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Biomedical subjects

L C Chumbley

Publications and source records attributed to L C Chumbley.

11 recordsLinked to original sources
PubMed1991

Doppler ultrasonography of the ophthalmic and central retinal vessels.

B-Scan-guided, pulsed Doppler ultrasonography of central retinal vessels and ophthalmic arteries of 72 normal subjects gave the following average peak flow velocities: central retinal artery, 9.5 +/- 3.1 cm/s; central retinal vein, 5.7 +/- 1.5 cm/s; and ophthalmic artery, 31.6 +/- 9.0 cm/s. Doppler shifts in the central retinal vessels were absent at intraocular pressures above 80 mm Hg. Ophthalmic artery systolic, middiastolic, and end-diastolic velocities significantly declined as a function of age. The technique is independent of the status of the ocular media, is noninvasive, requires little time, and causes minimal discomfort.

Adult↗
PubMed1991

Doppler ultrasonography of malignant melanomas of the uvea.

Doppler shifts were detected using duplex and color Doppler scanning in 41 of 42 patients with malignant melanomas of the uvea. Mean maximum tumor systolic velocity was 18.8 +/- 7.6 cm/s. Time-averaged maximum velocity in the tumor vessels was 12.3 +/- 5.3 cm/s. Maximum tumor velocity increased in four of eight tumors and was unchanged or had diminished in the other four 2 to 3 days after ruthenium plaque irradiation. Doppler shifts were undetectable in three tumors, markedly reduced in three tumors, and unchanged in one tumor 1 to 4 months after treatment. We detected minimal non-pulse-synchronized Doppler shifts in one of three tumors, and no shifts in the remaining two tumors 1 1/2 to 4 years after therapy. Color duplex scanning allowed a rapid overview of tumor vasculature and facilitated study of individual vessels.

Blood Flow Velocity↗
PubMed1990

Forces on intraocular lens haptics induced by capsular fibrosis. An experimental study.

Electronic dynamometry measurements, performed upon intraocular lens (IOL) haptics of prototype one-piece three-loop silicone lenses, accurately defined the relationships between elastic force and haptic displacement. Lens implantations in the capsular bag of dogs (loop span equal to capsular bag diameter, loops underformed immediately after the operation) were evaluated macrophotographically 5-8 months postoperatively. The highly constant elastic property of silicon rubber permitted quantitative correlation of subsequent in vivo haptic displacement with the resultant force vectors responsible for tissue contraction. The lens optics were well centered in 17 (85%) and slightly offcenter in 3 (15%) of 20 implanted eyes. Of the 60 supporting loops, 28 could be visualized sufficiently well to permit reliable haptic measurement. Of these 28, 20 (71%) were clearly displaced, ranging from 0.45 mm away from to 1.4 mm towards the lens' optic center. These extremes represented resultant vector forces of 0.20 and 1.23 mN respectively. Quantitative vector analysis permits better understanding of IOL-capsular interactions.

Animals↗
PubMed1990

Hydroxypropyl methylcellulose in extracapsular cataract surgery with intraocular lens implantation: intraocular pressure and inflammatory response.

We studied prospectively the effects of 2% hydroxypropylmethylcellulose (HPMC), instilled in to the anterior chamber during extracapsular cataract extraction with posterior chamber intraocular lens implantation in 122 patients. Significant pressure rise was noted at 12 and 24 hours post-operatively when HPMC was not removed at the end of surgery. This was prevented by washing HPMC from the anterior chamber at the end of surgery, or by using either acetazolamide or a combination of oxyphenbutazone and vitamin C without washing HPMC. There was no difference in intraocular inflammation between controls and the HPMC groups. The group receiving combined oxyphenbutazone and vitamin C had the least, the differences between these two groups being sufficient.

Acetazolamide↗
PubMed1977

Amyloidosis of the conjunctiva--an unusual complication of trachoma: a case report.

