Search Results - "International Ophthalmology"

1573-2630

central retinal vein occlusion ; resistance to activated protein C ; thrombophilia

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background: This study was carried out to determine the prevalence of genetic thrombophilia in patients with retinal vascular occlusion.Methods: We investigated 116 consecutive patients with central retinal vein occlusion (CRVO, n = 48), branch retinal vein occlusion (BRVO, n = 33), central retinal artery occlusion (CRAO, n = 21), branch retinal artery occlusion (BRAO, n = 14). All patients underwent comprehensive tests for coagulation disorders including determinations of protein C, protein S, lupus anticoagulants, prothrombin gene mutation (G20210A), resistance to activated protein C (APCR), and were screened for vascular disease risk factors. APC resistance was confirmed by a PCR method to detect the factor V R506Q mutation. A PCR method was also used to detect the G20210A mutation. For comparative purposes, we screened 209 consecutive patients with deep vein thrombosis (DVT) and 581 patients with coronary heart disease (control group) for APC resistance.Results: 13 (27%) of 48 patients with CRVO had the factor V R506Q mutation. The factor V R506Q mutation was detected in six (18%) of 33 patients with BRVO, but in only one patient with CRAO and in two patients with BRAO. Other thrombophilic defects were not detected. The APCR prevalence within the CRVO group was significantly increased when compared to the control group (8%). There was no significant difference in the factor V R506Q mutation prevalence between the CRVO group and the DVT group (19%).Conclusion: The factor V R506Q mutation is the most commoncause of genetic thrombophilia in patients with CRVO and has a similar prevalence as in DVT patients.

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1573-2630

bilateral penetrating keratoplasty ; corneal graft failure ; endothelial rejection ; review

Springer Online Journal Archives 1860-2000

Medicine

Abstract Purpose: To analyze the indications, functional results, and rates of graft rejection and failure after bilateral penetrating keratoplasty (PK) in a major eye care hospital and research center in India. Methods: Retrospective review of the case records of 38 patients who underwent bilateral PK and had at least 6 months follow-up after cornealtransplantation in the second eye. Results: The mean age of the 38 patients (20 M, 18 F) was 35 ± 25 years (range, 0.5 to 79 years). Mean follow-up was 49 ± 23 months (range, 13.4 to 116.4 months) after surgery in the first eye and 31 ± 22 months (range, 6.6 to 103.6 months) after surgery in the second eye. The average time interval between surgery in the first and second eye was 18 ± 10 months (range, 0 to 38 months). The commonest indications for surgery were corneal dystrophies (50%),aphakic bullous keratopathy (21%), and keratoconus (11%). Postoperatively, secondary glaucoma occurred in 2 first and 3 second eyes. Best-corrected visual acuity at last follow-up was 〉 6/12 in 34% of first eyes and 50% of second eyes, and was 〉 6/60 in 26% and 18% of first and second eyes respectively. Allograft rejection occurred in 4 of the first eyes and 3 of the second eyes. The two-year graft survival rate in first eyes was 70% and in second eyes was 83%. Worse outcomes were noted in grafts performed for secondary endothelial failure. Earlier graft failure occurred in first eyes (54 ± 5 months) compared to second eyes (79 ± 10 months) (Logrank Test p = 0.2311).Conclusions: Bilateral penetrating keratoplasty has reasonable success in selected patients. Corneal transplantation in the second eye does not seem to increase the risk of graft rejection in either eye.

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

uveo-scleral tissue ; intraocular pressure ; dopamine D1 receptors ; autoradiography ; human eye ; irido-corneal angle

Springer Online Journal Archives 1860-2000

Medicine

Abstract The aim of this paper is to clarify the distribution of Dopamine D1 (DA D1) receptors in the uveo-scleral tissue of human eyes with or without elevated intraocular pressure (IOP) and to study the relationships between DA D1 receptors and uveo-scleral tissue. Samples of human uveo-scleral tissue were taken from seven men undergoing eye surgery for a traumatic lesion of the anterior segment of the eye, without involvement of the iris-corneal angle and /or from eye donors. The subjects (in whom one eye bulb had been surgically enucleated) had been previously enrolled in our medical protocols because they suffered for increased IOP, while the eye donors (of both eye bulbs) had a normal IOP. Frozen sections from the uveo-scleral tissue were submitted to biochemical characterization and to morphological autoradiographic techniques for detection of DA-D1 receptors. [3H]-SCH-23390 was used as a ligand of Dopamine D1 receptors.[3H]-SCH 23390 was bound by sections of the human uveo-scleral tissue. The pharmacological profile of the binding was consistent with the labeling of D1 receptors. Light microscope analysis was used for localization of D1 receptors and revealed an accumulation of the radioligand in the human uveo-scleral tissue. In eyes with normal IOP there is a high reaction. The Bmax of radioligand decreases in the eyes with increased IOP.The possibility that dopaminergic receptors play a role in the controlling uveo-scleral tissue functions is suggested.

