| 1. |
- Havelius, Ulf, et al.
(författare)
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Accidental mydriasis from exposure to Angel's trumpet (Datura suaveolens).
- 2002
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907. ; 80:3, s. 332-335
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To report clinical findings after accidental instillation into the eye of sap from Angel's trumpet (Datura suaveolens). METHODS: We report findings on seven patients who developed sudden onset of unilateral mydriasis. At least three of them also had ipsilateral cycloplegia and one developed transient tachycardia. RESULTS: The symptoms evolved after ocular exposure to sap from Angel's trumpet, a plant containing natural alkaloids with parasympatholytic properties. Six patients were initially unaware of the cause of their symptoms. In these cases, patient history revealed recent contact with Angel's trumpet. CONCLUSION: Accidental ocular instillation of sap from Angel's trumpet should be noted as a cause of sudden onset of mydriasis in otherwise unaffected patients and also of general symptoms like tachycardia.
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| 2. |
- Havelius, Ulf
(författare)
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Clinical Studies on Dark Adaptation: with Particular Reference to Carotid Artery Disease
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: To study dark adaptation in patients with symptomatic carotid artery disease or polycythemia before and after treatment. This necessitated determinations of pupillary changes as such may influence the findings. To determine whether changes in the retinal blood flow in light and darkness occur in healthy humans. Methods: Repeated automatic dark adaptometry was recorded monocularly in 21 consecutive patients scheduled for first-time carotid endarterectomy and in 10 patients with polycythemia. All patients were studied before and after treatment. Analogue investigations were performed in 31 healthy control subjects. The systolic and diastolic blood flow velocities were measured by color Doppler in the ophthalmic and the central retinal arteries in 12 healthy individuals in light and darkness. The pupillary diameter was measured under defined conditions of darkness in all patients and control subjects. Photographic pupillometry was used in 21 patients with carotid artery disease before and after endarterectomy. Results: Dark adaptation was markedly impaired in both categories of patients compared to the control subjects. After carotid endarterectomy in the carotid patients and normalization of the red cell count, hematocrit and hemoglobin in the polycythemic patients, dark adaptation was markedly improved. There was no significant change in dark vision in the control subjects. The results could not be explained by any change in the pupillary diameter. In healthy individuals the systolic and diastolic flow velocities in the central retinal artery were markedly increased in darkness. Conclusions: These findings indicate a sustained but reversible neuronal hypofunction secondary to compromised macro- and microcirculation. Furthermore, the results indicate that darkness is associated with increased blood flow velocity in the central retinal artery, probably reflecting increased metabolic demands by the photoreceptors.
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| 3. |
- Havelius, Ulf, et al.
(författare)
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Kort historik över svensk ögonsjukvård
- 2005
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Ingår i: Svensk kirurgisk förening 100 år: 1905-2005. - 9163174669 ; , s. 112-112
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Havelius, Ulf, et al.
(författare)
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Ocular vasodynamic changes in light and darkness in smokers
- 2005
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Ingår i: Investigative Ophthalmology & Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 1552-5783. ; 46:5, s. 1698-1705
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To determine whether smokers have a reduced capacity for increased retinal blood flow velocity in darkness. METHODS. The peak systolic flow velocities (V-S) and end diastolic flow velocities (V-D) were measured by ultrasound ( i.e., color Doppler equipment), in light and darkness in the ophthalmic and central retinal arteries in 20 cigarette smokers and 20 matched nonsmokers. The resistive index ( RI) was calculated as RI = (V-S - V-D)/V-S. RESULTS. In the ophthalmic artery in nonsmokers, the V-D was markedly increased in darkness and the RI was correspondingly reduced. After the subject was re-exposed to light, the RI was markedly increased. In smokers the V-S and V-D did not change significantly in the different conditions of light and darkness. In the central retinal artery in nonsmokers, the V-S and V-D were markedly increased in darkness and decreased after re-exposure to light. In smokers, the corresponding changes were much smaller and not significant. CONCLUSIONS. The normal capacity for increased blood flow velocity in the central retinal artery in darkness was markedly reduced in smokers. This finding may explain the reduced dark vision after recent smoking reported in several studies and probably reflects the combined effects of an increased blood viscosity, the vasoconstrictive action of nicotine, and a reduced capacity of the blood to transport oxygen, as the hemoglobin is partly occupied by carbon monoxide.
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| 5. |
- Havelius, Ulf, et al.
