Search Results - "International Ophthalmology"

1573-2630

trachoma ; complication ; prevalence ; Al-Baha ; Bisha ; Saudi Arabia

Springer Online Journal Archives 1860-2000

Medicine

Abstract Trachoma remains one of the world's leading causes of blindness. A population based survey of the prevalence of trachoma was conducted in the South Western part of Saudi Arabia in the period of between July and November 1991. Overall, 7126 people were examined. Of these, 19 (0.26%) persons had active trachoma and 35 (0.5%) people had inactive trachoma. Sequelae of trachoma included conjunctival scarring, trichiasis and corneal scarring. Among 635 subjects with visual impairment, 6 (0.95%) patients had visual impairment due to trachoma. Trachoma does not seem to be a major ophthalmic problem in this area and proper management of the complications of trachoma will exclude it from the causes of blindness and visual impairment in this part of Saudi Arabia.

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1573-2630

acute toxoplasmic retinochoroiditis ; ocular toxoplasmosis ; vascular involvement

Springer Online Journal Archives 1860-2000

Medicine

Abstract The present study deals with the retinal vascular involvement in 64 patients with toxoplasmic retinochoroiditis during the acute phase of the disease and its evolution. Vascular involvement was noted in all 64 eyes during the acute phase of the disease. In 59 (92%) out of 64 cases the vascular involvement was located in the same retinal quadrant as the active toxoplasmic lesion. In the remaining 5 eyes (8%) the vascular participation was found in all four retinal quadrants. In 3 (5%) out of 64 cases, the vascular infiltration was extremely severe and resulted in retinal vascular obstruction. In all three cases the vessel traversed the active toxoplasmic lesion. In 35 (55%) out of 64 patients the initial vascular picture changed in the course of the acute phase of the disease. In these patients, the lesions had extended to the adjacent vessels or to other parts of the involved vessel. In the further course of the evolution of the active toxoplasmic lesion, the vascular involvement did not persist indiscriminately. It was noted that in 14 (22%) out of 64 cases the vascular lesions gradually regressed and eventually disappeared together with the active toxoplasmic lesion and the formation of the retinochoroidal scar. In the remaining 50 (78%) out of 64 cases the vascular involvement either disappeared after the establishment of the retinochoroidal scar in 3–12 months (29 cases) or remained permanently (21 cases).

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1573-2630

in vitro study ; retinal toxicity ; Shiva-1

Springer Online Journal Archives 1860-2000

Medicine

Abstract An investigation was undertaken to determine the toxicity of an intravitreal injection of a novel peptide drug, Shiva-1, in rabbits. The drug, a synthetic peptide modeled after lytic peptides secreted by certain insects, has antiproliferative and antibacterial properties. Initial in vitro experiments showed that the drug, at a concentration of 100 μM, was toxic to both Y-79 retinoblastoma cells and human retinal pigment epithelial cells. A wide range of doses (6–1200 μg) was injected into the rabbit vitreous in an attempt to determine the maximum tolerated dose. Retinal toxicity was evaluated clinically, by electroretinography, and by light microscopy. Some localized toxicity was evident at 200 μg; all doses of 240 μg and above were toxic. While the drug appears to exhibit a narrow range between effective and toxic doses, the results suggest that this and other peptides of similar design merit further investigation for the treatment of proliferative and infectious diseases of the eye.

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

central serous chorioretinopathy ; choroidal hyperpermeability ; indocyanine green angiography ; venous congestion

Springer Online Journal Archives 1860-2000

Medicine

Abstract There has been great controversy about the pathogenesis of the focal changes in the retinal pigment epithelium (RPE) causing detachment of the neurosensory retina in central serous chorioretinopathy (CSC). This study was performed to evaluate changes in choroidal perfusion in 15 patients with CSC. Fluorescein and indocyanine green (ICG) angiography was performed in patients with acute or chronic recurrent CSC. In all patients delayed arterial filling followed by capillary and/or venous congestion, in some cases adjacent to ischemic areas, was found in the choroid. Leakage from the RPE in fluorescein angiography was only observed in those areas with choroidal capillary and/or venous congestion. The preliminary results suggest that venous congestion possibly in association with ischemia causes hyperpermeability of choroidal vessels already described in the literature.

