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Biomedical subjects

G E Lang

Publications and source records attributed to G E Lang.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Ocular bacteriosis in a patient with aplastic anemia].

BACKGROUND: For more than a century it has been recognized that bacteria may infect the eye by way of the blood stream. Until fifty years ago, eyes so afflicted nearly always were blinded and a majority of the victims died from overwhelming sepsis. Although effective antibiotics are available today the prognosis is still guarded. CASE REPORT: A 39-year-old physician died 6 years after he was diagnosed for idiopathic aplastic anemia. He had developed pseudomonas aeruginosa bacteremia and later a therapy refractive pneumonia caused by aspergillus which had led to respiratory failure. The patient had experienced a marked loss of visual acuity in his left eye ten days before he died. Ophthalmic examination at that point displayed signs of endophthalmitis, hyphaema, and heterochromic irises. The eyes were obtained postmortem and histologic examination of the left eye displayed numerous bacilli forming cuffs around blood vessels and a sheet between the necrotic retinal pigment epithelium and Bruch's membrane. No inflammatory response to the bacilli was present. The bacilli could be demonstrated with a Giemsa stain and could also be identified with electron microscopic examination. DISCUSSION: The histologic results in our patient displayed numerous bacilli without inflammatory reaction which was a result of the aplastic state. Therefore, this disease was classified as "ocular bacteriosis". The blood-ocular barrier undergoes direct assault with intraocular inflammation and the impermeability to blood-borne antibiotics is lost. However, with the lack of an inflammatory reaction the permeability to antibiotics may be too low and the achieved concentration insufficient.

Adult↗
PubMed1999

Effect of thalidomide, octreotide, and prednisolone on the migration and proliferation of RPE cells in vitro.

PURPOSE: The retinal pigment epithelium (RPE) is involved in the pathogenesis of age-related macular degeneration. The purpose of this study was to assess the effect of thalidomide, octreotide, and prednisolone on the proliferation and migration of bovine RPE cells in vitro. METHODS: The migration assay was performed in double-chamber-wells separated by a membrane filter with 8 microm pores. Cells were allowed to migrate vertically for 7 hr, afterwards the cells on both filtersides were fixed, stained, and the migrated cells were counted. To examine RPE proliferation, bovine RPE cells were seeded subconfluently followed by an incubation with octreotide, thalidomide or prednisolone in a concentration gradient for 24 hr. Stimulation or inhibition of DNA synthesis was measured by [(3)H]-thymidine incorporation. Statistical analysis was performed with the paired student's t-test. RESULTS: Statistically significant (p < 0.05) inhibition of RPE cell proliferation was measured for thalidomide at a concentration of 10-50 microg/ml, for octreotide at a concentration of 5 x 10(-4) and 5 x 10(-5) M, and for prednisolone at a concentration of 250 and 500 microg/ml as compared to the negative control. RPE cell migration was significantly (p < 0.05) inhibited by thalidomide at a concentration of 10 microg/ml, by octreotide at a concentration of 5 x 10(-5) M, and also by prednisolone at a concentration of 500 microg/ml as compared to the negative control. CONCLUSIONS: Although the main effect of thalidomide, octreotide, and prednisolone when treating patients with choroidal neovascular membranes is probably related to the inhibition of angiogenesis it should be kept in mind that these substances may additionally inhibit RPE proliferation and migration.

Animals↗
PubMed1998

[Characteristics of drusen and changes in Bruch's membrane in eyes with age-related macular degeneration. Histological study].

BACKGROUND: Different types of drusen and changes in Bruch's membrane have been associated with age-related macular degeneration (AMD). METHODS: We compared 51 eyes with different stages of AMD with 40 age-matched controls using light microscopy. The degree of calcification of Bruch's membrane, fragmentation of Bruch's membrane, number of different types of drusen, and basal laminar deposit (BLD) were assessed. RESULTS: In the macular area, the presence of basal laminar deposit was most strongly associated with the presence of AMD. There was a statistically significant difference observed in the degree of calcification and fragmentation of Bruch's membrane in eyes with AMD as compared to controls. Eyes with AMD displayed significantly more soft, confluent, and large drusen as compared to controls. CONCLUSION: Calcification and fragmentation of Bruch's membrane, soft, confluent, and large drusen and BLD but not hard drusen correlated strongly with the histologic presence of AMD. Calcification and fragmentation of Bruch's membrane seem to facilitate ingrowth of choroidal neovascular membranes with consecutive development of exudative AMD.

