Showing papers in "British Journal of Ophthalmology in 1984"

Pterygium and ultraviolet radiation: a positive correlation.

Abstract: Pterygium has long been believed to be an environmental disease, Ultraviolet (UV) radiation playing a major role in its development. In examination of more than 100 000 Aborigines and non-Aborigines in rural Australia a strong positive correlation between climatic UV radiation and pterygium prevalence was found, providing further evidence of a causal relationship. In addition interesting differences were found in prevalence in the different racial groups and between the sexes. These differences may be explained by differences in lifestyle.

Long-term follow-up of central serous chorioretinopathy.

Abstract: The Wilmer Retinal Vascular Center's experience with central serous chorioretinopathy from 1970 to the end of 1979 was reviewed and compared with previous studies. Retrospective analysis of 73 patients seen at follow-up suggests no clinically significant effect of focal argon laser photocoagulation on final visual acuity or recurrence rate. Patients with initial visual acuity of 20/20 remained at that level, and patients with initial visual acuity of less than 20/30 gained, on average, two to three Snellen lines at follow-up. Approximately one-third of both untreated and treated patients had recurrence or presumed persistence during the follow-up period. With the inclusion of episodes that occurred before the first Wilmer Institute visit about half of each group had recurrence or presumed persistence. Recurrences were most often due to leakage from a site within one disc diameter of the original site of leakage.

Nuclear cataract and myopia during hyperbaric oxygen therapy.

Abstract: The effect on the human lens of prolonged hyperbaric oxygen therapy is reported. Eye examinations were given to 25 patients before, during, and after a series of 150 or more exposures to hyperbaric oxygen. All patients changed refraction in the direction of myopia during treatment. Fifteen of the patients had clear lens nuclei before treatment. Seven of these developed a nuclear cataract with reduced visual acuity during treatment. Reversible lens myopia has previously been noticed as a side effect of exposure to hyperbaric oxygen, but the cataractogenic effect in man has not been reported by other workers. This report strongly supports the theory of an oxidative damage to the lens proteins as a cause of nuclear cataract.

Retinal and epiretinal glia--an immunohistochemical study.

Abstract: Immunohistochemical techniques were used to examine the distribution of cells containing glial fibrillary acidic protein (GFAP) in normal and pathological human specimens, including 22 globes (13 of which contained epiretinal membranes 'in situ'), 16 surgically excised epiretinal membranes, and monolayers of cells obtained from five epiretinal membranes placed in tissue culture. The astrocytic cells of normal and pathological retinae stained with the glial-cell marker, but Muller cells were GFAP-negative in normal retinae at the antisera dilutions used. Muller cells did, however, stain in retinae from glaucomatous eyes and in eyes with prolonged retinal detachment. Electron microscopy did not reveal any obvious morphological difference between the intermediate filaments of normal (GFAP-negative) and GFAP-positive Muller cells. Ten of the 13 epiretinal membranes 'in situ', all 16 excised membranes, and three of the five monolayers contained glial cells. Purely glial membranes were not associated with retinal puckering or detachment, while all membranes causing tractional complications had a prominent fibrous, non-glial component. Our findings suggest that glial cells do not contribute significantly to the contractile forces generated by epiretinal membranes. They may, however, provide a scaffold on which other cells proliferate and contract and an anchorage by means of which tangential forces are transmitted into and through the retina.

Contrast sensitivity and visual disability in chronic simple glaucoma.

Abstract: A battery of vision tests was used to quantify visual defect in a group of 50 patients with chronic simple glaucoma. The vision tests were near and distance visual acuity, visual fields, and contrast sensitivity to static and temporally modulated sinusoidal grating patterns. Of these, static contrast sensitivity function appears to be the most sensitive method of measuring visual defect in glaucoma patients. The visual disability experienced by the glaucoma patients was quantified by means of a questionnaire, and the relationship between perceived visual disability and visual defect was examined. It was found that results from a group of tests, near visual acuity, visual field, and contrast sensitivity measures, are the best predictors of the difficulty experienced by patients in performing visually dependent daily activities.

Pathogenesis of tears of the retinal pigment epithelium.