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1573-2630

hypothermia ; intraocular pressure ; human ; corneal thickness

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background: The effects of intense systemic or local cooling on aqueous humor dynamics in animals are an increased total outflow facility and a decreased aqueous flow. Few studies suggest that only vasoconstriction of arteriolar segments of the episcleral vasculature may be the cause for a decrease in intraocular pressure after local cooling in humans. Because corneal changes may have influenced such studies, the effect of local cooling was assessed in normal subjects. Methods: Intraocular pressure and corneal thickness were measured in 18 healthy human subjects before and after exposure of the right eye to both, an air stream at 20° C, and an air stream at 0° C. Results: No significant changes in IOP or corneal thickness occurred under 20° C conditions. After local cooling, the mean corneal thickness increased from 0.52 ± 0.01 mm to 0.57 ± 0.02 mm (p 〈 0.001). Mean intraocular pressure decreased from 13.8 ± 2.9 mmHg to 12.9 ± 3.1 mmHg (p 〈 0.026). The observed decrease in IOP correlated significantly but negatively (R = − 0.53; p = 0.024) with the increase in corneal thickness, indicating that the cooling effect on IOP may be rather underestimated. Conclusion: The eye is very sensitive to local cooling effects, which may, however, partially be masked by changes in corneal thickness.

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1573-2630

intermediate uveitis ; pars planitis ; uveitis in childhood ; cystoid macular edema

Springer Online Journal Archives 1860-2000

Medicine

Abstract Medical records of 51 patients with a diagnosis of pars planitis (97 eyes) were reviewed. Based upon the severity of vitreous inflammation, in 34 eyes (35) the condition was classified as mild, in 38 (39) as moderate, and in 25 eyes (26) as severe. Vascular sheathing was present in 51 eyes (53), snowballs in 42 (43), snowbanks in 29 (30), cataract in 19 (20), cystoid macular edema in 26 (27), retinal detachment in 4 (4) and glaucoma in 3 (3) eyes. Treatment consisted of prednisone and periocular injections of deposteroids or immunosuppressive agents; 13 patients required surgery for retinal repair, glaucoma, vitreous opacities or cataract. After treatment the visual acuity improved in 58 of the eyes, did not change in 33, and worsened in 9.

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1573-2630

choroidopathy ; plasmapheresis ; serous retinal detachment ; systemic lupus erythematosus

Springer Online Journal Archives 1860-2000

Medicine

Abstract Systemic lupus erythematosus associated ocular manifestations usually consist of cotton-wool spots and retinal hemorrhages. The authors report one case of lupus choroidopathy revealed by bilateral serous retinal detachment, occurring 4 months after a systemic flare-up of the disease. An immune complexes-mediated phenomenon is involved in these manifestations, which are usually controlled by systemic corticosteroids and immunosuppressive agents. Plasma exchanges were successfully applied in this case, resulting in a disappearance of the retinal detachment in one month.

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1573-2630

docosahexaenoic acid ; lipid metabolism ; phospholipids ; rabbit retina ; retinal detachment ; triacylglycerol

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background Docosahexaenoic acid (22 ∶ 6n-3, DHA) is found in high concentration in phospholipids from retinal membranes, and is essential for their function. This study investigated the effect of in vivo retinal detachment on in vitro lipid metabolism using [3H]DHA. Methods Rabbit retina was detached from the retinal pigment epithelium by injecting physiological saline into the subretinal space of the eye. Retinal samples from control (non-operated) and sham (operated, no detachment) animals, and from attached and detached retinal areas from the same eye, were incubated in vitro with [3H]DHA for 4 hours, and then prepared for biochemical and autoradiographic analysis. Results In control and sham retinas, [3H]DHA was preferentially esterified into phospholipids (82%) with low labeling of free fatty acids (FFA) (5%). In samples from detached areas of the retina, a higher proportion of [3H]DHA was recovered in the FFA pool (up to 30%) and its esterification was shunted into triacylglycerol, thereby reducing the formation of [3H]DHA-phospholipids. Changes were sustained through 48 hours of postdetachment. High labeling of inner segments and synaptic terminals was observed autoradiographically in control retinas, while in detached retinas, clusters of labeling were detected in the neural retina, and eventually within the photoreceptor layer. Conclusion Retinal detachment induces longlasting changes in lipid metabolism which are reflected in lower labeling of [3H]DHA-phospholipids. Metabolic changes, sustained through 48 hours, may lead to inadequate synthesis/turnover of phospholipids, among them, those containing DHA, possibly resulting in defective disc membrane assembly with subsequent deterioration of visual cells.

