Blind Registration Research Articles

Multi-focus Image Fusion via Blind Deconvolution and Registration based on Photoacoustic Microscopy

Abstract Optical resolution photoacoustic microscopy (OR-PAM), which can present the microstructure of biological tissues is useful in the disease diagnosis. However, conventional OR-PAM can only obtain images with high resolution in a narrow range of depths around the focal plane. In this study, we proposed a multi-focus photoacoustic image fusion method based on the blind deconvolution. This method is divided into two steps. First, we used the method of blind deconvolution to obtain an approximate point spread function (PSF) for each photoacoustic images obtained from multiple layers, and then got the corresponding deblurred photoacoustic images. Second, we used the method of multi-focus images registration and fusion to accurately align the multi-focus photoacoustic images and effectively fuse the features of different images. Finally, the proposed method was applied to process the photoacoustic images obtained from photoacoustic imaging experiments on ants with irregular morphology using fast controllable confocal focus PAM (FC-PAM). The results show that our method improves the quality of photoacoustic images, and can quickly obtain multi-focus fused photoacoustic images with high resolution. It indicates that the proposed multi-focus photoacoustic image fusion method based on FC-PAM has great potential in fast imaging of living biological tissues at multiple imaging depths.

New trends in effective monitoring of inflammation in uveitis

Ocular inflammatory diseases account for a significant number of blind registrations worldwide, involving predominantly young patients. Differential diagnosis of uveitis cases maybe challenging as they are infrequent and share common features. With the evolution of multimodal imaging several new signs of inflammation have been described facilitating prompt and effective diagnosis. Non‐invasive modalities including OCT, OCT‐A and Autofluorescence along with traditional diagnostic techniques such as fluoresceine and indocyanine green angiography provide plausible evidence of activity or remission of inflammation which can be used to determine further management and follow‐up. This lecture will highlight imaging features essential in efficacious monitoring of uveitis.

Low-vision rehabilitation in Italy: Cross-sectional data from the Device and Aids Registry (D.A.Re).

We are reporting on the characteristics of low-vision adults attending large rehabilitation services which provide data to D.A.Re (Devices & Aids REgister) in Italy. D.A.Re aims to gather information about low-vision aids owned by Italian patients with visual impairment. We included consecutive patients attending low-vision rehabilitation centres providing data to D.A.Re from 2019 to July 2021. Demographic features, self-reported use of technology and aids, vision performance, and the Instrumental Activity of Daily Living (IADL) score were collected. 720 patients were included in the D.A.Re. About half of the patients were affected by Age-related Macular Degeneration (389, 54.9%). Patients reported a long interval between onset of vision disability and access to low-vision rehabilitation, which was over two years in almost 30% of cases. Blindness registration status was almost complete when reported, but almost 40% were unable to report on this. IADL scores were higher for younger people and those with better visual acuity and critical print size (CPS), and lower for visual field restriction (p < 0.01 for all predictors). Of interest, better IADL scores were recorded for those with computer knowledge who used optical aids and software in univariate analyses and multivariate analyses, adjusting for level of visual disability and employment status (p < 0.01 for all predictors). We report on the profile of low-vision patients using rehabilitation services in Italy. Longitudinal data during and after vision rehabilitation were collected. Our results support the validity of the D.A.Re to monitor the use of low-vision devices in Italy.

Comparison of colour contrast sensitivity in eyes at high risk of neovascular age‐related macular degeneration with and without subsequent choroidal neovascular membrane development

BackgroundNeovascular age‐related macular degeneration (nAMD) is a leading cause of blind registrations in the elderly. Unfortunately, it is difficult to detect the early stage of the disease, when treatment is more likely to be successful. Subjects with very early disease are likely to have abnormal macular function, even in the pre‐symptomatic stage. In this study, colour vision was evaluated to establish if subjects at high risk of developing nAMD can be identified, thus allowing earlier diagnosis and possible treatment.MethodsColour contrast sensitivity (CCS) was evaluated over time in the fellow unaffected eye of subjects with unilateral nAMD. Participants were divided into Group 1 (182 participants) or Group 2 (15 participants) according to whether nAMD did not or did develop in the study period respectively and the two groups were compared.ResultsCCS was increased (i.e. worse colour vision) compared with the age-matched reference range in a high proportion of fellow eyes in both Groups 1 and 2. Global mean CCS values did not show statistically significant differences between the two groups. However, there was a statistically significant difference between mean Group 1 CCS values and the last CCS value prior to nAMD diagnosis from Group 2 subjects.ConclusionThis study shows that in patients with unilateral nAMD, colour vision is frequently abnormal in the fellow unaffected eye. Abnormal CCS does not predict the development of nAMD within the 12 month period of the study and therefore it is not a viable screening tool for this pathology.

