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Biomedical subjects

B E Damato

Publications and source records attributed to B E Damato.

At least 19 recordsLinked to original sources
PubMed1997

Pulsatile ocular blood flow in eyes with untreated choroidal melanoma.

PURPOSE: To investigate the effect of choroidal melanoma on pulsatile ocular blood flow (POBF). METHODS: Seventeen patients (10 men and 7 women) with unilateral untreated choroidal melanoma and 22 controls matched for age and sex were studied. Intraocular pressure (IOP), pulse amplitude (PA) and POBF were measured using the OBF Tonograph. In each patient, mean inter-ocular differences were analysed using the paired t-test. The correlation coefficient between tumour thickness and POBF was calculated. To assess the variation of this parameter, the coefficient of variation for three repeated readings was determined for healthy and affected eyes. RESULTS: In the control group, there was no significant difference between eyes in any parameter. In patients with melanoma, there was no significant difference in IOP and PA between affected and unaffected eyes. Mean POBF was significantly higher in affected eyes (1040 microliters min-1) than unaffected eyes (876 microliters min-1) (p = 0.003). There was no correlation between tumour thickness and absolute POBF (r = -0.24) or between tumour thickness and inter-ocular difference in POBF between affected and unaffected eyes (r = -0.17). Mean coefficient of variation of three repeated readings of POBF was 7.76% in healthy eyes and 8.97% in affected eyes. CONCLUSIONS: These findings suggest a high tumour blood flow or a global increase in choroidal blood flow in the presence of melanoma. POBF measurement may be useful in the clinical assessment of eyes with choroidal melanoma.

Aged↗
PubMed1996

Preventable delays in the treatment of intraocular melanoma in the UK.

Intraocular melanoma should be treated urgently to improve the chances of survival and of conserving the eye and vision. The aims of this study were to determine the mode of presentation of intraocular melanoma in the United Kingdom and to identify any preventable causes of delay in treatment. A total of 112 patients were included and questioned about their initial symptoms, the type of practitioner consulted and their subsequent management. Thirty per cent of patients were asymptomatic and detected on routine ophthalmoscopy. Symptomatic patients presented with blurred vision (52%), photopsia (26%), visual field loss (9%) and miscellaneous symptoms (13%). Patients presented to an optometrist in 66 cases (59%), to a general practitioner in 30 cases (27%) and to an ophthalmologist in 16 cases (14%). The tumour was misdiagnosed in 12% of patients presenting to an optometrist and in 27% of cases presenting to a GP. The period from the time of onset of symptoms or detection of an abnormality to the time when the patient was referred to the Ocular Oncology Service averaged 6 months (range 0-36 months). Patients waited an average of 4 months if referred urgently as compared with 7.7 months if referred non-urgently (Mann-Whitney U-test, p = 0.0003). Patients were likely to be treated sooner if they were referred directly to the ophthalmologist rather than via the GP (7.8 months vs 4.8 months; Mann-Whitney U-test, p = 0.02).

Adult↗
PubMed1996

Risk factors for residual and recurrent uveal melanoma after trans-scleral local resection.

AIMS: The aims of this study were to report local tumour control after trans-scleral local resection of uveal melanoma and to identify risk factors for (i) clinical residual tumour recognised immediately after surgery, and (ii) delayed tumour recurrence from subclinical microscopic deposits. METHODS: The sample included 310 patients, treated by choroidectomy (188), cyclochoroidectomy (87), or iridocyclectomy (35), with follow up ranging from 42 days to 20.9 years (median 36 months), a mean basal largest tumour diameter of 13.2 mm, and a mean tumour thickness of 7.4 mm. RESULTS: There were 24 patients with residual tumour. Forward stepwise logistic regression indicated that posterior extension to within 1 disc diameter of the optic disc or fovea was the sole best indicator of the risk of residual disease (p < 0.001). After excluding these cases, 286 patients were studied for the development of delayed local recurrence, which occurred in 57 cases. Forward stepwise multivariate analysis showed the statistically significant predictors for recurrent tumour to be epithelioid cellularity (p = 0.002), posterior tumour extension to < 1 disc diameter of disc of fovea (p = 0.002), large tumour diameter > or = 16 mm (p = 0.019) and lack of adjunctive plaque radiotherapy (p = 0.018). CONCLUSIONS: The recurrence rate at 4 years varied from 6% if no risk factors were present to 57% if there were more than two risk factors.

Female↗
PubMed1996

Risk factors for metastatic uveal melanoma after trans-scleral local resection.