Abstract: This report confirms a previous report that elderly patients with serous detachments of the pigment epithelium prior to and after developing a pigment epithelial tear at one border present a characteristic ophthalmoscopic and fluorescein angiographic appearance. Evidence is presented that subpigment epithelial choroidal neovascularisation and not irregular separation of the basement membrane from its pigment epithelium is the primary cause of the detachment and tear in the pigment epithelium.

Senile atrophy of the human lacrimal gland: the contribution of chronic inflammatory disease.

Abstract: Histological examination of 99 human lacrimal glands showed a relationship between atrophy of the secretory acini and secretory duct obstruction, ascending periductal fibrosis, and obliteration of the adjacent blood vessels caused by lymphocytic and polymorphonuclear inflammation. Investigation of the subgroups of the B lymphocytic series by immunohistochemistry did not show any statistical change with age, sex, fibrosis, or lymphocytic inflammation. The concept of senile atrophy occurring as a result of senescent involution of the lacrimal gland is challenged on the basis of the histological findings.

Retinal pigment epithelial cells in epiretinal membranes: an immunohistochemical study.

Abstract: Immunohistochemical techniques were used to identify cells containing cytokeratins in sections or tissue-culture monolayers from ocular (reference) tissues and also from 22 epiretinal membranes obtained during closed microsurgery for macular pucker or massive preretinal retraction. Results of cytokeratin immunostaining in reference tissues indicated that this is a valuable means of determining the contribution and distribution of epithelial cells in epiretinal membranes, and that the epithelial cells in the membranes were probably derived from the retinal pigment epithelium. Epithelial cells were identified in 17 of the 22 epiretinal membranes, but they did not usually constitute the predominant cell type. We concluded that the fibroblasts or fibroblast-like cells thought to be responsible for the contraction of epiretinal membranes are seldom of retinal pigment epithelial origin. Biomicroscopic pigmentation of a membrane was shown to be a poor guide to its epithelial cell population.

Comparative bacteriology of chronic blepharitis.

Abstract: One hundred and fifteen patients with chronic blepharitis were compared with 47 normal controls. Six clinically distinct groups of blepharitis were observed: staphylococcal; seborrhoeic, alone, with associated staphylococcal superinfection, meibomian seborrhoea, or secondary inflammation of the meibomian glands; and meibomian keratoconjunctivitis (MKC). Staphylococcus aureus was isolated in appreciable frequency from the staphylococcal and the mixed staphylococcal/seborrhoeic groups in contrast to the normal and non-staphylococcal groups. Coagulase-negative Staphylococcus spp., Propionibacterium acnes, and cornyneform bacteria were the most commonly isolated bacteria from the lid for all groups. Cultures of material expressed from the meibomian glands yielded similar organisms but in reduced frequency. Testing of antibiotic susceptibility revealed Staph aureus to be usually sensitive to most commonly used ophthalmic antimicrobials except sulphonamides.

Low-contrast letter charts in early diabetic retinopathy, ocular hypertension, glaucoma, and Parkinson's disease.

Abstract: Diabetes can cause visual loss that is not detected by standard reading tests such as the Snellen test but can be detected by low-contrast letter charts. This visual loss is quite different from loss caused by refractive error. These low-contrast charts are diagnostically at least as sensitive as the sinewave grating contrast sensitivity test. They are inexpensive, and the test is brief and simple. Preliminary evidence is that patients with diabetes who have abnormal low-contrast chart results give abnormal intravenous fluorescein (IVF) test results, even though visual acuity is normal. Low-contrast charts also detect visual loss in patients with ocular hypertension, glaucoma, and Parkinson's disease, including patients with normal visual acuity.

Central serous chorioretinopathy complicating systemic corticosteroid treatment.

Abstract: Central serous chorioretinopathy developed in 2 cases of retrobulbar neuritis during systemic treatment with corticosteroids. Fluorescein angiography confirmed leakage surrounded by central serous detachment of the retina. In one case the central serous chorioretinopathy recurred 3 times during 3 separate courses of treatment. Spontaneous recovery accompanied a reduction in steroid treatment to a low level. It is suggested that high dosage corticosteroids may damage the posterior blood-ocular barrier.

Normal tear protein profiles and age-related changes.

