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Biomedical subjects

C J Lyons

Publications and source records attributed to C J Lyons.

At least 37 records · Page 2Linked to original sources
PubMed1994

Orbital decompression for disfiguring exophthalmos in thyroid orbitopathy.

BACKGROUND: Progressive exophthalmos from dysthyroid orbitopathy may result in marked disfigurement. Commonly affecting middle-aged women, it can be a significant social and psychologic handicap. Cosmesis is increasingly recognized as an indication for orbital decompression. Many argue, however, that decompression carries risks of operative complications which are only warranted where vision is threatened. METHODS: Between 1984 and 1990, the authors performed orbital decompression for cosmetic indications on 34 patients (65 orbits) with thyroid orbitopathy. The charts of these patients were reviewed to assess the results of surgery and the nature and incidence of complications. RESULTS: The mean retroplacement achieved was 4 mm (range, -1.0 to 10 mm). In 29 (85%) of the 34 patients, there was a difference of 1 mm or less in the proptosis of the two eyes postoperatively. Diplopia arose de novo in five (18%) previously asymptomatic patients. Postdecompression strabismus was managed successfully with adjustable surgery (mean, 1.3 operations per patient). With the exception of transient infra-orbital nerve hypoesthesia, there were no surgical complications. CONCLUSION: Decompression surgery is effective in reducing exophthalmos in dysthyroid orbitopathy. In this series of operations, complications were rare and treatable. Decompression is often the first of a series of operations that may be necessary to correct the cosmetic sequelae of this condition. It should be considered by experienced surgeons in carefully selected and counseled patients who have disfiguring thyroid orbitopathy.

Adult↗
PubMed1993

The management of punctal agenesis.

BACKGROUND: Agenesis of one or more lacrimal puncta is a rare cause of presentation to ophthalmologists. Where normal canalicular tissue lies within the lid, it may occasionally be successfully exteriorized to the conjunctival surface with relief of symptoms. The pattern of punctal agenesis, its relationship to the presence of underlying canalicular tissue, and its management have not been defined previously in a large cohort. METHODS: The authors reviewed the pattern of agenesis, underlying anatomic abnormalities and patient symptomatology in 57 patients seen over a 10-year period. A management plan was devised for eyes with no puncta and those with a single missing punctum. RESULTS: Both puncta were absent in 53 eyes, and a single punctum was missing in 41 eyes. In 86% of eyes with absence of both puncta, no canalicular tissue was identified when the lacrimal sac was opened at surgery. The underlying canaliculus also was absent in patients with one absent punctum. Nasolacrimal duct obstruction frequently accounted for the onset of symptoms in patients with a single punctum. Fifty-three (93%) of the 57 operated eyes were functionally cured at the completion of this report. CONCLUSION: Punctal agenesis usually is associated with the absence of underlying canalicular tissue. Where both puncta are absent, the authors recommend inspection of the internal opening of the common canaliculus at surgery and, if no canalicular tissue can be identified (86% in this series), insertion of a Lester-Jones tube. Symptomatic patients with a single punctum frequently require surgery to relieve nasolacrimal rather than canalicular obstruction.

Adolescent↗
PubMed1993

Excimer laser photorefractive keratectomy for myopia: 12 month follow-up.

A prospective study of excimer laser photorefractive keratectomy was performed with the aim of correcting a range of myopic errors between -1.00 and -10.00 dioptres. Corneal healing was monitored through the first post-operative year by serial assessments of refraction, contrast sensitivity, corneal haze, pachymetry and keratometry. Eighty-one patients were recruited for the study. At 12 months 81% were within +/- 1.00 dioptre of desired emmetropia and with unaided vision of 6/12. Contrast sensitivity was found by Pelli-Robson assessment to be reduced throughout the 12 months and regression analysis predicted recovery by 2 years. At 12 months, however, only 15% of patients were found to have lost a single line of best corrected Snellen acuity. Predictability of results was found to be greatest for initial errors less than -4.00 dioptres. No serious complications were observed during the follow-up period, but refraction had not stabilised in all cases and patients remain under review.