AIMS: This study reports the metastatic death rate after trans-scleral local resection of uveal melanoma and identifies relevant risk factors. METHODS: Local resection was performed in 332 patients (mean age 51 years), with follow up ranging to 20.9 years (median for living patients 33 months). The tumours had a mean largest basal diameter of 13.1 mm and mean thickness of 7.5 mm, with 135 containing epithelioid cells. Risk factors were identified by Cox analysis and metastatic rates demonstrated using Kaplan-Meier curves. RESULTS: There were 52 deaths from metastatic melanoma. The significant risk factors were (i) age more than 60 years at treatment (p = 0.001), (ii) mixed/epithelioid tumours (p = 0.003), (iii) superior location of mixed/epithelioid tumours (over and above (ii)) (p = 0.001), (iv) largest basal tumour diameter of 16 mm or more (p < 0.001), (v) lack of adjunctive radiotherapy (p = 0.031), (vi) secondary enucleation for bulky residual/recurrent tumour (p = 0.002), and (vii) secondary enucleation for small residual/recurrent tumour extraocularly (p = 0.019). Metastatic death was not significantly associated with (i) incomplete tumour excision (p = 0.163), and (ii) small residual/recurrent tumour treated by enucleation (p = 0.855). CONCLUSIONS: Survival diminished from 92% at 15 years if less than two risk factors were present to less than 30% in 3.5 years if more than three risk factors were present.

Combined Modality Therapy↗
PubMed1996

Objective detection of hemifield and quadrantic field defects by visual evoked cortical potentials.

AIMS/BACKGROUND: An objective method for detecting hemifield and quadrantic visual field defects has been developed using steady state visual evoked cortical potentials (VECPs), an adaptive noise canceller (ANC), and Hotelling's t2 statistic. The purpose of this study was to determine the sensitivity and specificity of the technique. METHODS: Nine subjects (mean age 44 years) were investigated with field loss due to a variety of causes including both anterior and posterior visual pathway lesions. Dynamic perimetry was performed by means of a Goldmann or Tübingen perimeter. VECP recordings were made from each visual field quadrant (23 degrees X 23 degrees) by means of a steady state reversing checkerboard (7.7 rev/s). The central 5 degrees of the visual field and the vertical and horizontal meridians were masked during these measurements. Recordings were made from three electrode sites, positioned over the visual cortex, relative to a mid frontal electrode. Each recording lasted 2 minutes, during which time fixation was monitored. The data from each recording were divided into 4 second segments, and the amplitude and phase of the VECP signal measured using the ANC. Hotelling's t2 statistic was applied to determine the probability of signal detection. Receiver operating characteristic curves were used to find the optimum signal detection threshold for identification of the visual field defects. RESULTS: The results of the study confirmed patterns of subjective visual field loss. The technique had a sensitivity and a specificity of 81% and 85%, respectively, for detecting 'non-seeing' areas in the inferior visual field, and 82% and 89%, respectively, for detecting 'non-seeing' areas in the superior visual field. CONCLUSION: These results demonstrate that the technique is of potential clinical value to ophthalmologists and neurologists when subjective perimetry is not possible.

Adolescent↗
PubMed1994

A personal computer-based visual evoked potential stimulus and recording system.

A system for recording electroretinograms and visual evoked cortical potentials has been constructed with the use of a personal computer and a digital signal processing card. The system is based on widely available commercial hardware. It has been designed to be capable of performing routine visual electrophysiology as well as allowing the development of novel visual stimuli and signal detection techniques. The system enables both transient and steady-state stimulation rates. Pattern stimuli can be presented in pattern-reversal, pattern-onset, pattern-offset or motion-onset modes. In addition to conventional signal averaging, the digital signal processing card can also provide on-line Fourier analysis and is facilitating the development of adaptive filtering techniques for the detection of steady-state visual evoked cortical potentials. This versatile system is in regular clinical use for the measurement of electroretinograms and visual evoked cortical potentials.

Electrophysiology↗
PubMed1994

Bilateral uveal melanoma presenting simultaneously.

A case of bilateral uveal melanoma in a 54-year-old man is described. On admission of the patient for a choroidal melanoma of the left eye, an asymptomatic ciliary-body tumour was detected in his right eye. A thorough general examination did not reveal any metastases. The left eye was enucleated and local excision of the tumour in the right eye was performed 2 months later. Histology confirmed the presence of malignant melanomas in both eyes. The tumours were of similar A/B spindle-cell type. The patient remained healthy, showing no sign of metastasis or local recurrence of melanoma 9 months after the date of diagnosis. The visual acuity in his remaining eye remained 6/6. Immunological assessment of the blood serum revealed abnormally high interleukin 1 beta (IL-1 beta) and IL-2 levels. Possible implications of these findings are discussed.

Choroid Neoplasms↗
PubMed1993

Computerised perimetry with moving and steady fixation in children.

The computer assisted moving eye campimeter (CAMEC) maintains the patient's interest and fixation by using a moving fixation target which must be tracked by the patient using a joystick for the test to proceed. In this study, 32 children were examined with the blind spot test programs of both CAMEC and the Dicon Auto-Perimeter. Among those who completed both tests the blind spot was detected in 18 eyes (75%) by the Dicon Auto-Perimeter and in 24 eyes (100%) by CAMEC. The mean CAMEC score (61.0%) was significantly higher than the mean Dicon Auto-Perimeter score (26.6%). CAMEC allowed better detection and quantification of scotomas in patients more than 4 years of age.