Abstract: The specific and non-specific tear proteins have been analysed by means of the ELISA technique to establish the normal and age-related values. There is a linear and related decline of lysozyme and lactoferrin with age, and a similar but unrelated reduction in tear volume. IgA levels gradually decline, while caeruloplasmin and IgG both increase after the fifth decade. The results suggest that tear IgG and caeruloplasmin are probably transudates from the serum, that IgA is secreted independently of tear volume, and that lysozyme and lactoferrin are secreted at the same site but independently of tear volume.

Screening for refractive errors in 6-9 month old infants by photorefraction.

Abstract: The method of isotropic photorefraction has been used in a trial of refractive screening of 6-9 month old infants. Data are presented on the calibration of the method against retinoscopic measurements and its reliability. In photorefractive screening of 1096 infants under cyclopentolate cycloplegia 5% were found to be hypermetropic (over +3.5 D), 4.5% myopic, and 1.3% anisometropic (over 1 D). These refractive errors were confirmed on retinoscopic follow-up (with the exception of a few anisometropes). Follow-up of controls shows that one small refractive error was missed in 52 infants. We conclude that photorefraction is a valid and practical screening technique. Longitudinal study of infants with refractive errors will assess the value of early detection, in particular for prediction and prevention of strabismus.

Orbital dermoids: clinical presentation and management.

Abstract: The authors have reviewed 15 cases of orbital dermoids representing 6% of orbital tumours seen at the University of British Columbia Orbital Clinic. They tended to occur as either asymptomatic superficial lesions in children or as complicated deep lesions in adolescents and adults. The superficial lesions were as frequent medially as laterally and could be dealt with by a direct uncomplicated surgical approach. The deep lesions in contrast, were frequently extensive and difficult to remove, requiring careful preoperative planning. Sites of origin, presentation, differential diagnosis, and management are discussed.

Postural change of IOP in normal persons and in patients with primary wide open-angle glaucoma and low-tension glaucoma.

Abstract: The values of intraocular pressure (IOP) measurements by an Alcon pneumatic tonometer and a Goldmann applanation tonometer were found to be close, with a correlation coefficient of 0.92. Measured by the pneumatonograph the IOP after 30 minutes in the supine position was highest in normal persons, in patients with primary wide open-angle glaucoma and low-tension glaucoma. The greatest difference in IOP between subjects sitting and supine was observed in patients with low-tension glaucoma.

Primary iris cysts: a review of the literature and report of 62 cases.

Abstract: The authors present their experience with the evaluation and follow-up of 62 patients with primary cysts of the iris, discuss their clinical and pathological features, and propose a simple classification for these lesions. The results suggest that the great majority of primary iris cysts, particularly those which arise from the iris pigment epithelial layers, are stationary lesions which rarely progress or cause visual complications. This finding is contradictory to the belief of certain authorities who stress that many such lesions lead to severe complications, with blindness and loss of the eye. The natural course of primary epithelial cysts differs from that of secondary iris cysts which follow surgical or nonsurgical trauma. The latter lesions do frequently enlarge and lead to severe complications such as inflammation and glaucoma. The major clinical importance of primary iris cysts lies in their similarity to neoplasms of the iris and ciliary body. It is concluded that the great majority of them are ophthalmic curiosities which require no treatment.

Bacterial contamination of intraocular lens surgery.

Abstract: One hundred sterile intraocular lenses were placed on the external eye of 50 patients during cataract surgery. Half of the specimens were cultured for bacteria, the other half were examined under the light microscope after fixing and staining. A bacterial contamination rate of 26% was recorded. This is significantly higher than that found in conjunctival swabs (6%) or irrigation specimens (8%) taken at the same time, and higher than that recorded in a group of control lenses (15.2%) exposed to operating theatre air alone. We propose that intraocular lenses contaminated with viable bacteria may be implanted into the eye and thereby account for some cases of postoperative uveitis in the pseudophakic eye.

Ocular changes in patients undergoing long-term desferrioxamine treatment.

Abstract: In a group of young patients with thalassaemia and iron overload treated by subcutaneous infusions of desferrioxamine we have found a number of minor alterations in retinal function. The incidence of such changes is not related to drug dosage or to ferritin level but to abnormality of the extended glucose tolerance test.

Retinal branch vein occlusion: a study of argon laser photocoagulation in the treatment of macular oedema.

