Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344232 (blurred vision)
 2,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normally light transmission through the eye is benign and serves to direct vision and circadian rhythm. However, with very intense light exposure, or with ambient light exposure to the aged eye and/or young or adult eye in the presence of light-activated (photosensitizing) drugs or dietary supplements, cosmetics, or diagnostic dyes, light can be hazardous, leading to blinding disorders. Light damage to the human eye is avoided because the eye is protected by a very efficient antioxidant system and the chromophores present absorb light and dissipate its energy. After middle age, there is a decrease in the production of antioxidants and antioxidant enzymes and an accumulation of endogenous chromophores that are phototoxic. The extent to which a particular exogenous photosensitizing substance is capable of producing phototoxic side effects in the eye depends on several parameters, including (1) the chemical structure; (2) the absorption spectra of the drug; (3) binding of the drug to ocular tissue (lens proteins, melanin, DNA); and (4) the ability to cross blood-ocular barriers (amphiphilic or lipophilic). For instance, compounds that have either a tricyclic, heterocyclic, or porphyrin ring structure and are incorporated into ocular tissues are potentially phototoxic agents in the eye. The extent to which these substances might damage the eye (photoefficiency) can be predicted using in vitro and photophysical techniques. With simple, inexpensive testing, compounds can be screened for their potential ocular phototoxicity at the developmental stage. It may be that a portion of the molecule can be modified to reduce phototoxicity while leaving the primary drug effect intact. Preclinical safety testing may prevent ocular side effects that can range from mild, reversible blurred vision to permanent blindness.
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PMID:Screening for ocular phototoxicity. 1253 45

Myopia is one of the most prevalent ocular conditions and is the result of a mismatch between the power of the eye and axial length of the eye. As a result images of distant objects are brought to a focus in front of the retina resulting in blurred vision. In the vast majority of cases the structural cause of myopia is an excessive axial length of the eye, or more specifically the vitreous chamber depth. In about 2% of the general population, the degree of myopia is above 6 dioptres (D) and is termed high myopia. The prevalence of sight-threatening ocular pathology is markedly increased in eyes with high degrees of myopia ( > -6 D). This results from the excessive axial elongation of the eye which, by necessity, must involve the outer coat of the eye, the sclera. Consequently, high myopia is reported as a leading cause of registered blindness and partial sight. Current theories of refractive development acknowledge the pivotal role of the sclera in the control of eye size and the development of myopia. This review considers the major biochemical mechanisms that underlie the normal development of the mammalian sclera and how the scleral structure influences the rate of eye growth during development. The review will characterise the aberrant mechanisms of scleral remodelling which underlie the development of myopia. In describing these mechanisms we highlight how certain critical events in both the early and later stages of myopia development lead to scleral thinning, the loss of scleral tissue, the weakening of the scleral mechanical properties and, ultimately, to the development of posterior staphyloma. This review aims to build on existing models to illustrate that the prevention of aberrant scleral remodelling must be the goal of any long-term therapy for the amelioration of the permanent vision loss associated with high myopia.
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PMID:Role of the sclera in the development and pathological complications of myopia. 1285 89

Toxoplasmosis was the most common cause of primary retinochoroiditis. The majority of cases of ocular toxoplasmosis were congenital. However, cases of acquired ocular toxoplasmosis have been reported. The clinical manifestations of congenital ocular toxoplasmosis were choroidal coloboma, strabismus, nystagmus, ptosis, microphthalmia, cataract and enophthalmia. The purpose of this study was to determine the clinical presentation and visual outcome of 173 patients with ocular toxoplasmosis at Dr Sardjito Hospital, Dr Yap Eye Hospital, and private practice during the last six years. A total of 173 subjects were studied--98 males and 75 females. The ages at which first diagnosis was established ranged from 3 months to 68 years, frequently in young adults and occurring mostly in students. The most-reported chief complaint was blurred vision in 70.5% and floaters in 6.1% of cases. The most frequent clinical manifestations were chorioretinitis (71.2%), macular scars (22.4%), squint (6.4%), congenital cataract (2.8%), nystagmus (6.4%) and atrophic optic papilla (2.8%). Bilateral involvement was found in 32.4% of all patients. The therapeutic outcome showed improvement, especially visual acuity in acute cases (25.6%). However, visual acuity categorized as blindness was 13.9%. The results of the study imply that suddenly blurred vision in the quiet eye in the young adult, squint, and nystagmus in children could be chorioretinal inflammation and scar caused by Toxoplasma gondii.
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PMID:Clinical manifestations of ocular toxoplasmosis in Yogyakarta, Indonesia: a clinical review of 173 cases. 1297 52