Adult↗
PubMed1998

[Central serous chorioretinopathy. Clinical, fluorescein angiography and demographic aspects].

UNLABELLED: The purpose of this retrospective study was to analyze the demographic characteristics of central serous chorioretinopathy (CSC). METHODS: Findings of 100 consecutive subjects with CSC were evaluated. Clinical and fluorescein angiographic findings, demographic characteristics, and visual acuity were analyzed. RESULTS: The age of the patients ranged from 28 to 68 years with a mean of 43 years. No significant sex differences were found concerning age and other parameters. The highest age peak was in the group of women. The male to female ratio was 5:1. Patients with chronic CSC were significantly older (P = 0.015) than patients with the other angiographic findings. Median visual acuity was 0.5. In 40% bilateral characteristics of CSC were found. Clinical and fluorescein angiographic findings showed no significant correlation with visual acuity. CONCLUSION: The range of age distribution in CSC is wide. In older patients distinguishing CSC from age-related macular degeneration can be difficult.

Adult↗
PubMed1998

Reproducibility of measurements with a new slit lamp-mounted ocular blood flow tonograph.

PURPOSE: To assess the reliability of measurements of intraocular pressure (i.o.p.), pulse amplitude (PA), and pulsatile ocular blood flow (POBF) and the validity of measurements of IOP with a new ocular blood flow tonograph. METHODS: Intraocular pressure pulse was assessed with pneumatic tonometry. In this study, we used the OBF Labs ocular blood flow tonograph with two different pneumatic probes, a modified Langham probe and a newly developed probe. One ophthalmologist compared two machines, first with the modified Langham probe and secondly with the newly developed probe (40 volunteers). Additionally, two ophthalmologists performed measurements on different days and in different sequence (34 volunteers). Furthermore, results of IOP measurements performed with this tonograph were compared to those of Goldmann applanation tonometry (213 volunteers). RESULTS: Using the modified Langham probe, POBF and PA were associated with the machine used for the test. However, using the newly developed pobe, no relevant or statistically significant differences were found for any variables, and reliability coefficients were between 0.70 and 0.90. Linear regression analysis of the Goldmann applanation tonometer on the measurements of IOP with the tonograph showed a regression coefficient of 0.765. CONCLUSIONS: Results of measurements performed with this ocular blood flow tonograph and the newly developed probe are expected to be reliable and comparable.

Adolescent↗
PubMed1998

Diabetic retinopathy in pediatric patients with type-1 diabetes: effect of diabetes duration, prepubertal and pubertal onset of diabetes, and metabolic control.

OBJECTIVE: The objective of this study was to determine the contribution of prepubertal and pubertal onset and duration of diabetes to the development of diabetic retinopathy. STUDY DESIGN: A total of 1391 standardized fundus examinations (stereo fundus-photography) were performed in 441 children or adolescents with type-1 diabetes (median age 15.5 years, median duration of diabetes 6.3 years). RESULTS: Mild nonproliferative retinopathy was present in 72 patients (median age 19.9 years). Life table analysis revealed a median duration of diabetes until retinopathy was first diagnosed at 16.6 years (95% confidence interval: 15.3 to 18.3). Patients were stratified according to diabetes onset before or in puberty (> or = 10.4 years in girls, > or = 12.2 years in boys). In children with a prepubertal onset of diabetes, retinopathy occurred after a pubertal duration of 10.9 years compared with 15.1 years in children with onset of diabetes in puberty (p < 0.01), demonstrating the additional risk conveyed by the prepubertal years of diabetes. Long-term metabolic control had a significant influence on the prevalence of retinopathy: patients with a median HbA1c > or = 7.5% had development of retinopathy on average after 15.5 years compared with 18.3 years in patients with lower HbA1c values (p < 0.05). CONCLUSION: Both prepubertal and pubertal duration of diabetes are relevant for the development of background retinopathy. Good metabolic control should be attempted irrespective of age.

Adolescent↗
PubMed1998

[Value of optical coherence tomography in diagnosis of age-related macular degeneration. Correlation of fluorescein angiography and OCT findings].

