David Alistair H Laidlaw

Guy's and St Thomas' NHS Foundation Trust · Department of Ophthalmology (The Ridley Clinic)

Background: Lack of clinical tests to quantify spatial components of distortion in patients with full thickness macular holes (FTMH) and epiretinal membranes (ERM). Aim: To develop a test for subjective evaluation of visual distortion in the central visual field around fixation in patients with unilateral FTMH or ERM. Settings and design: Pros...

To investigate the incidence of macula displacement and symptoms of distortion following rhegmatogenous retinal detachment (RRD) repair, quantify the displacement where seen and further characterise the nature of the displacement. Consecutive patients undergoing primary RRD repair were assessed postoperatively with fundus autofluorescence and optic...

The impression exists that picture acuity scores may overestimate function when subjects are switched to letter charts. This has not been systematically investigated. The aims of this study were to validate both printed crowded Kay picture (pCKP) and computerised CKP (cCKP) logMAR test acuity measurements against gold standard ETDRS letter chart sc...

The goals of this study were to investigate the effectiveness of computerized repeating and averaging of visual acuity measurements in reducing test-retest variability (TRV) and to estimate the increase in sensitivity and specificity that would be achieved in diagnosing visual acuity change. Timed, paired ETDRS chart and computerized acuity mean me...

The primary aim of this study was to evaluate the efficiency of air-gas exchange techniques and the factors that influence the final concentration of an intraocular gas tamponade. Parameters were varied to find the optimum method of performing an air-gas exchange in ideal circumstances. A computer model of the eye was designed using 3D software wit...

Purpose: The purpose of this study was to present a case of posterior rupture in a previously detached retina after blunt trauma. Method: This is a case report. Result: A child with idiopathic bilateral retinal dialyzes sustained accidental blunt trauma to the left eye while awaiting surgery. This caused a posterior rupture of the retina in an alre...

To study the effects of intravitreal foscarnet and the clinical differences between varicella zoster virus (VZV) and herpes simplex virus (HSV) induced acute retinal necrosis (ARN). Retrospective comparative case series. Eighty-one eyes of 74 patients. A retrospective case note analysis was performed in 2 tertiary referral centers. Presenting and f...

The authors report the long-term outcome of a 78-year-old man who experienced inadvertent entry of chloramphenicol ointment into the anterior chamber following small-incision sutureless cataract surgery. The chloramphenicol initially formed a single spherical mass on the interior aspect of the corneal section with no discernable effect on visual ac...

Contour interaction plays an important role in letter recognition and has long been known to influence clinical visual acuity measurements. LogMAR charts originally employed between-letter and line spacing of one letter width/height; however, in more recent designs, half letter width spacing has become accepted without validation. COMPlog is a comp...

To describe the use of intravitreal bevacizumab in idiopathic retinal vasculitis prior to vitrectomy and delamination. A young healthy male presented with idiopathic retinal vasculitis. His condition was refractory to panretinal photocoagulation and systemic steroids. The progression of his condition necessitated vitrectomy and delamination. Intrav...

To classify the clinical characteristics that might identify patients who may not require next-day follow-up following routine vitreoretinal intervention. Prospective case series. The only statistically significant factors for raised intraocular pressure (IOP) were gas tamponade and preoperative raised IOP. 44.7% (17/38) of patients with preoperati...

Data on the outcome of surgery facilitate informed preoperative patient counselling. Most studies on the outcome of surgery for idiopathic full thickness macular hole surgery have concentrated on rates of anatomical closure. The aim of this study was to identify factors predicting visual success (better than 20/40; 6/12 Snellen) following macular h...

To investigate the effectiveness of a new technique for the identification of occult retinal breaks in vitrectomy retinal detachment repair. Dye Extrusion Technique involves injection of sub retinal dye and extrusion through the unidentified breaks using perfluorocarbon liquid. Retrospective case note analysis. Main outcome measures: rate of break...

To determine the relationship between 'pigment clusters' on blood vessels (BvRPE) on the inferior retina in patients with rhegmatogenous retinal detachment, and existing proliferative vitreoretinopathy (PVR). A prospective observational non-comparative study of consecutive patients presenting with rhegmatogenous retinal detachment to a tertiary ref...

To describe the management of vitreoretinal complications of sickle cell retinopathy. A retrospective interventional case series. Review of an electronic patient record and clinical notes of 27 patients with vitreoretinal complications of sickle retinopathy. Six male patients and 21 female patients presented with a mean age of 41 years (range 28-67...

Proliferative vitreoretinopathy (PVR) is a severe complication of retinal detachment, which can be treated surgically by relaxing retinectomy. In this study, we describe patients with severe inferior retinal folding after this surgical intervention (SIRF). A retrospective review of the electronic patient records of 254 patients who received relaxin...

To determine whether uveal effusion syndrome (UES) is caused by altered scleral permeability to water and large molecules. Transscleral water movement was measured using surgically removed sclera clamped in a modified Ussing chamber and connected to a water column set at intraocular pressure. Sclera was also clamped between two hemichambers, and tr...

To briefly review and discuss the literature on vitrectomy for diabetic macular oedema. Literature review. There is a copious literature on the subject of vitrectomy for diabetic macular oedema (DMO). The most commonly hypothesised mechanism for the potential benefit of vitrectomy is relief of vitreomacular traction; however, both transvitreal oxyg...