Although laser treatment keeps vision damaged by diabetic retinopathy from becoming worse, it only rarely improves vision. If primary care physicians wait until the patient complains of blurred vision, it is too late--there is already permanent retinal injury, and the lost vision almost never can be restored. Unfortunately, only half of patients with diabetes undergo an appropriate examination every year. Only by teamwork between primary care physician and ophthalmologist can blindness from diabetic retinopathy be reduced.
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PMID:The internist's role in managing diabetic retinopathy: screening for early detection. 1498 91

Extraintestinal manifestations of inflammatory bowel disease (IBD) occur in one third of patients. Ocular complications are infrequent, occurring in less than 10% of cases, but can be associated with significant morbidity, including blindness. Ocular complaints are often nonspecific; clinical relevance may not be appreciated by patient or physician and, thus, be misdiagnosed. Evaluation of the eye should be a routine component in the care of patients with IBD. Clinicians must be aware of the spectrum of ocular symptoms and know that these complaints may precede a diagnosis of ulcerative colitis (UC) or Crohn's disease (CD). We review ocular pathology in IBD to alert clinicians to the diverse, at times confusing, spectrum of eye disorders associated with these diseases. Clinical manifestations include blurred vision, teary, burning or itchy eyes, ocular pain, photophobia, conjunctival or scleral hyperemia, loss of visual acuity, and possible blindness. Many patients are unaware that IBD has a risk of eye complications and, therefore, patient education is vital.
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PMID:Ocular manifestations of inflammatory bowel disease. 1516 14

Takayasu's arteritis is a rare idiopathic arteriopathy that produces narrowing and eventually closure of affected blood vessels. Ocular symptoms typically occur late in the disease process in those individuals who have severe involvement of the aortic arch and the carotid arteries. Visual loss typically occurs as a result of either systemic hypertension or concomitant ocular hypo-perfusion. We describe an unusual case of Takayasu's arteritis presenting in a child who complained of painful blurred vision. In this individual, no carotid artery disease was identified on vascular imaging and no evidence of impairment of ocular perfusion was demonstrable. Vision loss in this instance was due to anterior uveitis and cystoid maculopathy. These are atypical and rarely described features of Takayasu's arteritis. The patient responded well to anti-inflammatory treatment and his symptoms resolved. The clinical significance of these findings are discussed and the relevant literature reviewed.
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PMID:Anterior uveitis in a child with Takayasu's arteritis. 1518 Aug 52

In this review, 35 cases of acute, reversible, sometimes severe, disturbances of vision closely associated with the use of celecoxib or rofecoxib are described. These were identified from three different databases using strict selection criteria. The events included temporary blindness, visual field defect, scotoma, teichopsia, blurred vision, decreased vision and abnormal vision. The reactions had a mean onset time of 9.5 days and recovery occurred within 3 days following withdrawal of the drug. The reactions do not appear to be related to age, gender, dose, or indication for use. The incidence of reported cases is estimated to be not less than 5 per 10,000 patients. Possible mechanisms for this type of reaction are described. The most likely appears to be the result of interference with the retinal blood supply through reduced production of prostanoids. Genetic polymorphisms that affect drug metabolism or uptake could be risk factors and are discussed along with suggestions for research.
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PMID:Disturbance of vision by COX-2 inhibitors. 1550 Apr 19

