Biomedical subjects
Publications and source records attributed to G K Lang.
Allergic ocular diseases are frequently encountered in the ophthalmologic practice. The term covers a wide array of severity, ranging from seasonal allergic conjunctivitis to the sight-threatening variant of atopic keratoconjunctivitis. The pathophysiology of these diseases is complex. Recent studies showed that nerve growth factor and interleukin IV, seem to play a role in these mechanisms.
This article reviews literature regarding contact lenses and corneal shields published between February 1996 and January 1997 that will help the ophthalmologist to better understand some of the clinical effects of contact lenses and corneal shields. Progress has been made in understanding the interaction between contact lenses and the eye, and this may improve fitting. However, fitting presbyopic patients with contact lenses still remains a challenge. There is new insight in the pathomechanism of serious corneal infections caused by Acanthamoeba species and Pseudomonas aeruginosa, which may lead to decreases in these complications. Furthermore, in the era of different wear modalities and replacement schedules and the advent of daily disposable lenses, an update of contact lens terminology is provided.
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To minimize the risk of visual loss and to stop the progression of diabetic retinopathy argon laser treatment is the therapy of choice in proliferative diabetic retinopathy (PDR). The results after panretinal argon laser coagulation (ALC) were studied retrospectively considering visual outcome and frequencies of diabetic ocular complications. In all 95 patients were included in whom laser treatment had been performed due to clinically and angiographically diagnosed proliferative diabetic retinopathy at the Department of Ophthalmology between 1990 and 1994 with a follow-up of at least 1 year. The most frequent diabetic complications observed were vitreous haemorrhage in 9 (or 9.5%) and iris neovascularization in 10 cases (or 10.5%). Rare complications were neovascular glaucoma in 3 patients (or 3.2%) and tractional retinal detachment in 4 patients (or 4.2%). Nearly 70% of the patients maintained or improved visual acuity after laser treatment. The frequency of diabetic complications of PDR after ALC was significantly associated with older age, diabetes type II, longer duration of diabetes and elevated blood pressure.
PURPOSE: To investigate the effect of cataract extraction on ocular hemodynamics. SETTING: University Eye Clinic of Ulm, Germany. METHODS: In 51 consecutive patients assigned for cataract surgery, pulse amplitude, pulse volume, and pulsatile ocular blood flow were measured 1 day before and 3 days and 12 months after cataract extraction using an ocular blood flow tonograph. Statistical analysis was performed with Student's t-test and Wilcoxon signed-rank test. RESULTS: In the study eyes, 3 days after cataract surgery pulse amplitude, pulse volume, and pulsatile ocular blood flow had decreased from 2.5 to 2.1 mm Hg (P = .0014), 5.0 to 4.4 microliters (P = .0059), and 836.2 to 728.0 microliters/min (P = .0017), respectively. No statistically significant change between preoperative and 3 day postoperative measurements occurred in the fellow eyes. There was no significant difference in systemic blood pressure, heart rate, or IOP in study and fellow eyes before and 3 days after cataract surgery. The early reduction of pulse amplitude, pulse volume, and pulsatile ocular blood flow in the study eyes was not present 1 year postoperatively. CONCLUSION: Uncomplicated cataract extraction is associated with a temporary ipsilateral impairment of ocular hemodynamics. A neural mechanism triggered by cataract extraction may be involved in these temporary changes.
BACKGROUND: Over 98% of all meningiomas originate in the central nervous system including the optic fascicle. Spread outside this area occurs in 20% of cases. Ectopic (extradural) meningiomas that do not originate from either the optic fascicle or the intracranial meninges are exceedingly rare. We treated a patient with an ectopic meningioma of the orbit and reviewed the literature concerning ectopic orbital meningiomas. HISTORY AND SIGNS: A 30-year-old man presented with a painless tumor in the left medial canthal area. This tumor had developed over a period of two years. The patient complained of intermittent epiphora. Ophthalmologic examination revealed a slight lateral displacement of the left eye. There was a palpable medial orbital mass with an otherwise normal ophthalmological examination. Computed tomography and magnetic resonance imaging showed a homogeneous, well-marginated soft tissue mass. THERAPY AND OUTCOME: The lesion which had neither a contact to the dura of the anterior cranial fossa nor to the optic fascicle was excised and histologic examination showed a fibroblastic meningioma. There was no recurrent tumor after a follow-up of 18 months. CONCLUSION: Less than 50 ectopic (extradural) meningiomas of the orbit have been described in the literature. The most common histologic type is the meningotheliomatous (syncytial or transitional) meningioma. The mean age at diagnosis of these tumors is 31 years. After complete resection the prognosis is good.
