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Biomedical subjects

P G Griffiths

Publications and source records attributed to P G Griffiths.

32 records · Page 2Linked to original sources
PubMed1997

Effectiveness of topical diclofenac in relieving photophobia after pupil dilation.

PURPOSE: To test the effectiveness of topical diclofenac in relieving photophobia after pupil dilation. SETTING: Department of Ophthalmology, Newcastle General Hospital, Newcastle-upon-Tyne, United Kingdom. METHODS: Twenty healthy patients and volunteers from the outpatient ophthalmology clinic were enrolled in a prospective, double-blind, placebo-controlled comparison in which the patient's fellow eye served as a control. Photophobia after pupil dilation was tested subjectively using a visual analog scale and a neutralization scale at 30 minute intervals for 2 hours after instillation of topical diclofenac. RESULTS: Both tests show a statistically significant reduction in photophobia in the diclofenac-treated eyes at each time interval (P < or = .05). This difference was also considered clinically relevant. CONCLUSION: Topical diclofenac given at the time of pupil dilation significantly reduced photophobia. The mechanism of action is unknown and requires further evaluation.

Administration, Topical↗
PubMed1997

The effectiveness of topical diclofenac in relieving discomfort following traumatic corneal abrasions.

Diclofenac is a non-steroidal anti-inflammatory drug available in an ophthalmic preparation. We present a prospective randomised double-masked placebo-controlled trial involving 40 patients that assessed the effectiveness of topical diclofenac in relieving pain from traumatic corneal abrasions. Statistical analysis of visual analogue and categorical pain scores revealed a significant reduction in pain experienced by subjects in the diclofenac group (p < 0.02).

Administration, Topical↗
PubMed1996

Normal respiratory chain function in patients with low-tension glaucoma.

OBJECTIVE: To test the hypothesis that low-tension glaucoma has a pathogenesis similar to Leber's hereditary optic neuropathy and results from a defect in the mitochondrial respiratory chain. METHODS: Mitochondrial fractions were prepared from skeletal muscle samples collected from eight subjects with low-tension glaucoma. Their oxidative metabolism was compared with that of age- and sex-matched controls. Skeletal muscle DNA prepared from the subjects with glaucoma was also screened for the 3,460, 11,778, and 14,484 mitochondrial DNA mutations that are associated with Leber's hereditary optic neuropathy. RESULTS: No subject with low-tension glaucoma had a defect in respiratory chain activity or one of three mitochondrial DNA mutations that are commonly associated with Leber's hereditary optic neuropathy. CONCLUSION: Although these results do not exclude the possibility that low-tension glaucoma is caused by an organ-specific defect of mitochondrial function, we have excluded a systemic defect of the mitochondrial respiratory chain.

Adult↗
PubMed1996

Flashes and floaters as predictors of vitreoretinal pathology: is follow-up necessary for posterior vitreous detachment?

PURPOSE: The aim of the study was to determine whether patients presenting with an isolated posterior vitreous detachment require follow-up to identify retinal breaks not apparent at presentation and whether some histories are more predictive of associated serious posterior segment pathology. METHODS: The notes of 295 patients presenting to eye casualty with flashes and/or floaters were reviewed. RESULTS: One hundred and eighty-nine patients (64%) had isolated posterior vitreous detachments, 49 (16.6%) had retinal detachments and 31 (10.5%) had flat retinal tears. Three new breaks (3.3% of all tears found, 1.9% of review appointments) were identified only at follow-up. Although a subjective reduction in vision and a history of less than 6 weeks' duration were strongly predictive of retinal breaks, the large group of patients presenting with floaters alone (124/295, 42%) still harboured a significant proportion (26.7%) of the retinal breaks. CONCLUSIONS: A follow-up visit for patients with an isolated posterior vitreous detachment can be justified to detect the small percentage of asymptomatic retinal breaks. Although a subjective reduction of vision is the symptom most predictive of serious posterior segment pathology, it would be unsafe to identify particular subgroups of patients alone for careful examination.

Emergencies↗
PubMed1991

The value of plain radiography in suspected intraocular foreign body.

Patients presenting to an eye casualty department with a history of exposure to high velocity particles often undergo radiological investigation to rule out clinically undetected intraocular foreign bodies (IOFB). We reviewed the indications for and the results of X-rays performed in our eye department over a five year period to determine the effectiveness of such screening. Our results suggest that most of the X-rays are performed needlessly and that radiological investigation could be restricted to those patients with clinical evidence of penetrating ocular and orbital trauma and patients with subconjunctival haemorrhage.

Conjunctival Diseases↗
PubMed1991

Scanning EM studies of normal human lens fibres and fibres from nuclear cataracts.

Normal human lenses obtained from an eye bank, and the central nuclear regions from nuclear sclerotic cataracts, were examined using scanning electron microscopy. Lens fibres were found to possess a varied array of well defined interlocking processes. Fibres from brunescent nuclear cataracts showed complete preservation of membrane architecture in contrast to the extensive membrane disruption that has been seen in cortical cataracts.

Adult↗
PubMed1991

Effect on mydriasis of modifying the volume of phenylephrine drops.

The cardiovascular effects of topically administered phenylephrine 10% are well known and can be minimised by reducing the concentration of drops administered. By modifying the dimensions of the dropper tip we reduced the volume of the drops administered, and therefore the total dose of phenylephrine, without altering the concentration. No difference in the mydriasis produced by drops of small and normal volume could be detected. Since a smaller dose of phenylephrine is administered with smaller drops, the risk of systemic side effects could be reduced by modifying the tips of eyedroppers.

Dose-Response Relationship, Drug↗
PubMed1989

Adherence of Staphylococcus epidermidis to intraocular lenses.

We have demonstrated, with an in vitro model, that Staphylococcus epidermidis is able to colonise intraocular lenses. Adherent organisms were quantitated by light microscopy, scanning electron microscopy, and viable counting. Bacterial adherence was associated with production of a polysaccharide glycocalyx. Organisms which were attached to the lenses were resistant to apparently bactericidal concentrations of antibiotics, as determined by conventional testing. We speculate on the role of colonisation in the pathogenesis of endophthalmitis.

Bacterial Adhesion↗
PubMedDate not supplied

Unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus in an immune-competent adult.

PURPOSE: To report an immune-competent patient with unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus, and to highlight the importance of diagnostic vitreous biopsy and specific antiviral therapy in this condition. METHODS: Case report. RESULTS: A 75-year-old man with good general health had two episodes of acute retinal necrosis syndrome affecting his left eye. Vitreous biopsy was performed in each episode, and polymerase chain reaction analysis on the vitreous specimen was positive for cytomegalovirus and negative for varicella zoster virus and herpes simplex virus 1 and 2. On each occasion, investigations indicated past cytomegalovirus infection but no evidence of a systemic re-activation. No indication of immunodeficiency was found over a 2-year follow-up period. His management, which included systemic and intravitreal antiviral therapy, is discussed. CONCLUSIONS: To the authors' knowledge, only two other cases of acute retinal necrosis syndrome caused by cytomegalovirus have been reported previously in immune-competent patients. This case illustrates the importance of vitreous biopsy for viral polymerase chain re-action studies in cases of acute retinal necrosis syndrome, in order to direct appropriate antiviral treatment. It also illustrates the role of an intravitreal antiviral drug that is effective against all three herpetic viruses.

Aged↗