User-guided segmentation for volumetric retinal optical coherence tomography images

Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method.

Congenital ankyloblepharon in a leopard gecko (Eublepharis macularius)

A 6-month-old leopard gecko with unilateral partially fused eyelids since birth was presented for examination. A diagnosis of congenital ankyloblepharon was made and surgical correction was performed successfully.

Generic drugs for the treatment of ocular conditions: changing the treatment landscape

As global spending on medicinal products continues to rise, the availability of lower-cost generic substitutes is increasingly driving health care decision-making. US FDA does not require strict demonstration of human bioequivalence and/or therapeutic studies for the approval of generic ophthalmic compounds. Bioequivalence between generic and innovator compounds is presumed on the basis of matching active and inactive ingredient profiles. Generic compounds may differ from innovator agents with regards to performance under environmental stress, relative acidity and bottle size/rigidity. Matching ingredient profiles may therefore not result in consistently comparable drug compositions and clinical effects.

Capsular tension ring implantation after lens extraction for management of subluxated cataracts

PURPOSE

To evaluate the safety and efficacy of implantation of a capsular tension ring (CTR) and posterior chamber intraocular lens (PCIOL) after lens extraction in subluxated cataracts.

SETTING

Department of Ophthalmology,General Hospital of PLA, Beijing, China.

DESIGN

Prospective case series.

METHODS

We selected 36 eyes in 34 patients with zonular dialysis <150°. After emulsification and removal of the residual cortex, we inserted a CTR into the capsular bag to center the PCIOL. We measured preoperative and postoperative best corrected visual acuity (BCVA), centration of the CTR and IOL, and perioperative complications.

RESULTS

No capsule collapseor fluctuationof the anterior chamber occurred. Most eyes (63.89%) had nuclear sclerosis of ≥ 3+. A CTR was implanted into the capsular bag without extension of zonular dialysis. A traumatic subluxated cataract was the most common cause (20 of 36 [55.56%]). We found a subluxated cataract in 3 eyes (3 of 36 [8.33%]) with previous acute angle-closure glaucoma. Mean follow up was 20.3 ± 2.4 months. Preoperatively, only 5 eyes (13.89%) had a BCVA of ≥ 20/40, compared with 30eyes at the last visit (83.33%, P<.001). Improved BCVA was achieved in 33 eyes (91.7%) in week 1, and visual acuity remained stable up to 1 year. The CTRs with PCIOL were well centered at 1 year.

CONCLUSION

In patients with a subluxated hard cataract <120°, CTR implantation should be performed after lens extraction without extension of zonular dialysis and capsular destabilization. Maintaining anterior chamber depth and avoiding capsular bag collapse are critical.

Pigmented paravenous retinochoroidal atrophy (Review)

Pigmented paravenous retinochoroidal atrophy (PPRCA) is an uncommon disease characterized by perivenous aggregations of pigment clumps associated with peripapillary and radial zones of retinochoroidal atrophy that are distributed along the retinal veins. Patients are usually asymptomatic and the disease process is non-progressive or slow and subtly progressive. It is commonly bilateral and symmetric. The cause of the condition may be unknown or idiopathic, although a dysgenetic, degenerative, hereditary etiology or even an inflammatory cause has been hypothesized. A non-inflammatory cause is referred to as primary, while inflammation-associated PPRCA is referred to as secondary or pseudo PPRCA. The present study reviewed and summarized the features of PPRCA.

Optimization of liposomal encapsulation for ceftazidime for developing a potential eye drop formulation

Ceftazidime is a broad spectrum third generation cephalosporin antibiotic which is effective mainly against Gram-negative bacteria such as Pseudomonas aeruginosa, Acinetobacter and Enterobacteriaceae, the pathogens which most often cause ophthalmological infections. Unlike other commonly used beta lactam antibiotics, ceftazidime is resistant to several types of beta lactamases (e.g., TEM, SHV and PSE-1). Because of these advantages, ceftazidime is used in the treatment of eye infections. However, ceftazidime undergoes rapid degradation in aqueous solutions therefore eye drops containing ceftazidime in aqueous solutions are not commercially manufactured. In the present study, liposomal encapsulations of ceftazidime with various lipid compositions, hydrating solutions and pH-values have been studied in order to optimize liposomal composition for a potential eye drop formulation.

Respiratory complications associated with ketamine anesthesia for ophthalmic procedures following intraocular pressure measurement in children

BACKGROUND

We compared respiratory complications (RCs) in children who received intramuscular (IM) versus intravenous (IV) or no ketamine for intraocular pressure (IOP) measurement to test our observation that IM ketamine is associated with higher incidence of RCs.

MATERIALS AND METHODS

We analyzed 149 eye examinations under anesthesia with ketamine in 27 patients and 263 non-ketamine examinations under anesthesia in 81 patients using a mixed effects logistic regression model.

RESULTS

IM KETAMINE WAS STRONGLY ASSOCIATED WITH INCREASED ODDS OF RCS COMPARED TO NO KETAMINE (ODDS RATIO (OR): 20.23, P < 0.0001) and to IV ketamine (OR: 6.78, P = 0.02), as were higher American Society of Anesthesiologists (ASA) classification (OR: 2.60, P = 0.04), and the use of volatile agents (OR: 3.32, P = 0.02).

CONCLUSION

Further studies should be conducted to confirm our observation of increased RCs with IM ketamine.

Clinical, radiological, and genetic survey of patients with muscle-eye-brain disease caused by mutations in POMGNT1

BACKGROUND

To evaluate clinical, genetic, and radiologic features of our patients with muscle-eye-brain disease.

METHODS

The data of patients who were diagnosed with muscle-eye-brain disease from a cohort of patients with congenital muscular dystrophy in the Division of Pediatric Neurology of Dokuz Eylül University School of Medicine and Gaziantep Children's Hospital between 2005 and 2013 were analyzed retrospectively.

