Craig Wilde

The diagnostic accuracy of spectral-domain optical coherence tomography for neovascular age-related macular degeneration: a comparison with fundus fluorescein angiography

PurposeTo evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD-OCT) for neovascular age-related macular degeneration (nAMD): a comparison against fundus fluorescein angiography (FFA).MethodsA retrospective review of SD-OCT, colour fundus photographs (FP), and FFA of 411 consecutive patients referred to a rapid access Macular Clinic over a 4-year period was performed. FFA images were reviewed nonstereoscopically. SD-OCT images were acquired using the Topcon 3D OCT-1000 instrument. All FFA and OCT images were graded by at least two ophthalmologists independently. Side-by-side grading took place with immediate open discussion and adjudication. If there was disagreement between the two grading ophthalmologists or they were not 90% confident of their assigned grade, then adjudication by a third ophthalmologist was performed.ResultsA total of 278 eyes were graded as having choroidal neovascularisation (CNV) with SD-OCT and 231 diagnosed with FFA. The main diagnostic CNV classifications on FFA were: classic no occult in 27 eyes, predominantly classic in 16, minimally classic in 50, occult in 129, and 9 peripapillary membranes. There were a total of 47 false positives with SD-OCT: a rate of 16.9%. The sensitivity and specificity of SD-OCT alone for detecting CNV was 100 and 80.8%, respectively.ConclusionOur study confirms SD-OCT in comparison to the reference standard of nonstereoscopic FFA is highly sensitive at detecting newly presenting nAMD in the setting of a specialist AMD clinic where the investigations are interpreted by trained specialists. However, it does not seem accurate enough to replace FFA in the diagnosis on nAMD in current practice.

24-Hour versus daytime intraocular pressure phasing in the management of patients with treated glaucoma

Aims To determine the value of daytime and 24-h phasing in patients treated for progressive glaucoma despite apparently adequate intraocular pressure (IOP) control. Methods A retrospective analysis of a cohort of patients that had undergone either daytime phasing (08:00–18:00) or 24-h phasing was conducted. IOP measurements were compared between those taken in clinic, daytime phasing and 24-h phasing. The frequency with which phasing results changed clinical management was also compared between daytime and 24-h phasing. Results 76 patients fulfilling the study criteria were identified. Clinic and daytime phasing IOP were known for all 76 patients, nighttime IOP measurements were known for 41. There was no significant difference between mean IOP values measured in clinic and daytime phasing (p=0.062) or between clinic values and nighttime phasing (p=0.65). The mean daytime phasing IOP was significantly higher than the mean nighttime phasing IOP (p=0.038) (analysis of variance (ANOVA) for three groups, p=0.058). There was no significant difference between the mean peak IOP in clinic or daytime phasing (p=0.13) or between clinic and nighttime phasing (p=0.44). The mean daytime phasing IOP peak was significantly higher than the mean nighttime phasing IOP peak (p=0.015) (ANOVA for three groups, p=0.074). There was no significant difference in the frequency of a change in management that occurred as a result of phasing between the daytime and 24-h groups (p=0.65). Conclusions 24-H phasing offers little advantage over daytime phasing in the identification of IOP fluctuations or peaks in patients progressing despite acceptable clinic IOP readings. Daytime phasing is likely to be more cost-effective than 24-h phasing.

Prevalence of age-related macular degeneration in an elderly UK Caucasian population—The Bridlington Eye Assessment Project: a cross-sectional study

