Biomedical subjects

W J Power

Publications and source records attributed to W J Power.

At least 37 records · Page 2Linked to original sources

PubMed1995

Ocular trauma: evaluation with US.

PURPOSE: To examine the value of real-time ultrasonography (US) in the assessment of traumatized eyes with opaque ocular media. MATERIALS AND METHODS: Sixty-one eyes in 60 patients were prospectively examined with US; findings were correlated with findings of clinical and surgical follow-up. Patients with an intraocular foreign body (IOFB) also underwent computed tomography (CT). RESULTS: US demonstrated 56 vitreous hemorrhages, 21 retinal detachments, 12 vitreous detachments, five choroidal detachments, seven IOFBs, three dislocated lenses, and two retrohyaloid hemorrhages. Findings of US and surgery or clinical follow-up were in complete concurrence in 55 cases (90%) and partial concurrence in two cases (3%). US findings were incorrect in four cases (7%). In four cases, US allowed diagnoses that were unsuspected clinically. CONCLUSION: US accurately demonstrates ocular damage and may reveal unsuspected problems. US was superior to CT in demonstration of intraocular damage associated with IOFBs, although CT was superior in determination of the size and site of the IOFB. The presence of dense vitreous traction bands may indicate impending retinal detachment.

Adult↗

PubMed1995

Expression of collagens I, III, IV and V mRNA in excimer wounded rat cornea: analysis by semi-quantitative PCR.

A semi-quantitative polymerase chain reaction (PCR) methodology was used to evaluate the kinetic changes occurring in collagens I, III, IV and V mRNA in rat cornea following excimer laser keratectomy. cDNA was synthesized from RNA extracted from rat cornea at various times following excimer laser photoablative keratectomy. Collagen cDNA sequences were subsequently amplified using specific sets of oligonucleotide primers. Competitive PCR amplification was carried out using an internal standard so that a semi-quantitative analysis of message for synthesis of collagen types I, III, IV and V could be performed and time course dynamics of message for these collagens studied. There was a biphasic increase in the levels of collagens III, IV and V mRNA following excimer laser keratectomy. Collagen I mRNA levels demonstrated a more sustained increase and were still elevated at 6 weeks following wounding. Collagens IV and V mRNA showed the largest increase with an approximate three fold increase over controls between 4 days and 1 week. Our results demonstrate that upregulation of stromal collagens I, III, and V mRNA and basement membrane collagen IV mRNA occurs in rat cornea following excimer laser keratectomy.

Animals↗

PubMed1994

Adherence of human lens epithelial cells to conventional poly(methyl methacrylate), heparin-surface-modified, and polyHema lenses.

We developed an in vitro model to assess the adherence of human lens epithelial cells to three types of intraocular lenses: poly(methyl methacrylate) (PMMA), heparin-surface-modified PMMA (HSM-PMMA), and polyHema. Lenses were incubated with a fixed number of human lens epithelial cells. Adherent cells were counted after 72 hours in culture. Scanning electron microscopy showed significantly fewer cells adhering to the HSM-PMMA and polyHema lenses than to the PMMA lenses (P < .01). Repeat experiments on cell lines established from different donors confirmed these findings.

Cell Adhesion↗

PubMed1994

Daunomycin as an inhibitor of human lens epithelial cell proliferation in culture.

Posterior capsule opacification is still a major complication of both extracapsular cataract extraction and phacoemulsification. We evaluated the effects of the anti-proliferative agent daunomycin on cultured human and bovine lens epithelial cell viability and proliferation. After ten minutes of exposure, low concentrations of the agent markedly inhibited the proliferation of both cell types. The calculated LD50 for the drug against human cells was 2.20 micrograms/ml and against the bovine cells was 0.38 microgram/ml. The bovine cells appeared to be slightly more susceptible to the drug's effects, although this difference was not marked. Our results indicate that daunomycin is a potent inhibitor of both human and bovine lens epithelial cells in the laboratory.

Animals↗

PubMed1994

Sonography in optic disk drusen: imaging findings and role in diagnosis when funduscopic findings are normal.