RESULTS

From a cohort of 34 patients with congenital muscular dystrophy, 12 patients from 10 families were diagnosed with muscle-eye-brain disease. The mean age of the patients was 9 ± 5.5 years (2-19 years). Mean serum creatine kinase value was 2485.80 ± 1308.54 IU/L (700-4267 IU/L). All patients presented with muscular hypotonia at birth followed by varying degrees of spasticity and exaggerated deep tendon reflexes in later stages of life. Three patients were able to walk. The most common ophthalmologic and radiologic abnormalities were cataracts, retinal detachment, periventricular white matter abnormalities, ventriculomegaly, pontocerebellar hypoplasia, and multiple cerebellar cysts. All of the patients had mutations in the POMGNT1 gene. The most common mutation detected in 66% of patients was c.1814 G > A (p.R605H). Two novel mutations were identified.

CONCLUSIONS

We suggest that muscle-eye-brain disease is a relatively common muscular dystrophy in Turkey. It should be suspected in patients with muscular hypotonia, increased creatine kinase, and structural eye and brain abnormalities. The c.1814 G > A mutation in exon 21 of the POMGNT1 gene is apparently a common mutation in the Turkish population. Individuals with this mutation show classical features of muscle-eye-brain disease, but others may exhibit a milder phenotype and retain the ability to walk independently. Congenital muscular dystrophy patients from Turkey carrying the clinical and radiologic features of muscle-eye-brain disease should be evaluated for mutations in POMGNT1 gene.

Prevalence and correlates of diabetic retinopathy in a population-based survey of older people in Nakuru, Kenya

PURPOSE

To estimate the prevalence of and factors associated with diabetic retinopathy (DR) among people aged ≥ 50 years in Nakuru, Kenya.

METHODS

Probability-proportional-to-size sampling was used to select 100 clusters of 50 people aged ≥ 50 years during 2007-2008. Households within clusters were selected through compact segment sampling. Participants underwent dilated slit lamp biomicroscopy (SLB) by an ophthalmologist and digital retinal photography. Images were graded for DR at the Moorfields Eye Hospital Reading Centre, UK. Diagnosis of DR was based on retinal images where available, otherwise on SLB. Anthropometric measures, including random glucose, and lifestyle factors were measured.

RESULTS

We examined 4414 adults (response rate 88.1%), of whom 287 had diabetes. A total of 277 of these were screened for DR by SLB, and 195 also underwent retinal photography. The prevalence of any DR diagnosed by retinal images among diabetics was 35.9% (95% confidence interval, CI, 29.7-42.6%). The most common grade of DR was mild/moderate non-proliferative DR (NPDR; 22.1%, 95% CI 16.1-29.4%), while severe NPDR and proliferative DR were less frequent (13.9%, 95% CI 10.0-18.8%). SLB significantly underdiagnosed DR compared to retinal photography, particularly for milder grades. Of 87 individuals with DR, 23 had visual impairment (visual acuity <6/12). DR was associated with younger age, male sex, duration and control of diabetes, and treatment compliance. Coverage of photocoagulation in those needing immediate laser was low (25%).

CONCLUSION

DR remains a threat to sight in people with diabetes in this elderly Kenyan population. Screening diabetics may enable those requiring treatment to be identified in time to preserve their sight.

Gelatin-Based Materials in Ocular Tissue Engineering

Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology.

Transformational change: nurses substituting for ophthalmologists for intravitreal injections - a quality-improvement report

BACKGROUND

The dramatic increase in need for anti-vascular endothelial growth factor (anti-VEGF) intravitreal therapy in the treatment of retinal disease and the absence of an equivalent increase in ophthalmologists to undertake such intravitreal injections created a patient-safety risk. Timing of intravitreal therapy (IVT) is critical to prevent vision loss and local clinics lacked capacity to treat patients appropriately. We aimed to improve capacity for IVT by nurse injections.

MATERIALS AND METHODS

A multidisciplinary prospective service-improvement process was undertaken at two adjacent general hospitals in the northwest of England. IVT injections by nurses were a principal component of solution development. After we had obtained appropriate institutional approval, experienced ophthalmic nurses were trained, supervised, and assessed to undertake IVT. Ophthalmologists directly supervised the first 200 injections, and a retina specialist was always on site.

RESULTS

Nurses undertook 3,355 intravitreal injections between June 2012 and November 2013, with minor adverse events (0.3% subconjunctival hemorrhage and corneal abrasion). There were no patient complaints at either hospital.

CONCLUSION

Experienced ophthalmic nurses quickly learned how to perform such injections safely. IVT by nurses was well accepted by patients and staff. Hospital A trained three nurses sequentially for improved flexibility in scheduling. Novel use of appropriately trained non-medical staff can improve efficiency and access in an overburdened service with time-sensitive disease. Retinal assessment was undertaken by ophthalmologists only. Improved access to IVT is important, as treatment with anti-VEGF therapy reduces blindness at population levels.

Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μm, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrument's utility. With this system, it can provide anatomical dimensions of AS, including central corneal thickness, anterior chamber width, anterior chamber depth, crystalline lens vault, crystalline lens thickness, angle opening distance (AOD500/AOD750), and the area described by the trabecular-iris space (TISA500/TISA750) at 500/750  μm. We also use eAS-OCT to image and quantify dynamic functional changes of the AS in response to a light stimulus that induces physiological pupillary changes as well as accommodative efforts that induce lens changes. The results show that the described eAS-OCT is able to provide full anatomical biometry for AS and is useful for the studies where the dynamic response of AS compartment to certain stimulus is required.

