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Biomedical subjects

A J Foss

Publications and source records attributed to A J Foss.

36 records · Page 2Linked to original sources
PubMed1996

Trends in eye cancer mortality among adults in the USA and England and Wales.

Trends in eye cancer mortality are presented for the USA and England and Wales during the period 1955-89. Mortality rates have fallen by 58% in the USA during this period. The fall in mortality is paralleled by an equal fall in incidence rates in the USA. In England and Wales, mortality rates and incidence rates have remained relatively constant during the last three decades. The explanation for these differences between the USA and England and Wales is unknown.

Age Factors↗
PubMed1996

A comparison of slit-lamp supported versus hand-held biometry.

Biometry allows determination of the final refractive outcome following cataract extraction with intraocular lens implantation. We compared the accuracy of axial length measurement performed with the slit-lamp supported biometry probe versus a hand-held technique. The two methods of biometry were performed on 32 patients undergoing endocapsular cataract extraction with lens implantation. One of the methods was selected at random in order to predict implant power for a desired refractive outcome using the SRK-T formula. There was no difference in 'within-subject' variance of axial length measurement between the two methods (t = 1.74, p = 0.091), and there was no difference in refractive outcome when the power calculations for the two techniques were compared (t = 0.12, p = 0.906). The hand-held technique provides a useful alternative method of biometry in 'difficult' patients.

Biometry↗
PubMed1996

The immunoalkaline phosphatase technique in immunohistochemistry: the effect of permanganate-oxalate melanin bleaching upon four final reaction products.

Melanin bleaching prior to the application of primary antibody can alter the immunoreactivity of a number of antigens. The effect of melanin bleaching subsequent to antigen visualisation by four different chromogens used with an immunoalkaline phosphatase technique was investigated. Vector black was the only final reaction product that withstood exposure to the permanganate-oxalate sequence for a time sufficient to bleach melanin.

Choroid Neoplasms↗
PubMed1995

Estrogen and progesterone receptor analysis in ocular melanomas.

BACKGROUND: It has been suggested that pregnancy may promote metastases in melanoma and that the contraceptive pill may be an etiologic factor. The purpose of this study is to determine if uveal or conjunctival melanomas express estrogen or progesterone receptors. METHODS: Twenty-seven choroidal and five conjunctival melanomas were investigated. Immunohistochemistry was performed using the antibodies ER-D5, which recognizes heat-shock protein 27 (formerly called the estrogen receptor-associated cytoplasmic antigen); ER-1D5, which recognizes the estrogen receptor; and PgR, which recognizes the progesterone receptor. RESULTS: Most of the conjunctival and uveal melanomas stained strongly for heat-shock protein 27 but none of the tumors showed positive nuclear staining for either the estrogen or the progesterone receptor. CONCLUSIONS: No evidence was found for either estrogen receptor or progesterone receptor expression in choroidal or conjunctival melanomas. Based on the literature, there is little evidence for these hormones having a role in the development or progression of these tumors.

Adult↗
PubMed1995

The detection of melanoma cells in peripheral blood by reverse transcription-polymerase chain reaction.

Both cutaneous and uveal melanoma undergo haematogenous dissemination. Detection of tyrosinase mRNA by reverse transcription-polymerase chain reaction (RT-PCR) has been described as an extremely sensitive way of detecting circulating viable melanoma cells in the peripheral venous blood, and this technique may be of value in the early detection of dissemination. Also, it has been suggested that surgical manipulation of the eye, such as occurs during enucleation, can provoke uveal melanoma dissemination. The purpose of this study was to evaluate whether tyrosinase mRNA is detectable in the peripheral blood of patients with uveal and cutaneous melanoma and in patients with uveal melanoma undergoing surgical procedures on the eye harbouring the tumour. Venous blood samples from 36 patients diagnosed as having active uveal melanoma and from six patients with advanced metastatic cutaneous melanoma were analysed. In addition, blood samples were spiked with known numbers of cells from three cell lines and four primary uveal melanoma cultures. The reported sensitivity of the technique was confirmed, with an ability to detect down to one cell per ml of blood. All 51 blood samples from the 36 patients with uveal melanoma were negative, and this included 20 perioperative blood samples. The test was also negative for the six patients with advanced cutaneous melanoma. There were two positives among 31 control samples analysed. This study demonstrates that there are far fewer circulating viable melanocytes than has been previously supposed in patients with melanoma and that the RT-PCR is of no clinical value in detecting metastatic melanoma disease. There was no evidence for surgery causing a bolus of melanoma cells to enter the peripheral circulation.

Base Sequence↗
PubMed1995

Is the first day postoperative review necessary after cataract extraction?

