bluuebunny/crossref_metadata_2025_split huggingface dataset:
Latanoprost‐induced increase of tyrosinase transcription in iridial melanocytes
Authors: Stjernschantz Johan , Ocklind Anette , Wentzel Parri , Lake Staffan , Hu Dan‐Ning 
Published: March 2003

ABSTRACT.Purpose: Latanoprost, the active principle of XalatanR eye drops, has been shown to cause increased iridial pigmentation as a side‐effect in some patients. The purpose of the present study was to investigate whether latanoprost affects tyrosinase, the rate limiting enzyme in melanogenesis, at the gene transcription level in the iridial melanocytes.Methods: Four cynomolgus monkeys were treated unilaterally with 3 or 11 μg latanoprost once daily for 10 days. The contralateral eye received the vehicle only. Tyrosinase mRNA was visualized by in situ hybridization using radiolabelled riboprobes. The transcription of tyrosinase was also studied in vitro using cultivated human iridial melanocytes. Tyrosinase RNA was quantified by Northern blotting.Results: In the monkeys transcription of tyrosinase was found to be increased in iridial melanocytes of the treated eyes compared to the control eyes. Increased transcription of tyrosinase was in addition found in the iridial pigment epithelium and in melanocytes of the anterior choroid. Latanoprost was also found to increase the transcription of tyrosinase in melanocytes isolated from at least one human eye.Conclusions: Although the tyrosinase enzyme has to undergo complex post‐translational modification to become biologically active, which we have not studied, it appears that latanoprost treatment may increase the transcription of the tyrosinase gene in some individuals, consistent with increased melanogenesis in the iridial melanocytes leading to darker eye colour.
Morphology of epithelial keratitis in herpes zoster ophthalmicus
Authors: Tabery Helena M. 
Published: March 2003

ABSTRACT.Purpose: To investigate the in vivo morphology of epithelial changes in acute herpes zoster keratitis.Methods: 10 patients with acute disease. In 7, systemic acyclovir treatment was started at presentation, in 2 24 hours before, 1 was not treated. The corneae were examined with the slit lamp, followed intermittently for 3–30 days, and photographed at intervals ranging between 1 to 7 days.Results: All but one patient had epithelial changes at presentation; all developed new ones. The smallest discernible entities were abnormal cells of about 10–15 μm in diameter, singular or grouped. Larger foci measured about 100–200 μm. 2 patients showed pseudodendrites at presentation, and further 3/9 observed ≥2 weeks developed them. Some lesions showed white surface plaques. No ulcerations were observed. Healing occurred ≤10–22 days after the onset of symptoms.Conclusions: The study seemed to have followed the natural course of the disease.The rapidly changing morphology in the absence of ulcerative features indicated successive damage counteracted by reparative forces.
Optical coherence tomography (OCT) in acute macular neuroretinopathy
Authors: Feigl Beatrix , Haas Anton 
Published: March 2003

ABSTRACT.Purpose: To evaluate the value of ocular coherence tomography (OCT) concerning diagnosis and pathogenesis of acute macular neuroretinopathy.Methods: A 33‐year old woman complained of sudden onset of central scotomas in her right eye because of acute macular neuroretinopathy. We performed a direct ophthalmoscopy, a visual field testing, a fluorescein angiography (FA) a multifocal ERG (mf‐ERG) and an OCT.Results: We found typical paracentral scotoma in visual field testing, a normal FA and mf‐ERG in her right eye. In OCT there was a band of higher reflectivity (115 μm) overlying an intact band corresponding to the retinal pigment epithelium (RPE)/ choriocapillaris complex. Retinal thickness was within the normal range.Conclusion: OCT can be an additional valuable tool in acute macular neuroretinopathy as it is a disease with discrete pathology and often normal results in other diagnostic tests.
Cataract surgery and effectiveness 2. An index approach for the measurement of output and efficiency of cataract surgery at different surgery departments
Authors: Lundström Mats , Roos Pontus , Brege Klas Göran , Florén Ingrid , Stenevi Ulf , Thorburn William 
Published: March 2003