Progress on Developing Adaptive Optics-Optical Coherence Tomography for In Vivo Retinal Imaging: Monitoring and Correction of Eye Motion Artifacts

Recent progress in retinal image acquisition techniques, including optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO), combined with improved performance of adaptive optics (AO) instrumentation, has resulted in improvement in the quality of in vivo images of cellular structures in the human retina. Here, we present a short review of progress on developing AO-OCT instruments. Despite significant progress in imaging speed and resolution, eye movements present during acquisition of a retinal image with OCT introduce motion artifacts into the image, complicating analysis and registration. This effect is especially pronounced in high-resolution datasets acquired with AO-OCT instruments. Several retinal tracking systems have been introduced to correct retinal motion during data acquisition. We present a method for correcting motion artifacts in AO-OCT volume data after acquisition using simultaneously captured adaptive optics-scanning laser ophthalmoscope (AO-SLO) images. We extract transverse eye motion data from the AO-SLO images, assign a motion adjustment vector to each AO-OCT A-scan, and re-sample from the scattered data back onto a regular grid. The corrected volume data improve the accuracy of quantitative analyses of microscopic structures.

Tear film measurement by optical reflectometry technique

Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.

Ocular Tonometry and Sporadic Creutzfeldt - Jakob Disease (sCJD): A Confirmatory Case-Control Study

AIMS

To evaluate the hypothesis that sporadic Creutzfeldt-Jakob disease (sCJD) may be transmitted through ocular tonometry.

BACKGROUND

The infectious agent of sCJD may be present in the cornea prior to clinical symptoms. Cornea infectiousness has been documented by cornea transplants in guinea pigs and humans. sCJD is resistant to complete inactivity by conventional sterilization techniques. Thus contact tonometry equipment is not disinfected sufficiently to kill sCJD. We previously hypothesized that contact tonometry is a sCJD risk factor.

STUDY DESIGN

Population-based case-control study.

PLACE AND DURATION OF STUDY

Department of Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, USA; 4 years.

METHODOLOGY

An 11-state case-control study of pathologically confirmed definite sCJD cases, individually matched controls, and a sample of control surrogates was conducted. Ocular tonometry histories were obtained from case-surrogates, controls, and a sample of control-surrogates.

RESULTS

The odds ratio (OR) for ever vs never having had an ocular tonometry test was statistically significant for matched and unmatched analyses for 15 through 3 years prior to disease onset, using both control self-responses and control surrogates: ORs were ∞ and 19.4 with 1-sided P-values <0.0001 and 0.003 and ORs=∞ and 11.1 with 1-sided P-values <0.003 and 0.02, respectively. ORs increased as the number of tonometry tests increased during this age period: trend test, 2-sided P-value < 0.0001. For ≥5 vs <5 tonometry tests, the OR was 5.8 (unmatched) and 3.7 (matched), 2-sided P-value<0.00005. Respondents generally could not specify the type of tonometry. There was no indication of increased tonometry testing among cases within 2 years of disease onset.

CONCLUSIONS

The a priori hypothesis was supported. Contact tonometry, preferred by ophthalmologists, may be capable of transmitting sCJD. Consideration should be given to using disposable instrument covers after each use. The use the disposable covers or non-contact tonometry is preferable in the absence of effective disinfectant processes at this time.

Emergence of dual VEGF and PDGF antagonists in the treatment of exudative age-related macular degeneration

Neovascular ('wet') age-related macular degeneration (AMD) is the leading cause of blindness among Caucasians over the age of 55 in the USA and is an important cause of ocular morbidity worldwide. Progress in oncology, and more recently ophthalmology, led to the development of VEGF antagonists, three of which are now approved for the treatment of wet AMD. Recent discoveries in ophthalmology and vascular biology, however, suggest that combined inhibition of VEGF and platelet-derived growth factor (PDGF) may be more beneficial than inhibition of VEGF alone. Accordingly, numerous studies are underway to evaluate the role of anti-VEGF/PDGF combination therapies for the treatment of wet AMD. This review discusses the biology of VEGF and PDGF and current preclinical and clinical data exploring the use of combined VEGF/PDGF inhibitors in the treatment of neovascular age-related macular degeneration.

Clinical Presentation and Microbial Analyses of Contact Lens Keratitis; an Epidemiologic Study

INTRODUCTION

Microbial keratitis is an infective process of the cornea with a potentially and serious visual impairments. Contact lenses are a major cause of microbial keratitis in the developed countries especially among young people. Therefore, the purpose of the present study was to evaluate the frequency and microbiological characteristic of CLK in patients referred to the emergency department (ED) of teaching hospitals, Babol, Iran.

METHODS

This is a cross-sectional study of all patients with contact lens induced corneal ulcers admitted to the teaching hospitals of Babol, Iran, from 2011- 2013. An ophthalmologist examined patients with the slit-lamp and clinical features of them were noted (including pain, redness, foreign body sensation, chemosis, epiphora, blurred vision, discomfort, photophobia, discharge, ocular redness and swelling). All suspected infectious corneal ulcers were scraped for microbial culture and two slides were prepared. Data were analyzed using SPSS software, version 18.0.

RESULTS

A total of 14 patients (17 eyes) were recruited into the study (100% female). The patients' age ranged from 16-37 years old (mean age 21.58±7.23 years). The most prevalent observed clinical signs were pain and redness. Three samples reported as sterile. The most common isolated causative organism was pseudomonas aeroginosa (78.6%), Staphylococcus aureus 14.3%, and enterobacter 7.1%, respectively. Treatment outcome was excellent in 23.5%, good in 47.1%, and poor in 29.4% of cases.

CONCLUSION

Improper lens wear and care as well as the lack of awareness about the importance of aftercare visits have been identified as potential risk factors for the corneal ulcer among contact lens wearers. Training and increasing the awareness of adequate lens care and disinfection practices, consulting with an ophthalmologist, and frequent replacement of contact lens storage cases would greatly help reducing the risk of microbial keratitis.