Clinical and Genetic Re-Evaluation of Inherited Retinal Degeneration Pedigrees following Initial Negative Findings on Panel-Based Next Generation Sequencing.

Although rare, inherited retinal degenerations (IRDs) are the most common reason for blind registration in the working age population. They are highly genetically heterogeneous (>300 known genetic loci), and confirmation of a molecular diagnosis is a prerequisite for many therapeutic clinical trials and approved treatments. First-tier genetic testing of IRDs with panel-based next-generation sequencing (pNGS) has a diagnostic yield of ≈70–80%, leaving the remaining more challenging cases to be resolved by second-tier testing methods. This study describes the phenotypic reassessment of patients with a negative result from first-tier pNGS and the rationale, outcomes, and cost of second-tier genetic testing approaches. Removing non-IRD cases from consideration and utilizing case-appropriate second-tier genetic testing techniques, we genetically resolved 56% of previously unresolved pedigrees, bringing the overall resolve rate to 92% (388/423). At present, pNGS remains the most cost-effective first-tier approach for the molecular assessment of diverse IRD populations Second-tier genetic testing should be guided by clinical (i.e., reassessment, multimodal imaging, electrophysiology), and genetic (i.e., single alleles in autosomal recessive disease) indications to achieve a genetic diagnosis in the most cost-effective manner.

Induced Pluripotent Stem Cells for Inherited Optic Neuropathies-Disease Modeling and Therapeutic Development.

Inherited optic neuropathies (IONs) cause progressive irreversible visual loss in children and young adults. There are limited disease-modifying treatments, and most patients progress to become severely visually impaired, fulfilling the legal criteria for blind registration. The seminal discovery of the technique for reprogramming somatic nondividing cells into induced pluripotent stem cells (iPSCs) has opened several exciting opportunities in the field of ION research and treatment. A systematic review of the literature was conducted with PubMed using the following search terms: autosomal dominant optic atrophy, ADOA, dominant optic atrophy, DOA, Leber hereditary optic neuropathy, LHON, optic atrophy, induced pluripotent stem cell, iPSC, iPSC derived, iPS, stem cell, retinal ganglion cell, and RGC. Clinical trials were identified on the ClinicalTrials.gov website. This review article is focused on disease modeling and the therapeutic strategies being explored with iPSC technologies for the 2 most common IONs, namely, dominant optic atrophy and Leber hereditary optic neuropathy. The rationale and translational advances for cell-based and gene-based therapies are explored, as well as opportunities for neuroprotection and drug screening. iPSCs offer an elegant, patient-focused solution to the investigation of the genetic defects and disease mechanisms underpinning IONs. Furthermore, this group of disorders is uniquely amenable to both the disease modeling capability and the therapeutic potential that iPSCs offer. This fast-moving area will remain at the forefront of both basic and translational ION research in the coming years, with the potential to accelerate the development of effective therapies for patients affected with these blinding diseases.

Incidence of Newly Registered Blindness From Age-Related Macular Degeneration in Australia Over a 21-Year Period: 1996-2016.

Report the age-standardized annual incidence of blindness registration due to age-related macular degeneration (AMD) in Australia in patients aged 50 years and older. Frequencies of photodynamic therapy (PDT) and intravitreal therapy (IVT) were examined. Retrospective observational study. Registry of the Association for the Blind of Western Australia with best-corrected visual acuity worse than 20/200 in the better-seeing eye. Registering as blind aged 50 years or over. Annual age-standardized incidence of blindness over 3 time periods: 1996-2001 (pre-PDT), 2002-2007 (PDT era) and 2008-2016 (IVT era). The rates of PDT and IVT usage were assessed. Age-standardized annual incidence of blindness rose during the PDT era, reaching 72.5 cases per 100,000 person-years in 2004. The incidence declined from 2007 onwards, reaching 8.2 cases per 100,000 person-years in 2016 (IVT era). The age at AMD blindness registration increased from 82.7 to 84.9 and 83.7 to 86.0 years from the PDT era to the IVT era in both male and females (P < 0.001) respectively. Over the same time period, PDT usage increased in 2002 and declined in 2006, whereas IVT usage increased from 2009 by 3745 per year. The increase in new blindness registrations due to AMD coincided with public funding of verteporfin for PDT, whereas the subsequent decline occurred when bevacizumab was used off-label and ranibizumab and aflibercept were publicly funded. An understanding of the effect of retinal therapy on public health measures may inform improvements in the allocation of limited resources.

