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Biomedical subjects

R Wormald

Publications and source records attributed to R Wormald.

At least 19 recordsLinked to original sources
PubMed2001

Deprivation and late presentation of glaucoma: case-control study.

OBJECTIVE: To identify socioeconomic risk factors for first presentation advanced glaucomatous visual field loss. DESIGN: Hospital based case-control study with prospective identification of patients. SETTING: Three hospital eye departments. PARTICIPANTS: Consecutive patients newly diagnosed with glaucoma (n=220). Cases (late presenters) were those presenting with advanced glaucoma (n=110), controls were those with early glaucoma (n=110). RESULTS: Median underprivileged area scores were higher among late presenters (29.5; interquartile range 9.0-42.2) than in the control group (21.3; 6.1-37.4) (P=0.035). Late presenters were more likely to be of lower occupational class (odds ratio adjusted for age and referral centre 20.1 (95% confidence interval 2.6 to 155) for group III compared with group I-II and 86.0 (11.0 to 673 for group IV-V compared with group I-II), to have no access to a car (2.2; 1.2 to 4.0), to have left full time education at age 14 or less (7.5; 2.3 to 24.7), and to be tenants rather than owner occupiers (local authority tenants 3.2; 1.7 to 5.8, private tenants 2.1; 0.7 to 5.8). Effects of deprivation were partly accounted for by family history of glaucoma, time since last visit to an optometrist, and lack of an initial diagnosis of glaucoma by an optometrist. CONCLUSIONS: Area and individual level deprivation were both associated with late presentation of glaucoma. Existing evidence shows that late presentation is an important risk factor for subsequent blindness. Deprived groups thus seem to be at greater risk of going blind from glaucoma. Material deprivation may be associated with more aggressive disease as well as later presentation.

Adult↗
PubMed2001

Ivermectin for onchocercal eye disease (river blindness).

BACKGROUND: It is believed that ivermectin (a microfilaricide) could prevent blindness due to onchocerciasis. However, when given to everyone in communities where onchocerciasis is common, the effects of ivermectin on lesions affecting the eye are uncertain and data on whether the drug prevents visual loss is unclear. OBJECTIVES: The aim of this review is to assess the effectiveness of ivermectin in preventing visual acuity and visual field loss in onchocercal eye disease. The secondary aim is to assess the effects of ivermectin on lesions affecting the eye in onchocerciasis. SEARCH STRATEGY: We searched the Cochrane Eyes and Vision Group specialised register, the Cochrane Controlled Trials Register - CENTRAL, MEDLINE, EMBASE, the reference lists of identified trials, the Science Citation Index and we contacted investigators, experts and pharmaceutical companies to identify additional trials. SELECTION CRITERIA: We included randomised controlled trials with at least one year follow up, comparing ivermectin at a dose of 150 micrograms per kilogram of body weight with either placebo or no treatment. Participants were people normally resident in endemic onchocercal communities with or without one or more characteristic signs of ocular onchocerciasis. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality. Study authors were contacted for additional information. Trials varied in design and setting, so no meta-analysis was done. MAIN RESULTS: This review includes five trials with data from 3810 participants. All the trials compared ivermectin with placebo and were judged to be of moderate risk of bias in terms of methodological quality. No statistically significant difference was observed in any trial (reporting visual acuity outcome) between ivermectin and placebo groups for visual acuity loss. REVIEWER'S CONCLUSIONS: Questions about the effectiveness of ivermectin in preventing visual acuity loss have not been answered by best available evidence.

Anthelmintics↗
PubMed2001

Intra-operative mitomycin C for glaucoma surgery.