Lateral and axial measurement differences between spectral-domain optical coherence tomography systems

We assessed the reproducibility of lateral and axial measurements performed with spectral-domain optical coherence tomography (SDOCT) instruments from a single manufacturer and across several manufacturers. One human retina phantom was imaged on two instruments each from four SDOCT platforms: Zeiss Cirrus, Heidelberg Spectralis, Bioptigen SDOIS, and hand-held Bioptigen Envisu. Built-in software calipers were used to perform manual measurements of a fixed lateral width (LW), central foveal thickness (CFT), and parafoveal thickness (PFT) 1 mm from foveal center. Inter- and intraplatform reproducibilities were assessed with analysis of variance and Tukey-Kramer tests. The range of measurements between platforms was 5171 to 5290 μm for mean LW (p<0.001), 162 to 196 μm for mean CFT (p<0.001), and 267 to 316 μm for mean PFT (p<0.001). All SDOCT platforms had significant differences between each other for all measurements, except LW between Bioptigen SDOIS and Envisu (p=0.27). Intraplatform differences were significantly smaller than interplatform differences for LW (p=0.020), CFT (p=0.045), and PFT (p=0.004). Conversion factors were generated for lateral and axial scaling between SDOCT platforms. Lateral and axial manual measurements have greater variance across different SDOCT platforms than between instruments from the same platform. Conversion factors for measurements from different platforms can produce normalized values for patient care and clinical studies.

Systematic study of high-frequency ultrasonic transducer design for laser-scanning photoacoustic ophthalmoscopy

Photoacoustic ophthalmoscopy (PAOM) is a high-resolution in vivo imaging modality that is capable of providing specific optical absorption information for the retina. A high-frequency ultrasonic transducer is one of the key components in PAOM, which is in contact with the eyelid through coupling gel during imaging. The ultrasonic transducer plays a crucial role in determining the image quality affected by parameters such as spatial resolution, signal-to-noise ratio, and field of view. In this paper, we present the results of a systematic study on a high-frequency ultrasonic transducer design for PAOM. The design includes piezoelectric material selection, frequency selection, and the fabrication process. Transducers of various designs were successfully applied for capturing images of biological samples in vivo. The performances of these designs are compared and evaluated.

Recent advances in ophthalmic molecular imaging

The aim of molecular imaging techniques is the visualization of molecular processes and functional changes in living animals and human patients before morphological changes occur at the cellular and tissue level. Ophthalmic molecular imaging is still in its infancy and has mainly been used in small animals for pre-clinical research. The goal of most of these pre-clinical studies is their translation into ophthalmic molecular imaging techniques in clinical care. We discuss various molecular imaging techniques and their applications in ophthalmology.

Complement factor C3a alters proteasome function in human RPE cells and in an animal model of age-related RPE degeneration

PURPOSE

Complement activation plays an unequivocal role in the pathogenesis of age-related macular degeneration (AMD). More recent evidence suggests an additional role in AMD for the ubiquitin proteasome pathway (UPP), a protein-degradation nanomachinery present in all types of eukaryotic cells. The purpose of this study was to elaborate on these findings and investigate whether the complement system directly contributes to derangements in the UPP through the activated complement components C3a and C5a.

METHODS

In the retinal pigment epithelial cells (RPE) of monocyte chemoattractant protein-1-deficient CCL2(-/-) mice, a mouse model that may serve as a model for age-related atrophic degeneration of the RPE, proteasome function was investigated by immunohistochemistry of household (β5) and immuno (β5i) subunit expression. Subsequently, proteasome overall activity was determined using the BodipyFl-Ahx3L3VS probe in primary-cultured human retinal pigment epithelial cells (HRPE) cells that were exposed to different stimuli including C3a and C5a, using confocal laser scanning microscopy and flow cytometry. Gene expression and protein levels of proteasome subunits α7, PA28α, β5, and β5i were also studied in RPE cells after exposure to IFN-γ, C3a, and C5a by real-time PCR and Western blotting.

RESULTS

Retinal pigment epithelial cells of CCL2(-/-) mice showed immunoproteasome upregulation. C3a, but not C5a supplementation, induced a decreased proteasome overall activity in HRPE cells, whereas mRNA and protein levels of household proteasome and immunoproteasome subunits were unaffected.

CONCLUSIONS

In HRPE cells, C3a induces decreased proteasome-mediated proteolytic activity, whereas in a mouse model of age-related RPE atrophy, the immunoproteasome was upregulated, indicating a possible role for complement-driven posttranslational alterations in proteasome activity in the cascade of pathologic events that result in AMD.

Is it worthwhile to conduct a randomized controlled trial of glaucoma screening in the United Kingdom?

Objectives

To assess the value of conducting a glaucoma screening randomized controlled trial in the UK.

Methods

Decision model based economic evaluation and value of information analysis. Model derived from a previous health technology assessment. Model updated in terms of structure and parameter estimates with data from surveys, interviews with members of the public and health care providers and routine sources.

Results

On average, across a range of ages of initiating screening (40–60 years), glaucoma prevalence (1–5%), screening uptake (30–100%), and the performance of current case finding, screening was not cost-effective at a £30,000 threshold per quality adjusted life year (QALY) from the perspective of the National Health Service (NHS). The societal value of removing all uncertainty around glaucoma screening is £107 million at a threshold of £20,000 per QALY. For informing policy decisions on glaucoma screening, reducing uncertainty surrounding the NHS and personal social care cost of sight impairment (£74 million) was of most value, followed by reducing uncertainty in test performance (£14 million) and uptake of either screening or current eye care (£8 million each).

Conclusions

A glaucoma screening trial in the UK is unlikely to be the best use of research resources. Further research to quantify the costs of sight impairment falling on the NHS and personal social services is a priority. Further development of glaucoma tests and research into strategies to promote the uptake of screening or current eye care such as through the use of a behavioural intervention would be worthwhile.

Unanswered questions in headache: so what is photophobia, anyway?

Photophobia refers to a sensory disturbance provoked by light. However, because it arises distinctly in a broad range of clinical conditions, its definition remains elusive. Many underscore the painful sensory aspects of photophobia, while others emphasize its unpleasant, affective qualities. To add further complexity, recent discoveries in photophobia research have raised disparate and potentially conflicting results. In this installment of an occasional series, we asked clinicians and scientists to give their interpretation of what these discoveries tell us about photophobia in the clinic, and vice versa.