Adult↗
PubMed1993

Monocular visual outcome in untreated early onset esotropia.

The incidence of amblyopia was analysed in a group of 20 patients with early onset esotropia. These patients reached adulthood without any form of previous treatment. The incidence of amblyopia was compared in a group of 20 patients who received conventional treatment, including occlusion and early surgical alignment. Only three patients (15%) in the untreated group presented with amblyopia, compared with 16 (80%) in the treated group. After treatment 35% of the control group remained amblyopic. Spherical anisometropia of more than 2 dioptres was present in two of the patients with amblyopia in the untreated group, but was not associated with amblyopia in the control group. Early surgical alignment permits the development of peripheral fusion, allowing long term alignment stability, but amblyopia appears to be more common after surgical alignment.

Adolescent↗
PubMed1992

Impression cytology of conjunctival melanosis and melanoma.

Impression cytology using cellulose acetate paper has been used in various ocular surface disorders as a simple non-invasive diagnostic test. To assess its value in differentiating melanocytic tumours, 24 patients with a range of pigmented lesions of the conjunctiva were examined using this technique. Cytological and histological diagnoses were compared in 23 cases. In 73% of cases impression cytology predicted the histological diagnosis by detection of superficial atypical melanocytes and their proportion relative to benign epithelial cells. This pilot study shows impression cytology to be a useful diagnostic aid in the differentiation of pigmented tumours of the bulbar conjunctiva.

Adult↗
PubMed1991

Familial aggressive nevi of the iris in childhood.

We report the occurrence of amelanotic melanocytic tumors of the iris arising in the second decade of life in two successive generations. Clinically, both tumors enlarged rapidly, with subsequent enucleation of the eye in one patient. In both cases, histologic examination revealed an aggressive iris nevus composed of spindle A cells. Both lesions had similar argyrophilic nucleolar organizing region counts, which may be of prognostic significance. A possible autosomal-dominant pattern of inheritance for this rare tumor is discussed.

Adolescent↗
PubMed1990

Sclerokeratitis after keratoplasty in atopy.

The authors report a series of five markedly atopic patients in whom a severe sclerokeratitis developed within 1 to 4 weeks of keratoplasty. The onset was acute with discomfort, photophobia, hyperemia, and mucus production. This resulted in early loosening of sutures and was associated with microbial keratitis in two cases and graft rejection in one. The inflammatory reaction was controlled with high-dose oral steroids and did not recur when the treatment was terminated. Serum IgE levels were elevated in all these patients (range, 421-8434 kU/l). Binding of this IgE onto the surface of mast cells in the conjunctiva with subsequent degranulation may be involved in the pathogenesis of the induced inflammation. Principal recommendations include the use of interrupted sutures and early immunosuppression with high-dose oral steroids at the onset of this condition together with the control of risk factors for microbial keratitis.

Adolescent↗
PubMed1990

Report of a repositioned posteriorly dislocated intraocular lens via pars plicata sclerotomy.

A patient had an apparently uncomplicated extracapsular cataract extraction with insertion of a posterior chamber intraocular lens (IOL). Posterior dislocation of the implant was noted postoperatively. The IOL was successfully repositioned via a pars plicata sclerotomy and the haptic was sutured to the sclera. We believe this procedure is relatively atraumatic and is preferable to removal and replacement of a partially dislocated implant.

Aged↗
PubMed1990

Topical flurbiprofen: an effective treatment for episcleritis?

Topical flurbiprofen was compared with placebo and prednisolone 0.3% in the treatment of episcleritis by a randomised double-blind trial. Seventy-seven eyes were included in the trial. Rapid spontaneous improvement in symptoms and signs was noted in the majority of cases. There was no significant difference between the cure-rates of patients treated with flurbiprofen and placebo over a 3-week trial period. The proportion of patients treated with prednisolone 0.3% who were cured was significantly higher than in either of the other groups after 3 weeks.