Child↗
PubMed1993

Clustering of fixation targets in multifixation campimetry.

The multifixation campimeter has a central test stimulus and a series of numbered fixation targets and uses the patient's eye movements to position the stimulus in the visual field. The stimulus is constantly exposed so that the patient reads the numbers and identifies any which are associated with its disappearance. The aim of this study is to identify the effect of clustering fixation targets on sensitivity. Two hundred and seventy-two eyes of 139 normal individuals were tested with a multifixation campimeter in which either one or two of the fixation targets corresponded to the physiological blind spot. Sixty-nine individuals (138 eyes) were tested with chart A and 70 individuals (134 eyes) with chart B. The second fixation target increased the blind spot detection rate from 65% to 85% of the eyes respectively. In 10% of eyes the blind spot was detected on only one of two examinations. The performance of multifixation campimetry is improved if fixation targets are clustered in vulnerable parts of the field and distributed so as to test the blind spot repeatedly during the examination. Inconsistent results are an indication for re-examination of selected points, with intermittent stimulus presentation.

Adult↗
PubMed1993

Predictive factors of visual outcome after local resection of choroidal melanoma.

Local resection of choroidal melanomas is not widely performed so that the indications for this operation have not previously been defined statistically. Univariate and multivariate Cox regression analyses were used to identify the factors influencing visual acuity after 163 completed local resections for choroidal melanoma in patients with a preoperative visual acuity of counting fingers or better. The variables included in the analyses were patient age and sex; eye laterality and preoperative visual acuity; location of anterior and posterior tumour margins; tumour location (coronal and sagittal); tumour diameter, thickness, and cell type; ocular decompression by vitrectomy; and adequacy of surgical clearance. The surgical resections were performed using a lamellar scleral flap for eye closure, hypotensive anaesthesia for haemostasis, and, in the later years, ocular decompression by pars plana vitrectomy to improve access. The patients (94 men, 69 women) had a mean age of 50 years. The tumours had a mean diameter of 13.3 mm and a mean thickness of 7.4 mm, with 38 tumours extending to within 1 disc diameter (DD) of the optic disc, fovea or both (that is, 'posterior tumour extension'). Cox multivariate analysis showed that the most significant preoperative factors for predicting retention of good vision (6/12 or better) were nasal tumour location (p = 0.002) and distance of more than 1 DD between the tumour and the optic disc or fovea (p = 0.010). The most significant predictive risk factor for severe visual loss (hand movements or worse) was posterior tumour extension to within 1 DD of the optic disc and/or fovea (p = 0.009). One year post-operatively, all 28 patients with nasal tumours not extending to within 1 DD of the optic disc or fovea retained the eye with 57% having vision of 6/12 or better and 93% having vision of counting fingers or better. In 68 patients with temporal tumours, 90% retained the eye at 1 year with preservation of vision of counting fingers or better in 82% of 56 eyes without posterior tumours extension and in 50% of 12 eyes with posterior tumour extension. In patients with choroidal melanoma, conservation of the eye and vision can be achieved by local resection, especially if the tumour is located nasally and does not extend close to the disc or fovea.

Adult↗
PubMed1993

Clinical evaluation of a multi-fixation campimeter for the detection of glaucomatous visual field loss.

The multi-fixation glaucoma screening chart, which uses the oculokinetic perimetry (OKP) technique, is a hand-held tangent screen with a central black test stimulus on a white background and a series of 26 numbered fixation targets arranged around the stimulus at various locations. When the numbers on the chart are read by the patient from 40 cm distance, the test stimulus passes through the relevant parts of the central visual field which are most vulnerable to glaucomatous damage. The test is positive (that is, abnormal) if at least one fixation number is associated with consistent disappearance of the stimulus. The OKP test was performed in 222 eyes of 126 glaucoma patients (aged 16-91 years) and 186 right eyes of 186 normal individuals (aged 19-86 years) using a 1.5 mm diameter stimulus. A further 144 eyes of 88 glaucoma patients (aged 60-85 years) and 31 right eyes of 31 normal individuals (aged 60-85 years) were tested with a 3 mm diameter stimulus. All eyes were also tested with conventional perimetry and the results of the conventional perimetry were categorised according to the Aulhorn-Karmeyer classification by four ophthalmologists without any knowledge of the OKP results. When the 1.5 mm stimulus was used, a true positive OKP result was obtained in 45% of eyes with relative scotomas, 81% of eyes with small absolute scotomas separate from the blind spot and 100% of eyes with more severe visual field defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Local resection of uveal melanoma.

This article describes the techniques, indications, and results of local resection of intraocular melanomas using (1) the external approach with lamellar scleral dissection and hypotensive anaesthesia and (2) in the transvitreal approach (endoresection). In principle, local resection is indicated for iris and ciliary body tumours and for medium and large choroidal tumours which are not expected to do well after radiotherapy. Contraindications to local resection are optic disc involvement, significant extraocular tumour extension, and involvement of more than a third of the ciliary body or angle.

Anesthesia↗