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of blindness in industrialized countries. In this study, we used optical coherence tomography for evaluation of patients with AMD. METHODS: Optical coherence tomography imaging is analogous to ultrasound, except that reflected light instead of sound is used. The analysis of the reflected light is processed with the technique of low-coherence interferometry. In this study, 33 patients with different stages of AMD were examined with optical coherence tomography. The classification of AMD was according to the guidelines as proposed by the "International ARM Epidemiological Study group". RESULTS: With this method we were able to identify drusen, alteration of the retinal pigment epithelium, and secondary retinal changes. Other structures such as basal laminar (linear) deposits could not be identified with this method. Choroidal neovascularization was evident in the tomogram. Classic choroidal neovascular membranes presented with well-defined boundaries on optical coherence tomography and occult choroidal neovascular membranes had a less delineable structure with optical coherence tomography. CONCLUSION: Optical coherence tomography cannot replace conventional diagnostic techniques. This method provides no additional information in patients with non-exsudative AMD. In patients with choroidal neovascular membranes secondary to AMD optical coherence tomography may be able to characterize the relation of the membrane to the retinal pigment epithelium and imaging may be possible through hemorrhage. The interpretation of the optical coherence tomogram needs further studies including clinicopathologic correlation.

Aged↗
PubMed1998

[Intracanalicular trabeculostomy--a new approach to glaucoma surgery].

BACKGROUND: A new "ab externo" technique for glaucoma trabecular surgery creating multiple perforations of the trabeculum to improve outflow facility was tested. MATERIAL AND METHOD: In order to perform a draining canal to the anterior chamber, a quartz fiber (phi: 300 microns) with a side-firing tip, coupled to an Er:YAG laser (2.94 microns), was inserted into Schlemm's canal of an enucleated human eye. RESULTS: Eight pulses of 8 mJ each were sufficient to perforate the trabecular meshwork. Histologic analysis showed a rippled canal with 50 microns average diameter and a surrounding necrosis zone of 15-35 microns. CONCLUSIONS: The Er:YAG laser trabeculostomy, in conjunction with special fibers, shows promise as a new "ab externo" technique for minimally invasive therapy of open angle glaucoma.

Endoscopes↗
PubMed1998

[Ocular changes in primary hematologic diseases].

Ocular manifestations can be the presenting symptom of hematological diseases. Ocular changes can be found in up to 90% of the patients depending on the underlying disease. Most patients with ocular manifestations however are asymptomatic. Hematological disorders can manifest in all structures and adnexa of the eye. The most common manifestations are conjunctival pallor and hemorrhages, intraretinal hemorrhages and cotton wool spots. Retinal infiltrates, manifestations in the lids, anterior segment, optic nerve, orbit and adnexa are rare. Different ocular manifestations in anemia, leukemia, malignant Non-Hodgkin lymphoma, Hodgkin's disease, chronic myeloproliferative diseases, plasmocytoma, myelodysplastic syndromes, coagulopathies, and reticulo-histiocytic diseases are described. Not only the underlying disease but also chemotherapy, bone marrow transplantation can lead to ocular complications.

Eye Diseases↗
PubMed1998

Retinal pigment epithelial changes associated with systemic corticosteroid treatment: report of cases and review of the literature.

PURPOSE: The aim of our study was to describe two different manifestations of retinal pigment epithelial changes associated with systemic corticosteroid treatment. METHODS: We report 4 patients who developed maculopathy during treatment with systemic corticosteroids. Additionally, the literature was reviewed for similar cases. RESULTS: Two patients showed diffuse retinal pigment epitheliopathy. Two patients developed central serous chorioretinopathy with localized changes in the retinal pigment epithelium. A review of the literature revealed 51 patients with similar changes during treatment with corticosteroids. CONCLUSION: These 4 patients provide further evidence that systemic treatment with corticosteroids may cause central serous chorioretinopathy or diffuse retinal pigment epitheliopathy. Ophthalmologic examination is recommended on a regular basis for patients treated with systemic corticosteroids.

Adult↗
PubMed1998

Influence of special-effect contact lenses (Crazy Lenses) on visual function.

PURPOSE: Special-effect contact lenses (opaque, tinted soft contact lenses that incorporate decorative images such as "cateyes," stars, or hearts to alter eye color and structure) have become increasingly popular. The purpose of this study was to investigate whether such lenses impair visual function. METHODS: A clear soft contact lens and a special-effect soft contact lens (Crazy lens,) were fit in changing sequence in nine healthy subjects. The parameters studied included: visual acuity, contrast sensitivity (with and without glare), visual field, and mesopic vision (with and without glare). RESULTS: The following parameters displayed a statistically significant difference (P < 0.05). Visual acuity was decreased to 0.9 +/- 0.23 in the Crazy lens group as compared with 1.2 +/- 0.13 in the clear lens group. Goldmann visual field displayed a significant constriction of the isopters: III/4, I/4, and I/3. Mesopic vision without glare was reduced from 1:2.5 to 1:7.4. Contrast sensitivity was significantly reduced in a photopic condition with and without glare and in a scotopic condition without glare. Furthermore, the special-effect lenses were associated with a decrease in lens wearing comfort. CONCLUSIONS: Special-effect contact lenses were associated with a reduction of many visual functions, including visual acuity and contrast sensitivity. For some wearers this may interfere with activities where excellent vision is crucial, such as driving a car.

