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Biomedical subjects

N R Galloway

Publications and source records attributed to N R Galloway.

14 recordsLinked to original sources
PubMed1991

A comparison of the precorneal residence of an artificial tear preparation in patients with keratoconjunctivitis sicca and normal volunteer subjects using gamma scintigraphy.

The precorneal residence of an artificial tear preparation has been compared in twelve patients with keratoconjunctivitis sicca (KCS) and twelve normal healthy volunteers. The artificial tear solution was radiolabelled by the inclusion of 1 MBq technetium-99m diethylenetriaminepentaacetic acid (99Tcm-DTPA), and 25 microliters was instilled into one eye only. Deposition of the preparation was followed by gamma scintigraphy. Precorneal clearance of the solution was found to follow bi-exponential kinetics in all subjects with no significant differences in clearance rates between the two study populations. There was also no significant difference in the area under the time-activity profile for the two study groups. This suggests that the reduced reflex tearing and basal lacrimation in KCS patients, indicated by the Schirmer's test, are not important in the clearance of isotonic solutions from the eye surface.

Adult↗
PubMed1991

Bilateral retinal artery occlusion due to mitral valve prolapse.

We report a case of bilateral retinal artery occlusion due to mitral valve prolapse. Most patients with retinal ischaemia in whom it is found have not been previously known to have it. Since it is a common condition it would seem essential that it be included in the differential diagnosis of amaurosis fugax and retinal artery occlusion if future ischaemic events are to be prevented. All patients with retinal ischaemia should have a full cardiovascular examination supplemented by echocardiography.

Aged↗
PubMed1990

Evoked responses in patients with macular holes.

Thirty-two eyes with idiopathic macular holes and one eye with a traumatic macular hole were assessed by pattern-reversal electroretinography, ganzfeld electroretinography and pattern-reversal visual evoked potentials. Results were inspected for qualitative abnormalities and then measured in comparison with fellow eyes and 41 control eyes of similar age. Qualitative abnormalities occurred in some eyes with macular holes, most commonly a reduction in pattern-reversal electroretinogram or pattern-reversal visual evoked potential amplitude; 15' check amplitudes were significantly lower in eyes with macular holes than in control eyes, but no significant difference in latency was found. Control pattern-reversal electroretinogram and pattern-reversal visual evoked potential amplitudes were noted to decline with age, and paired t-tests on an age-matched subgroup of eyes with macular holes and control eyes showed appreciable differences only in the pattern-reversal electroretinogram q-r (N95) amplitude.

Aged↗
PubMed1990

Visual performance in idiopathic macular holes.

Previously published reports on the clinical features of idiopathic macular holes highlight the predilection for post-menopausal women and implicate vitreomacular traction in the aetiology of these lesions. Relatively little attention, however, has been paid to the quality of visual loss in eyes with macular holes. Histological studies of full-thickness macular holes have shown loss of all retinal layers in the area of the hole, and this would be expected to produce a central absolute scotoma of the same diameter. The majority of patients with full-thickness holes in this series did not have an absolute scotoma large enough to be detected on the Amsler Chart or when reading. It is suggested that following formation of a macular hole, enlargement may occur without further loss of foveal tissue and without enlargement of the absolute scotoma, due to tangential vitreous traction or contraction of an associated epiretinal membrane.

Aged↗
PubMed1989

Dark adaptation compared with electrooculography in primary biliary cirrhosis.

In a series of asymptomatic patients with primary biliary cirrhosis there was a significant impairment of dark adaptation thresholds as compared with a control group. Vitamin A levels were abnormally low in only two of the patients and these two both showed high dark adaptation thresholds. The electrooculogram was reduced in only the most severely affected case. It is suggested that visual function tests should be performed alongside vitamin A level measurements before deciding on treatment.

Adult↗
PubMed1988

Electrophysiological testing of eyes with opaque media.

