Search Results - "International Ophthalmology"

1573-2630

conjunctivitis ; Impression Cytology method ; Limbal Vernal Keratoconjunctivitis ; retinol ; trachoma ; xerophthalmia

Springer Online Journal Archives 1860-2000

Medicine

Abstract During a countrywide survey, we assessed the prevalence of clinical signs of xerophthalmia and of major conjunctival diseases in a randomized sample of 2,445 subjects representative of the population of the Republic of Djibouti. On a part of this sample, conjunctival Impression Cytology with Transfer (ICT) test and a plasma retinol determination were performed. Xerophthalmia as a public health problem was displayed by clinical signs (Bitot's spots, corneal scars among preschool children), low plasma retinol levels and ICT test results: 9.3% with deficient cytology in the rural area and 12.3% in the urban one (agestandardized rates). Results of ICT were related to age (p 〈 0.00001). Vitamin A deficiency was prevalent not only in preschool children but also up to 15 years. Moreover, ICT results are influenced by conjunctival diseases: compared to age-matched controls, there were more abnormal cytologies among patients with trachomatous inflammation (p=0.025), conjunctivitis (p=0.024) or Limbal Vernal Keratoconjunctivitis (p=0.015). Thus ICT shouldn't be performed among children with conjunctival diseases. In the region under study conjunctival diseases had high rates of prevalence: 16.4% of trachomatous scarrings in the urban area (standardized rate), 8% of conjunctivitis among rural preschool children, and 5% of Limbal Vernal Keratoconjunctivitis among children between 5 and 14 years in both areas.

Electronic Resource

1573-2630

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1573-2630

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1573-2630

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1573-2630

basic fibroblast growth factor ; electroretinogography ; intravitreal b-FGF injection ; retinal toxicity ; vitreoretinal pathology

Springer Online Journal Archives 1860-2000

Medicine

Abstract Basic fibroblast growth factor (b-FGF) is one of the multifunctional growth factors with important therapeutic potential in the field of ophthalmology. It is also implicated in pathogenesis of vitreoretinal proliferative diseases. In the present study, we evaluated its vitreoretinal toxicity by means of clinical observation, electroretinography (ERG), and histopathology after injection of different doses of b-FGF into the vitreous of rabbit eyes. Doses of b-FGF up to 2 μg per eye caused no toxicity; however, injection of 4 μg or more resulted in sight-threatening vitreoretinal proliferative changes. This information is important for studies aimed at evaluating the therapeutic potential of b-FGF in retinal diseases. Despite some degree of vitreous organization and opacification, retinal folds, and small areas of traction retinal detachment, the amplitudes of ERGs were normal or even increased (hyperpolarization) in eyes which received 8 μg of b-FGF.

Electronic Resource

1573-2630

mid-infrared laser ; photoablation ; glaucoma surgery ; trabecular meshwork ; sinostomy

Springer Online Journal Archives 1860-2000

Medicine

Abstract Current trends of laser technology towards low-thermal photoablative pulsed mid-infrared lasers open new, more adequate approaches to experimental surgical procedures which have already been evaluated in the past. Transcorneal laser ablation of the trabecular meshwork (internal sinostomy) in human autopsy eyes was performed with a Q-switched CTE:YAG laser (wavelength: 2.69 μn, pulse width: 1 μs). Beam delivery was achieved with conventional optical quartz fibers (Low-hydroxy-fused-silica: 0,3 ppm, 50 cm length, 200 μn diameter). Light- and scanning-electron-microscopy were used for histological examination and micromorphological analysis. By applying two laser pulses (6 J/cm2) to the functional trabecular meshwork, a round sinostomy with a diameter corresponding to the diameter of the fiber-tip was achieved. It was possible to set several internal sinostomies into the chamber angle opposite to the entering paracentesis of the laser fiber-tip. Collateral thermal tissue alteration reached up to 50 μm, and since fiber-tip contact was maintained during laser application, thermal tissue alteration was also found around the opposite wall of Schlemm's canal. At higher energy fluences mechanical (disruptive vaporization) effects were significantly enhanced. It can be concluded, that low-thermal pulsed mid-infrared lasers are adequate instruments to perform transcorneal trabecular ablation (abinterno sinostomy). The laser used in this study (CTE:YAG) bears the advantage that its radiation can easily be delivered in conventional optical quartz fibers.

