摘要:

AbstractThe results of a population‐based (age ≥ 65 years) examination of the frequency distribution of IOP are reported. 3726 eyes in 1887 individuals were included in the examination. By consistent use of conventional, well‐defined criteria, glaucoma was diagnosed in 6.4% of the individual eyes. In the total material, the average IOP was 18.0 mmHg. Average IOP was 28.7 mmHg in eyes with glauoomatous damage, vs 17.2 mmHg in the normal eyes. Variance of IOP was much higher in the glaucoma group as compared with the normal group. The IOP frequency distribution curve did not fit with a Gaussian curve; it was asymmetric, skewed to the right. The distribution curve obtained by plotting the recorded frequencies was disturbed by irrelevant irregularities, both random and systematic. The irregularities could be evened out by the application of regression analysis, using the equation for the gamma distribution. The IOP frequency distribution is well represented by a gamma distribution curve. The fit is improved by excluding eyes with extremely high and lo

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04839.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe probability of having glaucoma is indicated by the quotient (number of eyes with glaucoma)/(number of eyes in the total population). This quotient was calculated for each value of IOP. The number of eyes at each IOP value was taken from IOP frequency distribution curves for glaucomatous and normal eyes, calculated from values obtained by a population survey. By plotting the probability of having glaucoma vs IOP, a sigmoid curve was obtained. The curve indicates that while the glaucoma probability is near zero at IOP = 18 mmHg, it is 0.5 at 27–28 mmHg, and the probability approaches 1, i.e. certainty, at an IOP around 35 mmHg. The frequency distribution of the tolerance limit of IOP was calculated by derivation of this curve. The distribution of IOP tolerance limit was close to a normal distribution with average = 27.9 mmHg and standard deviation = 3.2 mmH

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04840.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractOn the basis of a glaucoma survey in a total population ≥ 65 years of age, the IOP in eyes with and without pseudo‐exfoliation (PE) has been compared. The average IOP was 22.2 mmHg in eyes with PE versus 17.4 in eyes without. The corresponding averages in eyes without glaucomatous damage were 18.6 and 17.1 mmHg, and in eyes with glaucoma 31.5 and 25.5 mmHg. The IOP elevation connected with the PE process was 4.8, 1.5, and 6.0 mmHg in the total, normal and glaucomatous population, respectively. The IOP frequency distribution curves of these 3 groups were compared. The right shift of the distribution curves of the PE groups was more pronounced at high pressure levels. The PE process seems to elevate the IOP particularly in eyes with a high IOP, which is in correspondance with hydrodynamical laws. At a certain IOP, the probability of having glaucomatous damage was higher in eyes with PE than in those without, indicating an increased vulnerability of PE eyes to an elevated IOP. PE may be a glaucoma risk factor also on its own, i.e. independent of the pressure elevation connected with this syndr

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04841.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractIn a case‐finding study in a municipality in central Sweden, 128 cases of chronic open‐angle glaucoma with visual field defects (VFD) were found. The prevalence amounted to 1.4% in those ≥ 45 years of age. Sixty‐three percent had capsular glaucoma. Advanced visual field defects (AVFD), i.e. a restriction of the visual field to a diameter of ≤ 20°, were seen in 49 patients. Four patients had AVFD in both eyes. Patients with AVFD were older, had had the disease longer, had higher mean initial intraocular pressure (IOP), and had more extensive VFD at the time of diagnosis. When age and duration were taken into consideration, the risk of developing AVFD was 14 times greater in those with VFD stage III at the time of diagnosis, i.e. a Bjerrum scotoma with nasal breakthrough or more widespread VFD. An IOP of ≥ 35 mmHg signified that the risk of having VFD stage III at the time of diagnosis, when age and type of glaucoma were taken into consideration, was 8.6 times greater than if the IOP