Cortical blindness after complicated general anesthesia in urological surgery

Patient: Male, 4

Final Diagnosis: Cortical blindness after complicated general anesthesia

Symptoms: Blindness • fine motor activity derangements

Medication: —

Clinical Procedure: General anesthesia for unilateral inguinal hydrocelectomy

Specialty: Anesthesiology

Whole genome sequencing in patients with retinitis pigmentosa reveals pathogenic DNA structural changes and NEK2 as a new disease gene. Proc Natl Acad Sci U S A. 2013;110:16139-16144. [PMID: 24043777 DOI: 10.1073/pnas.1308243110]

We performed whole genome sequencing in 16 unrelated patients with autosomal recessive retinitis pigmentosa (ARRP), a disease characterized by progressive retinal degeneration and caused by mutations in over 50 genes, in search of pathogenic DNA variants. Eight patients were from North America, whereas eight were Japanese, a population for which ARRP seems to have different genetic drivers. Using a specific workflow, we assessed both the coding and noncoding regions of the human genome, including the evaluation of highly polymorphic SNPs, structural and copy number variations, as well as 69 control genomes sequenced by the same procedures. We detected homozygous or compound heterozygous mutations in 7 genes associated with ARRP (USH2A, RDH12, CNGB1, EYS, PDE6B, DFNB31, and CERKL) in eight patients, three Japanese and five Americans. Fourteen of the 16 mutant alleles identified were previously unknown. Among these, there was a 2.3-kb deletion in USH2A and an inverted duplication of ~446 kb in EYS, which would have likely escaped conventional screening techniques or exome sequencing. Moreover, in another Japanese patient, we identified a homozygous frameshift (p.L206fs), absent in more than 2,500 chromosomes from ethnically matched controls, in the ciliary gene NEK2, encoding a serine/threonine-protein kinase. Inactivation of this gene in zebrafish induced retinal photoreceptor defects that were rescued by human NEK2 mRNA. In addition to identifying a previously undescribed ARRP gene, our study highlights the importance of rare structural DNA variations in Mendelian diseases and advocates the need for screening approaches that transcend the analysis of the coding sequences of the human genome.

Stem cells set their sights on retinitis pigmentosa

Skin cells from a patient with a form of inherited blindness have been reprogrammed into retinal cells and successfully transplanted into mice.

Multiparametric optical coherence tomography imaging of the inner retinal hemodynamic response to visual stimulation

The hemodynamic response to neuronal activation is a well-studied phenomenon in the brain, due to the prevalence of functional magnetic resonance imaging. The retina represents an optically accessible platform for studying lamina-specific neurovascular coupling in the central nervous system; however, due to methodological limitations, this has been challenging to date. We demonstrate techniques for the imaging of visual stimulus-evoked hyperemia in the rat inner retina using Doppler optical coherence tomography (OCT) and OCT angiography. Volumetric imaging with three-dimensional motion correction, en face flow calculation, and normalization of dynamic signal to static signal are techniques that reduce spurious changes caused by motion. We anticipate that OCT imaging of retinal functional hyperemia may yield viable biomarkers in diseases, such as diabetic retinopathy, where the neurovascular unit may be impaired.

Three-dimensional anterior segment imaging in patients with type 1 Boston Keratoprosthesis with switchable full depth range swept source optical coherence tomography

A high-speed (100 kHz A-scans/s) complex conjugate resolved 1 μm swept source optical coherence tomography (SS-OCT) system using coherence revival of the light source is suitable for dense three-dimensional (3-D) imaging of the anterior segment. The short acquisition time helps to minimize the influence of motion artifacts. The extended depth range of the SS-OCT system allows topographic analysis of clinically relevant images of the entire depth of the anterior segment of the eye. Patients with the type 1 Boston Keratoprosthesis (KPro) require evaluation of the full anterior segment depth. Current commercially available OCT systems are not suitable for this application due to limited acquisition speed, resolution, and axial imaging range. Moreover, most commonly used research grade and some clinical OCT systems implement a commercially available SS (Axsun) that offers only 3.7 mm imaging range (in air) in its standard configuration. We describe implementation of a common swept laser with built-in k-clock to allow phase stable imaging in both low range and high range, 3.7 and 11.5 mm in air, respectively, without the need to build an external MZI k-clock. As a result, 3-D morphology of the KPro position with respect to the surrounding tissue could be investigated in vivo both at high resolution and with large depth range to achieve noninvasive and precise evaluation of success of the surgical procedure.

Total average blood flow and angiography in the rat retina

High-resolution angiography and total average blood flow measurements in the rat retina using optical coherence tomography (OCT) are presented. Recently, an en face integration method, which does not require explicit calculation of vessel angles, was introduced to calculate blood flow using Doppler OCT. Using this method, rapid two-dimensional scanning has been shown to quantify pulsatile flow. However, high scanning speeds sacrifice transverse sampling density and may lead to biased velocity estimates. Alternatively, we show here that by using a volumetric scanning protocol that asynchronously samples a single vessel with respect to the heartbeat, it is possible to obtain accurate time-averaged flow measurements, even without explicit information about the pulsatile waveform. Total average retinal blood flows calculated using either arteries or veins are comparable, supporting the accuracy of this method.

Keeping blood vessels out of sight

Researchers have identified a soluble receptor that prevents blood vessels forming in the outer retina-a process that can lead to blindness-by sequestering vascular endothelial growth factor.

Providing comprehensive genetic-based ophthalmic care

The diagnosis of an inherited retinal dystrophy can have a significant impact on both the physical and emotional lives of patients and their families. In order to optimize the health and quality of life for these individuals, a comprehensive approach to clinical care starting at the time of diagnosis and continuing throughout their lifespan is critical. A multidisciplinary team approach integrating ophthalmic and genetic counseling services can optimize the diagnostic process and long-term management of these patients. When vision loss is first appreciated, the diagnostic specificity of an ophthalmic evaluation can be enhanced by a detailed genetic work-up. This evaluation can help confirm the diagnosis and allow for accurate risk counseling of the patient and their family. Genetic counseling is critical at the time of diagnosis and is an opportunity to provide education about the diagnosis, discuss low-vision rehabilitation, and explore impacts on academics and employment. In addition, counseling can help patients deal with the current psychological aspects of their vision loss, prepare for the lifelong impact of their diagnosis and over time adjust to the impact of progressive vision loss.