OBJECTIVE: Optic disk drusen are relatively benign lesions of the eye but can cause visual symptoms and may occasionally mimic papilledema on funduscopy. We studied the range of sonographic findings and determined if sonography can be used to diagnose this condition in the absence of typical funduscopic findings. SUBJECTS AND METHODS: Sonography of the eyes was performed in 12 patients with known or suspected optic disk drusen by using a 10-MHz transducer. Optic disk drusen were diagnosed clinically in 16 of the 24 eyes. The funduscopic appearance was typical in 11 eyes and atypical in five eyes. In these five patients, the diagnosis was made on the basis of an abnormal appearance of the disk and either a strong family history of drusen (four patients) or funduscopic findings that were typical of drusen in the opposite eye (one patient). RESULTS: The head of the optic nerve was abnormal in 19 of 24 eyes on sonography and in 16 on funduscopy. In all cases with abnormal findings on sonograms, an ovoid echogenic lesion was evident at the junction of the retina and the optic nerve. The lesions varied in size from 1.5 to 4.0 mm in diameter and from 1 to 3 mm in thickness and projected posteriorly rather than into the vitreous body. Calcification was evident on sonograms in 16 cases. The degree of acoustic shadowing was proportional to the size of the echogenic focus. In the three cases in which funduscopic findings were normal, sonography showed small drusen deposits. In the five eyes that showed disk abnormality but were not typical of drusen on funduscopy, sonography showed lesions of varying size; cases with typical funduscopic appearances tended to show large lesions on sonography. CONCLUSION: Optic disk drusen can be diagnosed on the basis of their typical sonographic appearance even in the absence of typical funduscopic findings. Optic disk drusen may be seen incidentally when sonograms are made for other conditions, and the finding should not be confused with more serious lesions of the optic nerve.

Adolescent↗

PubMed1994

Ocular sonography.

High-frequency ocular sonography is the ideal method for imaging the eye and intraocular structures. In the presence of opaque ocular media, a complete view of the fundus may be impossible ophthalmoscopically, and in these cases sonography is invaluable. Although high field strength MR imaging with surface coils provides excellent detail of normal and pathologic ocular structures, major shortcomings are lack of spatial resolution and poor specificity with certain lesions. Sonography is superior to CT or MR imaging in detecting ocular lesions such as small melanomas that are 2 mm or less in thickness. The eye can be examined dynamically during eye movements, which is of value in localizing abnormalities. The sonographic appearance of a variety of ocular pathologic conditions is illustrated in this essay.

Eye↗

PubMed1993

Effect of topical cyclosporin A on conjunctival T cells in patients with secondary Sjögren's syndrome.

The effect of topical cyclosporin A on conjunctival T cells was studied in nine patients with secondary Sjögren's disease. Patients had conjunctival biopsies performed before and after a 6-week course of topical cyclosporin. Epithelium and substantia propria in the Sjögren's patients before treatment showed significantly more CD4+ cells than specimens taken from nine age- and sex-matched controls. Following treatment with topical cyclosporin, there was a significant reduction in the number of CD4+ cells in both the conjunctival epithelium and substantia propria. Despite the fact that the treatment resulted in immunopathological improvement, the clinical benefit was not as favorable. Our results suggest that topical cyclosporin may have a local immunosuppressive effect on the conjunctiva in patients with Sjögren's disease.

Administration, Topical↗

PubMed1992

Twice daily 4% Sodium Cromoglycate vs. 2% Sodium Cromoglycate used four times daily in seasonal (grass pollen) allergic conjunctivitis.