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04842.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractWe assessed the acute effect of ACE‐inhibition (captopril) on blood‐retina barrier (BRB) permeability in 10 hypertensive insulin‐dependent diabetic patients with background retinopathy in a double‐masked placebo controlled cross‐over study. All patients underwent ophthalmological examination, fundus photography, fluorescein angiography, vitreous fluorometry, and continuous blood pressure recording within 3 h of the drug/placebo administration. The decrease in mean arterial blood presure, from placebo treatment 149/92 ± 17/7 to captopril treatment 132/83±14/7 mmHg (mean ± sd),P<0.01 was not accompanied by a significant decrease in BRB permeability, which was 2.51 (1.24–9.15) with placebo and 3.02 (1.25–13.93) ± 10‐7cm/s during captopril treatment (geometric mean and range), NS. Our study suggests that abnormal leakage through the BRB in hypertensive insulin‐dependent diabetic patients with background retinopathy is caused predominantly by structural changes in the retinal vessels whereas hydrostatic for

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04843.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractFundus photography plays an important role in detection and assessment of diabetic retinopathy. This study compared the detectability of diabetic retinopathy lesions on Polaroid prints and Ektachrome slides obtained with a non‐mydriatic camera. The number of lesions detected with Ektachrome slides was higher compared to Polaroids. The method of viewing the Ektrach‐rome slides was also shown to be important. Slides when projected onto a white screen revealed a higher number of lesions compared to the same slide viewed through a macroscope. If a non‐mydriatic camera is used to screen diabetic retinopathy, judgement from a projected Ectrachrome slide is recom

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04844.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe sorbitol shunt has been studied in bovine retinal tissue at incubation times from 1 to 24 h. It was shown that an elevated glucose concentration (22 mM) of the medium was accompanied by a slight increase in sorbitol content already after 3 h. At longer incubation times, but lower glucose concentration (11.1 mM) there was a similar increase. Addition of an aldose reductase (AR) inhibitor prevented the sorbitol increase. Addition of fructose to the medium significantly increased the sorbitol accumulation above the effet seen with glucose alone and this effect was not influenced by the AR inhibitor. Thus the sorbitol concentration in the retina may be increased after a short incubation time and further enhanced by the presence of fructose.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04845.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe contribution of the central and the surrounding peripheral retina to the pattern reversal visual evoked response (PVER) was analyzed simultaneously using double frequency stimulation and the Fast Fourier transform (FFT) method. The Scanning Laser Ophthalmoscope (SLO) was used to project the pattern stimulus, a square subtending 10 degrees on a side, on a specific location in the fundus and to monitor accurately the stimulus position during PVER testing. When the stimulus' area on the central retina was ≤ 50 min of are on a side, or 0.69% of the total area was stimulated (a square of 10 degrees on a side), the contribution from the central retina was neglibible, and the PVER was dominated by surrounding peripheral retinal activity. When the stimulus area of the central retina was ≥ 100 min of are on a side, or 2.78% of the whole area was stimulated, activity from the central retina became more evident. When the stimulus area projected on the central retina became 150 min on a side (6.25% of the area or greater), activity from the central retina showed an increase and exceeded that of the peripheral retina. When the central area became larger, its activity dominated the PVER, and the contribution from the peripheral retina became negligible at this stage. The PVER was highly dependent upon the activity of the central retina, and activity levels from the central and surrounding peripheral retina were correla

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04846.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractComputerized image processing was used to analyze color fundus photographs of 11 patients (22 eyes) with macular drusen who were followed for more than 2 years (mean follow‐up, 4.7 years). Significant changes over time (more than ± 20% of baseline area) were measured in the surface area of macular drusen in 18 of 22 (82%) eyes. An increase in the drusen area was associated significantly with eyes with mostly hard drusen and an initially smaller drusen area; but a decrease was associated with eyes with mostly soft drusen and an initially larger drusen area (P<0.01). The mean absolute rate of change in the drusen area was more than twice as great in eyes with mostly soft drusen compared with those with mostly hard drusen (P<0.05). All eye pairs studied showed a concomitant increase or decrease in the drusen ar

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04847.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractStandard personal computers with appropriate graphic user interfaces can now be configured for work with near photographic quality colour image handling. Advantages and limitations of digitized colour image work, including cost considerations, are discussed in relation to some common ophthalmic photography situations. Practical methods are briefly described. Future developments are outlined, particularly methods for direct acquisition of high quality colour images and image compression/reduction.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1991.tb04848.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY