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26.  Hydroxychloroquine retinopathy screening 
The British journal of ophthalmology  2008;92(12):1653-1655.
Aim
To compare current hydroxychloroquine retinopathy screening practices with the published 2002 American Academy of Ophthalmology (AAO) Preferred Practice Patterns (PPP).
Methods
A multiple-choice survey was distributed to 105 ophthalmologists to assess current screening practices and knowledge of patient risk factors. Results were compared with the PPP guidelines. A cost analysis of the PPP and survey paradigms was conducted.
Results
Sixty-seven (64%) of 105 surveys were completed. The majority (90%) of physicians screen for hydroxychloroquine retinopathy with either central automated threshold perimetry or Amsler grid as recommended by the PPP. Most survey respondents could not correctly identify the evidence-based risk factors. The majority screen more frequently than recommended: 87% screen high-risk patients and 94% screen low-risk patients more frequently than recommended in the PPP. The increased screening frequency of low-risk patients translates into an excess of $44 million in the first five years of therapy. If all patients were screened using exact PPP paradigm, savings could exceed $150 million every 10 years.
Conclusions
Ophthalmologists currently screen for hydroxychloroquine retinopathy correctly, however, their lack of familiarity with evidence-based guidelines may result in excessive follow up. Increasing awareness and implementation of the PPP could potentially reduce hydroxychloroquine retinopathy screening costs significantly.
doi:10.1136/bjo.2008.144402
PMCID: PMC4397565  PMID: 18829634
hydroxychloroquine; plaquenil; toxicity; screening; cost analysis
27.  Simulation contact lenses for AMD health state utility values in NICE appraisals: a different reality 
Background/aims
The National Institute for Health and Care Excellence (NICE) has recommended the use of ranibizumab for neovascular age-related macular degeneration (AMD) and for diabetic macular oedema (DMO) as part of its health technology appraisal process. In the economic evaluations of both interventions, utility values were derived from members of the general public wearing contact lenses with a central opacity that was meant to simulate the blind spot experienced by many patients with advanced retinal disease. This paper tests the validity of the contact lens simulation, and finding it to be invalid, explores the impact on prior economic evaluations.
Methods
Visual acuity, contrast sensitivity and visual fields were assessed with and without simulation lenses in five healthy subjects with normal vision.
Results
We identified important differences between the contact lens simulation and vision loss experienced by patients with AMD. The contact lens simulator did not cause the central scotoma which is characteristic of late-stage AMD and which leads to severe difficulty with everyday activities such as reading or recognising faces and objects. The contact lens instead caused a reduction in retinal illumination experienced by the subjects as a general dimming across the retina.
Conclusions
A contact lens with a central opacity does not simulate a central scotoma. The clinical differences between simulated and actual AMD suggest there has been an underestimation of the severity of AMD health states. This brings into question the validity of the economic evaluations of treatments for AMD and DMO used by NICE.
doi:10.1136/bjophthalmol-2014-305802
PMCID: PMC4392203  PMID: 25351679
Retina; Vision
28.  Advising patients on visual fitness to drive: implications of revised DVLA regulations 
Aim
To examine the relationship between the two UK vision standards for driving: the ability to read a number-plate at 20 m and achieving 6/12 (+0.30 logMAR).
Methods
120 participants were assessed without refractive correction in this cross-sectional study. Vision was assessed with a Snellen chart, Early Treatment of Diabetic Retinopathy Study (ETDRS) style logMAR letter chart and logMAR chart using Landolt rings. Ability to read a post-2001 number-plate was assessed outdoors.
Results
For all charts, there was an ‘overlap zone’ of visions within which it was uncertain whether participants would pass the number-plate test. Within this zone, sensitivity and specificity of the 6/12 cut-off for predicting number-plate performance were reasonable for Snellen and ETDRS style charts, but poor for Landolt. All participants with 6/7.5 Snellen (+0.10 logMAR ETDRS) or better could read a number-plate. Some participants (2–6%) with vision between this level and 6/12 could not read a number-plate, and 14%–15% could read a number-plate but not achieve 6/12.
Conclusions
To best predict drivers’ ability to read a number-plate, vision should be assessed using a logMAR letter chart or a Snellen chart scored by full line. Drivers with 6/7.5 (+0.10 logMAR) or better vision can be advised that they meet the driving standard. Drivers with acuity between 6/9 and 6/12 (+0.12—+0.30 logMAR) should be advised to check their ability to read a number-plate, as some may not be able to. Clinicians will see patients who can read a number-plate, but do not achieve 6/12, who will need improved vision to meet visual requirements for driving.
doi:10.1136/bjophthalmol-2014-306173
PMCID: PMC4392215  PMID: 25381011
Vision
29.  Weight at first detection of retinopathy of prematurity predicts disease severity 
The British journal of ophthalmology  2014;98(11):1565-1569.
Objective
To investigate whether postnatal weight at first detection of retinopathy of prematurity (ROP) can predict preterm infants who will develop severe ROP warranting treatment.
Design
This modern, population-based cohort included 147 infants born at gestational age (GA) <32 weeks in the Gothenburg region during 2011–2012 and screened for ROP at Sahlgrenska University hospital. GA, birth weight (BW), and weekly postnatal weight from birth until postmenstrual age (PMA) 40 weeks data were retrospectively retrieved. Birth weight SD scores (BWSDS) were calculated. ROP data, including first detected ROP stage, maximal ROP stage, ROP treatment, and PMA at first detected sign of ROP were also retrieved. Weight SDS (WSDS) at first ROP detection was calculated.
Results
Stepwise multivariate logistic regression analysis revealed that the best fit-model of risk factors for developing severe ROP warranting treatment included; GA (OR=0.28, CI 95% 0.12 to 0.66, p<0.01) and WSDS at first ROP detection (OR=0.22, CI 95% 0.05 to 0.89, p<0.05).
Conclusions
Low weight and low WSDS at first ROP detection can be useful predictors for ROP warranting treatment.
doi:10.1136/bjophthalmol-2014-304905
PMCID: PMC4389626  PMID: 24963022
30.  Eye features in 3 Danish patients with Multi Systemic Smooth Muscle Dysfunction Syndrome 
The British journal of ophthalmology  2012;96(9):1227-1231.
Aims
to specify ophthalmic findings in multi systemic smooth muscle dysfunction syndrome, recently clarified as due to a R179H mutation in the ACTA2 gene encoding smooth muscle cell α-actin.
Methods
An observational clinical series of three children who underwent full ophthalmic evaluation.
Results and conclusions
a) congenital mydriasis with wisps from the iris collarette appears as the primary marker of the rare disorder. b) the main fundus finding is arteriolar tortuosity from infancy, and with a trend of slight progression. One case had vessel loops and minute breaks of the blood-retina barrier in a temporal sector. c) defective accommodation was documented in 2 of the 3 cases. d) the poor imaging condition from day one after delivery was not amblyopiogenic and apparently did not hamper subsequent visual development. e) the paediatric ophthalmologist should be part of a multi-specialist team due to the risk of systemic smooth muscle related complications, among them primarily serious cardiac and cerebrovascular pathology.
doi:10.1136/bjophthalmol-2011-301462
PMCID: PMC4358743  PMID: 22790431
Fixed dilated pupil; Patent duct; Tortuous retinal vessels; ACTA2 gene
31.  Myopic choroidal neovascularisation: current concepts and update on clinical management 
Choroidal neovascularisation (CNV) is a common vision-threatening complication of myopia and pathological myopia. Despite significant advances in understanding the epidemiology, pathogenesis and natural history of myopic CNV, there is no standard definition of myopic CNV and its relationship to axial length and other myopic degenerative changes. Several treatments are available to ophthalmologists, but with the advent of new therapies there is a need for further consensus and clinical management recommendations. Verteporfin photodynamic therapy has been an established treatment for subfoveal myopic CNV for many years, but this treatment does not restore visual acuity and is associated with long-term chorioretinal atrophy. More recently, clinical trials investigating the efficacy and safety of anti-vascular endothelial growth factor agents in patients with myopic CNV have demonstrated substantial visual acuity gains and quality of life increases compared with photodynamic therapy. These enhanced outcomes provide updated evidence-based clinical management guidelines of myopic CNV, and increase the need for a generally accepted definition for myopic CNV. This review critically summarises the latest myopic CNV literature in the context of clinical experience and recommends a myopic CNV treatment algorithm.
doi:10.1136/bjophthalmol-2014-305131
PMCID: PMC4345796  PMID: 24990871
Neovascularisation; Treatment Medical; Retina
32.  Ranibizumab in retinal vein occlusion: treatment recommendations by an expert panel 
Retinal vein occlusion (RVO) is a common cause of retinal vascular disease, resulting in potentially irreversible loss of vision despite the existence of several therapeutic options. The humanised monoclonal antibody fragment ranibizumab binds to and inhibits vascular endothelial growth factor, a key driver of macular oedema in RVO. In 2010, ranibizumab was approved in the USA for the treatment of macular oedema in RVO and, in 2011, ranibizumab was approved in the European Union for the treatment of visual impairment caused by macular oedema secondary to RVO in branch and central RVO. Ranibizumab provides an additional therapeutic option for this complex disease: an option that was not fully considered during the preparation of current international guidelines. An expert panel was convened to critically evaluate the evidence for treatment with ranibizumab in patients with visual impairment caused by macular oedema secondary to RVO and to develop treatment recommendations, with the aim of assisting physicians to optimise patient treatment.
doi:10.1136/bjophthalmol-2014-305041
PMCID: PMC4345884  PMID: 25075121
Macula; Retina
33.  Service innovation in glaucoma management: using a web-based electronic patient record to facilitate virtual specialist supervision of a shared care glaucoma programme 
Aim
To assess the importance of specialist supervision in a new model of glaucoma service delivery.
Methods
An optometrist supported by three technicians managed each glaucoma clinic. Patients underwent testing and clinical examination before the optometrist triaged them into one of five groups: ‘normal’, ‘stable’, ‘low risk’, ‘unstable’ and ‘high risk’. Patient data were uploaded to an electronic medical record to facilitate virtual review by a glaucoma specialist.
Results
24 257 glaucoma reviews at three glaucoma clinics during a 31-month period were analysed. The clinic optometrists and glaucoma specialists had substantial agreement (κ 0.69). 13 patients were identified to be high risk by the glaucoma specialist that had not been identified as such by the optometrist. Glaucoma specialists amended 13% of the optometrists’ interim decisions resulting in an overall reduction in review appointments by 2.4%.
Conclusions
Employing technicians and optometrists to triage glaucoma patients into groups defined by risk of blindness allows higher risk patients to be directed to a glaucoma specialist. Virtual review allows the glaucoma specialist to remain in overall control while reducing the risk that patients are treated or followed-up unnecessarily. Demand for glaucoma appointments can be reduced allowing scarce medical resources to be directed to patients most in need.
doi:10.1136/bjophthalmol-2014-305588
PMCID: PMC4345905  PMID: 25336582
Epidemiology; Glaucoma; Telemedicine; Public health
34.  Does cognitive impairment influence outcomes from cataract surgery? Results from a 1-year follow-up cohort study 
Background/aims
To assess the impact of impaired cognition on visual outcomes 1 year following cataract surgery in a cohort of older people.
Methods
Participants aged 75 years or more with bilateral cataract and scheduled for cataract surgery were recruited consecutively. Cognition was assessed using the revised Addenbrooke's cognitive examination (ACE-R). Participants were divided into two groups: normal (ACE-R ≥88) and impaired cognition (ACE-R <88). Visual quality of life (VQOL) and logarithm of minimum angle of resolution visual acuity (VA) were assessed at baseline and 1 year following cataract surgery.
Results
Of 112 participants, 48 (43%) had normal cognition and 64 (57%) had impaired cognition. One year following cataract surgery participants in both groups had significant improvements in VQOL and VA. Visual outcomes at 1 year were significantly better in participants with normal cognition than in those with impaired cognition (95% CIs for difference 0.4–7.0 and 0.02–0.1, for VQOL and VA, respectively). Regression analyses correcting for potential confounders showed a relationship between baseline cognition and VA at 1 year (R2=0.30, p=0.001) and a possible relationship between baseline cognition and VQOL at 1 year (R2=0.41, p=0.01, this became insignificant after removal of outliers).
Conclusions
Patients with impaired cognition benefit from cataract surgery, but not to the same extent as patients with normal cognition.
doi:10.1136/bjophthalmol-2014-305657
PMCID: PMC4345983  PMID: 25287367
35.  Correlation between visual acuity and cognitive functions 
A possible association between visual acuity (VA) and dementia was investigated in 2716 subjects who were aged between 53 and 102 at first visit and had varying degrees of dementia. Better VA was found to be significantly correlated with a lower dementia level (person coefficient range 0.146–0.261 over 10 years of follow-up, all correlations are significant, p<0.0001) as well as with a higher global cognitive score (person coefficient range −0.254 to −0.318 over 10 years of follow-up, all correlations are significant, p<0.0001), a grade encompassing 19 different cognitive tests. This correlation remained significant after adjustment for age, years of education, gender, use of ophthalmic drugs and years of follow-up.
doi:10.1136/bjophthalmol-2013-304149
PMCID: PMC4060517  PMID: 24169658
36.  Quality of Life and Cancer-Related Needs in Patients with Choroidal Melanoma 
The British journal of ophthalmology  2013;97(11):10.1136/bjophthalmol-2013-303635.
Aims
To assess quality of life (QoL) indices and their associations with treatment modality, sociodemographics, and cancer-related needs in choroidal melanoma patients.
Methods
Patients (N=99) treated at the University of California, Los Angeles for choroidal melanoma within the prior 5 years (M = 2.05) completed questionnaires assessing demographics, cancer-related needs, vision-specific QoL, depressive symptoms, and concern about recurrence. Visual acuity, comorbidities, treatment modality (radiotherapy, enucleation), and years since diagnosis were gathered from medical records. Primary analyses were multiple regressions.
Results
Although concern about cancer recurrence was elevated, QoL was better than in other oncology samples and comparable to healthy samples on some outcomes. Enucleation was associated with worse vision-specific QoL, and presence of comorbid diseases was associated with worse vision-specific QoL, depressive symptoms, and concern about cancer recurring (all ps<.05). Patients who experienced at least one stressful life event in the past year (versus no events) reported more depressive symptoms (p<.01). Report of more unmet cancer needs was associated with worse vision-specific QoL, depressive symptoms and more concern about recurrence (all ps<.05), uniquely explaining 5%–12% of the variance.
Conclusions
For choroidal melanoma patients an average of two years after treatment, number of physical comorbidities and unmet cancer needs were the strongest correlates of poorer QoL.
doi:10.1136/bjophthalmol-2013-303635
PMCID: PMC3838665  PMID: 24037609
quality of life; choroid neoplasms; cancer
37.  Optic Nerve Head Morphology in Glaucoma Patients of African Descent is Strongly Correlated to Retinal Blood Flow 
The British journal of ophthalmology  2014;98(11):1551-1554.
BACKGROUND/AIMS
To examine the relationship between change in optic nerve head (ONH) morphology and retinal blood flow in patients with open-angle glaucoma (OAG) of African (AD) and European descent (ED) over three years.
METHODS
112 patients with OAG (29 AD; 83 ED) underwent assessment of ONH morphology using Heidelberg retinal tomography (HRT-III) and retinal blood flow using confocal scanning laser Doppler. Repeated measures analysis of covariance was used to compare baseline and 3-year measurements and Pearson correlations were calculated to evaluate the relationships.
RESULTS
In OAG patients of AD, change in superior mean retinal blood flow was strongly, negatively correlated with change in cup/disc (C/D) area ratio (r=−0.78, p=0.020) and cup area (r=−0.75, p=0.0283) and strongly, positively correlated with change in rim area (r=0.74, p=0.0328) over three years. In OAG patients of AD, change in inferior mean retinal blood flow was strongly, negatively correlated with changes in C/D area ratio (r=−0.88, p=0.0156) and linear C/D ratio (r=−0.86, p=0.0265) over three years. In OAG patients of ED, these correlations were weak and did not reach statistical significance.
DISCUSSION
OAG patients of AD may have a stronger vascular component to their glaucoma pathophysiology than patients of ED.
doi:10.1136/bjophthalmol-2013-304393
PMCID: PMC4206567  PMID: 24964797
glaucoma; retina; optic nerve
38.  A new method using xenogeneicacellular dermal matrix in the reconstruction of lacrimal drainage 
The British Journal of Ophthalmology  2014;98(11):1583-1587.
Aims
To prospectively evaluate the reliability and efficacy of a new treatment for the reconstruction of the lacrimal duct using a new histo-engineered material, xenogeneic (bovine) acellular dermal matrix.
Method
Five patients (five eyes) with partial or total absence of the lacrimal duct were included in the study. Four patients (four eyes) suffered from traumatic injuries to the lacrimal duct and one patient (one eye) had congenital absence of the lacrimal drainage system. A pedal graft of conjunctiva was taken from the fornix area and rolled into a tube structure after being attached to the acellular dermal matrix.
Results
The average duration of follow-up for the patients was 7.2 months (ranging from 6 to 12 months). After surgery, the new duct in the nasal cavity could be observed above the middle turbinate by nasal endoscopy. Patency was confirmed by pressing in the area of the lacrimal sac and visualising air bubbles in the nasal cavity. Additionally, the meatus above the middle turbinate of the nasal cavity was stained and visualised after patients underwent Jones dye test 1 (JDT1). Five tear ducts proved to be effective through irrigation testing and epiphora symptoms were alleviated in all cases.
Conclusions
The newly reconstructed lacrimal duct, formed by the shift of autogenous conjunctival petal and the attachment of acellular dermal matrix, was successful in all five cases and suggests a new solution for the complex lacrimal duct lesion and congenital anomalies of the lacrimal duct.
doi:10.1136/bjophthalmol-2014-304932
PMCID: PMC4215284  PMID: 25271909
Lacrimal duct; Graft
40.  Early diagnosis of keratoconus: what difference is it making? 
The British Journal of Ophthalmology  2014;98(11):1465-1466.
doi:10.1136/bjophthalmol-2014-305120
PMCID: PMC4215270  PMID: 24759873
Cornea; Vision
41.  Concordance between common dry eye diagnostic tests 
Purpose
Large variations in results of diagnostic tests for mild to moderate dry eye are widely recognised. The purpose of this study was to assess if there was concordance between common dry eye diagnostic tests.
Methods
A total of 91 subjects were recruited to the study. The tear film and ocular surface were evaluated using the phenol red thread test, tear break up time (TBUT), biomicroscopic examination and impression cytological (IC) assessment of conjunctival goblet cells. Dry eye symptoms were assessed using McMonnies questionnaire and statistical correlations between all tests were assessed.
Results
This study cohort did not include severe aqueous deficient dry eye patients as determined by the phenol red thread test (PRT). A statistically significant difference was noted between PRT results and all other tests (***P ≤ 0.001). Only meibomian gland pathology, McMonnies questionnaire, reduced goblet cell density and TBUT (≤7 seconds) demonstrated correlation determined by McNemar’s test.
Conclusion
A correlation was only found between tests assessing lipid/mucous deficiency (meibomian gland evaluation, goblet cells density, TBUT, and McMonnies questionnaire).
doi:10.1136/bjo.2007.131722
PMCID: PMC4211111  PMID: 18782801
correlation dry eye diagnostic tests
42.  OCT for glaucoma diagnosis, screening and detection of glaucoma progression 
The British Journal of Ophthalmology  2013;98(Suppl 2):ii15-ii19.
Optical coherence tomography (OCT) is a commonly used imaging modality in the evaluation of glaucomatous damage. The commercially available spectral domain (SD)-OCT offers benefits in glaucoma assessment over the earlier generation of time domain-OCT due to increased axial resolution, faster scanning speeds and has been reported to have improved reproducibility but similar diagnostic accuracy. The capabilities of SD-OCT are rapidly advancing with 3D imaging, reproducible registration, and advanced segmentation algorithms of macular and optic nerve head regions. A review of the evidence to date suggests that retinal nerve fibre layer remains the dominant parameter for glaucoma diagnosis and detection of progression while initial studies of macular and optic nerve head parameters have shown promising results. SD-OCT still currently lacks the diagnostic performance for glaucoma screening.
doi:10.1136/bjophthalmol-2013-304326
PMCID: PMC4208340  PMID: 24357497
Glaucoma
43.  Optical coherence tomography imaging of ocular and periocular tumours 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii40-ii46.
Optical coherence tomography (OCT) has become pivotal in the practice of ophthalmology. Similar to other ophthalmic subspecialties, ophthalmic oncology has also incorporated OCT into practice. Anterior segment OCT (AS-OCT), ultra-high resolution OCT (UHR-OCT), spectral domain OCT (SD-OCT) and enhanced depth imaging OCT (EDI-OCT), have all been described to be helpful in the diagnosis, treatment planning and monitoring response of ocular and periocular tumours. Herein we discuss the role of OCT including the advantages and limitations of its use in the setting of common intraocular and adnexal tumours.
doi:10.1136/bjophthalmol-2013-304299
PMCID: PMC4208341  PMID: 24599420
Imaging; Neoplasia; Pathology
44.  Optical coherence tomography in the preoperative and postoperative management of macular hole and epiretinal membrane 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii20-ii23.
Optical coherence tomography (OCT) imaging plays an essential role in the diagnosis and treatment of macular diseases, including those of the vitreomacular interface. OCT enables accurate diagnosis and differentiation of full thickness macular hole, lamellar macular hole and epiretinal membrane, with or without the presence of vitreomacular adhesion. This information enables earlier diagnosis and treatment when necessary, and can guide the choice of therapy. OCT is useful to facilitate discussions with patients and manage the visual expectations. Postoperatively, OCT can be helpful to optimise patient comfort and visual outcomes. As the technology continues to improve, OCT will become increasingly critical for all aspects of care for patients with macular hole and epiretinal membrane.
doi:10.1136/bjophthalmol-2013-304447
PMCID: PMC4208342  PMID: 24627250
Imaging; Macula; Vitreous; Retina
45.  Recent advances in OCT imaging of the lamina cribrosa 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii34-ii39.
The lamina cribrosa (LC) is believed to be the site of injury to retinal ganglion cell axons in glaucoma. The ability to visualise this structure has the potential to help increase our understanding of the disease and be useful in the early detection of glaucoma. While for many years the research on the LC was essentially dependent on histology and modelling, a number of recent advances in optical coherence tomography (OCT) have dramatically improved the ability to visualise the LC, such that it is now possible to image the LC in vivo in humans and animals. In this review, we highlight recent advances in OCT imaging of the LC, in the technology, processing and analysis, and discuss the impact that these will have on the ability to diagnose and monitor glaucoma, as well as to expand our understanding of its pathophysiology. With this manuscript, we aspire to share our excitement on the achievements and potential of recent developments as well as advise caution regarding the challenges that remain before imaging of the LC and optic nerve can be used routinely in clinical practice.
doi:10.1136/bjophthalmol-2013-304751
PMCID: PMC4208343  PMID: 24934221
Glaucoma; Imaging; Intraocular Pressure; Optic Nerve; Anatomy
46.  On improving the use of OCT imaging for detecting glaucomatous damage 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii1-ii9.
Aims
To describe two approaches for improving the detection of glaucomatous damage seen with optical coherence tomography (OCT).
Methods
The two approaches described were: one, a visual analysis of the high-quality OCT circle scans and two, a comparison of local visual field sensitivity loss to local OCT retinal ganglion cell plus inner plexiform (RGC+) and retinal nerve fibre layer (RNFL) thinning. OCT images were obtained from glaucoma patients and suspects using a spectral domain OCT machine and commercially available scanning protocols. A high-quality peripapillary circle scan (average of 50), a three-dimensional (3D) scan of the optic disc, and a 3D scan of the macula were obtained. RGC+ and RNFL thickness and probability plots were generated from the 3D scans.
Results
A close visual analysis of a high-quality circle scan can help avoid both false positive and false negative errors. Similarly, to avoid these errors, the location of abnormal visual field points should be compared to regions of abnormal RGC+ and RNFL thickness.
Conclusions
To improve the sensitivity and specificity of OCT imaging, high-quality images should be visually scrutinised and topographical information from visual fields and OCT scans combined.
doi:10.1136/bjophthalmol-2014-305156
PMCID: PMC4208344  PMID: 24934219
Glaucoma; Imaging; Optic Nerve; Psychophysics
47.  Characterisation of Schlemm's canal cross-sectional area 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii10-ii14.
Purpose
To compare three methods of Schlemm's canal (SC) cross-sectional area (CSA) measurement.
Methods
Ten eyes (10 healthy volunteers) were imaged three times using spectral-domain optical coherence tomography (Cirrus HD-OCT, Zeiss, Dublin, California, USA). Aqueous outflow vascular structures and SC collector channel ostia were used as landmarks to identify a reference location within the limbus. SC CSA was assessed within a 1 mm segment (±15 frames of the reference, 31 frames in all) by three techniques. (1) Using a random number table, SC CSA in five random frames from the set of 31 surrounding the reference were measured and averaged. (2) The most easily visualised SC location (subjective) was measured, and (3) SC CSA was measured in all 31 consecutive B-scans, and averaged. (comprehensive average, gold standard). Subjective and random CSAs were compared with the comprehensive by general estimating equation modelling, and structural equation modelling quantified agreement.