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1573-2630

pressure gauges ; intraocular pressure ; glaucoma ; scleral buckle ; conductive elastomere

Springer Online Journal Archives 1860-2000

Medicine

Abstract An implantable variable resistance pressure gauge has been constructed from a conductive elastomere in the form of a scleral buckle which is suitable for recording intraocular pressure in vivo continuously over an indefinite period of time. The similarity of the pressure transducer to the standard scleral buckles used to reduce retinal detachments suggests that it will be tolerated over a period of years without significant effect on intraocular pressure. The electrical output from these pressure gauges appears to be both well defined and of sufficient magnitude to operate a valve to control intraocular pressure.

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1573-2630

glaucoma ; visual field ; automatic perimetry ; long-term fluctuations ; detection of changes

Springer Online Journal Archives 1860-2000

Medicine

Abstract The analytical programme Delta was used to determine longterm fluctation and accuracy of measurement of the programme 31 of Octopus when used on glaucoma patients. Programme 31 examines the 30° field. The test locations are arranged in a square grid with 6° resolution. The programme Delta determines and compares 1) the disturbed area in %; 2) the total loss, the total sensitivity being around 2000 dB; 3) the loss in dB per mean number of disturbed points. Thirty-two eyes of 22 patients with established glaucomatous field defects were examined twice within two to six days and two months later again twice. The size of the disturbed area served for classification of our sample into three groups: 1st group: disturbed area 1–33%; 2nd group: disturbed area 34–66%; 3rd group: disturbed area 67–100%. Long-term fluctuations and accuracy of measurement could be determined as respectively follows: 1) Disturbed area between 0.7 ± 8% in group 3 and 1.7 ± 13% in group 2. 2) The total loss increases proportionately to the disturbed area and was 4.9 ± 29.2 dB in group 1 and 31.8 ± 82.4 dB in group 3. 3) The total loss per mean number of disturbed points was 0.5 ± 2 dB in group 1 and 0.3 ± 1.2 dB in group 2. This signifies that if the learning effect is over, changes of more than 2 dB, especially if several adjacent points are affected, are a significant loss. The learning effect, as determined in an earlier study, may go up as high as 2 dB per point.

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1573-2630

beta-blocking agents ; corneal sensitivity ; tear production ; Schirmer test ; primary open-angle glaucoma

Springer Online Journal Archives 1860-2000

Medicine

Abstract A double-masked study was carried out to assess the effect of timolol ophthalmic solution on corneal sensitivity in seven normal volunteers. No significant change in corneal sensitivity was demonstrated during four weeks of timolol administration. Corneal sensitivity was determined in two age-matched groups, one comprising 27 glaucomatous patients on timolol therapy for at least three months and the other consisting of 24 normal individuals who had never been on any beta-blocking agents. No significant difference in corneal sensitivity was noted between the two groups. The tear production was determined by means of the Schirmer test I in 15 patients with primary open-angle glaucoma or ocular hypertension prior to and during timolol therapy of 13 months duration. No significant change in tear production was noted.

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1573-2630

glaucoma ; intra-ocular pressure ; guanethidine ; adrenaline

Springer Online Journal Archives 1860-2000

Medicine

Abstract A long term study was undertaken to evaluate the efficacy of combined guanethidine (1%) and adrenaline (0.05–0.5%) therapy in controlling intra-ocular pressure in 89 patients with chronic open angle glaucoma, in whom ocular tensions proved difficult to control on miotics and/or carbonic anhydrase inhibitors. Visual acuity, fields of vision, applanation tension, size of the pupil, anterior chamber depth and gonioscopic examination of the angle were recorded before and during treatment. The follow-up extended over a period of 12 to 42 months, the mean being 28 months. The combined therapy was found to lower the intra-ocular pressure significantly in a large number of patients and the most potent combination was guanethidine 1% and adrenaline 1/4% and the average fall of intraocular pressure with the combined therapy was around 8 mm Hg. Intolerance to the combined preparation was noticed in three patients during a period of 12–18 months with the symptoms of sore eyes, conjunctival hyperaemia and lid irritation of such severity that the treatment had to be withdrawn. Resistance to treatment developed in four patients during a period of 12–36 months and treatment had to be changed. Addition to guanethidine (1%) and adrenaline up to 1/4% to pilocarpine therapy (2–4%) in eyes with narrow angles did not result in any appreciable change of the width of the angle, the size of the pupil and the depth of the anterior chamber.