Electronic Resource

1573-2630

childhood blindness ; retinopathy of prematurity ; Vitamin A deficiency

Springer Online Journal Archives 1860-2000

Medicine

Abstract Using WHO definitions of visual loss and a standardised methodology, 256 children were examined in schools for the blind in Thailand (1 school) and the Philippines (3 schools). 244 (95%) were blind (BL) or severely visually impaired (SVI). Causes of SVI and blindness were classified anatomically and aetiologically, and avoidable causes identified. Causes of visual loss in Khon Kaen, Thailand (n = 65) and Manila, Philippines, (n = 113) were similar, with conditions of the whole globe accounting for 27.7 and 27.4% of SVI/BL; retinal disease 29.2 and 23.0%; cataract 16.9 and 16.8%; corneal disease 12.3 and 13.4%; and optic nerve disease and glaucoma 6.2 and 8.8%. Perinatal factors accounted for 20.0 and 23.0% of SVI/BL; hereditary disease 13.8 and 17.7%; and 12.3 and 15.0% was due to events occurring during childhood. The underlying aetiology could not be determined in 50.8 and 41.6% of cases, respectively. In the two schools together twenty six children (15%) were blind from retinopathy of prematurity (ROP) and 16 (9%) from corneal scarring attributed to Vitamin A deficiency. 103 of 178 (58%) children had avoidable causes of visual loss. In the Filipino towns of Baguio and Davao (n = 66), the causes of visual loss were different from those in Khon Kaen and Manila, with 54.8 and 42.9% of SVI/BL being due to corneal disease, and only 3.2 and 8.5% to retinal disease. Childhood factors were more important (61.3 and 57.1%) than hereditary (9.7 and 17.1%) or perinatal factors (0 and 2.9%). Thirty one children (47%) had SVI/BL attributed to Vitamin A deficiency. No child was blind from ROP. 42 of 66 (64%) of children had avoidable causes of blindness. Overall 60% of children with SVI/BL had avoidable causes of visual loss in these 4 schools. Approximately half could have been prevented by primary health and eye care services and half could have been managed by surgical ophthalmological procedures. The causes of blindness identified in this blind school study suggest that the major causes are different for schools serving rural populations compared to those serving urban communities. Different control strategies are required for the different situations.

Electronic Resource

1573-2630

cataracts ; ophthalmic surgery ; primary eye-care

Springer Online Journal Archives 1860-2000

Medicine

Abstract Cataract remains the leading cause of blindness worldwide, curable though, by a simple procedure. The backlog of cataract patients in developing countries is mounting despite sustainable and downright efforts by health ministries, international voluntary and non-governmental organisations [1]. The current situation has put many developing countries in a difficult dilemma. The authors present a review of a pilot-project in decentralised eye-care in Mutasa District, Zimbabwe. Cataract surgery is performed by a district general doctor as an alternative to clearing the cataract back-log in developing countries, as suggested in several studies [2–5]. It is important to persuade the health ministries to adopt this simple and cheap policy [6, 7].