Mechanical ocular trauma remains a leading cause of visual loss and blindness and often affects young individuals. Approximately 75% of people with trauma-induced visual impairment are monoculary blind. Furthermore, the human, social, and economic consequences of eye injuries are enormous in all parts of the world. Because most eye injuries are preventable, efforts could be spent much more effectively on preventing eye injuries rather than treating them. It is important to make the public aware of the benefits of using protective equipment, which is almost universally available, and was the main concern of most of the authors reporting on ocular trauma in the past year. Of great importance seems to be the introduction of an international standardized classification of ocular trauma.
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We prospectively analyzed the course of intraocular pressure (IOP) within the first 20 h after uncomplicated phacoemulsification with lens-implantation in the capsule sac with and without acetazolamide. Sixty patients were divided into two groups with 30 patients each, group 1 [mean age 72.3 years, (49-88 years); preoperative IOP 14.2 +/- 2.41 mmHg (10-18 mmHg)] did not receive systemic IOP-lowering medication; group 2 [mean age 72.4 years, (53-88 years); preoperative IOP 14.7 +/- 2.98 mmHg, (9-20 mmHg)] received .250 mg acetazolamide intravenously immediately after surgery. The IOP was measured 6 and 20 h postoperatively with an applanation tonometer. In group 1 the IOP was 17.9 +/- 5.50 mmHg (7-28 mmHg) after 6 h, in group 2 16.6 +/- 5.51 mmHg (9-32 mmHg). In group 1, 8 patients (26.6%) had an IOP of more than 21 after 6 h and in group 2, 6 patients (20%). Statistically, there was no significant difference between groups after 6 h (P > 0.05). After 20 h the IOP was 15.9 +/- 4.50 mmHg (7-28 mmHg) in group 1 and 13.5 +/- 4.46 mmHg (7-26 mmHg) in group 2. Additionally, the two groups tended to be equal with 2 patients each with an IOP of more than 21 mmHg. After 20 h, there was a significant reduction in the IOP each group. Intravenous acetazolamide (250 mg) did not have a clinical relevant influence on IOP after uncomplicated phacoemulsification.
BACKGROUND: Nonarteritic anterior ischemic optic neuropathy (AION) is the most common cause of visual loss in older patients with optic disc swelling. METHOD: In our study all patients with acute AION examined clinically and by fluorescein angiography between 1986 and 1994 were retrospectively reviewed. The prevalence of associated systemic diseases and the results of Doppler sonographic examinations of extracranial vessels were investigated. RESULTS: The records of 86 patients (60 male, 26 female) with AION were available. The mean age at the time of onset of AION was 61 years (range 41 to 85 years, SD = 11.9 years). In 50 patients the right and in 36 the left eye was involved. In 36% of the patients optic atrophy of the other eye because of AION was found. The median visual acuity was 0.25 (range, light perception to 1.25). Fluorescein angiography showed diffuse edema of the optic disc in 23% (20/86) of patients and localized segmental edema in 77% (66/86). Statistical analysis revealed a predominant involvement of the temporal quadrants. Ninety-three percent of patients with AION showed underlying systemic diseases. In 15% of these patients the systemic diseases were unknown at the time of onset of the AION; 58% (50/86) of the patients had hypertension, 28% (24/86) had diabetes mellitus, and 37% (32/86) had disorders of lipid metabolism. Seven percent (6/86) of patients showed no risk factors. Doppler sonographic examinations of extracranial vessels revealed hemodynamic relevant stenosis in 11% (6/56), and non stenotic plaques in 28% of patients (16/56). CONCLUSION: Because of the high percentage of associated systemic diseases in patients with AION a general examination and adequate treatment are necessary.