P systems with limited number of objects

P systems are a model of compartmentalized multiset rewriting inspired by the structure of living cells and the way they function. In this paper, we focus of a variant in P systems in which membranes have limited capacity, i.e., the number of objects they may hold is limited by a fixed bound. This feature corresponds to an important physical property of cellular compartments. We propose several possible semantics of limited capacity and show that one of them allows real-time simulations of partially blind register machines, while the other one allows for obtaining computational completeness.

Demographic and Clinical Factors that Influence the Visual Response to Anti-Vascular Endothelial Growth Factor Therapy in Patients with Neovascular Age-Related Macular Degeneration: A Systematic Review.

BackgroundNeovascular age-related macular degeneration (nAMD) is a leading cause of blind registrations in the developed world. Standard therapy includes the use of anti-vascular endothelial growth factor (anti-VEGF) drugs, and whilst the clinical efficacy is well established, there is variability in the clinical effect of visual outcome. The purpose of this systematic review is to identify whether there is evidence for the influence of demographic and clinical factors on the effectiveness of anti-VEGF therapy in patients with nAMD, in settings comparable to the National Health Service (NHS).MethodsThis systematic review followed the PRISMA guidelines for systematic reviews. Electronic databases Medline, EMBASE, Web of Science, CINAHL and the Cochrane Library were searched for studies dated from 2005 onwards. Studies were appraised using the Newcastle–Ottawa Score, and a narrative synthesis was used.Eligibility CriteriaPopulation: Patients with nAMD being treated with anti-VEGF therapy. Comparator: Presence or absence of potential predictive demographic and clinical factors. Settings: Comparable settings to NHS hospitals. Outcomes: Predicting demographic and clinical factors. Study designs: Randomised controlled trials, prospective cohort studies, retrospective cohort studies and case series dated from 2005.ResultsThirty papers were identified in this review. The evidence suggests that the number of anti-VEGF injections that patients receive, age and lesion size at baseline are factors that influence how effective anti-VEGF therapy is in the short and long term. There was also evidence that suggested that baseline visual acuity influenced the effectiveness of anti-VEGF therapy at longer time points of more than 2 years. Due to a lack of standardised statistical reporting among the included studies, it was not possible to undertake a meaningful statistical synthesis or meta-analysis.ConclusionsThis review has demonstrated that there is some evidence of clinical and demographic factors that affect the effectiveness of anti-VEGF therapy and hence variation in visual acuity (VA) outcome. However, this review was unable to identify as wide a range of factors as was hoped. The findings of this review are important because some of the factors, such as VA and lesion size at diagnosis and the number of injections, are potentially modifiable through improvements in early diagnosis and service provision. Future work also needs to focus on the importance of this variation, such as the effect on patients’ quality of life, and how variation can be minimised.Systematic Review RegistrationThis review has been registered with PROSPERO (Registration number CRD42018094191).Electronic supplementary materialThe online version of this article (10.1007/s40123-020-00288-0) contains supplementary material, which is available to authorized users.

Cardiovascular and respiratory considerations with topical beta-blockers: is it really old news?

Objective The aim of this study was to identify the prevalence of prescribing topical beta-blockers (TBB) despite documented contraindications in general practice and whether patients were involved in decisions about treatment. Design This was a primary-care-based cross-sectional descriptive study. Introduction Glaucoma is one of the commonest causes of irreversible blindness in the United Kingdom, causing ∼5.9% of blind registration. TBB are currently considered the best adjunctive treatment and are well known for their systemic effects. The effect of concurrent prescription of TBB with systemic contraindications was found to significantly increase the rate of hospitalization and emergency room visits. Patients and methods Electronic medical records of four primary care providers in the North East of England were searched for primary open-angle glaucoma, use of TBB, and known systemic contraindications. Included records were further searched for correspondence from ophthalmology departments to primary care. We contacted those patients whose records showed no documentation of communicating potential risks with patients and rationale of using TBB. Results Of the 49 816 patients registered with the four primary health care providers, 798 (1.6%) had primary open-angle glaucoma. Of these, 279 (35%) were prescribed TBB; 260 (93.2%) of whom had no systemic contraindications. Conclusion Nineteen (6.8%) patients with systemic contraindications were prescribed TBB despite alerts from electronic medical records. Furthermore, these patients were not made aware of the potential risk.