Abstract: A control trial is reported which demonstrates that treatment with argon laser photocoagulation to certain patients with macular oedema following a branch vein occlusion does not alter significantly their visual prognosis. It confirms that patients with an intact perifoveal capillary arcade have a better prognosis than those with a broken arcade.

Diagnostic implications of tear protein profiles.

Abstract: Concentrations of lysozyme, lactoferrin, ceruloplasmin, IgA, and IgG have been measured in tears by the ELISA (enzyme-linked immunosorbent assay) technique. Tears were collected on weighed filter paper discs, after which they were eluted into buffer and transported frozen to a remote laboratory for assay. Patients with sicca, questionably dry eyes and ocular pemphigoid were sampled, as were 54 normal volunteers. Tear protein profiles were established which were unique for each condition and clearly differed from the normal controls. The assay developed is considered suitable for other proteins such as IgE, and could also be used for monitoring the effects of drugs on the lacrimal gland.

Pterygium in welders.

Abstract: Pterygium is thought to be hyperaemia of fibrovascular tissue on to the cornea caused by ultraviolet radiation of sunlight. We observed a significantly high incidence of pterygia in welders who were exposed occupationally to excess ultraviolet radiation and found a close relationship between the incidence and the length of employment as a welder (r = 0.975, p less than 0.05). This study attempts to clarify the causative relationship between ultraviolet radiation and pterygia.

Prolonged rod dark adaptation in retinitis pigmentosa.

Abstract: The time course of rod dark adaptation was measured in 12 patients and carriers of retinitis pigmentosa (RP). In contrast to previous studies the rod absolute threshold was determined prior to any exposure to the bleaching light. For seven of the patients and carriers the recovery of rod sensitivity to the prebleach level was prolonged, with the delay ranging from mild to severe. The prolongation appeared to be limited to the late phase of bleaching recovery; the early portion of rod dark adaptation, measured following a weak bleach, was normal. These results suggest a selective impairment in the processes underlying rod dark adaptation in some patients with RP.

Uveitis: A Clinical Approach to Diagnosis and Management

Abstract: This is a uveitis book for the clinician, and it is refreshing not to have to read a large prelude of basic immunology before the clinical material, as has been a feature of most books on the subject recently. The 2 authors work at the Estelle Doheny Eye Foundation, Los Angeles, and the Francis I. Proctor Foundation in San Francisco, 2 of the most dynamic institutes in uveitis research in the USA. The contents are divided into 3 broad sections: general principles, special clinical problems, and specific clinical entities. The first section deals with classification, signs, and treatment. It is generally good, with much of interest and practical help such as an excellent chapter on the aims of treatment, but the text, in common with the rest of the book, has a rather concise and simplistic style which can be irritating to the British reader. Chapters on how to refer a patient to a physician and how to write the referral letter reflect the differences between British and American medicine. The second section deals with topics such as corneal disease with uveitis, retinal vasculitis, or hypopyon. Each topic occupies a 'chapter' of about 2 pages, which is hardly adequate for detailed discussion. For instance, scleritis, episcleritis, and uveitis are dealt with in just over one page. Scleromalacia perforans is not mentioned, nor is any advice given on the management of scleritis, a difficult subject in its own right. The final section has similar chapters of a few pages discussing specific clinical entities such as toxoplasmosis, sarcoid, or pars planitis and arranged in random order. These short chapters would be much improved by being expanded with more details and a bibliography, but all references (which are not annotated in the text) are lumped together at the end of each section. These are comprehensive, but the difficulty of sorting out those on sarcoid, for example, from the rest of the 7 pages of references makes them of no great practical use. At the end of the book there are 12 pages of colour prints which are previously referred to in the text. These are helpful and of good quality. This is a good book for the junior ophthalmologist or those with a passing interest in the subject. Overall, it has a different and useful approach to the subject but would have benefited from more thought and detail in its planning. It is too concise and lacking in detail to be authoritative, but perhaps further editions might remedy this. (The authors ask in the preface for advice from their readers for future editions.) In spite of these failings I think it is probably the best book on uveitis for clinicians available at present.