ABSTRACT. Purpose: To describe a model for comparing the performance of cataract surgery among ophthalmology departments in terms of economic efficiency.Methods: An index approach for the measurement of outcome of cataract surgery is modeled. The index approach uses information about activities and difficulties in daily life as well as visual acuity and age. The change in activities and difficulties after surgery is expressed by changes in distances, and an overall index score is calculated as ratios of values to distances. Values to distances are estimated as solutions to linear programming problems. Index scores are calculated for two groups of patients, those with an ocular co‐morbidity and those without. Economic efficiency is also estimated by use of an index approach. In the estimation of efficiency we use the calculated index scores of outcome of surgery as a measure of output of the ophthalmology department. Four different departments providing cataract surgery are compared.Results: The studied departments showed differences to a great extent when traditional measures of cataract surgery outcomes were used. These differences changed when the outcomes were compared by use of index scores. When economic efficiency was calculated the difference between the departments was further reduced and only one department was considered inefficient according to the model.Conclusion: An index approach was used to study outcomes of cataract surgery and economic efficiency in four departments. This approach takes into account the complexity of cost in relation to feasible outcome. The ranking between the departments described by traditional methods turned out differently using the model.
Gender and referral to cataract surgery in Sweden
Authors: Olofsson Per , Lundström Mats , Stenevi Ulf 
Published: March 2003

ABSTRACT. Purpose: To investigate how cataract surgery was initiated and analyse possible gender difference in referral to surgery.Methods: Consecutive patients scheduled for first eye cataract surgery at three Swedish community‐run eye departments were interviewed concerning how surgery was initiated.Results: 649 patients were interviewed and 63.2% were female. The number of patients referred to surgery by an earlier contact with a health care provider was 271 (41.8%) and the remaining 378 (58.2%) patients had actively requested advice or help because of visual problems caused by cataract and without a prior regular contact. 44.7% of female patients were referred through a health care provider they visited for reasons other than cataract and the corresponding number for male patients was 36.8%. This gender difference is statistically significant at the 5% level.Conclusion: A health care provider that patients visited for other problems than cataract referred female patients to cataract surgery to a significantly higher degree than male patients.
Scanning laser polarimetry versus frequency‐doubling perimetry and conventional threshold perimetry: Changes during a 12‐month follow‐up in preperimetric glaucoma. A pilot study
Authors: Holló Gábor , Szabó Antal , Vargha Péter 
Published: March 2003

ABSTRACT. Purpose: To evaluate the possibility for detecting the progression in preperimetric primary open angle glaucoma (POAG) using scanning laser polarimetry (SLP), frequency‐doubling technology (FDT), and conventional automated perimetry (AP).Patients and methods: 22 eyes of 11 preperimetric POAG patients were evaluated using SLP (Nerve Fiber Analyzer, GDx), AP (Humphrey 24–2 threshold test) and FDT (30 ° threshold test). All eyes had intraocular pressure (IOP) higher than 21 mmHg before treatment, but were consistently lower than 22 mm Hg with unchanged topical medication before and during the study. At the initial evaluation session optic nerve heads showed mild glaucomatous changes but the visual fields were normal (MD better than 2.0 dB, Glaucoma Hemifield Test: within normal limits or borderline). AP and FDT measurements were repeated 6 months later, and all three tests were repeated 12 months after the first investigation.Results: IOP, AP and FDT measurements showed no statistically significant changes during the 12‐month follow up period. In contrast to this, a tendency for a glaucomatous type decrease was seen with SLP in the retinal nerve fibre layer (RNFL) thickness parameters (mean superior and inferior sector thickness values, ellipse average thickness and maximal modulation). The mean decrease of RNFL thickness in the superior and inferior sectors was 2.77 μm and 2.48 μm, respectively. Using the two‐way nested ANOVA, which considers the relation between the right and left eyes of the subjects, the decrease was statistically significant (p=0.021) for the inferior sector RNFL thickness.Conclusion: The results suggest that scanning laser polarimetry is a useful technique to detect and measure glaucomatous progression in early glaucoma. Scanning laser polarimetry of the RNFL may help to detect and quantify early progression even if worsening is not seen with perimetry and FDT tests.
Visual screening of Swedish children: An ophthalmological evaluation
Authors: Kvarnström Gun , Jakobsson Peter , Lennerstrand Gunnar 
Published: March 2003