Characterizing Disease Burden and Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration

To understand levels of disease burden and progression in a real-world setting among patients from the United Kingdom with bilateral geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Retrospective cohort analysis of a multicenter electronic medical record (EMR) database. Patients who were aged ≥50 years with bilateral GA and no history of choroidal neovascularization (CNV) and who attended 1 of 10 clinical sites using the EMR. A deidentified data set was constructed from the records held at the 10 sites. An algorithm was used to extract cases with a GA diagnosis, of which 1901 had bilateral GA and form the basis of this report. A sample of records randomly selected from each center was used to validate disease definitions. Progression to blindness (visual acuity [VA] <20 letters or Snellen 3/60 in the better-seeing eye), driving ineligibility (VA ≤70 letters or Snellen 6/12 in the better-seeing eye), progression to CNV, loss of 10 or more letters, and mean change in VA over time. At first record of GA, 7.1% had a VA in the better-seeing eye equal to or lower than the cutoff for blindness registration and 71.1% had a VA that would have rendered them ineligible to drive. Over time, 16% became legally blind (median time to outcome, 6.2 years) and 66.7% became ineligible to drive (median time to outcome, 1.6 years). In the worse-seeing eye, 40.1% lost ≥10 letters in 2.4 years. Among patients with baseline and 24-month VA measurements, mean VA decline was 6.1 letters in the worse-seeing eye (n= 413) and 12.4 letters in the better-seeing eye (n= 414). The rate of progression to CNV in either eye was 7.4% per patient-year. At initial diagnosis, based on VA in the better-seeing eye, a high proportion of patients with bilateral GA were ineligible to drive and approximately 7% were eligible for UK blindness registration. The subsequent reduction in VA that occurred in the better-seeing eye would render a further two-thirds ineligible to drive. These findings emphasize the severity of the visual disability associated with GA secondary to AMD.

Digital Imaging Tool to Enhance Otolith Microstructure for Estimating Age in Days in Juvenile and Adult Fish

Age estimation based on fish otolith microstructure analysis is a very repetitive and time-consuming task. The lack of appropriate image analysis software, capable of both overlaying a number of images automatically and recording a high number of daily increments, has been a significant limitation in counting and measuring daily growth increments in large otoliths from juvenile and adult fish individuals. This paper presents a new software to assist marine biologists with faster, more efficient, and more reliable microstructure readings of fish otoliths. Open source code is preferred so that software packages can be updated with new image processing algorithms developed by the scientific community. The approach consists of three steps: 1) a single grayscale digital image combining images of different parts of the same fish otolith is obtained using the blind image registration technique fast normalized cross correlation; 2) the growth rings of the image are enhanced for age estimation purposes, using the adaptive histogram equalization technique; and 3) a semiautomatic interactive tool draws a simple polygonal chain along which the microstructures are easily identifiable and the points of interest can be marked, whose data will be saved automatically. This new tool opens up the opportunity of aging juvenile and adult fish individuals at regular intervals by counting growth rings in the otolith microstructure and facilitates working with other calcified pieces of marine species that exhibit a daily ring pattern, such as cephalopod beaks and mollusk shells.

Multiview Marker-Free Registration of Forest Terrestrial Laser Scanner Data With Embedded Confidence Metrics

Terrestrial laser scanning has demonstrated increasing potential for rapid comprehensive measurement of forest structure, especially when multiple scans are spatially registered in order to reduce the limitations of occlusion. Although marker-based registration techniques (based on retro-reflective spherical targets) are commonly used in practice, a blind marker-free approach is preferable, insofar as it supports rapid operational data acquisition. To support these efforts, we extend the pairwise registration approach of our earlier work, and develop a graph-theoretical framework to perform blind marker-free global registration of multiple point cloud data sets. Pairwise pose estimates are weighted based on their estimated error, in order to overcome pose conflict while exploiting redundant information and improving precision. The proposed approach was tested for eight diverse New England forest sites, with 25 scans collected at each site. Quantitative assessment was provided via a novel embedded confidence metric, with a mean estimated root-mean-square error of 7.2 cm and 89% of scans connected to the reference node. This paper assesses the validity of the embedded multiview registration confidence metric and evaluates the performance of the proposed registration algorithm.