Results
The average from five random locations (4175±1045 µm2) was not significantly different than that obtained from the gold standard comprehensive assessment (4064±1308 µm2, p=0.6537). Subjectively located SC CSA (7614±2162 µm2) was significantly larger than the comprehensive gold standard SC CSA (p<0.0001). The average of five random frames produced significantly less bias than did subjective location, yielding a calibration line crossing the ‘no-bias’ line.
Discussion
Subjectively located SC CSA measurements produce high estimates of SC CSA. SC assessed by measuring five random locations estimate CSA was similar to the gold standard estimate.
doi:10.1136/bjophthalmol-2013-304629
PMCID: PMC4208345  PMID: 24590558
Aqueous humour; Imaging
48.  Optical coherence tomography shows retinal abnormalities associated with optic nerve disease 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii30-ii33.
Optical coherence tomography (OCT) of the macula in patients with primary optic neuropathy has revealed the presence of structural changes in the neurosensory retina in addition to the nerve fibre layer. Subretinal fluid has been documented in papilloedema and non-arteritic ischaemic optic neuropathy, and may account for decreased visual acuity in affected patients. Subretinal fluid has also been described from other causes of optic nerve head swelling including diabetic papillopathy and papillitis. Drugs used in the treatment of multiple sclerosis, such as corticosteroids and fingolimod can cause decreased vision due to central serous and cystoid macular oedema sometimes confused with recurrent optic neuritis. A subset of patients with various types of optic atrophy show microcystic changes in the inner nuclear layer on spectral domain OCT imaging. The pathophysiology and visual significance of these retinal changes remain unclear, but may affect the diagnosis and management of optic nerve disorders.
doi:10.1136/bjophthalmol-2013-304301
PMCID: PMC4208346  PMID: 24627251
Optic Nerve; Imaging; Retina
49.  Optical coherence tomography imaging of macular oedema 
The British Journal of Ophthalmology  2014;98(Suppl 2):ii24-ii29.
Macular oedema (ME) occurs in a wide variety of pathological conditions and accounts for different degrees of vision loss. Early detection of ME is therefore critical for diagnosis and therapeutic management. Optical coherence tomography (OCT) is a non-contact, diagnostic method that uses infrared light, which allows the analysis of the retinal structure by means of high-resolution tomographic cross sections. The identification, localisation, quantification and long-term follow-up of fluid collections are the most important capabilities of OCT. Since the introduction of OCT in clinical practice, it has become an invaluable diagnostic tool and different patterns of ME have been reported. The purpose of this manuscript is to review OCT profiles of ME according to the aetiology and describe what has been reported regarding intraretinal features in vivo.
doi:10.1136/bjophthalmol-2014-305305
PMCID: PMC4208347  PMID: 24934220
Macula; Imaging; Retina; Vitreous
50.  Examining the Association Between Age-Related Macular Degeneration and Motor Vehicle Collision Involvement: A Retrospective Cohort Study 
The British journal of ophthalmology  2013;97(9):10.1136/bjophthalmol-2013-303601.
Background
Little is known about motor vehicle collision (MVC) risk in older drivers with age-related macular degeneration (AMD). The purpose of this study is to examine associations between MVC involvement and AMD presence and severity.
Methods
In a retrospective cohort study pooling the samples from four previous studies, we examined associations between MVC rate and older drivers with early, intermediate, or advanced AMD as compared to those in normal eye health. MVC data were based on accident reports obtained from the state agency that compiles this information.
Results
MVC rate was highest among those in normal eye health and progressively declined among those with early and intermediate disease, and then increased for those with advanced AMD. However, only for drivers with intermediate AMD was the MVC rate significantly different (lower) as compared to those in normal eye health, regardless of whether the rate was defined in terms of person-years (RR 0.34, 95% CI 0.13–0.89) or person-miles (RR 0.35, 95% CI 0.13–0.91) of driving.
Conclusion
These results suggest that older drivers with intermediate AMD have a reduced risk of collision involvement. Further research should investigate whether self-regulatory driving practices by these drivers (avoiding challenging driving situations) underlies this reduced risk.
doi:10.1136/bjophthalmol-2013-303601
PMCID: PMC3837568  PMID: 23832967
driving; age-related macular degeneration; vision impairment

Results 26-50 (296)