It is well established that 2% Sodium Cromoglycate is an effective treatment for a number of allergic eye diseases. It has been shown to be non-toxic. It can be used longterm and in serious allergic problems it is a useful adjunctive therapy to steroids. The main problem with Sodium Cromoglycate is that the recommended dosage is a four times daily application and patient non-compliance is common. One of the main objectives of any therapy is to reduce the frequency of dosage and the current study has been designed to investigate the efficacy of a 4% solution of Sodium Cromoglycate, used twice daily, versus a 2% solution used four times daily in seasonal allergic conjunctivitis. A multicentre study, therefore, was carried out to assess the efficacy of both drugs and to assess any possibility of side effects. In addition, a unit dose was used, thus eliminating preservatives and it was used specifically in seasonal allergic conjunctivitis in the pollen season. This study showed that 4% Sodium Cromoglycate used twice daily was at least as affective as 2% Sodium Cromoglycate used four times daily.

Adolescent↗

PubMed1992

The current management of herpetic eye disease.

Herpes simplex disciform keratitis is a difficult condition. The general feeling is that it is an immune disease, mediated by the virus, possibly located in the endothelial cells. It is frequently combined with inflammation in the trabecular meshwork and with uveitis. There is some controversy in relation to treatment and it has been suggested that anti-virals will control herpetic disciform keratitis, particularly if the patient has never had steroids previously. The authors of this paper have, in the past, published data which showed that Acyclovir, with corticosteroid, was necessary in the management of disciform keratitis. The data suggested that Acyclovir on its own was not effective. It remained to be answered whether Acyclovir on its own would be effective in patients who never had steroids for any reason previously. This paper demonstrates clearly that it is necessary, irrespective of whether patients have had steroids in the past or not, to combine corticosteroids with Acyclovir in the management of herpetic disciform keratitis. Acyclovir, on its own, is shown to be ineffective. It has also been suggested that Acyclovir is non-toxic. In a general way this is true, but the authors suggest that Acyclovir ointment does produce a punctate keratitis in patients with tear film disease, and that oral Acyclovir is preferable in such patients.

Acyclovir↗

PubMed1992

Preoperative pupil fatigue.

Pupils are frequently dilated on the day before cataract surgery and for retinal detachment surgery so the fundus can be examined. This may, however, interfere with pupil mydriasis on the day of surgery. This study looked at the effect of pupil dilation with tropicamide 1% and with cyclopentolate 1% on pupil mydriasis 24 hours later, using phenylephrine 10% and cyclopentolate 1%, in 40 cataract patients. The pupils dilated with cyclopentolate one day previously demonstrated a mean reduction in subsequent mydriasis of 0.73 mm compared with pupils that had been dilated with tropicamide (P less than .0001). The magnitude of this difference was not related to the patient age (P = .12) or to iris color (P = .21). If it is necessary to dilate pupils on the day before surgery, tropicamide 1% rather than cyclopentolate 1% should be used, as it is less likely to interfere with the pupil mydriasis produced with cyclopentolate 1% and phenylephrine 10% on the day of surgery.

Aged↗

PubMed1992

Acyclovir ointment plus topical betamethasone or placebo in first episode disciform keratitis.

Thirty patients with first episode disciform keratitis and with no previous steroid exposure were randomly assigned to double blind treatment with 3% acyclovir ointment and 0.1% betamethasone (Betnesol) drops or acyclovir ointment and matching placebo. In the steroid group 14 of the 15 patients healed in a mean time of 21.8 days. In the placebo group eight of the 13 patients healed in a mean time of 34.5 days. The difference in mean healing time between the two groups was significant (p < 0.05). The cumulative rate of healing was also quicker in the steroid group when compared with the placebo group (p < 0.001). Other clinical parameters improved more favourably in the combination treatment group. Four patients, two in either group, experienced a mild transient punctate epitheliopathy, but no other serious adverse effects were noted. There has been no significant difference in the recurrence rate between the two groups after a mean follow-up period of approximately 3 years.

Acyclovir↗

PubMed1992

Electron microscopic appearances of human corneal endothelium following Nd:YAG laser iridotomy.

We looked at the electron microscopic appearances of the corneal endothelium following neodymium:YAG (Nd:YAG) laser iridotomy in a patient with a shallow anterior chamber. An area of denuded endothelial cells approximately 500 microns in diameter was produced when no contact lens was used. The area of cell loss was reduced by approximately 50% when an Abraham YAG goniolens was used. We conclude that the use of a positive plus contact lens can help minimize cell loss following Nd:YAG laser iridotomy.