ABSTRACT. Purpose: This study describes the various ophthalmological conditions detected in the Swedish visual screening program for children.Methods: The study was longitudinal and retrospective. All children (3126) born in 1982 in three Swedish municipalities have been followed from birth to ten years of age. Visual acuity was examined at the ages of 4, 5.5, 7 and 10 years. Before the age of 4, a gross examination of the eyes was performed.Results: The prevalence of ametropia in the population was 7.7%, the prevalence of strabismus 3.1%, and the prevalence of organic lesions 0.6%. Seven children (0.2%) were visually handicapped (visual acuity ≤0.3 in the better eye). Refractive errors and microtropias were mainly detected at the age of 4, when the first visual acuity test was performed, while manifest strabismus was in many cases detected before this age. With this screening and subsequent diagnosis and treatment, the prevalence of deep amblyopia (visual acuity ≤0.3) has been reduced from 2% to 0.2%. With treatment, 47% of the amblyopic children achieved a visual acuity better than 0.7.Conclusion: Visual screening is effective in detecting visual and ocular disorders. Most conditions are discovered before the age of 6. Compared to an unscreened population, the prevalence of amblyopia is greatly reduced.
A new technique for rigid gas permeable contact lens fitting following penetrating keratoplasty
Authors: Eggink Fred A. G. J. , Nuijts Rudy M. M. A. 
Published: March 2003

ABSTRACT. Purpose: To evaluate a new, rigid gas permeable contact lens fitting technique following penetrating keratoplasty.Methods: For the correction of postoperative anisometropia or astigmatism, a rigid gas permeable, tetra‐curve contact lens with an overall diameter of 12.0 mm and a back optic zone diameter of 8.5 mm was fitted in 36 eyes of 33 patients, 7 months after penetrating keratoplasty. The contact lens back optic zone radius was selected using the videokeratography values over the elevated edges of the transplant wound (with the sutures in place). Graft clarity, visual outcome, and corneal topography were evaluated up to 3 years after surgery at intervals of 6 months.Results: Throughout the follow‐up period (range 6–36, mean 19.3±sd 11.8 months), all grafts remained clear. Mean contact lens daily wearing time averaged 13.6 (±sd 4.7) hours. Mean best‐corrected visual acuity improved from +0.36 (±sd 0.18) LogMAR with spectacles to +0.11 (±sd 0.11) LogMAR with contact lenses (p<0.0001). One patient was excluded from the study due to a lack of motivation and one had an adverse reaction to the stitches.Conclusions: To improve the visual performance following penetrating keratoplasty, the described fitting technique, guided by videokeratography, eased selection of the back optic zone radius of the initial trial lens. The large diameter contact lenses with a tetra‐curve design were well tolerated in all patients for more than 13 hours daily.
The therapeutic effects of retinal laser treatment and vitrectomy. A theory based on oxygen and vascular physiology
Authors: Stefánsson Einar 
Published: March 2003

ABSTRACT.The physiologic mechanism of photocoagulation can been seen in the following steps. The physical light energy is absorbed in the melanin of the retinal pigment epithelium. The adjacent photoreceptors are destroyed and are replaced by a glial scar and the oxygen consumption of the outer retina is reduced. Oxygen that normally diffuses from the choriocapillaris into the retina can now diffuse through the laser scars in the photoreceptor layer without being consumed in the mitochondria of the photoreceptors. This oxygen flux reaches the inner retina to relieve inner retinal hypoxia and raise the oxygen tension. As a result, the retinal arteries constrict and the bloodflow decreases. Hypoxia relief reduces production of growth factors such as VEGF and neovascularization is reduced or stopped. Vasoconstriction increases arteriolar resistance, decreases hydrostatic pressure in capillaries and venules and reduces edema formation according to Starling’s law.Vitrectomy also improves retinal oxygenation by allowing oxygen and other nutrients to be transported in water currents in the vitreous cavity from well oxygenated to ischemic areas of the retina. Vitrectomy and retinal photocoagulation both improve retinal oxygenation and both reduce diabetic macular edema and retinal neovascularization.
Different clinical expressions in two families with Stargardt’s macular dystrophy (STGD1)
Authors: Eksandh Louise , Ekström Ulf , Abrahamson Magnus , Bauer Birgitta , Andréasson Sten 
Published: March 2003