Marker-Free Registration of Forest Terrestrial Laser Scanner Data Pairs With Embedded Confidence Metrics

Terrestrial laser scanning (TLS) has emerged as an effective tool for rapid comprehensive measurement of object structure. Registration of TLS data is an important prerequisite to overcome the limitations of occlusion. However, due to the high dissimilarity of point cloud data collected from disparate viewpoints in the forest environment, adequate marker-free registration approaches have not been developed. The majority of studies instead rely on the utilization of artificial tie points (e.g., reflective tooling balls) placed within a scene to aid in coordinate transformation. We present a technique for generating view-invariant feature descriptors that are intrinsic to the point cloud data and, thus, enable blind marker-free registration in forest environments. To overcome the limitation of initial pose estimation, we employ a voting method to blindly determine the optimal pairwise transformation parameters, without an a priori estimate of the initial sensor pose. To provide embedded error metrics, we developed a set theory framework in which a circular transformation is traversed between disjoint tie point subsets. This provides an upper estimate of the Root Mean Square Error (RMSE) confidence associated with each pairwise transformation. Output RMSE errors are commensurate with the RMSE of input tie points locations. Thus, while the mean output $\text{RMSE}=16.3 \text{cm}$ , improved results could be achieved with a more precise laser scanning system. This study 1) quantifies the RMSE of the proposed marker-free registration approach, 2) assesses the validity of embedded confidence metrics using receiver operator characteristic (ROC) curves, and 3) informs optimal sample spacing considerations for TLS data collection in New England forests. While the implications for rapid, accurate, and precise forest inventory are obvious, the conceptual framework outlined here could potentially be extended to built environments.

The Cost of Blindness in the Republic of Ireland 2010-2020.

Aims. To estimate the prevalence of blindness in the Republic of Ireland and the associated financial and total economic cost between 2010 and 2020. Methods. Estimates for the prevalence of blindness in the Republic of Ireland were based on blindness registration data from the National Council for the Blind of Ireland. Estimates for the financial and total economic cost of blindness were based on the sum of direct and indirect healthcare and nonhealthcare costs. Results. We estimate that there were 12,995 blind individuals in Ireland in 2010 and in 2020 there will be 17,997. We estimate that the financial and total economic costs of blindness in the Republic of Ireland in 2010 were €276.6 million and €809 million, respectively, and will increase in 2020 to €367 million and €1.1 billion, respectively. Conclusions. Here, ninety-eight percent of the cost of blindness is borne by the Departments of Social Protection and Finance and not by the Department of Health as might initially be expected. Cost of illness studies should play a role in public policy making as they help to quantify the indirect or “hidden” costs of disability and so help to reveal the true cost of illness.

Health Service Use and Mortality of the Elderly Blind

To determine whether blindness in older people is associated with increased health service use and mortality. Retrospective matched cohort study from July 1, 1999, through June 30,2010. A blind cohort 65 years of age and older from a volunteer blind register and a cohort of age- and gender-matched controls selected randomly from the Western Australian electoral roll. Person-level linked hospital, emergency department (ED), mental health, and death records for the blind and control cohorts were used. Generalized estimating equations assuming a negative binomial distribution were used to estimate relative rates of hospital admissions, lengths of stay, and mortality after adjusting for sociodemographic variables and comorbidity. Emergency department and mental health service visits also were quantified. Relative rates of hospital admissions, lengths of stay, and mortality, as well as crude proportions of ED and mental health service visits. The blind cohort comprised 1726 individuals alongside 1726 matched controls; 39% were men, and the mean age was 83 years. Combined, the cohorts accumulated a total of 34 130 hospital admissions amounting to 201 867 bed-days. After adjusting for the principal reason for hospital admission and comorbidity, the blind cohort was admitted to the hospital 11% (95% confidence interval [CI], 6%-17%) more often than the control cohort. The blind cohort also stayed in the hospital longer than the controls, but this effect varied by age. Blind participants 65 to 69 years of age spent 88% more days (95% CI, 27%-178%) in the hospital compared with age-matched controls, whereas there was no difference in length of stay between the cohorts by 80 years of age (rate ratio, 1.10; 95% CI, 0.97-1.25). A larger proportion of the blind cohort visited a hospital ED and accessed mental health services compared with the control cohort. Health service use is increased for the elderly blind compared with age-matched controls after accounting for comorbidity. The elderly blind have more hospital admissions, ED visits, and mental health-related visits. The younger elderly blind stay longer in hospital. However, there was no evidence of worse mortality outcomes after adjusting for comorbidity.