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1573-2630

consultation ; diagnostic and therapeutic recommendations ; location

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background Although a number of diagnostic and therapeutic methods are available to assist the ophthalmologist, relatively little attention has been given to mail consultations. By this method, a clinical summary and photographs, fluorescein angiograms, ultrasonograms, and/or other relevant materials are mailed to a consultant who then renders an opinion by telephone and/or return mail. Materials and methods The records of all mail consultations that were sent to the senior author and his colleagues during a 20 year period were reviewed to determine the total number of mail consultations, the reasons for the consultations, and the diagnoses and therapeutic recommendations that were made by the consultant. Results A total of 1357 mail consultations were received during the 20 year period, with a progressively increasing number of consultations each year. Consultations were received from 757 physicians representing all 50 states in the United States and 32 other countries. Because of the authors' subspecialty in ocular oncology and medical retinal diseases, the majority of the consultations received were related to those topics. In many cases, the initial diagnosis and treatment plan were altered based on our opinion through mail consultation. Based on the material received, the recommendations that we made included observation in 635 cases, enucleation in 152, surgical excision of a lesion in 120, plaque radiotherapy in 102, laser photocoagulation in 81, systemic evaluation in 40, external beam irradiation in 36, fine needle aspiration biopsy in 33, orbital exenteration in 25, chemotherapy in 21, and cryotherapy in 14. Conclusion Although not as ideal as direct patient examination, mail consultation can be an effective method of making or confirming a diagnosis and obtaining a therapeutic opinion. Although the authors have received mail consultations related to ocular oncology, this method may be applicable to other subspecialties in ophthalmology and to general medicine.

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1573-2630

complication ; glaucoma ; hypotony ; Mitomycin C ; trabeculectomy

Springer Online Journal Archives 1860-2000

Medicine

Abstract Despite the fact that trabeculectomies performed with Mitomycin C (MMC) have a high rate of success as repeatedly reported, the rate of complications encountered draws much of the attention of this substance to those cases that are unsatisfactory. To ascertain a possible relationship between some of these complications and concentrations of MMC used, we performed, in a prospective study, trabeculectomies for complicated cases of glaucoma with either concentrations of 0.5 mg/ml of MMC (group 1) or 0.2 mg/ml of MMC (group 2). The two groups were followed-up for 6 months and consisted of 49 and 40 cases, respectively. Two eyes in the first group and 3 in the second had to be considered as surgical failures that developed increasingly high pressures. Complications included hypotony most frequently (33%, both groups) with severely decreased vision in 3 cases (6%) of the first group and 8 (20%) in the second. Other results including visual acuities, IOP, and the rate of other complications were not significantly different in both groups and indicate that there may be no large difference between the two concentrations of MMC used.

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1573-2630

diagnosis ; retinoblastoma ; ultrasonography

Springer Online Journal Archives 1860-2000

Medicine

Abstract A and B-scan ultrasonographic records of 132 eyes of 126 patients with suspected retinoblastoma were evaluated retrospectively. Six patients had bilateral lesions. The results were compared with the histopathologic diagnoses obtained after enucleation in 129 cases and with the indirect ophthalmoscopic examination in 3 bilateral cases. Ultrasonographic diagnosis was correct in 115 cases (87.12%), false-negative in 12 cases (9.09%) and falsepositive in 5 cases (3.79%). Echographic tumor typing was made in 88 cases and the mixed tumor type was the most frequent with 74 cases (84.09%). Cystic, solid and diffuse infiltrating types were the other echographic diagnoses. Our experience confirms the accuracy of ultrasonography in the diagnosis of retinoblastoma.

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1573-2630

glaucoma ; Mitomycin C ; nerve ; pathology ; rabbit ; toxicity ; trabeculectomy ; ultrastructure

Springer Online Journal Archives 1860-2000

Medicine

Abstract Prolonged postoperative hypotony is a severe complication frequently associated with trabeculectomies performed with a single perioperative application of Mitomycin C. We performed an animal experiment using 8 pigmented rabbits applying different concentrations of Mitomycin C, ranging from 0.05 to 1.0 mg/ml, under the conjunctiva on the intact sclera for 5 minutes. The eyes were examined by light and electron microscopy after 4 weeks. The nerves within the ciliary body in areas adjacent to the region of treatment showed toxic effects related to the concentrations of Mitomycin C applied. In cases where small concentrations were used, only the unmyelinated nerves were damaged with the myelinated remaining intact. In eyes treated with high concentrations, both groups of nerves exhibited severe signs of destruction. This effect is likely to compromise the production of aqueous humor in rabbits, and possibly also in humans.