Electronic Resource

1573-2630

cortical blindness ; head trauma ; migraine ; vasospasm

Springer Online Journal Archives 1860-2000

Medicine

Abstract Five patients: three children, one adolescent, and one young adult, examined in an emergency room setting were diagnosed with post-traumatic transient cortical blindness. This syndrome is characterized by transient visual loss, normal pupillary response and normal funduscopic examination following minor head trauma. In each case, vision returned to normal within minutes to hours following injury, leaving no neurological sequelae. Headache, confusion, irritability, anxiety, nausea and vomiting were the most common related symptoms. While the mechanism responsible for the transient blindness is unknown, most authors propose an abnormal vascular response to trauma with resultant transient hypoxia and cerebral dysfunction. The similarity between the symptoms accompanying this syndrome and those seen during a classic migraine attack has led many investigators to suggest a common underlying pathophysiology. The purpose of this report is to highlight the salient clinical features and diagnostic approaches to this syndrome, thereby providing ophthalmologists and emergency room physicians a heightened awareness of this entity and the means to detect it.

Electronic Resource

1573-2630

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1573-2630

Proliferative neovascular retinopathies ; Vitrectomy ; Contraction of proliferative tissue

Springer Online Journal Archives 1860-2000

Medicine

Abstract Proliferative neovascular retinopathies may be caused by the release of a hypothetical vasoproliferative factor, but mechanical factors seem to self-perpetuate the disease as well. Contraction of proliferative tissue causes vitreous detachment and traction on the retina. Congestion of vascular fronds by traction further stimulates vascularization. Traction on vessels results in hemorrhages. Surgical removal of all intravitreal scaffolds by vitrectomy seems to eliminate the development of this vicious cycle. Results of vitreous surgery seem to indicate that the hypothesis of scaffold removal is valid.

Electronic Resource

1573-2630

Optic nerve ; Blood supply ; Ischemic optic neuropathy (ION) ; Anterior ischemic optic neuropathy (AION) ; Posterior ischemic optic neuropathy (PION)

Springer Online Journal Archives 1860-2000

Medicine

Abstract Ischemic optic neuropathy (ION), based on vascular anatomy of the optic nerve, pathogenesis and clinical picture, consists of two distinct entities: anterior (AION) and posterior (PION) ischemic optic neuropathies. AION is due to interference with posterior ciliary artery supply to the optic nerve head and retrolaminar part of the optic nerve; it initially presents with visual loss and optic disc edema which progresses to optic atrophy in a month or two. PION is due to occlusion of nutrient arteries to the posterior part of the optic nerve; in this condition during the initial stages the optic disc is normal in spite of marked visual loss, but the atrophy develops later on. Their pathogeneses, causes, clinical pictures, diagnosis and management are discussed briefly.

Electronic Resource

1573-2630

Diabetic retinopathy ; Light coagulation ; Focal coagulation ; Indirect metabolic effect

Springer Online Journal Archives 1860-2000

Medicine

Abstract The beneficial effect of photocoagulation in diabetic retinopathy is now established (2–6, 10). Whereas the capability of providing photocoagulation is widespread, the indications and actual techniques are poorly defined. In this paper, we propose to discuss the principles of photocoagulation. In a following paper the detailed techniques required for the treatment of individual lesions and of different types of retinopathy will be discussed.

Electronic Resource

1573-2630

Penetrating ocular trauma ; Pars plana vitrectomy ; Fibrous proliferation ; Vitreous hemorrhage

Springer Online Journal Archives 1860-2000

Medicine

Abstract Thirty-four severely injured eyes were operated with pars plana vitrectomy. The nine cases with involvement exclusively of the anterior segment alone were operated with success in all cases. However, the injuries of the posterior segment still reflect significant problems in that only 50 percent obtained successful visual results. This reflects, in great part, the degree of severity of the initial damage. The theoretical rationale for pars plana vitrectomy in penetrating ocular trauma is discussed. Because of the many variables from patient to patient and injury to injury, conflicting clinical impressions as to appropriate management prevail. In the abscence of a definitive clinical trial or suitable experimental model, our guidelines for the role and proper timing of pars plana vitrectomy for penetrating ocular trauma are presented.

