14 research outputs found

    The Importance of the Relationship Between The Position of the Correcting Lens Principal Planes (H\u271-H\u272) and Principal Planes (H1-H2) of the Optical Eye System ā€“ Aphakic Correction

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    In the clinical refraction of the eye, aniseikonia and anisometropia are inevitably used terms. Image formation and its retinal size is the function of the power of the dioptric eye system. However, the correcting lens in front of the eye and the eye optical system represent a unique optical afocal system, in which the distance between correcting lens and corneal vertex is of utmost importance, since it determines the size (together with appropriate correcting lens) of the retinal image. In the case of a monoculus, the size of the retinal image is not important. But, when correcting one eye while the other is emmetropic, it is important to correct it in the way that the image of the corrected eye does not produce considerable aniseikonia as a consequence of anisometropia. The authors hereby present mathematical calculation proving that if the principal point of the correcting lens P\u272 is in the F1 of the emmetropic eye, meaning that? is equal to the front focal length of the emmetropic eye, there is no change in the refractive eye system, i.e. it becomes emmetropic and there is no change in the size of the retinal image. It means that an ideal position of the correcting lens in front of the eye guarantees no aniseikonia even in the extreme case of monocular aphakic spectacle correction

    Solar Spectral Lines (Ā»Solar HaloĀ«) ā€“ Healing or Harmful for The Retina?

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    The sungazing method has been known for thousands of years as healing method based on chromotherapeutic principle. Our examinations on the island of Rab show that it is acceptable only if applied 10 min before the sunset. Gazing has to be directed towards the green-yellow part of the spectrum, since the remaining part of the sun halo contains harmful energy. However, authors suggest that it would be preferable to use spectacles with medical filters transmitting wavelight of green-yellow colour, especially for treatment of macular degeneration

    Personal Identification by Eyes

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    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems

    Incidence of Age Related Macular Degeneration in Correlation with Age, Sex and Occupation

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    This study assesses the relation between age related macular degeneration (ARMD) and age, sex and occupation. It is designed as a retrospective study conducted on patients presenting to the Eye Polyclinic Ā»Dr. L. Pavi~evi}Ā«, Rijeka, Croatia, during the years 1995, 2000 and 2005. and included total of 6617 patients. The number of patients diagnosed with ARMD, their age and sex distribution, as well as the correlation between occupation type (indoor /outdoor) and the incidence of ARMD were analyzed. The results of our study show that the incidence of ARMD is slightly increased in female vs. male, strongly age related, as expected, and significantly increased in patients with outdoor type of occupation. Besides, an increasing trend of incidence is noted

    Sunlight and Incidence of Pterygium on Croatian Island Rab ā€“ Epidemiological Study

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    The aim of this epidemiologic study, on small island Rab, in North Adriatic Sea, is to estimate correlation between climatic factors, specially chronic exposure to strong visible and UV light, and appearance of pterygium and exfoliation syndrome. In the first group of population which live in a village and who are agriculturists and fishermen (480 persons) appearance of pterygium is in 23% (16% in males and 7% in females), but 0.0% in urban people (61 people). The appearance of exfoliation syndrome was in the first group of agriculturists and fishermen population in 21%, of which 19% of males and 2% of females, and in urban people 0.0%. The higher intraocular pressure in exfoliation syndrome was 92%. All population in this examination were in the highest age (mean age is 65ā€“80 years). Chronic exposure to sunlight caused the high percentage appearance of pterygium and exfoliation syndrome

    Dental Inflammation and Central Retinitis ā€“ It Is Important to Protect the Retina from the Harmful Sunlight

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    During 3-year study of 73 patients with dental inflammation, sinusitis, otitis and 5 cases with granuloma, in 9 cases we observed the development of central retinitis. All patients were medicated with the same antibiotics and parabulbar depo of Prednisolonacetate. To 50% of these patients, we suggested eye protection with Yellow Medical filters during two months. In the first group with medication we observed better vision in 69%, but in the second group with eye protection with Yellow Medical filters we observed normalization of vision in 100%

    Long Term Results of Age-Related Macular Degeneration Therapy with Prednisolone Acetate ā€“ Special Refer to Peripheral Visual Field Changes

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    In the north Croatian Adriatic area in the period of seven years (from January 2001 to September 2007) 475 patients (39 to 80 years of age) with dry form of age related macular degeneration (AMD) were diagnosed. Complete ophthalmologic examination with special reference to visual field testing (Perimetric analysis) was performed. Peripheral visual field defects were found in 85% of patients. Elderly patients with more advanced forms of macular degeneration had more peripheral visual field defects. In 400 patients corticosteroid therapy (5 mg Prednisolonacetate, anterior H-inject, Winthorp) was administered via parabulbar injections every day/five days. Control group consisted of 75 patients treated with regular polyvitamine therapy (Lutein, Beta Karoten, Vitamin E). Patients treated with corticosteroids had peripheral visual field improvements from 10 to 25 degrees and central field improvements from 5 to 20 %. In the control group treated with vitamins, central visual field showed improvements from 0.5 to 1% in 43 patients but without peripheral visual field improvements after 6 months

    Ultraviolet Sun Radiation and Incidence of Age-Related Macular Degeneration on Croatian Island Rab

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    This epidemiological study is completed on island Rab, located in North Adriatic Sea. For this study it is important that Adriatic Sea has one of the highest solar radiations in geographical area of Europe. The aim of this epidemiological study is to estimate correlation between incidence of Age-Related Macular Degeneration (AMD) and exposure of sunlight in two different populations on island Rab. In the first group of population of island Rab, agriculturists and fishermen (n=1300), incidence of AMD was in 18%, but in urban population only 2.5%. It is very interesting that correlation exists between incidence of AMD and exfoliation syndrome. In the group of chronic exposure to sunlight (agriculturists and fishermen) exfoliation syndrome exists in 28%, but in urban population it has never been seen. The age in both populations was 45ā€“65 years. We can conclude that there is a very significant correlation between chronic exposure to sunlight and appearance of AMD

    Personal Identification by Eyes

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    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems

    Appearance of Age Related Maculopathy after Cataract Surgery

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    The pathogenesis of age-related maculopathy (ARM), the most common cause of visual loss after the age of 60 years, involves a variety of hereditary and environmental factors. When the cataractous lens is removed and replaced by clear intraocular lens, a significant increase in ocular transmittance of optical radiation occurs. The aim of this study was to assess whether cataract surgery in older persons may increase the risk for development of ARM. This is a retrospective study. Medical records of 307 patients, aged 43 to 96 years, (163 male and 144 female) were randomly evaluated. They had undergone cataract extraction (phacoemulsification or extracapsular lens extraction) with clear intraocular lens implantation from January 2001 to December 2005 at the Department of Ophthalmology, University Hospital Rijeka. Patients were examined two weeks after surgery and followed up for at least two years. Based on the exclusion criteria, only patients without any sign of AMD at the first postoperative check up were included. A total of 80 patients (26%) showed development of ARM at the last check up, which was at least 2 years after surgery. Our results indicate that pseudophakia is a risk factor for development of ARM
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