Adult↗

PubMed1991

Idiopathic inflammatory pseudotumour of the orbit: CT features correlated with clinical outcome.

Idiopathic orbital pseudotumour is an inflammatory condition which usually presents as an orbital mass. The response to treatment is variable and often unpredictable. In this study we have assessed the spectrum of computed tomographic (CT) appearances in 17 patients. Four categories of orbital pseudotumour were identified by CT based on the location and extent of the inflammatory process within the orbit. Patients within each of the four categories had broadly similar clinical outcomes. CT was valuable in identifying certain prognostic features enabling better clinical and therapeutic planning.

Adolescent↗

PubMed1991

Randomised double-blind trial of bromovinyldeoxyuridine (BVDU) and trifluorothymidine (TFT) in dendritic corneal ulceration.

The results of a randomised double-blind clinical trial of 0.1% bromovinyldeoxyuridine (BVDU) and 1% trifluorothymidine (TFT) in 60 patients with corneal dendritic ulceration are presented. There was no significant difference between BVDU and TFT in terms of numbers of ulcers healed (p = 0.61), mean healing time (p = 0.065), and cumulative healing rate (p = 0.058). No serious side effects were observed, though transient stinging was recorded in five patients receiving TFT and in three patients receiving BVDU. One patient in the group treated with TFT developed a punctate epitheliopathy.

Adolescent↗

PubMed1991

Welding arc maculopathy and fluphenazine.

A 45-year-old male patient presented with a bilateral maculopathy following unprotected exposure of less than two minutes' duration to a manual metal arc welding unit. He had been receiving the drug fluphenazine for the previous 10 years for treatment of depression. We believe that the drug fluphenazine, which had accumulated in his retinal pigment epithelium, may have rendered him particularly susceptible to retinal photic damage.

Fluphenazine↗

PubMed1991

Bromovinyldeoxyuridine (BVDU) and trifluorothymidine (TFT) in dendritic corneal ulceration: a double blind controlled study.

Fifty patients with corneal dendritic ulceration were randomly entered into a double blind clinical trial comparing BVDU eyedrops with TFT eyedrops. Of those receiving TFT 100% healed in a mean time of 6.7 days, while 92% of those receiving BVDU healed in a mean time of 8.7 days. There was no statistical difference between the two groups in terms of numbers healed, but BVDU was significantly slower in terms of days to heal. After a mean follow-up period of 7.5 months there has been one recurrence in each group.

Administration, Topical↗

PubMedDate not supplied

The pattern ERG in Best's disease.

The aim of this study was to assess inner retinal function in patients with Best's disease using the pattern ERG (PERG). Nine patients with Best's disease, who had good visual acuity, were studied. Five of the nine had abnormal PERGs. All five had some reduction in central visual acuity. We believe that the abnormal PERGs in these patients represents photoreceptor cell loss which is occurring at an early stage in Best's disease.

Adult↗

PubMedDate not supplied

Evaluation of efficacy and safety of ciprofloxacin ophthalmic solution versus chloramphenicol.

The results of this clinical study demonstrate that ciprofloxacin ophthalmic solution 0.3% is as safe and as effective as 0.5% chloramphenicol ophthalmic solution in the treatment of conjunctivitis and blepharitis of bacterial aetiology. Both agents achieved microbiological improvement rates in excess of 90% after 1 week's treatment. On ciprofloxacin 93.5% of patients were judged clinically cured or improved versus 84.6% on chloramphenicol after 1 week. There were no serious adverse affects. One patient in each group suffered drug-related side-effects (chemosis, erythema) which resolved on discontinuation or changing of therapy. Cirpofloxacin is not associated with the rare, but serious, side effect of aplastic anaemia which is associated with chloramphenicol use. On the evidence of this study ciprofloxacin would appear to be an appropriate agent for general use as a topical ophthalmic formulation.

Acute Disease↗