BACKGROUND: Trabeculectomy is performed as a treatment for many types of glaucoma in an attempt to lower the intra-ocular pressure. Mitomycin C is an antimetabolite applied between the sclera and conjunctiva during the initial stages of a trabeculectomy to prevent excessive post-operative scarring and thus reduce the risk of failure. OBJECTIVES: The objective of this review is to assess the effects of intra-operative application of mitomycin C in eyes of people undergoing trabeculectomy. SEARCH STRATEGY: We searched the Cochrane Eyes and Vision Group specialised register, The Cochrane Controlled Trials Register - CENTRAL, MEDLINE, EMBASE and the reference lists of relevant articles. We used the Science Citation Index to search for articles that cited the included studies. We contacted investigators and experts for details of additional relevant trials. SELECTION CRITERIA: We included randomised trials of intra-operative mitomycin C compared to placebo in trabeculectomy. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. We contacted trial investigators for missing information. Data were summarised using relative risk, odds ratio and weighted mean difference. MAIN RESULTS: This review includes 11 trials involving a total of 698 participants. The trials included three types of participants (those at high risk of failure, those undergoing trabeculectomy combined with cataract surgery, and those with no previous surgical intervention). Mitomycin C appears to be effective in reducing the relative risk of failure of trabeculectomy both in eyes at high risk of failure (relative risk 0.32, 95% confidence interval 0.20 to 0.53) and those undergoing surgery for the first time (relative risk 0.29, 95% confidence interval 0.16 to 0.53). No significant effect on failure was noted in the group undergoing trabeculectomy combined with cataract extraction. Mean intra-ocular pressure was significantly reduced at 12 months in all three participant groups receiving mitomycin C compared to placebo. No significant increase in permanent sight threatening complications was detected. Some evidence exists that mitomycin C increases the risk of cataract. The quality of trial reporting is poor in eight trials. Repeat analysis with three trials rated as low risk of bias did not yield different results. REVIEWER'S CONCLUSIONS: Intra-operative mitomycin C reduces the risk of surgical failure in eyes that have undergone no previous surgery and in eyes at high risk of failure. Compared to placebo it reduces mean intra-ocular pressure at 12 months in all groups of participants in this review. Apart from an increase in cataract formation following mitomycin C, no demonstrable significant increase in other side effects was detected.

Antimetabolites↗
PubMed2000

Post-operative 5-fluorouracil for glaucoma surgery.

BACKGROUND: Trabeculectomy is performed as a treatment for many types of glaucoma in an attempt to lower the intra-ocular pressure. The surgery involves creating a channel through the sclera, through which intra-ocular fluid can leave the eye. If scar tissue blocks the exit of the surgically created channel intra-ocular pressure rises and the operation fails. Antimetabolites are used to inhibit wound healing to prevent the conjunctiva scarring down on to the sclera. The principal antimetabolites used are 5-Fluorouracil and Mitomycin C. Both may be applied on a sponge between the conjunctiva and sclera at the beginning of surgery. 5-Fluorouracil may also be given as one or more injections under the conjunctiva after the surgery. OBJECTIVES: The objective of this review is to assess the effects of post-operative injections of 5-Fluorouracil in eyes of people undergoing surgery for glaucoma. SEARCH STRATEGY: We searched the Cochrane Eyes and Vision Group specialised register, The Cochrane Controlled Trials Register (CENTRAL), MEDLINE and EMBASE. We searched the reference lists of relevant articles for additional trials, and we used the Science Citation Index to search for articles that cited the included studies. We contacted investigators and experts for details of additional relevant trials. SELECTION CRITERIA: We included randomised trials of post-operative 5-Fluorouracil injections compared to placebo injections or no injections in trabeculectomy for glaucoma. DATA COLLECTION AND ANALYSIS: We independently assessed trial quality and extracted data. We contacted trial investigators for missing information. Data were summarised using relative risk, Peto odds ratio and weighted mean difference as appropriate. MAIN RESULTS: Eight trials, which randomised a total of 536 participants, are included in the review. As far as can be determined from the trial reports, the methodological quality of the trials was not high. 5-Fluorouracil when delivered by post-operative injection appears to be effective in reducing the likelihood of surgical failure of trabeculectomy both in eyes at high risk of failure and those undergoing surgery for the first time. Complications are more common after 5-Fluorouracil injections, especially early and late wound leaks and temporary damage to the ocular surface. Whilst no evidence was found of an increased risk of serious sight threatening complications, people undergoing initial trabeculectomy had a substantially increased risk of ocular hypotony. None of the trials reported on the participants' perspective of care. REVIEWER'S CONCLUSIONS: This treatment is now rarely used on the basis of a planned series of post-operative injections.This presumably reflects an aspect of the treatment that is unacceptable to both patients and doctors. None of the trials reported on the participants' perspective of care which constitutes a serious omission for an invasive treatment such as this. Increasingly, injections are used on an ad hoc basis. The effectiveness of this strategy is the subject of a future systematic review.