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1573-2630

aging ; hyperacuity ; spatial vision ; vernier acuity

Springer Online Journal Archives 1860-2000

Medicine

Abstract Purpose/background: Many visual functions change with age. Hyperacuity vernier thresholds, however, seem to remain practically invariant with age. Methods: We critically review reports on age-related changes in hyperacuity thresholds and present new data using two and three-point vernier hyperacuity thresholds. Results: It appears as though the vernier (two dot or two line) alignment hyperacuity thresholds are not sensitive to age. Significance: Based on these studies we propose that hyperacuity (vernier) thresholds be used as a benchmark, or a gold standard for aging studies. This measurement can serve as a valuable control and reference for other clinical studies of aging.

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Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

choroid ; choroidal circulation ; choroidal innervation ; Bruch's membrane ; angioid streaks ; drusen

Springer Online Journal Archives 1860-2000

Medicine

Abstract Based on previous work, this paper describes the anatomical and functional characteristics of the choroidal vasculature, namely the choriocapillaris, the arterial and arteriovenous anastomosis, the segmental distribution of the short posterior ciliary arteries, and the choroidal veins. The characteristics of the choroidal innervation with reference to the sensory nerve endings are reviewed. Some features of Bruch's membrane may explain the fundoscopic and angiographic appearance of the angioid streaks and the role of its basement membranes in the formation and transport of drusen.

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1573-2630

suprachoroidal hemorrhage ; hyaluronic acid ; posterior sclerotomy

Springer Online Journal Archives 1860-2000

Medicine

Abstract We report on an aphakic 30 year-old patient who underwent penetrating keratoplasty on his only functioning eye. On the first day after the operation he developed a total choroidal detachment due to suprachoroidal bleeding. The patient had no sense of orientation. Vision decreased to faulty light perception. One week postoperatively a posterior sclerotomy was performed in order to drain the suprachoroidal blood. Via a paracentesis the globe was pressurized with hyaluronic acid. The following day the suprachoroidal blood had almost disappeared. The retina had become reattached. During a follow-up period of 2 years the visual acuity remained 20/30.

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1573-2630

choroidal hemangioma ; diagnosis ; ultrasonography

Springer Online Journal Archives 1860-2000

Medicine

Abstract Circumscribed choroidal hemangioma (CCH), a relatively rare benign tumor, can cause differential diagnostic problems by its atypical appearance at the time of presentation. Ancillary test such as fluorescein angiography, indocyanin green angiography, ultrasonography, computer tomography (CT), magnetic resonance imaging (MRI) bring not always additional information and their results are not always pathognomic. We retrospectively reviewed the clinical records of 40 patients with the ultrasonographical diagnosis of CCH compiled in the last 20 years. Ultrasonography appeared to be uniform in its lesion characteristics and reliable in the diagnosis. During a mean follow-up time of 7.4 years there were no clinical or posttherapeutical developments that made a correction of the diagnosis necessary.

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1573-2630

indocyanine green angiography ; juvenile haemorrhagic choroidopathy ; macular choroidal neovascularization

Springer Online Journal Archives 1860-2000

Medicine

Abstract Juvenile haemorrhagic choroidopathy (JHC) is an idiopathic syndrome marked by macular choroidal neovascularization (CNV) in patients under the age of 50. We used fluorescein angiography (FA) and indocyanine green angiography (ICGA) to examine 17 patients with macular CNV and JHC. CNV was always unilateral. On ICGA examination the CNV were weakly fluorescent in 59% of cases, hyperfluorescent in the remaining 41%. ICGA showed up the following alterations: a) areas with diffuse choroidal hyperfluorescence at the posterior pole or in the peripapillary region in 11 affected eyes (65%), in the fellow eye too in 5 patients; b) areas of choroidal hypofluorescence at the posterior pole but also outside the vascular arcades in 2 affected eyes (12%). In conclusion, ICGA does not appear indispensable for detecting CNV in JHC but this method does show up diffuse choroidal alterations not detectable with FA. The pathogenetic implications of the ICGA findings are discussed.

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