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1573-2630

glaucoma ; visual field ; intraocular pressure ; visual acuity correlations

Springer Online Journal Archives 1860-2000

Medicine

Abstract In a retrospective study of 114 patients under treatment for chronic glaucoma (81 without and 33 with visual field defect) over an 11-year period of observation, a highly significant correlation between intraocular pressure and progression of visual field defects could be demonstrated. This correlation could be shown for the visual field outer boundary in 81 eyes with ocular hypertension and for typical visual field defects in 33 eyes with chronic glaucoma. The relationship was, however, only significant when both the standard deviation of the annual intraocular pressure and the influence of cataract development upon visual acuity were considered. Quantitative analysis of the results of Goldmann perimetry was by planimetry and took into account only changes during the 11-year observation period.

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1573-2630

blindness prevention ; ocular hypertension control ; primary open angle glaucoma ; cost-benefit analysis ; epidemiology

Springer Online Journal Archives 1860-2000

Medicine

Abstract From a case-control study we have quantified the effect (relative risk) of presenting intraocular pressure on visual field loss in primary open angle glaucoma. We found this effect to be modified by both age and sex. Using these effect values we have estimated the potential for prevention of glaucomatous blindness in clinical and community settings. The clinical, public health, and research implications of these findings and estimates are discussed.

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1573-2630

viscose rayon industry ; CS2 toxicity ; microangiopathy ; fluorescein angiography ; ERG ; EOG

Springer Online Journal Archives 1860-2000

Medicine

Abstract As a pilot study preliminary to a large scale survey on chronic CS2 toxicity 30 workers of a viscose rayon industry in Belgium have been examined. Twenty of them were working in the xanthation spinning department where chronic CS2 intoxication is more likely to occur and ten controls were chosen form the supposedly safe bleaching division. Ophthalmological evaluation included visual fields, coulour vision testing, fluoro-angiography, ERG and EOG. In both groups fundus anomalies, abnormal EOG's and subnormal or supranormal ERG's were found. The fundus anomalies consisted either of discrete pigmentary changes in the posterior pole or microvascular retinal lesions.

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

epidemiology ; primary open angle glaucoma ; decision making ; computerised clinical records ; sensitivity-specificity trade off curve

Springer Online Journal Archives 1860-2000

Medicine

Abstract We have described the epidemiological analysis of one aspect of the King's College Hospital computerised data base; namely initial intraocular pressure as an indicator of visual field loss. The methods involved the use of the four-fold table to determine sensitivity and specificity at different pressure levels. From these results (1) the changes in the pre and post test probability of field loss are calculated and (2) a ‘sensitivity/specificity trade off curve’ or ‘decision curve’ is constructed. In this way the optimal ‘cut-off level’ or ‘operating point’ for a population of specific type and composition can be determined. The factors concerned in decision making are always complex but such an approach allows a rational and quantifiable alternative to reliance on clinical impression and intuition. The results have significance in relation to decisions on the management of patients and on population screening programmes for glaucoma.

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

Wagner's vitreoretinal degeneration ; chorioretinal dysplasia ; fluorescein angiography

Springer Online Journal Archives 1860-2000

Medicine

Abstract Six young patients from three pedigrees with Wagner's disease were submitted to fluorescein angiography of the peripheral fundus. All eyes showed aberrant areas, characterized by: 1. localization principally in equatorial region of temporal half of the fundus. 2. whitish appearance of neuroretina with sharp demarcations. 3. absence of retinal vasculature. 4. marked atrophy of choriocapillaris and retinal pigment epithelium. 5. abnormal deflections of retinal vessels at the posterior margin of these areas. Arguments are presented in support of the hypothesis that these areas were dysplastic and not degenerative. The difference with lattice degeneration, another wellknown finding in Wagner's disease, is that retinal vasculature never developed in the dysplastic peripheral areas. It is probable that hypoplasia of the choroid has led to a too inferior structure of the overlying retina to permit development of retinal vessels. The frequent occurrence of retinal breaks in young patients with Wagner's disease, especially in the temporal periphery, seems to be a consequence of the poor condition of the retina in these dysplastic areas caused by the inferior development of both retinal and choroidal vasculature.

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1573-2630

diabetic retinopathy ; H. L. A. antigens

Springer Online Journal Archives 1860-2000

Medicine

Abstract One hundred and four patients with diabetes mellitus present for at least 15 years were tissue typed for HLA antigens AI and B8. Fifty six patients had severe proliferative retinopathy and 48 patients no retinopathy. The results were compared with a group of 200 normal blood donors. There was no significant difference in frequency of AI and B8 between the two groups of diabetic patients. The HLA pattern AI - B8 + was more frequently present among the group of patients with proliferative retinopathy.

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1573-2630

pupil ; paradoxical reaction to light/darkness ; congenital achromatopsia ; retina adaptation ; gain control

Springer Online Journal Archives 1860-2000

Medicine

Abstract Children with congenital achromatopsia possess an interesting paradoxical pupillary constriction to darkness that has not been previously described. This paper describes three children in whom this paradoxical pupillary reaction was documented with infrared pupillometry. The literature on the pupil in achromatopsia is reviewed and a tentative testable model of the reaction is hypothesized.

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