Electronic Resource

1573-2630

Melanocytoma ; Optic nerve tumors

Springer Online Journal Archives 1860-2000

Medicine

Abstract The melanocytoma of the optic disc is a deeply-pigmented tumor located on the optic nerve head. In contrast to malignant melanoma, it appears to occur in equal frequency in whites and non-whites. Histologically, it consists of deeply-pigmented plump nevus cells with benign characteristics. No treatment is usually necessary and the prognosis is excellent.

Electronic Resource

1573-2630

Gyrate atrophy ; Retinal pigment epithelium ; Hyperornithinaemia

Springer Online Journal Archives 1860-2000

Medicine

Abstract A 10 year old white girl is presented with gyrate atrophy of the choroid and retina (atrofia gyrata). She also showed reticular pigmentations at the level of the retinal pigment epithelium temporal to both maculas. A generalized hyperornithinaemia was demonstrated in this patient and cultured fibroblasts established the underlying ornithine-keto-acid-transaminase (OKT) deficiency for the first time. Pharmacologic doses of vitamin B6 nor restriction of dietary protein resulted in a significant decrease of the serum ornithine concentration. It is probable that hyperornithinaemia in itself is not the cause of the gyrate atrophy.

Electronic Resource

1573-2630

EGb 761 ; glutathione peroxidase ; lens induced uveitis ; lipid peroxidation ; pigmented guinea pigs

Springer Online Journal Archives 1860-2000

Medicine

Abstract An acute lens-induced necrotizing intraocular inflammation was produced in pigmented guinea pigs. Treatment of these animals by 100 mg/kg/day EGb 761 a free oxygen radical scavenger for 10 days, reduced retinal lipid peroxidation (p〉0.05) and increased the retinal glutathione peroxidase level (p 〉 0.05). Although not significantly, these findings suggest that EGb 761 could be combined with other antiinflammatory drugs and may be beneficial in the treatment of uveitis.

Electronic Resource

1573-2630

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1573-2630

biomicroscopy ; classification ; iris fluorescein angiography ; pigmented iris tumors

Springer Online Journal Archives 1860-2000

Medicine

Abstract The classification of pigmented iris tumors is a difficult clinical problem. Based on the retrospective observation of colour photographs and iris angiograms of 44 pigmented iris tumors observed over 19 years, the authors present an original grading scheme with scores depending on both the biomicroscopical and the fluoroiridographic patterns of the tumors. The biomicroscopical parameters considered were: thickening of the iris in the area of tumor, pupillary distortion and/or ectropion uveae and uneven pigment density. The fluoroiridographic parameters were: early visibility of the anomalous tumoral network, hyperfluorescence inside or around the tumor, and dye leakage at sites remote from the mass. Based on the score of each tumor, the 44 cases were divided into 3 groups with the different degrees of malignancy confirmed by either histological examination or by follow-up behaviour. The authors suggest that routine use of biomicroscopic-fluoroiridographic classification of pigmented iris tumors would be useful.

Electronic Resource

1573-2630

amaurosis fugax ; carotid artery duplex scanning ; neuro-ophthalmology ; retinal artery occlusion

Springer Online Journal Archives 1860-2000

Medicine

Abstract To assess the diagnostic value of an extensive cardiac screening and of carotid artery duplex scanning in patients suspected of suffering from retinal embolism, we examined 41 consecutive patients (mean age 59.6 years, range 36–74) who presented either with amaurosis fugax or with a retinal artery occlusion. In spite of extensive investigations, we found no cause in 27 patients (66%). In 11 patients (27%), symptoms were likely to be due to a stenosis or an occlusion of the ipsilateral carotid artery. In only 1 patient (2%), the heart was likely to be a source of embolism. We conclude that in patients in this age group suffering from either amaurosis fugax or a retinal artery occlusion, a carotid artery duplex scanning should be performed first as this investigation is more likely to provide useful information than an extensive cardiac screening (ECG, Holler 24-hour monitoring and precordial echocardiography).

Electronic Resource