Antimetabolites↗
PubMed2000

Photodynamic therapy for neovascular age-related macular degeneration.

BACKGROUND: In neovascular age-related macular degeneration, new vessels grow under the retina, distorting vision and leading to scarring. This is further exacerbated if the blood vessels leak. Photodynamic therapy, originally used in cancer treatment, has been investigated as a way to treat the neovascular membranes without affecting the retina. OBJECTIVES: The aim of this review is to examine the evidence for the safety and effectiveness of photodynamic therapy in the treatment of neovascular age-related macular degeneration. SEARCH STRATEGY: We searched for trials in the Cochrane Eyes and Vision Group trials register (available in the Cochrane Controlled Trials Register), the Cochrane Controlled Trials Register, Medline and Embase. We used the Science Citation Index to search for reports that cited identified relevant study reports. We contacted experts in the field for further trials information, and we searched the reference lists of identified relevant studies for further trial reports. Searches were conducted in December 1999. SELECTION CRITERIA: We included randomised trials of photodynamic therapy in people with choroidal neovascularisation due to age-related macular degeneration. DATA COLLECTION AND ANALYSIS: Two reviewers extracted the data independently. Meta analysis was not performed. MAIN RESULTS: One published trial was identified. Outcome data were available at 12 months after the first treatment. Patients received an average of 3.7 treatments. The relative risk of losing three or more lines of visual acuity at 12 months comparing the intervention with the control group was 0.72 (95% confidence interval 0.61 to 0.86). The relative risk of losing six or more lines of visual acuity at 12 months comparing the intervention with the control group was 0.62 (95% confidence interval 0.44 to 0.87). Subgroup analyses suggest that the benefits may be confined to people with no occult choroidal neovascularisation. REVIEWER'S CONCLUSIONS: Photodynamic therapy in people with classic choroidal neovascularisation due to age-related macular degeneration is effective in preventing visual loss. This evidence is drawn from a subgroup analysis of 143 participants in one trial. Outcomes and potential adverse effects of this treatment should be monitored closely. There is no evidence that photodynamic therapy is beneficial for people with evidence of occult choroidal neovascularisation. These people should be offered treatment in the context of a randomised trial.

Humans↗
PubMed2000

Risk factors for development of post-trabeculectomy endophthalmitis.

BACKGROUND/AIMS: Although adjunctive use of antiproliferative agents improves the success rate of glaucoma filtration surgery it profoundly alters the morphology of the filtering bleb. In view of these structural changes, which have been suggested to predispose to bleb infection, the relative importance of potential risk factors in the development of post-trabeculectomy endophthalmitis was investigated. METHODS: A case-control study was performed on patients with post-trabeculectomy endophthalmitis presenting to a single academic centre over a 6 1/2 year period. Cases were diagnosed by the combination of vitreous and aqueous inflammation occurring 4 or more weeks postoperatively with control patients chosen by selecting the three patients undergoing trabeculectomy immediately following each index case. RESULTS: Analysis of these data, derived from 23 cases and 69 controls, demonstrated that an episode of blebitis and the presence of diabetes mellitus were statistically significantly associated with subsequent endophthalmitis (odds ratios (OR) 11.8, 95% CI: 2.21-88.31, p = 0.003 and OR 4.51, 95 % CI 1.02-20.29, p = 0.04 respectively). The data also suggest an association exists between antiproliferative use and endophthalmitis (OR 3.3, 95% CI 0.95-15.19, p = 0.07) as the time interval between filtration surgery and development of endophthalmitis was significantly shorter in patients treated with antiproliferative agents (p = 0.001). CONCLUSIONS: These results provide strong evidence of an increased risk of late endophthalmitis in patients who have diabetes mellitus or have had an episode of blebitis and suggest antiproliferative agents may also have an important role.