Long-term visual outcomes of intravitreal ranibizumab treatment for wet age-related macular degeneration and effect on blindness rates in south-east Scotland.

To evaluate patient visual acuity outcomes and blindness rates attributable to wet AMD with a potential 5-year follow-up from intravitreal ranibizumab treatment (IVTR) in south-east Scotland. Data was analysed from 104 eyes of 96 patients who initiated treatment prior to September 2008. The main outcome measures were LogMAR visual acuity, number of clinic visits and the number of injections. Annual blind registration data in south-east Scotland were analysed using blind certifications recorded by the Royal National Institute of Blind People. Patients had a mean clinical follow-up of 4 years and 1 month and a mean loss of 5.5 letters over the study period. Of the treated eyes 9.6% gained ≥ 15 letters whilst 24.0% lost ≥ 15 letters during this period. An average of 9.56 injections were administered per patient. The age-sex standardised incidence of legal blindness attributable to wet AMD in south-east Scotland peaked at 9.1 cases per 100,000 of the population in 2006 in either eye. Following the introduction of IVTR there were annual decreases in the incidence of blindness attributable to AMD falling to a trough of 4.8 cases per 100,000 of the population in 2011. This study demonstrates that the majority of patients in a south-east Scotland maintain their vision following IVTR in wet AMD in the real-world setting. Our study also suggests that the introduction of IVTR has had population wide benefits in reducing the blindness attributable to wet AMD in the south-east Scotland population.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel.

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind. We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness. The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased. During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

Report on the creation of a diabetes register and retinopathy screening outcomes in the Mid-West of Ireland.

With concerns that blind registration in Ireland due to diabetic retinopathy is continuing to rise, a structured retinopathy screening service is in the process of being rolled out nationally. To report on the validation process for creating a register of diabetics in the Mid-West of Ireland, and findings following retinopathy screening of a representative sample. National primary care databases were employed in generating provisional lists of diabetic patients in the Health Service Executive (HSE) Mid-West area. Subsequent engagement with the corresponding general practices over a three year period between 2010 and 2013 facilitated the validation of these lists. A summary of the retinopathy screening outcomes of 1,434 patients and pre-existing screening patterns is reported. The number of patients on the Mid-West diabetes register to date is 11,126. Of the 1,434 patients screened, 288 (20.1 %) had background retinopathy, while 117 (8.2 %) had sight-threatening retinopathy. Seventeen (19.8 %) of the 86 patients identified with maculopathy required treatment with intravitreal injections. Of the 610 patients questioned about previous screening events, 389 (63.8 %) said they had undergone an ocular examination within the previous 12 months. The HSE Mid-West has over 11,000 patients on its database ready to be screened by the national programme, with the treatment of maculopathy expected to have the largest impact on resources. Although the majority of patients are already undergoing screening in the community in an ad hoc fashion, the rates of sight-threatening retinopathy encountered highlight the timeliness of the full implementation of the national programme.

Prevalence and incidence of blindness and other degrees of sight impairment in patients treated for neovascular age-related macular degeneration in a well-defined region of the United Kingdom.

This study aimed to evaluate the incidence and prevalence of blindness, sight impairment, and other visual acuity (VA) states in patients receiving ranibizumab for neovascular age-related macular degeneration (nAMD) in Gloucestershire. Serial VA and injection data for all treatment-naive patients receiving their first intravitreal injections of ranibizumab for nAMD in the Gloucestershire National Health Service Ophthalmology department between 2008 and 2010 were extracted from an electronic medical record system. The prevalence of blindness (VA in the better-seeing eye ≤25 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) at the time of first intravitreal injection was 0.8%, increasing to 3.5% after 3 years. The prevalence of sight impairment (VA in the better-seeing eye 26-39 ETDRS letters) increased from 4.1% at baseline to 5.5% after 3 years. The incidence of initiating ranibizumab treatment for nAMD in people aged ≥50 years in Gloucestershire was 111 people per 100 000 population in 2009, and 97 people in 2010. The incidence of patients meeting the visual criteria for blindness and sight impairment registration from treated nAMD in people aged ≥50 years in Gloucestershire was 3.5 and 9.7 people, respectively per 100 000 population in 2010. This is the first real-world study on the incidence and prevalence of eligibility for blindness and sight impairment registration in treated nAMD in the UK based on VA data. The incidence and prevalence of eligibility for certification of blindness or sight impairment in patients treated with ranibizumab for nAMD is low in Gloucestershire, with only 3.6% of the incident population progressing to blindness in 2010.