A 25-year-old Shona woman with chronic bilateral trachoma developed bilateral, painless, massive conjunctival tumefactions over a period of 2 years. Subtotal removal of the masses yielded tissue which showed the typical staining characteristics of amyloid and contained a heavy plasmacytic infiltration. Systemic examination revealed no other abnormality. The trachoma provided the setting in which the amyloid reaction developed.

Adult↗
PubMed1977

Impressions of eye diseases among Rhodesian Blacks in Mashonaland.

A study of ophthalmic patients at Harari Hospital indicates that Rhodesian Blacks in Mashonaland constitute a population with interesting ophthalmic features. There is a low incidence of refractive error, with a total incidence of 8,5% of myopia in adults. Functional concomitant squint is uncommon, with an incidence of 0,8% in children under 15 years of age. Non-traumatic, idiopathic primary retinal detachments occur rarely, while secondary retinal detachments occur with low frequency (about 0,55 per 100 000 population per year). Acute and painful congestive angle closure glaucoma is not seen, although chronic angle closure glaucoma is sometimes encountered. Hypertensive retinopathy is not infrequently seen, while diabetic retinopathy is uncommon. Visual loss and blindness from corneal disease are wide-spread. The population has a remarkably low incidence of senile macular degeneration (1,13% of adults over 65 years of age).

Adolescent↗
PubMed1977

Allergic granulomatosis and angiitis (Churg-Strauss syndrome). Report and analysis of 30 cases.

The clinical and morphologic findings of allergic granulomatosis and angiitis of Churg and Strauss in 21 men and 9 women were reviewed. The classic features are those of systemic vasculitis in a setting of bronchial asthma and eosinophilia. Pathologically there is necrotizing vasculitis of small arteries and veins with extravascular granulomas, and infiltration of vessels and perivascular tissues with eosinophilia. These features differentiate it from poly-arteritis nodosa. The lungs, peripheral nerves, and skin are most frequently involved. Renal failure was encountered in only one patient in this series. Shortness of the interval from onset of asthma to appearance of vasculitis is an unfavorable prognostic sign. Corticosteroids seem to influence long-term survival favorably.

Adolescent↗
PubMed1976

Low-tension glaucoma.

A retrospective study of 45 patients with low-tension glaucoma revealed the mean age at diagnosis to be 66 years. Seventeen patients had follow-up visual field examinations, the average follow-up period being 6.4 years. There was no significant difference in prognosis of the ocular course between patients with Po/C equal to or greater than 100 and those with Po/C less than 100. The presence of splinter hemorrhages at the optic disk (10% of affected eyes) or of systemic arterial hypertension (diastolic blood pressure greater than 100 mm Hg) was associated with progression of visual field defects. Patients with sudden visual loss or associated hemodynamic events (33% of the total patients) had a more favorable prognosis regarding stability (lack of progression) of visual field defects than those without such an event. Extension of visual field defects across the macula was a common finding (25% of affected eyes). No firm evidence was obtained to indicate that treatment of the low-tension glaucoma improved the prognosis of the ocular course.

Aged↗
PubMed1975

Adult cytomegalovirus inclusion retino-uveitis.

A 27-year-old male renal transplant recipient acquired cytomegalovirus (CMV) infection of both eyes. This was characterized early by a distinctive necrotic retinitis with discrete advancing edges. A large exudative retinal detachment and hypopyon developed in one eye, and cultures from the anterior chamber aspirate grew CMV. Cytomegalovirus was also isolated from the urine and throat; after serial negative base-line titers, CMV antibody titer became positive. At autopsy CMV was isolated from lung, esophagus, and kidney tissue. Light and electron microscopic studies demonstrated extensive necrosis and disruption of the sensory retina and retinal pigment epithelium with exudative retinal detachments. The diseased retinal cells contained a multiplicity of viral particles in various stages of maturity. Cytomegalic inclusion-bearing cells were demonstrated in the choroid of the more severely affected eye.

Adult↗