Satisfaction with ophthalmology residency training from the perspective of recent graduates: a cross-sectional study

BACKGROUND

Few studies have evaluated satisfaction with medical residency programs from the perspective of residents or recent graduates. Knowledge of current conditions of teaching might help to identify deficiencies and to provide adequate training. So, the aim of this study was to assess the satisfaction with residency training and to identify deficiencies in this training from the perspective of recent graduates in ophthalmology residency.

METHODS

For this purpose, we developed a questionnaire and gaved it to recent graduates in ophthalmology residency in São Paulo, Brazil, from January to December 2010. The questions contained demographic information (age, sex and time of practice in ophthalmology), a Likert scale to evaluate the level of satisfaction with medical residency concerning clinical knowledge, surgical skills and doctor-patient relationship and questions about deficiency in clinical and surgical areas.

RESULTS

The areas in which recent residency graduates were very or extremely satisfied were: acquisition of clinical knowledge (89.1%), acquisition of surgical skills (93.4%) and the development of doctor-patient relationship (74.9%). Specific areas of clinical knowledge in which they perceived more deficiency were orbit (48.3%) and ophthalmic pathology (47.9%), and in surgical skills were refractive surgery (65.9%) and orbit (59.2%)

CONCLUSIONS

The assessment of the satisfaction with residency training in ophthalmology from the perspective of recent graduates showed high level of satisfaction and identified specific deficiencies in ophthalmic pathology, refractive surgery and orbit.

The Newport eye: design and initial evaluation of a novel foreign body training phantom

To improve SHO confidence in corneal foreign body removal, a novel training phantom is proposed. This phantom is a polyvinyl and gelatine-based model, easily fabricated in the emergency department (ED). Use of the phantom results in a significant improvement in SHO confidence, and therefore, makes a useful, cost-effective adjunct for ED training.

A prospective observational study of techniques to remove corneal foreign body in the emergency department

INTRODUCTION

Patients  with corneal foreign bodies (CFBs) often present to the emergency department (ED). However, removal techniques vary among emergency physicians (EPs). A prospective, single-blinded, observational study was performed to compare slit-lamp-aided (SLA) versus non-slit-lamp-aided (NSLA) CFB removal by EPs.

METHODS

Five EPs enrolled consecutive patients with a CFB over 3 months. One blinded EP reviewed patients after 3 days. The study end points were: change in visual acuity; visual analogue pain scale (VAS) score at 12 and 24 h; satisfaction rating; symptoms at follow-up; and rate of complications.

RESULTS

54 patients were enrolled: 28 had SLA removal and 26 NSLA removal; 52 were male; 22 had undergone previous CFB removal; six were wearing eye protection at the time of injury. Forty-three patients were reviewed: 26 by attendance and 18 by telephone. There was no difference in any end points at review. However, patients in the SLA group had median VAS scores that were 1.5 cm lower after 24 h than patients in the NSLA group (p=0.43, 95% CI -2.0 to 1.0). One patient in the SLA group developed keratitis.

CONCLUSIONS

We show that patient satisfaction ratings, complications and visual acuity were similar for the two methods. There was a trend for increased pain in the NSLA group at 12 and 24 h. Slit-lamp biomicroscopy and the use of magnification to remove CFBs remains the gold standard of care, and more intensive training should be given to EPs at the departmental level, particularly in EDs that receive patients with eye injuries.

Scope of resident ophthalmology consultation service and patient follow-up rates at a level 1 trauma center in Brooklyn, New York

BACKGROUND

The purpose of this study was to investigate the most common reasons for urgent ophthalmology consultations in both the emergency room and inpatient settings at a large public hospital served by a busy ophthalmology residency program, and to track patient follow-up rates.

METHODS

We reviewed the medical records of all patients evaluated by the ophthalmology consultation service at Kings County Hospital Center from June 2003 to October 2005 using a retrospective hospital-based study design. We categorized emergency room patients and inpatients into traumatic and nontraumatic subgroups, and looked at diagnoses and patient demographics, as well as follow-up patterns for emergency room consultations.

RESULTS

In total, 743 patients were evaluated; 436 (59%) were emergency room patients and 307 (41%) were inpatients. Consultation for traumatic eye injury was provided for 399 patients (54%), accounting for 284 (65%) of the emergency room consults and 115 (37.5%) of the inpatient consults. The most common reason for inpatient consultation was to rule out ocular manifestations of systemic disease (57 patients, 29.7%), while the most common final diagnosis for trauma inpatient consultation was orbital wall fracture (59 patients, 51.3%). In total, 262 patients (60%) in the emergency room consultation group returned for follow-up care; 162 (57%) of the trauma patients followed up and 100 (66%) of the nontrauma patients followed up.

CONCLUSION

This study provides a comprehensive analysis of the eye conditions and follow-up rates evaluated by the ophthalmology service at Kings County Hospital Center. By evaluating the follow-up patterns of these patients, we may be able to alter patient counseling to increase patient compliance.

Non-mydriatic ocular fundus photography and telemedicine: past, present, and future

Non-mydriatic ocular fundus photography is a promising alternative to direct ophthalmoscopy, particularly when combined with telemedicine. This review discusses these technologies from a longitudinal perspective: past, present, and future. The focus is directed to the role that non-mydriatic fundus photography and telemedicine have played in medical research and patient care, with emphasis on the major advances to date. Also discussed are the challenges to their widespread application and their substantial promise for revitalizing the importance of the ocular fundus examination in patient care, providing improved access to ophthalmic consultative services, and facilitating clinical and epidemiologic research.

