerv
In vitro sensitivity testing of human renal cell carcinoma with cytostatic agents and interferon alpha-2a
SUSTAINABLE DEVELOPMENT AND THE PROCESS OF JUSTIFYING CHOICES IN A CONTROVERSIAL UNIVERSE
All in all, neither the path of the generic principle nor that of the reduction to existing principles would appear to be fully satisfactory as the basis for establishing the legitimacy of sustainable development or as a way of making sustainability a principle of legitimacy by its own. We should probably resign ourselves to seeing in this idea a composite construction, still striving towards the formation of a new "superior common principle", without this principle yet being able to be completely clarified and validated. What we have here is an example of the sort of "compromise" described by Boltanski and Thévenot (1991, p.338): "In the compromise, the participants abandon the idea of clarifying the principle of their agreement but endeavour to maintain a frame of mind aiming at the common good." If we want to consolidate the compromise developing around sustainability, it would be well advised to seek the support of tests using well-formed objects. To this end, steps should be taken to move the emphasis away from long-term and unknowable sustainability requirements and closer to secondbest criteria focused on the transitional developments and possible risks of intentional human action, the ways of managing the linking of the different temporalities in play -- as regards the biophysical phenomena, their understanding and the main worlds of legitimacy (Godard, 1992) -- and the introduction of deliberation within the present generations as to what they feel best describes their identity, those things they would like to pass on
Improving precision for detecting change in the shape of the cornea in patients with keratoconus
To investigate a method for precision analysis to discriminate true corneal change from measurement imprecision in keratoconus (KC). Thirty patients with KC and 30 healthy controls were included. Coefficients of repeatability and limits of agreement (LOA) were compared using multiple measurements for inter-observer and inter-device agreement with the Pentacam HR, Orbscan IIz, and Tomey Casia SS-1000. Correlation of repeated measurements was evaluated using a linear mixed effect model (also called random effect model). A formula was derived for the theoretical expected change in precision and compared with measured change. Correlation between measurements from the same eye was small (R = 0.13). The 99.73% LOA (3 SD) of the mean of three measurements, provided better precision than 95% LOA (2 SD) of single cut-off values as expected from statistical theory for uncorrelated measurements for evidence of a significant change in corneal shape in patients with keratoconus. This enabled the determination of cut-off values for the detection of true change in corneal shape. The mean of three repeated measurements will provide better precision when there is minimal correlation. Three (rather than two) standard deviations provides a precise estimate of the LOA within or between observers and can be used as a reliable measure for identifying stage-independent corneal shape changes (progression) in keratoconus
Optic Nerve Head Change in Non-Arteritic Anterior Ischemic Optic Neuropathy and Its Influence on Visual Outcome
To evaluate changes in cup/disc (C/D) diameter ratios and parapapillary atrophy in patients with non-arteritic anterior ischemic optic neuropathy (NA-AION), using morphometric methods.The clinical non-interventional study included 157 patients with unilateral or bilateral NA-AION. Optic disc photographs taken from both eyes at the end of follow-up were morphometrically examined.Follow-up was 86.3±70.3 months. Horizontal and vertical disc diameters (P = 0.30;P = 0.61, respectively), horizontal and vertical C/D ratios (P = 0.47;P = 0.19,resp.), and size of alpha zone and beta zone of parapapillary atrophy (P = 0.27;P = 0.32,resp.) did not differ significantly between affected eyes and contralateral normal eyes in patients with unilateral NA-AION. Similarly, horizontal and vertical disc diameters, horizontal and vertical C/D ratios, and size of alpha zone and beta zone did not vary significantly (all P>0.05) between the unaffected eyes of patients with unilateral NA-AION and the eyes of patients with bilateral NA-AION. Optic disc diameters, C/D ratios, size of alpha zone or beta zone of parapapillary atrophy were not significantly associated with final visual outcome in the eyes affected with NA-AION (all P>0.20) nor with the difference in final visual acuity between affected eyes and unaffected eyes in patients with unilateral NA-AION (all P>0.25).NA-AION did not affect C/D ratios nor alpha zone and beta zone of parapapillary atrophy. Optic disc size was not related to the final visual acuity outcome in NA-AION
Five-Year Follow-Up of Parapapillary Atrophy: The Beijing Eye Study
Purpose: To assess longitudinal changes in parapapillary atrophy in the adult population of Greater Beijing. Methods: The population-based Beijing Eye Study 2006 included 3251 subjects who had participated in the Beijing Eye Study 2001 and returned for re-examination. The mean age was 60.4610.1 years. Using optic disc photographs, we measured parapapillary atrophy which was divided into alpha zone and beta zone. Results: Overall progression rate of alpha zone was seen in 0.660.1 % (95 % confidence interval (CI):0.3,0.9) of the subjects and of beta zone in 8.260.5 % (95%CI:7.2,9.1) of the subjects. In binary regression analysis, rate of progression of alpha zone was significantly associated higher age (P = 0.04) and the co-progression of zone Beta (P,0.001). Rate of progression of beta zone was significantly associated with higher age (P,0.001; odds ratio (OR):1.11;95%CI:1.10,1.14), higher intraocular pressure (P,0.001;OR:1.10;95%CI:1.05,1.14), higher myopic refractive error (P,0.001;OR:0.71; 95%CI:0.67,0.75), rural region of habitation (P = 0.002;OR: 0.58; 95%CI:0.41,0.82), presence of glaucomatous optic nerve damage (P,0.001;OR:2.89; 95%CI:1.62,5.14), co-progression of alpha zone (P,0.001;OR:7.13;95%CI:2.43,20.9), absence of arterial hypertension (P = 0.03;OR: 0.70; 95%CI:0.51,0.96), and thicker central corneal thickness (P = 0.02;OR:1.01;95%CI:1.00,1.01). Subjects with a non-glaucomatous optic nerve damage (n = 22) as compared to the remaining subjects did not vary in the progression rate of alpha zone (0.0 % versus 0.660.1%; P = 1.0) and beta zone (8.260.5 % versus 6.360.6%;P = 1.0)
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