ImportanceThere is paucity of data on prevalence and disease asymmetry of age-related macular degeneration (AMD), particularly the earlier stages, in the UK population.Objective and PurposeTo determine the prevalence of age-related macular degeneration in an elderly Caucasian UK population.DesignCross-sectional population study, 2002–2006.ParticipantsResidents in the study area of Bridlington aged 65 years and older.MethodsFull-ophthalmic examination was undertaken in 3549 participants, of eligible 6319 Caucasian population (response rate of 56%). Non-stereoscopic Colour fundus photographs (30°) were graded masked using a modified Rotterdam Classification for 3475 (98%) participants with gradable images. Prevalence for different AMD grades were calculated. Demographic details were analysed then integrated with the AMD gradings for full analysis. Prevalence rates for the different AMD Grades were calculated, as well as the age-specific prevalences.ResultsAMD prevalence in the worst eye were 38.5% grade 0, 41.4% grade 1, 12.8% grade 2, 2.8% grade 3, and 4.6% grade 4. Geographic atrophy (grade 4a) occurred in 2.5%, and neovascular AMD (grade 4b) in 1.8%. Prevalence increased with age such that grade 4 (advanced) AMD was 2.2% in the 65–69 years group, 15.8% for the 85–90, and 21.2% for over 90 years. There was significant asymmetry between the two eyes of individuals with advanced AMD (P<0.001), such that vision loss was unilateral. Persons with more advanced AMD grades were more likely to be dissatisfied with their vision.ConclusionsAdvanced AMD occurs more commonly in the UK Caucasian population than previously reported. Significant asymmetry between the two eyes occurs in individuals with unilateral advanced AMD so that visual impairment statistics do not represent true prevalence of advanced AMD. Persons with more advanced AMD were more likely to be dissatisfied with their vision.

Prevalence of reticular pseudodrusen in eyes with newly presenting neovascular age-related macular degeneration.

Purpose To use multimodal imaging to evaluate the prevalence of reticular pseudodrusen (RPD) in eyes with newly presenting neovascular age-related macular degeneration (nAMD) in a UK population and explore associations with RPD and angiographic subtypes of nAMD. Methods A retrospective review of all spectral-domain optical coherence tomography, color fundus photographs, red-free and blue channel images, and fundus fluorescein angiograms of 202 consecutive patients who presented to a rapid access macular clinic over a 4-year period was performed. All images were graded by at least 2 ophthalmologists for the presence of RPD and choroidal neovascular membrane (CNV) subtypes. Results A total of 231 consecutive eyes were studied, of which 131 (56.7%) were in women. Of these, 51 eyes with CNV (22.1%) had identifiable RPD, with one or more imaging methods in that eye. A total of 30.3% of patients with newly presenting CNV in either or both eyes had identifiable RPD. The RPD were bilateral in 85.4% of patients and were identified more commonly in women than men (72.5% vs 27.5%), a difference that reached statistical significance (p = 0.011). No association between RPD and any particular CNV subtype was demonstrated, including for retinal angiomatous proliferations (RAP). Conclusions Reticular pseudodrusen have a high prevalence in eyes presenting with nAMD (22.1%), although at rates much lower than that of conventional drusen. They are largely a bilateral finding, occurring more frequently in women. Unlike other previous reports, we found no difference in their occurrence between the different subtypes of CNV including RAPs.

Reference Clinical Database for Fixation Stability Metrics in Normal Subjects Measured with the MAIA Microperimeter

Purpose The purpose of this study was to establish a normal reference database for fixation stability measured with the bivariate contour ellipse area (BCEA) in the Macular Integrity Assessment (MAIA) microperimeter. Methods Subjects were 358 healthy volunteers who had the MAIA examination. Fixation stability was assessed using two BCEA fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2). Statistical analysis was performed with linear regression and Pearsons product moment correlation coefficient. Results Average areas of 0.80 deg2 (min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg2 (min = 0.20, max = 11.70, SD = 2.04) for the index BCEA@95% were found. The average values of P1 and P2 were 95% (min = 76, max = 100, SD = 5.31) and 99% (min = 91, max = 100, SD = 1.42), respectively. The Pearsons product moment test showed an almost perfect correlation index, r = 0.999, between BCEA@63% and BCEA@95%. Index P1 showed a very strong correlation with BCEA@63%, r = −0.924, as well as with BCEA@95%, r = −0.925. Index P2 demonstrated a slightly lower correlation with both BCEA@63% and BCEA@95%, r = −0.874 and −0.875, respectively. Conclusions The single parameter of the BCEA@95% may be taken as accurately reporting fixation stability and serves as a reference database of normal subjects with a cutoff area of 2.40 ± 2.04 deg2 in MAIA microperimeter. Translational Relevance Fixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index.

A retrospective review of the management of asymptomatic retinal emboli identified during diabetic retinopathy screening: a case of inappropriate referral?