Aged↗
PubMed1999

Retrospective analysis of risk factors for late presentation of chronic glaucoma.

BACKGROUND: Why some individuals present to the ophthalmologist in the early stages of chronic glaucoma but others present with very advanced visual field loss is a question which has received little attention. This study is an attempt to identify some basic characteristics of people who present with late glaucoma. METHODS: A retrospective case-control study by medical record review was employed. 100 cases and 100 controls were identified from the notes of patients presenting to Moorfields Eye Hospital glaucoma service between July 1993 and July 1995. Cases were defined as new patients presenting with absolute field loss within five degrees of fixation and a cup to disc ratio of greater than 0.8 in one or both eyes. Controls were new patients with no absolute field loss within 20 degrees in either eye, but otherwise typical glaucomatous field loss and a cup to disc ratio of greater than 0.5 or a difference of 0.2 or more between the discs. RESULTS: The ethnic origin, sex, referral source, presenting IOP, and age of the subjects studied were independently associated with late presentation. An African Caribbean patient is estimated to be four and a half times more likely to attend with advanced field loss than a white patient of similar age, sex, IOP, and referral source (adj OR: 4.55, 95% CI [1.57, 13.18]). A female patient is estimated to be one third (0.34, [0.15, 0.74]) as likely to attend late than a male patient of the similar age, IOP, ethnic origin, and referral source. A patient referred via any source other than an optometrist with the correct diagnosis is estimated to be greater than four times (4.32 [1.89, 9.88]) more likely to be a late attender than a patient of the same sex, ethnicity, and similar age but referred with a diagnosis of glaucoma. There was a trend of increasing odds of late presentation with increasing age (adj OR per 10 years, baseline 40-49 years 1.68 [1.22, 2.20]). A patient whose presenting IOP is 21-25 mm Hg is estimated to be a quarter (0.24, [0.09, 0.64]) as likely to attend with advanced field loss than a patient of the same ethnic origin, sex, age, referral source, but with presenting IOP of greater than 31 mm Hg. CONCLUSIONS: These data strongly suggest that certain subgroups of patients with glaucoma are likely to be at greater risk of presenting with advanced and irremediable field loss.

Adult↗
PubMed1999

Risk factors for late presentation in chronic glaucoma.

PURPOSE: To identify the risk factors for having advanced glaucomatous visual field loss on the first visit at three hospital eye services. METHODS: This was a hospital-based, case-control study involving patients newly diagnosed with glaucoma at first visit to one of three ophthalmic departments in the United Kingdom. Patients with a previous history of ocular hypertension or any documented suspicion of glaucoma (within the hospital eye service) were excluded. RESULTS: Occupational group, initial intraocular pressure (IOP), family history of glaucoma, method of referral to hospital, and the number of years since the last visit to an optometrist were found to be independently associated with late presentation. A linear trend of increasing odds of late attendance was associated with increasing Standard Occupational Classification. Those in managerial (category II) and skilled (category III) groups estimated (95% confidence intervals) to be, respectively. 0.2 (0.00, 0.16) and 0.27 (0.1, 0.8) as likely to attend with advanced glaucomatous field loss as unskilled (category V) people with similar initial IOP, family history, referral route, and time since last optometrist visit. The data strongly suggest an association between IOP and advanced field loss at initial hospital examination. There was a 1.2 (1.12, 1.28) increase in the OR of late presentation per unit increase in millimeters of mercury after adjustment for the other mentioned factors. People with a family history of glaucoma were estimated to be almost one third (adjusted OR, 0.29 [0.12, 0.74]) as likely to have advanced field loss as those with no family history. People referred by any source other than an optometrist who has made the correct diagnosis of glaucoma were 4.5 times (adjusted OR, 4.53 [1.52, 13.48]) more likely to be late attenders than patients so referred but similar in other mentioned factors. These data also provide strong evidence that the more years since the last visit to an optometrist, the greater the likelihood of having advanced glaucomatous visual field loss on the first visit to the eye service (adjusted OR per year, 1.25 [1.10, 1.42]). CONCLUSIONS: These data strongly suggest that certain subgroups of people with glaucoma were at greater risk of having advanced and irremediable field loss on first visiting the eye services studied.