The EPIC-Norfolk Eye Study: rationale, methods and a cross-sectional analysis of visual impairment in a population-based cohort

OBJECTIVES

To summarise the methods of the European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study, and to present data on the prevalence of visual impairment and associations with visual impairment in the participants.

DESIGN

A population-based cross-sectional study nested within an on-going prospective cohort study (EPIC).

SETTING

East England population (the city of Norwich and its surrounding small towns and rural areas).

PARTICIPANTS

A total of 8623 participants aged 48-92 years attended the Eye Study and underwent assessment of visual acuity, autorefraction, biometry, tonometry, corneal biomechanical measures, scanning laser polarimetry, confocal scanning laser ophthalmoscopy, fundal photography and automated perimetry.

OUTCOME MEASURES

Visual impairment was defined according to the WHO classification and the UK driving standard, and was based on presenting visual acuity. Summary measures of other ophthalmic measurements are also presented.

RESULTS

The prevalence (95% CI) of WHO-defined moderate-to-severe visual impairment and blindness was 0.74% (0.55% to 0.92%). The prevalence (95% CI) of presenting visual acuity worse than the UK driving standard was 5.87% (5.38% to 6.37%). Older age was significantly associated with visual impairment or blindness (p<0.001). Presenting visual acuity worse than UK driving standard was associated with older age (p<0.001), female sex (p=0.005) and lower educational level (p=0.022).

CONCLUSIONS

The prevalence of blindness and visual impairment in this selected population was low. Visual impairment was more likely in older participants, women and those with a lower educational level.

Personalized Medicine in Ophthalmology: From Pharmacogenetic Biomarkers to Therapeutic and Dosage Optimization

Rapid progress in genomics and nanotechnology continue to advance our approach to patient care, from diagnosis and prognosis, to targeting and personalization of therapeutics. However, the clinical application of molecular diagnostics in ophthalmology has been limited even though there have been demonstrations of disease risk and pharmacogenetic associations. There is a high clinical need for therapeutic personalization and dosage optimization in ophthalmology and may be the focus of individualized medicine in this specialty. In several retinal conditions, such as age-related macular degeneration, diabetic macular edema, retinal vein occlusion and pre-threshold retinopathy of prematurity, anti-vascular endothelial growth factor therapeutics have resulted in enhanced outcomes. In glaucoma, recent advances in cytoskeletal agents and prostaglandin molecules that affect outflow and remodel the trabecular meshwork have demonstrated improved intraocular pressure control. Application of recent developments in nanoemulsion and polymeric micelle for targeted delivery and drug release are models of dosage optimization, increasing efficacy and improving outcomes in these major eye diseases.

Current treatments in diabetic macular oedema: systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review is to appraise the evidence for the use of anti-VEGF drugs and steroids in diabetic macular oedema (DMO) as assessed by change in best corrected visual acuity (BCVA), central macular thickness and adverse events

DATA SOURCE

MEDLINE, EMBASE, Web of Science with Conference Proceedings and the Cochrane Library (inception to July 2012). Certain conference abstracts and drug regulatory web sites were also searched.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Randomised controlled trials were used to assess clinical effectiveness and observational trials were used for safety. Trials which assessed triamcinolone, dexamethasone, fluocinolone, bevacizumab, ranibizumab, pegaptanib or aflibercept in patients with DMO were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias was assessed using the Cochrane risk of bias tool. Study results are narratively described and, where appropriate, data were pooled using random effects meta-analysis.

RESULTS

Anti-VEGF drugs are effective compared to both laser and placebo and seem to be more effective than steroids in improving BCVA. They have been shown to be safe in the short term but require frequent injections. Studies assessing steroids (triamcinolone, dexamethasone and fluocinolone) have reported mixed results when compared with laser or placebo. Steroids have been associated with increased incidence of cataracts and intraocular pressure rise but require fewer injections, especially when steroid implants are used.

LIMITATIONS

The quality of included studies varied considerably. Five of 14 meta-analyses had moderate or high statistical heterogeneity.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The anti-VEGFs ranibizumab and bevacizumab have consistently shown good clinical effectiveness without major unwanted side effects. Steroid results have been mixed and are usually associated with cataract formation and  intraocular pressure increase. Despite the current wider spectrum of treatments for DMO, only a small proportion of patients recover good vision (≥20/40), and thus the search for new therapies needs to continue.

Sailing a safe ship: improving patient safety by enhancing the leadership skills of new consultant specialist surgeons

INTRODUCTION

The potential for "discontinuities in care" arising from the turbulent transition from specialist trainee to consultant specialist presents risks to patient safety. But it is easy to lose sight of the affective needs of individuals facing the burden of keeping patients safe. This article describes a 2-day program focused on new and prospective consultant specialist ophthalmic surgeons entitled "Sailing a Safe Ship" (SASS). The purpose was to facilitate understanding and analysis of their personal holistic learning needs and enhance individual agency in optimizing learning during the transition period.

METHODS

The program used gaming, team challenges, meta-planning, role play and professional actors, interactive presentations, and self-analysis tools to portray the real world of consultant specialist practice in terms of ill-defined problems requiring "elite communication" and effective negotiation of value differences and priorities for their resolution. Participants' insights into their individual learning were recorded in scheduled reflective sessions. The immediate impact on their learning was also considered in terms of direct (instructional) and indirect (nurturant) effects.

RESULTS

Participants' insights reflected 4 key themes: admitting vulnerability and uncertainty, taking responsibility for managing risk, being self-aware and reflexive, and internalizing authentic leadership. Four instructional and 4 nurturant effects were revealed. Preliminary findings on long-term impact on participants' practice are outlined.

DISCUSSION

Evidence from the evaluation indicated that participants felt empowered to construct a personal strategic response to unfamiliar and unanticipated workplace demands and pressures, adopt a capability mindset that would accelerate their capacity to fulfill an enhanced leadership role, and take a holistic approach to their continuing self-directed development as leaders and educators.