BACKGROUND: In current ophthalmic practice day-case surgery cataract patients are conventionally discharged and then reviewed the following morning thus limiting the advantages of what 'true' day-case surgery strives to achieve. The aim of this study was to see if there was a difference in outcome between 'true' day-case cataract surgery and non-day-care surgery. METHODS: A total of 387 consecutive cataract operations were followed, comprising 122 local anaesthetic day-cases, 149 local anaesthetic non-day-cases, 63 general anaesthetic non-day-cases, and 53 general anaesthetic day-cases. RESULTS: Although not randomised the groups were comparable with respect to age, operator grade, sex, presence of diabetes, anaesthetic type, pre and postoperative visual acuities, and time to first planned outpatient visit. There were 10 early postoperative complications in the day-case group (5.71% of total) and 14 in the non-day-case group (6.6% of total), the commonest complications in both groups were raised intraocular pressure, corneal oedema, and wound leaks. One patient in each group had an early complication that necessitated attending the casualty department. The visual outcomes in both groups were comparable. CONCLUSIONS: These findings suggest that there were no preventable complications within the constraints of the number of operations studied and that no additional risk is attached to 'true' day-case surgery relative to non-day-case surgery.

Aged↗
PubMed1995

Immunohistochemical techniques: the effect of melanin bleaching.

This study addresses two questions: i) which antigens can withstand bleaching by 2.5 g/L of potassium permanganate followed by 10 g/L of oxalate, before immunohistochemical staining; and ii) are any other steps in the immunohistochemical staining technique resistant to bleaching? A panel of 10 antigens was stained immunohistochemically and the results compared with staining performed with a bleaching step interpolated at different steps in the procedures. Four antigens (HMB-45, S-100, factor VIII-related antigen and collagen type IV) were unaffected by bleaching; two antigens (CD-20 and CD-45) had their staining enhanced by bleaching; one had the staining reduced (hsp27); and in three it was abolished (CD-45Ro, CD-31 and Ulex/anti-ulex antibody) by bleaching. Two antibodies (UCHL-1 and L-26) showed evidence for altered specificity following bleaching. None of the steps after application of the primary antibody was resistant to bleaching. Three chromagens used for peroxidase demonstration-amino ethyl-carbazole, diaminobenzidine and chloro-naphthol-were also found to be sensitive to bleaching. While some antigens were resistant to the effects of bleaching, some were not, and no other step in the immunohistochemical procedure could withstand bleaching.

Antigens, Neoplasm↗
PubMed1994

Are most intraocular "leiomyomas" really melanocytic lesions?

BACKGROUND: Intraocular smooth muscle tumors have long been a subject of controversy. The advent of immunohistochemistry with antibodies against HMB-45, S-100, smooth muscle actin, desmin, and vimentin has helped greatly in the distinction between smooth muscle tumors and melanocytic lesions. METHODS: Twenty-seven archival tissue blocks from patients who had had intraocular leiomyomas or leiomyosarcomas diagnosed were located and fresh sections cut and stained for the above markers. The cases constituted 24 iris lesions and 3 ciliary body lesions. RESULTS: All 24 iris tumors were reclassified as iris melanocytic lesions. Two of the three ciliary body leiomyomas retained their classification, and the third was reclassified as a spindle B-cell melanoma. CONCLUSION: The authors suggest that intraocular leiomyomas are much rarer than previously suggested and that many of the cases previously reported in the literature are open to question.

Actins↗
PubMed1994

Uveal melanoma: is solar ultraviolet radiation a risk factor?

Age-standardized mortality rates for cancers of the eye among adults in England and Wales are compared with those for cutaneous malignant melanoma. While cutaneous malignant melanoma rates have increased three-fold since 1950-54, rates for cancers of the eye have remained relatively constant over the same period. Collectively, the inconclusive findings of case-control studies for an association between exposure to ultraviolet radiation and uveal melanoma, the lack of supporting dosimetry data, together with the lack of an upward trend in mortality rates for cancers of the eye, suggests that exposure to ultraviolet radiation may not be a major factor in the etiology of uveal melanoma.

Adult↗
PubMed1994

Current indications for scleral contact lenses.

Scleral contact lenses have been largely superseded by corneal contact lenses, but they still retain a role as a treatment of choice for a small group of patients who have tried other types of contact lens wear without success and who are not good candidates for surgery. We performed a cross sectional survey of 44 patients attending clinics at Moorfields Eye Hospital who were successful long-term scleral contact lens wearers and reviewed their indications. Twenty-one patients had been fit to improve visual acuity, 20 for therapeutic indications, and three for cosmetic reasons. Scleral lenses were most useful were with patients with ocular surface disorders, such as Stevens-Johnson syndrome, and for visual rehabilitation of patients with grossly irregular corneal topography. All patients were benefiting from scleral contact lens wear, and none had serious complications as a result of the scleral lens wear. We conclude that all ophthalmic departments should have access to these lenses.

Adolescent↗
PubMed1993

Anterior hyaloidal fibrovascular proliferation after extracapsular cataract extraction in diabetic eyes.