Adult↗
PubMed1998

Visual acuity and its relationship to early growth, eye disease, and aging in north Hertfordshire.

We investigated the relationship between visual acuity, early growth and eye disease in a retrospective cohort study of 700 individuals in North Hertfordshire. Records of birth weight and weight at one year were used to determine early growth. We measured visual acuity and age-related eye diseases using standard instruments in those same individuals (now aged 63 to 73). Visual acuity below the legal threshold for driving in the UK (6/11 or poorer) was present in 13% of subjects. There was no clear association between birth weight or weight at one year and visual acuity. Vision impairment was found to be associated with refractive error, cataract, age-related maculopathy, and elevated macular threshold. After controlling for the effects of eye disease, increasing age remained a significant predictor of poorer visual acuity.

Aged↗
PubMed1998

BD8 certification of visually impaired people.

BACKGROUND: There is debate as to the completeness of the blind and partial sight registers in England and Wales. The purpose of this study was to estimate the proportion of eligible visually impaired people attending the hospital eye service who have a BD8 certificate and to identify factors associated with not being certified. METHODS: Cross sectional survey of patients attending outpatients by medical record review analysed by multiple logistic regression. RESULTS: 51% (43%, 58%) of patients identified as eligible for registration did not have a BD8 certificate. The severity of visual impairment and the main diagnosis in terms of requirements for treatment, permanence of visual loss, and visual field loss were independently associated with non-certification. A partially sighted patient is estimated to be three times more likely to not have a BD8 certificate as a blind patient of similar diagnosis (adj OR: 3.4 (95% CI: 1.7, 6.8)). A patient whose impairment is due to abnormal visual fields is estimated to be greater than three times more likely to be non-certified than one with low visual acuity of similar severity and cause (adj OR: 3.6 (95% CI: 1.0, 12.7)). People whose impairment is potentially reversible are estimated to be eight times (8.3 (2.2, 31.4)) more likely not to have a certificate compared with people who had permanent non-treatable visual loss; and in those with permanent visual loss, a requirement for ongoing treatment was found to be associated with a lower odds of certification. CONCLUSIONS: These data strongly suggest that epidemiological data collected during registration are biased towards permanent, non-treatable causes of visual loss and those which affect central rather than peripheral vision. Certain subgroups of the visually impaired are likely to be at greater risk of non-certification. BD8 guidelines need to be simplified.

Aged↗
PubMed1998

Impaired motion sensitivity as a predictor of subsequent field loss in glaucoma suspects: the Roscommon Glaucoma Study.

AIM: To determine if impaired motion sensitivity is a significant predictor of subsequent field loss in glaucoma suspects. METHOD: A population based prospective study; a 5 year follow up of all glaucoma suspects who had been identified from a population based random sample survey in the west of Ireland. 78 glaucoma suspects whose visual field function was annually measured by Henson CFS 2000 and for whom data on family history of glaucoma, ocular status, and motion impairment had been recorded. Visual field loss was defined as Henson visual field survival score of 94 or less. RESULTS: 18 people developed visual field loss in at least one eye. Motion impairment at baseline was associated with a 2-18 times greater risk of development of the visual field loss (p < 0.001). This association was independent of sex, family history of glaucoma, intraocular pressure, and C/D ratio at baseline. The Cox's proportional hazards regression analysis confirmed the above results after adjustment for age and the C/D ratio. CONCLUSION: Motion impairment is an independent predictor of visual field loss in glaucoma suspects, although it is not clear how long motion impairment precedes visual field loss.