BackgroundDiabetic retinopathy screening generates many referrals of diabetic patients to ophthalmic clinics for incidental non-retinopathy pathology such as asymptomatic retinal emboli. Evidence exists that these patients have a 10 fold increased relative risk of stroke. With this in mind we evaluated our current management for this group.MethodsA retrospective review was conducted for patients referred by the screening programme to the Eye Clinic, Derbyshire Royal Infirmary in 2008. Data were collected on modifiable cardiovascular risk factors, investigations conducted and treatment decisions.ResultsNineteen patients were identified with asymptomatic retinal emboli: nine (47%) had known vascular disease; 13 patients (68%) were taking anti-platelet agents and 11 (58%) a statin. The mean blood pressure (BP) was 152/81 mmHg, but 10 patients (53%) had a BP > 140 mmHg and 47% were on antihypertensive medication. Carotid Doppler scans were performed on eight patients (42%), of whom two (25%) had stenosis over...

Optimisation of intravitreal injection technique using a Barraquer speculum with solid flat blade and finger stabilisation

Intravitreal injections (IVTs) are common ophthalmic interventions and core competency for ophthalmologists. Although simple and relatively safe, complications do occur, including cataract and retinal detachment. It is common to encounter subjects who squeeze their eyes excessively during injections. Others move unexpectedly, particularly if pain is felt or if patients suffer dementia. Such situations add additional risk and may alarm the injector. Hard eye squeezing causes several problems. It narrows the palpebral aperture (PA), reducing the distance between injection site and eyelid margin, increasing risk of eyelash touch. Squeezing can elicit a Bell’s phenomenon, with upward gaze of the globe. If pain is felt, squeezing and movement can be marked and sudden, being particularly problematic with the needle in the eye. If movement is deemed too risky, injection treatment may be discontinued temporarily or permanently. No literature exists on optimal management of these situations. Often injectors do not adapt the IVT technique in these patients. We describe a simple and effective IVT technique which reduces severity and impact of these problems, and could be adopted as the default technique. It improves control of the injection process offering additional risk reduction in patients with the aforementioned difficulties. The technique has been adopted in real injection clinics. A series of photographs (Fig. 1a–f) were taken using a volunteer (Mary Awad) for demonstration of the technique without delivering an IVT, illustrating the advantages in a superotemporal IVT. The injector places a Barraquer speculum with solid flat blade (Fig. 1a). Figure 1a further shows inferonasal gaze without squeezing, demonstrating a large area of superotemporal sclera for injection. Figure 1b illustrates inferonasal gaze, with purposeful hard eye squeezing. The PA is significantly narrowed, limiting available injection sites. Figure 1c was taken after eliciting a sudden severe squeeze (with upward globe movement) secondary to unexpected instillation of G. Proxymetacaine onto the ocular surface and exposed eyelashes by the injector in an attempt to alleviate the problem. Figure 1d illustrates hand positioning for the modified IVT technique. The injector instructs the patient to look inferonasally, holding the syringe in their non-dominant hand between thumb and index finger. The point of injection is marked superotemporally with a calliper. The ring finger is placed on the upper solid part of the speculum and firm downward pressure applied, stabilising the globe in its downward gaze position, offering increased resistance to sudden ocular movements, securing the globe in a more stable position. The authors find it reduced narrowing of the PA during squeezing, maintaining a more constant distance between the upper speculum/eyelid margin and injection site. The dominant hand is free to inject the drug. This technique offers significant advantages over alternative methods of globe stabilisation, including utilisation of forceps, which results in a one-handed injection technique. A right-handed injector, if desired, can use this technique with their nondominant hand to stabilise the speculum either standing superiorly for left eyes or indeed standing on the right side of the patient for right eye injections, making the technique easy to learn and perform. * Winfried M Amoaku wma@nottingham.ac.uk

Prevalence of reticular pseudodrusen in an elderly UK Caucasian population—The Bridlington Eye Assessment Project (BEAP): a cross-sectional study (2002–2006)