ABSTRACT.Purpose: To describe the clinical expressions, with emphasis on electrophysiological examinations, in two Swedish families with Stargardt’s macular dystrophy (STGD1).Methods: Two pairs of siblings with STGD1, for whom diagnosis had been confirmed by genetic linkage to the ABCA4 gene region, were examined regarding visual acuity, kinetic perimetry, fundus photography, full‐field ERG and multifocal ERG (MERG). Possible disease‐causing mutations were screened for by DNA sequencing of selected regions of the ABCA4 gene.Results: All STGD1 patients had visual acuity 0.07–0.1. The two families presented different fundus appearances, MERGs and implicit times on 30 Hz flicker white light full‐field ERGs. Genetic analysis revealed one unique sequence variation in exon 19 of the ABCA4 gene, in one allele from the patients of one of the families. This point mutation causes the amino acid substitution T972N in the ABCR protein.Conclusion: Two pairs of siblings with STGD1 presented two different expressions of the disease regarding the distribution of the retinal dysfunction. One possible molecular explanation to the different clinical expressions may be the T972N substitution present in the ABCR protein in one of the STGD1 families investigated.
Spider keratouveitis A case report
Authors: Sandboe Frode D. 
Published: March 2003

ABSTRACT.Purpose: To present a case report on a patient with keratouveitis after exposure to a tarantula.Material: A 15‐year‐old boy presented with ocular redness and discomfort after his pet tarantula (Chilean Rose) had walked over his face.Methods: Clinical examination revealed inflammatory reactions in the corneas and the anterior chamber. After nine months, two subepithelial infiltrates of the cornea emerged, surrounding tarantula hairs of the stroma. The hairs were removed.Results: Topical steroids relieved the symptoms, but ten months after exposure there was still a mild reaction in the anterior chamber of the right eye.Conclusion: Hairs from pet tarantulas might penetrate deeply into the eye and give keratouveitis. The hairs might be difficult to detect. Though rare, this phenomenon should be known by both ophthalmologists and the public.
Putative non‐uniting double central retinal artery system
Authors: Beiran Itzchak , Gelfand Yuval , Miller Benjamin 
Published: March 2003

ABSTRACT.Purpose: To report a case of probable non‐uniting double retinal arterial circulation.Methods: Case report. A 66‐year‐old man suffered central retinal artery occlusion.Results: The medical findings and angiographic workup supported the existence of double central retinal circulation not uniting before entering the globe and independently branching in the retina.Conclusions: In previously recognized unusual anatomic structures of the central retinal artery two parallel arteries were recognized, both of which united before entering the globe. We have described a rare anatomic variant in which those arteries remained separated after entering the globe, including while branching in the retina.
The frequency of amblyopia among visually impaired persons
Authors: Jakobsson Peter , Kvarnström Gun , Abrahamsson Mariann , Bjernbrink‐Hörnblad Eva , Sunnqvist Birgitta 
Published: March 2003

ABSTRACT.Purpose: To investigate the frequency of amblyopia among visually handicapped patients.Methods: The study is a retrospective investigation of all living patients registered in four Visual Rehabilitation Centres in a region in southern Sweden. The area's total population numbered 865,612 persons of whom 11,365 were registered as visually handicapped (with visual acuity ≤ 0.3 in the better eye).Results: Amblyopia was the main cause of decreased visual acuity in one eye in 1.72% (195 of 11,365) of the patients. The average age of the patients with amblyopia was 69 years (9−95 years) and 28.2% of these patients were less than 65 years old (the age for retirement in Sweden).The median visual acuity in the amblyopic eye among these patients was 0.1. The median visual acuity in the nonamblyopic eye was 0.2. The most common cause of decreased vision in the nonamblyopic eye was macular degeneration (39.5%). Bilateral amblyopia was present in 13 (6.7%) of the amblyopic patients. By comparing this study with earlier studies, we can calculate that about 1.2% of the persons with amblyopia 0.3 or lower will eventually become visually handicapped.Conclusion: A small but considerable number of patients who attend the Visual Rehabilitation Centres have amblyopia as a cause of their visual impairment. Since amblyopia can be treated if detected in childhood, later visual rehabilitation of these patients can be avoided or delayed, thereby reducing rehabilition costs for society.
Colour contrast sensitivity in ocular hypertension. A five‐year prospective study
Authors: Friström Björn 
Published: March 2003