PURPOSE/METHODS: A 74-year-old woman had multiple tumors including a retinal mass. Her medical history included cutaneous sebaceous adenomas, adenocarcinoma of the breast, and colonic adenocarcinoma. Her involved eye became painful and was enucleated. RESULTS/CONCLUSIONS: Examination of the enucleated eye disclosed metastatic adenocarcinoma to the retina with retinal detachment. The patient described has a retinal metastasis of an unknown primary tumor site with Muir-Torre syndrome, characterized by an association of a sebaceous gland tumor with an internal malignancy.
BACKGROUND: Juvenile xanthogranuloma is an uncommon benign skin disease primarily affecting infants and young children. Ocular involvement is rare and most often affecting the iris. Isolated xanthogranulomas of the corneoscleral limbus are reported in the literature in only a few patients. HISTORY AND FINDINGS: A 10-year-old boy presented in October 1993 with a yellow solid tumor at the limbus of his left eye. The other ocular and extraocular structures were normal. Furthermore, he showed a preauricular nodular skin lesion. THERAPY AND OUTCOME: We suspected a dermoid of the corneoscleral limbus and performed an excision of the tumor. Histological examination revealed a juvenile xanthogranuloma. The tumor had regrown to its original size 2 months after excision. Treatment with topical corticosteroids resulted in an acceptable but incomplete regression of the tumor. CONCLUSION: Juvenile Xanthogranulomas of the corneoscleral limbus are rare tumors. The majority of previously reported cases showed a recurrence of the tumor at the original site after simple excision. In the case of unsuccessful therapy with topical corticosteroids a lamellar graft is recommended.
Ocular allergies are commonly encountered in clinical practice. The familiarity with the typical constellation of signs and symptoms, as well as the pathophysiology of these syndromes, is of utmost importance in diagnosing and treating these diseases. Several new therapeutic options have been tested in clinical settings in recent time. Lodoxamine tromethamine is a mast cell stabilizer at least as effective as cromolyn sodium, which is currently not available in the United States. Nedocromil sodium in addition to its mast cell stabilizing effect, has anti-inflammatory properties. Levocabastine hydrochloride is a very selective and potent H1 antihistamine. Ketorolac tromethamine is a topical nonsteroidal anti-inflammatory agent.
Desferrioxamine (DFO) is the most important drug in the treatment of thalassemia major and other hematological diseases requiring regular transfusion. It eliminates excessive ferritin by building up chelate complexes. Different mechanisms of possible DFO toxicity are induction of oxidation, damage of the blood-retina barrier, or reduction in other metalloions (Cu2+, Zn2+). The objective of the present study was to evaluate the ocular side effects of DFO treatment. We prospectively examined 17 patients aged 5 to 25 years, all of them treated with DFO. Visual acuity, pupillary reaction, anterior segment, lens and fundus were checked. If possible, visual fields, color vision, dark adaptation, stereoscopic vision, and contrast sensitivity were investigated. Lens opacities were found in 41% (7/17), changes in the retinal pigment epithelium in 35% (6/17), tortuosity of retinal vessels in 24% (4/17), dilation and sheathing of the retinal vessels in 18% (3/17), defects in color vision in 29% (5/17), and abnormal dark adaptation in 18% (3/17) of the patients. The oculotoxicity of DFO is dose-dependent. Major side effects like depression of the visual acuity are partially reversible after discontinuing the therapy. Regular ophthalmological check-ups are therefore necessary.
BACKGROUND: The treatment of patients with subfoveal choroidal neovascular membrane in age-related macular degeneration is unsatisfactory because only a limited number of patients are eligible. The aim of this study was to prospectively evaluate a new perifoveal treatment technique in patients with subfoveal choroidal neovascular membrane. METHODS: Between April 1992 and January 1994, 385 patients underwent clinical examination and fluorescein angiography. Eligibility criteria were met by 21 (5.5%) patients (22 eyes): well or poorly defined subfoveal choroidal neovascular membrane (< or = 3.5 disc diameters), without fibrosis, with visual acuity < or = 0.25. Visual acuity, morphological findings and complications were studied. The follow-up period was 12-32 months. RESULTS: The visual acuity before laser treatment ranged from counting fingers up to 0.25 (median 0.06). At the end of the follow-up (median 18 months) 28% (6/21) of patients showed a better visual acuity, whereas 44% (9/21) were unchanged and 28% (6/21) had deteriorated compared to visual acuity before treatment. In 71% (15/21) of eyes, resolution of the choroidal neovascular membrane was achieved with development of an atrophic laser scar. CONCLUSION: The visual outcome and the morphological findings after perifoveal laser treatment of subfoveal choroidal neovascular membrane in age-related macular degeneration show it to be an alternative method of treatment with favourable results. Due to inclusion criteria it is suitable only for a limited number of patients.