Electrodiagnostic tests as applied to the eye are now widely used in the investigation of patients with inherited retinal degenerations but their value in patients with opaque media is perhaps less well recognised. The choice of stimulus is all important and a flash VEP and flash ERG probably provide the best combination of tests at present. A comparison with the fellow eye, if it is normal, greatly improves the value of the result. A pitfall of this type of test is its failure to detect amblyopia and a carefully recorded history is important in helping to interpret the traces.

Amblyopia↗
PubMed1988

Blindness in the city of Nottingham (1980-1985).

An analysis has been made of data obtained from all available blind and partially sighted registration forms (Form BD8) for the City of Nottingham between the years 1980 and 1985 inclusive. Senile macular degeneration was the commonest cause for registration followed by glaucoma and then diabetic retinopathy. The rate of registration per 100,000 of population for different age groups is compared with similar figures for all England obtained 10 years previously. There is an apparent increase in the rate of registration of senile macular degeneration but a reduction in the rate of registration of glaucoma and cataract. The rate of registration of patients with diabetic retinopathy is also reduced but only in elderly patients.

Adolescent↗
PubMed1979

Intraocular pressure reduction in chronic simple glaucoma by continuous infusion of dilute pilocarpine solution.

Ten hospital outpatients with bilateral chronic simple glaucoma received a single drop of 2% pilocarpine to one eye and a continuous infusion of 0.1 % pilocarpine at a flow rate of 0.01 ml/min to the other eye (both solutions were at pH 7.2). On another occasion the treatments were reversed. Measurements of intraocular pressure (IOP) and pupil diameter were made at 30 min intervals for 2 hours. The continuous infusion of dilute solution was as effective as the single drop of more concentrated solution in reducing IOP and in constricting the pupil; the drop was somewhat faster in producing its effect.

Aged↗
PubMed1976

A comparison of the pupilloconstrictor effect of pilocarpine solution administered to the conjunctival sac as a single drop or as a continuous infusion in normal subjects.

Pilocarpine was administered into the conjunctival sac of normal volunteers by single-drop administration or by continuous infusion of a solution to the inner canthus by means of a fine Silastic tube. Using pupilloconstriction as a measure of response it was shown that infusion with a 0-01 per cent solution of pilocarpine was as effective as a single drop of 0-5 per cent pilocarpine. The response to the single drop was faster at onset. It was demonstrated that at pH 7-2 pilocarpine was more effective than at acid pH. The infusion method is simple to use, comfortable for long periods, has potential for reducing the need for frequent drop administration and for reducing the total amount of drug administered, and could be used for drugs other than pilocarpine.

Administration, Topical↗
PubMed1976

Continuous infusion of the conjunctival sac with pilocarpine in normal subjects and in patients with chronic glaucoma.

(1) A drug solution can be infused into the conjunctival sac by a simple method that does not cause overflow of solution. (2) At near neutral pH, pilocarpine infused at 1 mug/min was as effective as a single dose of 125 mug as a pupilloconstrictor in normal subjects. (3) At near neutral pH, pilocarpine infused at 10 mug/min was as effective as a single dose of 1 mg as an ocular hypotensive in cases of chronic simple glaucoma. (4) The infusion system described could find application in those situations in which it is essential to maintain a known and constant concentration of drug in the conjunctival sac.

Conjunctiva↗
PubMed1976

Continuous infusion of the conjunctival sac with chloramphenicol in preoperative cataract patients.

(1) Administration of a drug solution to the conjunctival sac by means of continuous infusion through a fine-bore silicone elastomer tube has been shown to be a simple and practical method in hospital inpatients. The use of a body-borne clockwork-driven syringe ram allows the patient to be ambulant. (2) The use of continuous infusion reduces the nursing supervision required compared with repeated administration of drops. (3) Further work will be needed to established the optimum concentration of chloramphenicol needed to equal that achieved by repeated instillations. (4) The flow rate of the infusion producing no overflow, particularly in elderly patients, is likely to be less than 0-01 ml/min.

Aged↗