Four patients with proliferative diabetic retinopathy developed anterior hyaloidal fibrovascular proliferation after extracapsular cataract extraction and posterior chamber lens implantation. This complication of cataract extraction has been described after vitrectomy in diabetic eyes. Risk factors for this entity after extracapsular cataract extraction include proliferative diabetic retinopathy, iris neovascularization, and anterior ischemic retina. Anterior hyaloidal fibrovascular proliferation was observed an average of 12 months postoperatively and affected vision in one of four patients. No progression was seen within an average of six months of follow-up, and no complications such as traction retinal detachment and vitreous hemorrhage developed.

Aged↗
PubMed1993

No-needle one-quadrant sub-tenon anaesthesia for panretinal photocoagulation.

Panretinal photocoagulation (PRP) is tolerated well by most patients using topical anaesthesia alone, though there are a significant number of patients who experience pain. Additional local anaesthesia alternatives for these patients include retrobulbar, peribulbar or subconjunctival injection. Deep introduction of a sharp needle may rarely cause damage to orbital structures, whereas no-needle sub-Tenon irrigation of local anaesthetic solution to the posterior Tenon's space theoretically avoids these risks. A one-quadrant, inferior-nasal, sub-Tenon delivery of 1.5-2 ml plain 2% lignocaine was administered and PRP performed on 12 eyes of 12 patients who were previously intolerant of PRP by topical anaesthesia alone. To assess the efficacy of anaesthesia, patients were asked to score pain, using a visual analogue score chart graded from 0 to 10. If patients were unable to see the chart, or read the accompanying text, a verbal explanation and description of the scoring chart was performed. Where PRP was performed with topical amethocaine 1% alone, pain scores were graded as median 8, mean 8.5 and range 6-10. The administration of sub-Tenon anaesthesia was well tolerated with a median pain score of 1.5, mean 1.9 and range 0-5. PRP after sub-Tenon administration was successfully completed in 11 of the 12 patients with a median pain score of 1.5, mean 1.8 and range of 0-9. The range was wide due to one patient with a high pain score who was intolerant of PRP in spite of the sub-Tenon delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1993

Retinal detachment following anterior chamber lens implantation for the correction of ultra-high myopia in phakic eyes.

The development of retinal detachment is reported in three eyes, of two patients, following implantation of an anterior chamber intraocular lens (AC-IOL) in phakic eyes for the correction of ultra-high myopia. The presence of an AC-IOL may hamper the identification of retinal breaks and removal of the intraocular lens may prove necessary to improve visualisation. Shallowing of the anterior chamber may also occur during, or following, vitreoretinal surgery with risk of endothelial contact. The risks and relative contraindications of AC-IOL implantation into phakic eyes are discussed.

Adult↗
PubMed1993

Detection of melanocytes from uveal melanoma in peripheral blood using the polymerase chain reaction.

PURPOSE: Uveal melanoma is the most common intraocular malignancy in adults and can cause loss of vision in the affected eye and death from metastasis, usually to the liver. The techniques currently used to detect cellular dissemination from the tumor are inadequate, and lack the sensitivity required for the detection of low levels of melanocytes in the peripheral blood of patients. The detection of circulating melanocytes is important as an early indication of the possibility of metastasis. METHODS: The viability of reverse transcription/polymerase chain reaction amplification of the tyrosinase gene to detect circulating melanocytes was examined as a first sign of dissemination from uveal melanoma. RESULTS: It was shown that it is possible to detect as few as ten circulating melanocytes in 5 ml of blood. Blood-borne dissemination was also detected in three of six patients with uveal melanoma examined. Two of these patients had clinically confirmed widespread metastases. A positive result was also recorded in one patient in whom there was no other evidence for tumor dissemination. Overt metastatic disease developed in this patient 9 months after blood collection. CONCLUSIONS: The success of this technique has important implications for the detection of circulating tumor cells from uveal melanoma, as an early indication of dissemination. This may be important when considering the administration of adjuvant therapy.

Adult↗
PubMed1992

Transient vessel wall sheathing in acute retinal vein occlusions.

Three cases are reported which had features similar to, and evolved in a pattern consistent with central retinal vein occlusions and a fourth case is reported which behaved as a hemispheric vein occlusion. However, they differed from classic retinal vein occlusions by having prominent sheathing of the retinal venous vasculature at presentation, which in all four cases resolved within three weeks. There was no evidence for any of these cases having an inflammatory vasculitis. The significance of this transient sheathing is uncertain.

Acute Disease↗
PubMed1992

Interstitial keratitis and iridoschisis in congenital syphilis.

Bilateral interstitial keratitis and iridoschisis are reported in four cases with extraocular stigmata of congenital syphilis and positive syphilis serology. The iridoschisis was extensive in two cases giving the iris an unusual ragged appearance, while it was slight in one case. Iridoschisis may suggest the diagnosis of congenital syphilis, especially when interstitial keratitis is mild. Chronic open-angle glaucoma should be excluded in all patients with interstitial keratitis and iridoschisis.

Aged↗