Administration, Topical↗
PubMed1990

Botulinum toxin therapy in dysthyroid strabismus.

We report our experience with the use of Botulinum toxin injection in 38 patients (64 injections) with severe dysthyroid strabismus. Three quarters of the injections led to a decrease in the angle of the squint by a mean 75% of the initial deviation. The average duration of effect was two months. Twenty six patients went on to surgery after stabilisation of their squint and endocrine status. Six patients achieved a stable long-term result with Botulinum toxin only. We suggest these results of treatment of early dysthyroid myopathy are more consistent with the characteristics of inflammatory spasm than contracture. The value of Botulinum toxin as a temporary means of maintaining binocularity in these young patients is discussed.

Adult↗
PubMed1990

Symptomatic nocturnal lagophthalmos.

Nocturnal lagophthalmos producing symptoms of corneal exposure is not uncommon. We diagnosed 40 patients with the condition over a six-month period. In 12 (30%), alcohol intoxication preceded the symptoms. Other factors included the use of hynotics, cosmetic blepharoplasty, botulinum toxin injection for blepharospasm, facial palsy, dysthyroid eye disease and cicatrising skin disease of the lids. In the largest group (17 patients, 42%), no cause could be found, but five of these had either first-degree relatives who slept with their eyes open, or had been observed with nocturnal lagophthalmos. In most patients, symptoms were unilateral. Testing of Bell's phenomenon did not predict eye position during sleep as manifested by distribution of punctate corneal staining. All patients were relieved of their symptoms by simple treatment modalities and none required surgery.

Adult↗
PubMed1990

Detection of ocular malignancies.

The case notes of new patients attending the oncology clinic at Moorfields Eye Hospital during the first 5 months of 1988 were analysed retrospectively with regard to the origin of the primary referral, the presence of symptoms, the diagnosis and management. Sixty-eight of 94 new patients were diagnosed as having malignant ocular lesions. Of these 68, 47% were first seen and referred by an optician. Half of these patients were asymptomatic at the time of detection.

Adolescent↗
PubMed1989

Chorioretinal scarring following the Faden operation. A retrospective study of 100 procedures.

Following reports of a high incidence of chorioretinal scarring related to the Faden Procedure, a retrospective study was carried out at Moorfields Eye Hospital. One hundred unselected Faden procedures were followed up with orthoptic and fundoscopic examination. Our indications and technique for performing this operation are described. A 7% incidence of chorioretinal scarring was noted; this compares well with previously published figures for conventional squint surgery and this operation should therefore be considered safe.

Adolescent↗
PubMed1989

The effect of magnetic resonance imaging on metal spine implants.

In Part 1 of this study, the forces and torques exerted on metallic spine implants by a 0.3-T magnetic field were evaluated using a cantilever system sensitive to forces as low as 250 mg and torques as low as 4 g/cm. Results indicated that the 0.3-T magnification field did not cause forces or torques that could be measured within this range. It is concluded that patients with spine implants may safely undergo magnetic resonance scanning. In Part 2, the magnetic resonance scans from 33 patients (61 studies) then were reviewed to determine which, if any, parameters could be adjusted to minimize artifact. Magnetic power, slice thickness, plane of scan, and pulse sequence were considered. Plane of scan was found to be the most significant parameter in achieving useful studies, with the sagittal plane being the preferred orientation. Scans of patients who had posterior wiring were more likely to be useful, while scans of patients with spinal rods usually showed a large amount of artifact.

Humans↗
PubMed1989

Development of the gas-permeable impression-moulded scleral contact lens. A preliminary report.

Although superceded by corneal hard and soft contact lenses for the correction of simple refractive error, the scleral lens still has numerous medical applications in modern ophthalmological practice. However, a major problem with scleral lenses has been the limited wearing time due to corneal occlusion and consequent hypoxia. We present two alternative methods for the production of moulded gas permeable scleral contact lenses.

Contact Lenses↗