(författare)
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Reduced examination time by monocular and bilateral examination in the same session with a new computerized dark adaptometer
- 2005
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Ingår i: Techniques in Ophthalmology. - 1542-1929. ; 3:1, s. 37-42
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Tidskriftsartikel (refereegranskat)abstract
- To reduce the examination time for dark adaptometry, which including preadaptometry normally takes 30 minutes for an eye, a computerized adaptometer was constructed allowing monocular examination of both eyes simultaneously. The total examination time was thereby reduced from 60 to 30 minutes. This improvement was achieved by the use of electronically monitored transparent shutters that were alternately opened for the right eye, the left eye, or both eyes. Eighteen healthy subjects were examined 3 times each, and the results were recorded separately for the right eye, the left eye, and binocularly. The test results were presented graphically and numerically. The results of the examinations were in good agreement between the right and left eyes and also demonstrated good reproducibility between the three separate examinations. The alternating transparent light shutters did not cause any fixation problems for 10 subjects with phoria. The computerized dark adaptometer is by the 50% reduction of examination time a relief for future patients without any expected loss of diagnostic information.
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| 6. |
- Havelius, Ulf, et al.
(författare)
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Sustained attention analyzed by a new computerized dark adaptometer
- 2005
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Ingår i: Techniques in Ophthalmology. - 1542-1929. ; 3:2, s. 100-105
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Tidskriftsartikel (refereegranskat)abstract
- A new computerized dark adaptometer was developed achieving a 50% reduction of examination time. Functions were implemented for the recording of sustained attention (ie, the capacity to maintain focus and alertness over time (vigilance)). Eighteen healthy subjects were tested three times each on different days. All tests were analyzed for parameters analogous to measurements derived from continuous performance tests (ie, values for responding frequency and periods of decreased concentration). The test results were presented graphically and numerically. The automatic recording of sustained attention during clinical testing of dark adaptation is a new approach giving information on the co-operability of the patients and also information on the possible change of vigilance after various treatments performed for the condition being the actual indication for dark adaptometry.
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| 7. |
- Havelius, Ulf, et al.
(författare)
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Ögonläkarföreningen bildas
- 2008
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Ingår i: Svensk ögonvård under ett sekel - Sveriges ögonläkarförenings jubileumsskrift 2008. - 9789197716802 ; , s. 25-25
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Havelius, Ulf, et al.
(författare)
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Ögonsjukvården och ögonläkarnas ställning före 1908
- 2008
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Ingår i: Svensk ögonvård under ett sekel - Sveriges ögonläkarförenings jubileumsskrift 2008. - 9789197716802 ; , s. 5-5
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Havelius, Ulf, et al.
(författare)
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Ögonsymtom vid carotisstenoser
- 2007
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Ingår i: Stroke och cerebrovaskulär sjukdom. - 9789144033914 ; , s. 67-67
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Thylefors, Joakim, et al.
(författare)
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Dark adaptation during systemic hypoxia induced by chronic respiratory insufficiency
- 2009
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Ingår i: Investigative Ophthalmology & Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 1552-5783. ; 50:3, s. 12-1307
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate dark adaptation during hypoxia in patients with chronic respiratory failure.METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in 13 patients with chronic respiratory insufficiency treated by long-term oxygen therapy. At visits 1 and 3, the patients were administered their usual oxygen supplement. At visit 2, no oxygen was given. At each visit, an analysis of arterial blood gases measured pH, partial pressure of O(2) (Pao(2)), partial pressure of CO(2) (Paco(2)), base excess (BE), standard bicarbonate (HCO(3)), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded.RESULTS: Significant differences were recorded between visits 1 and 2 and between visits 2 and 3 for Pao(2), arterial oxygen saturation, and POX; no differences were found for pH, Paco(2), BE, or HCO(3). No differences were seen between visits 1 and 3 for any of the laboratory parameters. All patients had normal and unchanged dark adaptation at the three visits.CONCLUSIONS: Hypoxia in chronic respiratory insufficiency was associated with normal dark adaptation, in contrast to hypoxia in healthy persons at high altitudes, which is known to produce impaired dark adaptation. The result may partly reflect the influence of Paco(2) on the lumen of choroidal and retinal vessels. At high altitudes, with hypocapnic vasoconstriction the oxygen supply to the retina is further compromised, resulting in reduced dark adaptation. The authors hypothesize that respiratory insufficiency with hypercapnia or normocapnia will have larger choroidal and retinal vessel lumens, added to by further dilation of retinal vessels during hypoxia. The tentative net effect would be preserved dark adaptation.
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