Age Factors↗
PubMed1998

Brain natriuretic peptide: identification of a second natriuretic peptide in human aqueous humour.

AIMS/BACKGROUND: To measure aqueous humour levels of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in humans. To compare peptide levels in glaucomatous and control eyes to test the hypothesis that these peptides are increased in glaucoma. BNP and ANP are cyclic endopeptides whose principal biological effects are natriuresis and vasodilatation. Experimental glaucoma in animal models results in elevated aqueous ANP. Intravenous ANP administration in both animals and humans causes lowering of intraocular pressure (IOP). There are equivocal data to support a role for ANP in IOP regulation in human eyes. There are as yet no published data on BNP in human aqueous humour. METHOD: This was a case-control study. Cases were primary open angle, pseudoexfoliation, and mixed mechanism glaucoma eyes undergoing trabeculectomy. Controls were cataract extraction eyes. There were 47 trabeculectomy eyes (44 patients) and 47 cataract extraction eyes (46 patients) matched for age, sex, race, systemic medications, and type of anaesthetic. 100-200 microliters of aqueous humour were aspirated by paracentesis as the first step in the surgical procedure. Peptide levels were later measured by radioimmunoassay. RESULTS: The presence of BNP and ANP in human aqueous humour was confirmed. BNP was present in higher concentrations than ANP. BNP levels tended to be greater in control eyes--glaucoma median 56.5 (range 0-3526.5) pg/ml versus control median 65.16 (range 0-1788) pg/ml (Wilcoxon signed rank test p = 0.78). ANP levels tended to be greater in glaucoma eyes than in controls: glaucoma median 3 (range 0-68.5) pg/ml versus control median 0 (range 0-60) pg/ml (Wilcoxon signed rank test p = 0.82). ANP and BNP were log linearly related in both groups (r glaucoma group = 0.961, r control group = 0.894). CONCLUSION: This is the first report of BNP and ANP in human aqueous humour. Peptide levels did not differ significantly between glaucoma and cataract extraction eyes. A linear relation between log BNP and ANP was found. Further studies are required to clarify the role of these peptides in aqueous humour production and IOP regulation.

Adult↗
PubMed1997

Retinal vascular network architecture in low-birth-weight men.

BACKGROUND: Low birth weight is associated with hypertension and increased cardiovascular mortality, but the mechanism of this association is not known. Hypertension is accompanied by abnormalities of the microvasculature including rarefaction. OBJECTIVE: To test the hypothesis that low birth weight is associated with an alteration in microvascular architecture. DESIGN: A stratified random sample of 100 men aged 64-74 years was selected from a cohort of men whose birth weights were known. They were of relatively high or low birth weight ('high' > or = 3700 g, 'low' < or = 3200 g) and high or low systolic blood pressure (high > or = 160 mmHg, low < or = 140 mmHg). METHODS: Retinal arteriolar geometry was defined in terms of arteriolar bifurcation angles and junction exponents (a measure of the relative diameters of parent and daughter vessels), measured from photographic diapositives using operator-directed image analysis. RESULTS: Members of low-birth-weight groups had significantly narrower bifurcation angles than did members of high-birth-weight groups (74 +/- 1 degree versus 78 +/- 1 degree, P= 0.017 by analysis of variance). There was no significant difference between angles in members of groups with high and low blood pressures. Neither birth weight nor blood pressure grouping affected junction exponents. CONCLUSIONS: Narrower bifurcation angles are associated with increased circulatory energy costs and may be related to a lower than normal microvascular density. Our finding of differences in retinal microvascular architecture might reflect a persistent alteration in vascular architecture as a result of an impairment of foetal development and could provide a mechanistic link between low birth weight and subsequently increased cardiovascular risk.

Aged↗