Routes of clearance of radioactive water from the rabbit vitreous

Abstract: The movement of water to and from the vitreous across the retina and pigment epithelium is important in relation to an understanding of such conditions as retinal detachment and its surgical cure, central serous retinopathy, and retinal oedema. Experiments were carried out to determine the main routes for removal of water injected into the vitreous and to see if the removal could be explained on the basis of diffusion or whether bulk flow was also implicated. 25 microCi of 3H2O in 25 microliter were injected into a central position in the vitreous humour of living rabbits under general anaesthesia. For 9 animals blood was collected from one of the 4 vortex veins draining the choroid and the radioactivity in the samples measured. For another 6 rabbits similarly injected the radioactivity in samples of aqueous humour was determined. The percentage of injectate recovered from the vortex vein blood ranged between 13% and 38%, mean 25 +/- 3%. The percentage of injectate recovered from the aqueous humour ranged between 1.2% and 5.2%, mean 2.8 +/- 0.6%. Analysis of the time course of isotope activity in the samples revealed a mean transit time from the mid vitreous to the choroid of 32 +/- 2 minutes, and from the mid vitreous to the anterior chamber of 84 +/- 3 minutes. By means of a computer model it was calculated that diffusion alone could effect this transfer; if active transport were involved in the transport of 3H2O to the choroid, this was not a limiting factor under the conditions of the experiment.

Dynamics of ocular surface pH.

Abstract: We studied ocular surface pH in 161 subjects. The mean pH for 133 normal volunteers was 7 . 11, SD 1 . 5. We found that older women had a more alkaline pH than other subjects, that the pH shifted from acid to alkaline during the day, that one hour of eyelid closure caused an acid shift in pH, and that pH recovered to baseline values within 40 minutes after acid drop instillation. We explored the mechanism of pH regulation, and we believe that pH changes could affect contact lens toleration, drug effectiveness, and clinical signs in disease processes.

Rod-cone interaction in flicker perimetry.

Abstract: We have assessed the influence of the rod system on cone flicker sensitivity during flicker perimetry. For temporal frequencies above 18 Hz extrafoveal cone-mediated flicker thresholds for a white test stimulus are as much as 1.5 log units lower when measured against a large background light that saturates the rods than when measured in darkness. Following a Ganzfeld bleach extrafoveal cone flicker thresholds are at their minimum once the cones have recovered their sensitivity, but then thresholds rise as the rods begin to recover from the bleach. Our results indicate that the flicker sensitivity of the extrafoveal cone system at high temporal frequencies is influenced by the rods surrounding the flickering test stimulus. The rods reduce flicker sensitivity maximally in the dark adapted state, and their suppressive influence is minimised only by strong rod bleaches or by large backgrounds that saturate the rod system.

Pharmacokinetics of oral acyclovir (Zovirax) in the eye.

Abstract: Patients due for cataract extraction received 5 doses of 400 mg acyclovir (Zovirax) orally during the 24 hours prior to surgery. Aqueous humour levels of acyclovir (mean 3.26 microM) were well above the normal ED50 range for herpes simplex virus type 1, and showed a significant correlation with plasma concentrations (mean 8.74 microM). There was also a correlation between the age of the patient and the concentration of acyclovir in the plasma. Oral acyclovir was well tolerated.

Vitrectomy and fluid/silicone-oil exchange for giant retinal tears: results at six months.

Abstract: The results of vitrectomy combined with fluid/silicone-oil exchange in 73 eyes with giant retinal tears are reported at six months after surgery. Initial anatomical success was achieved in 71 out of 73 eyes (97%) and, prior to removal of silicone-oil, in 66 out of 73 eyes (90%). In 63 eyes (86%) the retina remained attached six months after surgery. Of these visual acuity was 6/60 or better in 44 (70%). The high proportion of eyes with macular detachment before surgery and the frequency of macular abnormalities are thought to account for reduced vision in many of the anatomically successful cases.

Progressive subretinal fibrosis and uveitis.

Abstract: Three patients with intraocular inflammation and unusual progressive subretinal lesions are described. This entity is characterised by a chronic vitreous inflammation in association with whitish "fibrotic'-like subretinal lesions which progressively enlarge and coalesce. The patients all developed cystoid macular oedema. The differential diagnosis of this entity is discussed. These patients appear to have a unique and previously undescribed inflammatory disorder. The macular oedema responded to corticosteroid therapy in only one patient, and no therapy appeared to alter the course of the disease. Unlike many other patients with posterior uveitis these did not respond to the retinal S-antigen.