The COMPlog clinical visual acuity measuring system is being developed for both routine and research use. This study aimed to validate its performance in amblyopic children and both normal and diseased adults against the gold standard ETDRS chart and the E-ETDRS computerised acuity measurement algorithm. Timed test and retest fully interpolated fiv...

To determine factors associated with anatomical and functional outcomes of macula-off retinal detachment surgery in a modern vitreoretinal unit. A retrospective casenote review of 185 patients presenting with macula-off retinal detachment was performed. Demographic and ocular characteristics were determined. Logistic regression analysis was used to...

CommentThe drugs described have varying degrees of antiplatelet activity. NSAIDs competitively and reversibly bind cyclo‐oxygenase (COX) and are ineffective as antiplatelet drugs alone, but may potentiate other agents. Aspirin irreversibly inhibits COX and, as monotherapy is not associated with increased risk of haemorrhage in vitreoretinal surgery...

To select the best surgical technique and predict the surgical success in cases of progressive symptomatic retinal detachment complicating retinoschisis (PSRDCR). Cases were divided into three groups: group I, those with outer layer breaks (OLBs) positioned anterior to the equator and no proliferative vitreoretinopathy (PVR); group II, those with O...

To determine preoperative demographic, clinical, and optical coherence tomography (OCT) factors which might predict the visual and anatomical outcome at 1 year in patients undergoing vitrectomy and inner limiting membrane peel for diabetic macular oedema (DMO). A prospective, interventional case series of 33 patients who completed 1 year follow up....

Recognised risk factors for the formation of idiopathic full thickness macular holes (IFTMH) include age, female, sex, and high myopia.1,2 However, we noticed that patients with IFTMH within our population, tended to have shorter than normal axial lengths. An age and sex matched case‐control study was therefore performed to test this hypothesis and...

The optimal method and timing of the surgical treatment for idiopathic macular holes remains unknown. The aim of this retrospective study was to identify factors associated with anatomical and visual success in macular hole surgery. Case records of 55 patients undergoing macular hole surgery at three units in the 2-year period up to July 2002 were...

(1) To evaluate whether vitrectomy is preferable to further macular laser in improving visual acuity and resolving retinal thickening in patients with diabetic macular oedema (DMO) despite previous laser and no macular traction. (2) To determine the feasibility of further trials in this population in terms of magnitude of comparative clinical effec...

Pretreatment laboratory values (followed by reference ranges) includedthe following: white blood cells, 9.9 × 10³/µL (5.0-15.0× 10³/µL); lymphocytes, 6.5 × 10³/µL(2.0-9.5 × 10³/µL); monocytes, 0.7 × 10³/µL (0.3-1.5 × 10³/µL); eosinophils, 0.2× 10³/µL (0.3-0.8 × 10³/µL);basophils, 0.1 × 10³/µL (0-0.2 × 10³/µL);red blood cells, 5.0 × 10⁶/µL (3.7-5.3...

Estimates of test-retest variability (TRV) in the form of a 95% range have been suggested as providing a cutoff value (or "change-criterion") against which measured acuity changes can be judged to decide whether they are indicative of a clinically important change. This approach is based on ensuring that the specificity of the procedure is 95% in i...

Vitreous cysts are rare structural entities of uncertain aetiology. Although most do not produce troublesome visual symptoms, they can cause diagnostic difficulties in clinical practice. Two different types are described and the possible aetiologies of congenital and acquired vitreous cysts are discussed.

Vitreous cysts are rare structural entities of uncertain aetiology. Although most do not produce troublesome visual symptoms, they can cause diagnostic difficulties in clinical practice. Two different types are described and the possible aetiologies of congenital and acquired vitreous cysts are discussed.

The "compact reduced logMAR" (cRLM) chart is being developed as a logMAR alternative to the Snellen chart. It is closer spaced and has fewer letters per line than conventional logMAR charts. Information regarding the performance of such a chart in amblyopes and children is therefore required. This study aimed to investigate the performance of the c...

All visual acuity data are subject to test-retest variability (TRV). This measurement error obscures true clinical change and reduces the statistical power of clinical trials using acuity as a primary outcome measure. This study was designed to assess whether a computerised system can reduce TRV by taking repeated acuity measurements and averaging...

This study aimed to evaluate a new chart designed to improve the collection of visual acuity data in population-based surveys. The Reduced logMAR E chart (RLME) employs three letters per line, 'tumbling E' optotypes, and conforms to accepted contemporary design principles. The performance of the chart was assessed within a population-based glaucoma...

To determine the sensitivity to change and specificity achieved when published test-retest variability (TRV) data are used to determine whether measured changes in ETDRS logarithm of the minimum angle of resolution (logMAR) visual acuity reflect true clinical change or are attributable to measurement error alone. Various degrees of change in visual...

To identify risk factors for retinal redetachment after removal of silicone oil. To determine the effectiveness of prophylactic laser in preventing retinal redetachment after removal of silicone oil. A nonrandomized retrospective comparative interventional trial. Three hundred seventy-six patients undergoing vitrectomy with silicone oil tamponade f...

Objectives To identify risk factors for retinal redetachment after removal of silicone oil. To determine the effectiveness of prophylactic laser in preventing retinal redetachment after removal of silicone oil.

The advantages of logMAR acuity data over the Snellen fraction are well known, and yet existing logMAR charts have not been adopted into routine ophthalmic clinical use. As this may be due in part to the time required for a logMAR measurement, this study was performed to determine whether an abbreviated logMAR chart design could combine the advanta...