Extended imaging depth to 12 mm for 1050-nm spectral domain optical coherence tomography for imaging the whole anterior segment of the human eye at 120-kHz A-scan rate

ABSTRACT. We demonstrate a 1050-nm spectral domain optical coherence tomography (OCT) system with a 12 mm imaging depth in air, a 120 kHz A-scan rate and a 10 μm axial resolution for anterior-segment imaging of human eye, in which a new prototype InGaAs linescan camera with 2048 active-pixel photodiodes is employed to record OCT spectral interferograms in parallel. Combined with the full-range complex technique, we show that the system delivers comparable imaging performance to that of a swept-source OCT with similar system specifications.

Complex conjugate artifact-free adaptive optics optical coherence tomography of in vivo human optic nerve head

We acquired in vivo images of the human optic nerve head (ONH) using an adaptive optics-optical coherence tomography (AO-OCT) system. In order to improve imaging of the lamina cribrosa in the ONH with high lateral resolution and sensitivity, we implemented a complex conjugate artifact-free Fourier domain OCT (Fd-OCT) acquisition scheme with a reference arm-based phase shifting method. This allowed positioning of the lamina cribrosa structures near the zero path length difference where AO-OCT imaging achieves highest sensitivity. Implementation of our complex conjugate artifact removal (CCR) method required constant phase shifts between consecutive axial scans (A-scans), generated by continuous beam path-length changes from offsetting the pivot point of the scanning mirror placed in the reference arm. Fourier transform along the transverse axis and a filtering algorithm allowed reconstruction of CCR AO-OCT images. The suppression ratio of the mirror artifact was approximately 22 dB (at 18,000 A-scans per second acquisition speed) with a paperboard test target and an optimum phase-shift value. Finally, we reconstructed the three-dimensional structure of human ONH with enhanced depth range and sensitivity using CCR AO-OCT.

Retinal optical coherence tomography image enhancement via shrinkage denoising using double-density dual-tree complex wavelet transform

ABSTRACT. Image enhancement of retinal structures, in optical coherence tomography (OCT) scans through denoising, has the potential to aid in the diagnosis of several eye diseases. In this paper, a locally adaptive denoising algorithm using double-density dual-tree complex wavelet transform, a combination of the double-density wavelet transform and the dual-tree complex wavelet transform, is applied to reduce speckle noise in OCT images of the retina. The algorithm overcomes the limitations of commonly used multiple frame averaging technique, namely the limited number of frames that can be recorded due to eye movements, by providing a comparable image quality in significantly less acquisition time equal to an order of magnitude less time compared to the averaging method. In addition, improvements of image quality metrics and 5 dB increase in the signal-to-noise ratio are attained.

Effect of axonal micro-tubules on the morphology of retinal nerve fibers studied by second-harmonic generation

Many studies suggest that the degradation of microtubules in the retinal ganglion cells may be an early event in the progression of glaucoma. Because reflectance and birefringence of the retinal nerve fibers arise primarily from microtubules, the optical properties have been intensively studied for early detection of the disease. We previously reported a novel nonlinear optical signal from axonal microtubules for visualizing the retinal nerve fibers, namely second-harmonic generation (SHG). We demonstrate the use of axonal SHG to investigate the effect of microtubules on the morphology of the retinal nerve fiber bundles. Time-lapse SHG imaging of ex vivo rat retinal flat mounts was performed during pharmacological treatment of nocodazole, and the intensity of axonal SHG and the changes in nerve fiber bundle morphology were monitored. We found that the microtubule disruption does not lead to immediate modification in the morphology of the nerve fibers. Our results indicate that microtubular SHG may provide a useful means for sensitive detection of axonal injuries. Since the intrinsic radiation depends on the regular architecture of the cytoskeleton element as maintained by active cellular regulations, the intensity of signal reflects the health of the retinal ganglion cell axons.

Evaluation of cyclodextrins for enhancing corneal penetration of natamycin eye drops

A new group of pharmaceutical excipients called cyclodextrins can be introduced into ophthalmology for delivering such water insoluble drug. This group of excipients is able to solubilize many water insoluble drugs which were previously impossible to be formulated as aqueous eye drop solution by forming their inclusion complexes. Analysis of pure drug and excipients by physical test, melting point determination, chemical test and solubility determination were carried out in this study. It may be concluded that cyclodextrin complexes of Natamycin can lead to an aqueous formulation (Natamycin eye drop) having better trans corneal permeability and thus can be proved to have faster and better antifungal efficiency.

Eye malformations in Cameroonian children: a clinical survey

SUMMARY

The aim of this work was to describe the clinical aspects of eye malformations observed at the ophthalmology unit of the Yaoundé Gynaecology, Obstetrics and Pediatrics Hospital.

PATIENTS AND METHODS

We carried out a retrospective study of all malformations of the eye and its adnexae observed among children aged 0-5 years who were seen at the ophthalmology unit from January 2003 to December 2009.

RESULTS

Out of the 2254 children who were examined, 150 (6.65%) presented eye malformations. The mean age was 14.40 ± 4 months. Eye malformations were diagnosed in 71.66% of cases during the first year of life. The most frequent malformations were congenital lacrimal duct obstruction (66.66%), congenital cataract (10.9%), congenital glaucoma (10.9%), microphthalmos (5.03%), and congenital ptosis (3.77%).

CONCLUSION

Eye malformations among children can lead to visual impairment and are a cause for discomfort to children and parents. Therefore, systematic postnatal screening is recommended to enable early management.

Exploration of the Visual System: Part 2: In Vivo Analysis Methods: Virtual-Reality Optomotor System, Fundus Examination, and Fluorescent Angiography

The mouse has emerged as an animal model for many diseases. At IRO, we have used this animal to understand the development of many eye diseases and treatment of some of them. Precise evaluation of vision is a prerequisite for both these approaches. In this unit we describe three ways to measure vision: testing the optokinetic response, and evaluating the fundus by direct observation and by fluorescent angiography. Curr. Protoc. Mouse Biol. 2:207-218 © 2012 by John Wiley & Sons, Inc.