ABSTRACT.Purpose:  To evaluate a peripheral colour contrast sensitivity test as a tool for early diagnosis of glaucoma in a five‐year prospective study.Patients and methods
:
Peripheral colour contrast sensitivity was measured with a computer graphics system developed by Arden et al. The test colours were varied along the protan, deutan and tritan colour confusion axes on a scale from 0 to 100 percentage units. Fifty‐five ocular hypertensive (OH) patients examined with the colour contrast test, stereoscopic photography of the optic discs, and measurements of visual fields (Humphrey 24–2 glaucoma hemifield test (GHT)) in 1994, were re‐examined after five years.Results:  Ten patients were ‘outside normal limits’ in the GHT at follow‐up. This group of 10 patients did not differ in colour contrast thresholds at the test in 1994 from the 45 who were still ‘normal’ (or ‘borderline’) at follow‐up. Neither were there proportionally more patients with GHT ‘outside normal values’ for the patients with high colour contrast thresholds (> 30% units) in 1994 regarding any of the three colour axes. As judged from patient files, 27 patients had developed glaucoma during follow‐up. Although there were differences between these 27 glaucoma patients and the remaining OH group at the colour contrast test in 1994, these differences did not reach statistical significance for any of the colour axes (largest difference in the tritan axis: 6.2% units, P = 0.0745). At follow‐up, however, there was a significant difference in colour contrast for the protan axis between the clinical glaucoma group and the OH group (6.7% units, P = 0.0105).Conclusion
:
The method used for colour contrast measurement did not reveal glaucomatous changes before conventional perimetry (Humphrey 24–2, GHT). Neither did it predict the patients who, in our clinic, subsequently developed glaucoma during a five‐year period. A change over time in colour contrast in the protan axis for an OH patient may, however, indicate glaucoma development.
Biochemical markers of the L‐arginine‐nitric oxide pathway in the aqueous humour in glaucoma patients
Authors: Kotikoski Hanna , Moilanen Eeva , Vapaatalo Heikki , Aine Esko 
Published: March 2003

ABSTRACT.Purpose:  To study the role of the L‐arginine‐nitric oxide (NO) pathway in aqueous humour dynamics by measuring nitrate, nitrite and cyclic (cGMP) levels in guanosine 3′,5′‐monophosphate the aqueous humour of glaucomatous and nonglaucomatous cataract patients.Methods:  The study involved 38 glaucoma patients undergoing unilateral cataract surgery in the glaucomatous eye and 38 cataract control patients matched for sex, age, smoking habits and organic nitrate medication. All subjects underwent ophthalmic examination, and blood pressure was measured preoperatively. Nitrite, nitrate and cGMP levels were measured in aqueous humour and serum.Results:  The NOx (nitrite + nitrate), nitrite and cGMP concentrations in the aqueous humour were slightly higher in the glaucoma patients than in the control patients, but the differences did not reach statistical significance. The levels of cGMP in serum were higher in the glaucoma patients (P = 0.053). The subgroup of glaucoma patients with pseudoexfoliation had lower NOx and nitrite values in the aqueous humour (P = 0.046 and P = 0.345, respectively) than the matched controls, while cGMP levels were higher (P = 0.043). Levels of NOx and nitrite in the aqueous humour were higher in patients using oral nitroglycerin (P = 0.062 and P = 0.042, respectively) than in patients without this medication. Blood pressure was higher in the glaucoma patients, with a mean of 165/89 mmHg as compared to 153/81 mmHg in the controls (P‐values 0.071/0.008).Conclusions:  No differences in NO metabolites were found between glaucoma and control patients. However, any real changes may have been disguised by optimal medication of glaucoma. Low NOx and high cGMP levels in the aqueous humour of pseudoexfoliation patients warrant further evaluation in a larger study.