Adult↗
PubMed1997

[Central serous chorioretinopathy in systemic therapy with corticosteroids].

PURPOSE: To describe retinal pigment epithelial changes associated with systemic corticosteroid treatment. METHODS: We report on five patients who developed maculopathy during treatment with systemic corticosteroids. A thorough ophthalmologic examination including perimetry, fundus photography, and fluorescein angiography was performed. RESULTS: Three patients displayed focal and two patients showed diffuse retinal pigment epithelial changes comparable to the acute and chronic form of central serous chorioretinopathy, respectively. Four of five patients had a complete visual recovery after decrease or cessation of treatment with corticosteroids. CONCLUSION: These five patients provide further evidence that systemic treatment with corticosteroids may damage the posterior blood-retinal barrier, leading to central serous chorioretinopathy. Visual acuity may increase after reduction of the dosage or cessation of treatment with corticosteroids. Patients on systemic corticosteroid treatment should be informed about possible symptoms of central serous chorioretinopathy in order to prevent irreversible visual loss.

Adrenal Cortex Hormones↗
PubMed1997

[Posterior scleritis in Wegener disease].

BACKGROUND: Wegener's granulomatosis is a focal necrotizing granulomatous vasculitis of unknown etiology. It manifests initially as localized inflammation, usually of the lungs, and preceeds to the state of generalisation which can be life-threatening due to renal failure. Ocular and orbital involvement occurs in 28-58% of patients with Wegener's granulomatosis. More often, the anterior segments of the eye are involved whereas inflammation of the posterior segments is quite uncommon. PATIENTS AND METHODS: We report a case of posterior scleritis as the initial manifestation of Wegener's granulomatosis in a 65-year-old woman. RESULTS: Posterior scleritis responded favourably to therapy with systemic steroids and cyclophosphamide. CONCLUSIONS: Wegener's granulomatosis can have a poor prognosis if not diagnosed and treated in time. Knowledge of posterior scleritis as a possible presenting symptom may therefore facilitate early diagnosis and treatment and prevent progression of the disease.

Aged↗
PubMed1997

High-altitude retinopathy.

PURPOSE: To report a patient with high-altitude retinopathy. METHODS: A 30-year-old man with high-altitude retinopathy was examined and treated. RESULTS: After spending 2 weeks at an altitude of 7,000 meters and then descending to sea level, the patient's visual acuity was RE, 20/20 and LE, 20/50. Intraretinal hemorrhages in both eyes and a scotoma in the left eye were found. Blood cell count was normal, but hematocrit had increased to 53%. The patient was treated with isovolemic hemodilution, pentoxifylline, and aspirin, which reduced hematocrit to 41%. Visual acuity and visual field returned to normal, and intraretinal hemorrhages resolved. CONCLUSIONS: High-altitude hemoconcentration should be treated in patients with high-altitude retinopathy.

Adult↗
PubMed1997

[Risk factors for retinal occlusive diseases].

Retinal vascular occlusions are the second most common retinal vascular diseases following diabetic retinopathy. Central retinal artery occlusion and branch retinal artery occlusion are most often caused by emboli. The mean age of patients with retinal artery occlusion and branch retinal artery occlusion is 62 and 58 years, respectively. The most common risk factors are arterial hypertension (65%), diabetes mellitus (25%), valvular diseases of the heart (25%), and carotid artery stenosis or plaques (45%). Rare causes are arteritis and vascular spasm. The pathogenesis of retinal branch vein occlusion and central retinal vein occlusion remains speculative. Two different mechanisms have been postulated, i.e. thrombosis in the vein due to a compression by atherosclerotic changes in the adjacent artery and a local alteration of the blood flow due to unfavourable physiologic factors. Retinal vein occlusion manifests at a mean age of 65 years. The most common risk factors are arterial hypertension in 34-75% and primary open angle glaucoma in 2.1-82%. In 5.6% of the patients with retinal branch vein occlusion retinal vasculitis is present.

Humans↗