Severe ocular complications in multiple sclerosis are rare. A 43-year-old patient had a history of diplopia episodes and optic neuritis in the right eye between 1979 and 1980. In 1984, multiple sclerosis had been diagnosed. The patient presented with visual deterioration in the right eye in 1992. Ophthalmoscopy and fluorescein angiography showed severe occlusive retinal periphlebitis with diffuse retinal hemorrhages and large areas of nonperfusion. At the time of presentation the patient was in general good health and presented no neurological sign. Examinations for other causes of periphlebitis were negative. Although treatment with laser therapy and corticosteroids was initiated, the patient developed recurrent vitreous hemorrhages that required pars plana vitrectomy. In 1993 the patient suffered from a general deterioration of the disease course and was treated with systemic immunosuppressive medication. Vitreous hemorrhage is a rare complication of multiple sclerosis.
The vascular reactivity to breathing carbon dioxide represents a widely used method in neurology to diagnose microvascular cerebral disorders. Fifteen eyes of 15 patients suffering from confirmed normal pressure glaucoma were included in the study. The ocular carbon dioxide reactivity was determined by recording ocular pulse amplitudes (OPA) by means of oculo-oscillo-dynamography (OODG). The initial pulse amplitudes were found to be comparable to healthy subjects. According to the results obtained during breathing increased carbon dioxide concentrations (95% O2; 5% CO2; endtidal CO2 approx. 6.5%), the collective of 15 patients could be subdivided into two subgroups. One group (n = 9) showed a carbon dioxide reactivity that was comparable to healthy subjects, i.e., an increase of ocular pulse amplitudes of 57%. The remaining six eyes, however, showed a statistically significantly higher OPA increase compared to the first subgroup. According to the results obtained and to evaluate the hypothesis that these hemodynamic changes are accompanied by functional improvements, central visual fields were performed during breathing room air or increased inspiratory carbon dioxide concentrations. After exposure to carbon dioxide the visual fields improved significantly in patients who showed a significant increase in OPA. An increased carbon dioxide reactivity in some normal pressure glaucoma patients, i.e., a significant increase of OPA and a significant improvement of the central visual field during exposure to increased inspiratory carbon dioxide concentrations, may be due to an initial ocular vasospasm in these patients, which can be released by induced vasodilation due to carbon dioxide exposure.
BACKGROUND: After bone marrow transplantation various ocular diseases have been described. Ocular involvement is very common in patients with chronic Graft-versus-Host Disease (GvHD). These patients show clinical and histological evidence of a dry-eye condition in 60-100 per cent. A severe complication is the development of a corneal ulcer with possible corneal perforation. Two patients with a severe dry-eye condition and development of corneal stroma ulceration are described. The corneal ulcers healed after treatment with collagen-shield. HISTORY AND SIGNS: In a 13-year-old boy an allogeneic bone marrow transplantation was performed in April 1989 because of Fanconi's anemia. In November 1989 a severe dry-eye condition occurred due to GvHD with skin, liver, and gastrointestinal tract manifestation. In April 1991 he presented with corneal stroma ulceration of the right eye. In a 24-year-old patient an allogeneic bone marrow transplantation was performed because of chronic myeloid leukemia in August 1989. In December 1989 he developed dry-eye condition due to GvHD with skin, mucosa and liver involvement. In December 1991 a corneal ulcer of the left eye occurred. THERAPY AND OUTCOME: Repeated conjunctival and corneal smears were negative. Local antibiotic and antiviral treatment showed no effect. Corneal ulcers deteriorated progressively with corneal thinning. Both patients were therefore treated with daily collagen-shields and hourly polyvinyl-pyrrolidon eye-drops resulting in healing of the corneal ulcer within 3 and 2 weeks respectively. CONCLUSION: Treatment of corneal stromal ulceration in dry eye condition caused by chronic GvHD is difficult. In noninfectious ulcers daily application of collagen-shields and hourly artificial tears may prevent severe ocular complications like corneal perforation.