Sickle cell disease has varied manifestations in all systems of the body, ocular manifestations can be severe and sudden blindness may result amidst other complications. The study aims at determining the ocular findings in patients with sickle cell anaemia (HbSS) and sickle cell haemoglobin C disease (HbSC). 99 subjects were recruited into the study carried out at the Lagos University Teaching Hospital over a 2 year period. A structured interview questionnaire was administered and physical examination was carried out at the Medical Out Patients' Sickle Cell Clinics. Subsequently in the (Guinness) Eye centre, examination for ocular manifestations was carried out using Snellen's chart, Slit light microscopy, direct and indirect ophthalmoscopy under mydriasis (with Gutt Tropicamide 1% , epinephrine 10% ) as well as tonometry and gonioscopy. The age of the 99 (51 males, 48 females) patients ranged from 13 to 43 years with a mean +/-SD of 20.42 +/- 6.13. There were 88 (88.9% ) SS and 11 (11.1% ) SC patients. The male to female ratio was 1.1: 1. Normal vision was present in 95 (96% ) of the patients [86 (97.8% ) SS and 9 (81.8% ) SC] while 4 (4.0% ) of the patients [2 (2.2% ) SS and 2 (18.2% ) SC] had impaired vision. Of the complaints, blurred vision was found in 12 (13.6% ) SS and one (9.0% ) SC patients. Itching of the eyes was found in 15 (17.0% ) SS and 3 (27.3% ) SC patients. Icterus was found in 50 (50.5% ), conjunctival signs were found in 49 (49.5% ), retinal vascular tortuosity was in 12 (12 .10% ), peripheral retinal degeneration was in 5 (5% ), iridescent spots was in 3 (3% ) and optic atrophy in 2 (2% ) patients. The tortuosity of major fundus vessels were graded into 4 according to Hook and Cooper's criteria 87 (87.9% ) of the patients were in grade 0. The conjunctival vessels anomalies were classified into 5 grades (criteria of Sergeant). 37 (37.5% ) were in grade 0, 35 (35.3% ) in grade 1, 8 (8.1% ) in grade 2, 7 (7.1% ) in grade 3 and 12 (12.1% ) in grade 4. Conjunctival abnormalities occur commonly while proliferative retinopathy and optic atrophy were uncommon in sickle cell disease patients in Lagos. Further studies are required with a larger number of subjects to investigate the low incidence of proliferative retinopathy and optic atrophy in Lagos.
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PMID:Ocular findings in sickle cell disease patients in Lagos. 1550 51

To determine the ocular morbidity, visual disability and potential for blindness in leprosy patients recently released from treatment. In-patients from Eku leprosy settlement were interviewed and examined for ocular disease from leprosy and other causes. They were examined using the Snellen's chart, pentorch, Kowa portable slit-lamp, direct ophthalmoscope and the pulsair non-contact tonometer. The patients were also refracted. In all, 60 inpatients who were recently released from treatment, comprising 39 men (65%) and 21 women (35%), were examined. Fifty-eight patients (96.67%) had ocular symptoms, the most common being blurred vision in 23 patients (38.33%). Nine patients (15%) were blind. Cataract was the most common cause of blindness occurring in three of the nine patients (33.33%). The most common types of ocular lesions were madarosis (31.67%), lagophthalmos (16.67%) and cataract (16.67%). Potentially blinding conditions due to leprosy were seen in 42 patients (70%). The incidence of ocular involvement, blindness and potentially blinding conditions are high in leprosy patients recently released from treatment. Regular ophthalmic evaluation and integration into Vision 2020 programmes are recommended.
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PMID:Ocular leprosy in Nigeria: a survey of an Eku leprosorium. 1648 26

The posterior superior alveolar nerve (PSAN) is a major sensory branch of the maxillary division of the trigeminal nerve. A PSAN block is a dental nerve block used for profound anesthesia of the maxillary molars. Complications arising from the PSAN block include hematoma formation, transient diplopia, blurred vision, and temporary blindness. This article presents a case of temporary paresis in the lateral pterygoid muscle following a PSAN block that utilized a 27-gauge long needle. The anatomical parameters and pathogenesis of such a complication are reviewed.
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PMID:Transitory paresis of the lateral pterygoid muscle during a posterior superior alveolar nerve block--a case report. 1805 May 79


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