Aims:To determine prevalence, associations, and risk factors for reticular pseudodrusen (RPD) in a UK population.Methods:Cross-sectional study of Bridlington residents aged ≥65 years. Masked grading of colour fundus photographs from 3549 participants. RPD presence, phenotype, and topography were recorded, demographic details were analysed, and prevalence was calculated.Results:RPD was detected in 281 eyes (176 individuals) of 3476 participants (5.06%) with gradable images, and bilateral in 76.6%. Digital enhancement increased detection by 15.7%. Prevalence increased significantly with age from 1.18% (65–69 years) to 27.27% (≥90 years) (mean age 81.1, SD 6.01; OR 1.18, 95% CI 1.15–1.21, p value <0.001), was higher in females (5.9% vs 4.0%; OR 1.52, 95% CI 1.09–2.13, p = 0.014), and associated with diabetes (OR 1.97, CI 1.20–3.17, p = 0.005). History of antihypertension treatment appeared protective (OR 0.64, 95% CI 0.46–0.90, p = 0.009). RPD subtypes were dot in 18.5%, ribbon in 36.7%, and mixed in 36.3%. RPD were located outside the ETDRS grid in 88%, and most commonly in the outer superior subfield. Central grid involvement occurred in 12.1% of right and 14.3% of left eyes. RPD occurred in 25.9% of participants with grade 4 AMD in at least one eye. RPD was associated with visual dissatisfaction after controlling for age (OR 0.63, 95% CI 0.45–0.88, p = 0.007).Conclusion:RPD occur more commonly than previously reported, most frequently in the upper–outer macular subfield, but also within the central subfield, albeit with reduced frequency and altered morphology. RPD may be associated with visual dissatisfaction and diabetes, but are less frequent in persons receiving antihypertension therapy.

Prevalence of reticular pseudodrusen in newly presenting adult onset foveomacular vitelliform dystrophy

PurposeTo report the association and prevalence of reticular pseudodrusen (RPD) in eyes with newly presenting adult onset foveomacular vitelliform dystrophy (AFVD). To compare the strength of association with other pathologies resulting from dysfunction of the choroid-Bruch’s membrane–retinal pigment epithelium (RPE) complex, including eyes with geographic atrophy (GA) and angioid streaks.MethodsRetrospective single-centre review of all consecutive newly presenting AFVD. Multimodal imaging with spectral domain optical coherence tomography, fundus photographs, red-free/blue light images, and fundus fluorescein angiograms were graded for the presence of RPD. For comparison, all consecutive newly presenting cases of GA and eyes with angioid streaks were studied.ResultsFifteen (15) patients were identified with AFVD (mean age of 77.3 years; 73.3% female). Mean age of patients with AFVD and RPD was 80.5 years (SD 3.7), whereas that of patients with AFVD without RPD was 75.1 years (SD 7.0). This age difference did not reach statistical significance, P=0.1. Six (40%) had identifiable RPD; being a bilateral finding in 100% of patients. No males with AFVD and RPD were identified. A total of 92 eyes presented with GA. Twenty-three (23) of these (25.0%) had RPD. Twelve (12) patients presented with identifiable angioid streaks, with 4 (36.4%) having RPD.ConclusionRPD are a frequent finding in eyes with newly presenting AFVD; not being restricted to AMD, but a finding common among diseases where pathophysiological mechanisms involve damage to Bruch’s membrane and the RPE, whether genetic or degenerative. Our study supports the concept that they occur with high but variable frequencies in eyes with various pathologies.

Response to ‘Comment on: Optimisation of intravitreal injection technique using a Barraquer speculum with solid flat blade and finger stabilisation’

We thank the authors for their interest in our technique and congratulate them on the development of their device, which we expect will make a useful contribution to the safe delivery of intravitreal injections (IVT) [1]. Such a device offers distinct safety advantages, particularly with reference to stabilising the globe, determining the point of injection from the limbus, as well as the angle and depth of injection, making the technique user friendly. We have seen several cases of lens and retinal trauma from IVT over the years, and such a device should hopefully reduce the incidence of these uncommon, but significant problems. For the majority of patients and trained surgeons the traditional IVT procedure is not difficult or dangerous, and special devices are not required. Reluctance to trial these new products may limit their adoption and widespread use. A comparison against the traditional IVT technique may be required to assess both patient and surgeon preference. Establishing definite advantages of such IVT devices, including more comfort for patients, increased speed of procedure, or indeed reduced realworld cost, will more likely lead to wider adoption, especially when established instrumentation and techniques like ours are readily available in most eye units. For now, while devices like the one described here (BVI Malosa), or the InVitrea Injection Assistant (FCI Ophthalmics), have limited uptake across the UK, we hope that people including the non-medical injectors will find our technique for globe stabilisation useful.