ameet shah | King's College London (original) (raw)
Papers by ameet shah
Cochrane Database of Systematic Reviews, 2020
PLOS Genetics, 2020
Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure ... more Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure glaucoma (PACG) but the causative gene is not known. We used genetic linkage and whole genome sequencing to identify Spermatogenesis Associated Protein 13, SPATA13 (NM_001166271; NP_001159743, SPATA13 isoform I), also known as ASEF2 (Adenomatous polyposis coli-stimulated guanine nucleotide exchange factor 2), as the causal gene for PACG in a large seven-generation white British family showing variable expression and incomplete penetrance. The 9 bp deletion, c.1432_1440del; p.478_480del was present in all affected individuals with angle-closure disease. We show ubiquitous expression of this transcript in cell lines derived from human tissues and in iris, retina, retinal pigment and ciliary epithelia, cornea and lens. We also identified eight additional mutations in SPATA13 in a cohort of 189 unrelated PACS/PAC/PACG samples. This gene encodes a 1277 residue protein which localises to the nucleus with partial co-localisation with nuclear speckles. In cells undergoing mitosis SPATA13 isoform I becomes part of the kinetochore complex co-localising with two kinetochore markers, polo like kinase 1 (PLK-1) and centrosome-associated protein E (CENP-E). The 9 bp deletion reported in this study increases the RAC1-dependent guanine nucleotide exchange factors (GEF) activity. The increase in GEF activity was also observed in three other variants identified in this study. Taken together, our data suggest that SPATA13 is involved in the regulation of mitosis and the mutations
Acta Ophthalmologica, 2019
Investigative Opthalmology & Visual Science, 2014
PURPOSE. To explore changes in iris curvature over a 2-year period. To investigate associations b... more PURPOSE. To explore changes in iris curvature over a 2-year period. To investigate associations between iris curvature and ocular biometric parameters. To explore relationships between a number of nonocular measurements and ocular biometric parameters. METHODS. Schoolboys enrolled 2 years previously were invited to return for anterior segment optical coherence tomography, corneal hysteresis (CH), corneal resistance factor (CRF), and axial biometric measurements. Refractive error was assessed and measures of height, weight, waist circumference, digit ratio, and percentage body fat taken. RESULTS. Mean spherical equivalent refraction reduced by 0.76 diopters and mean iris concavity, defined as a measurement of less than or equal to À0.1 mm, increased by 0.018 mm at distance fixation and 0.04 mm on accommodation. Compared with 2 years previously, the prevalence of iris concavity increased from 24% to 32% on distance fixation and from 65% to 84% on accommodation. Variables significantly associated with nonaccommodating iris curvature were anterior chamber depth (ACD, P ¼ 0.029) and mean scleral spur angle (P ¼ 0.0001). Variables significantly associated with accommodating iris curvature were ACD (P ¼ 0.02), lens vault (P ¼ 0.047), and scleral spur angle (P < 0.0001). Significant association was again found between CH and accommodating spur-to-spur distance (R 2 ¼ 0.13, P ¼ 0.007). CONCLUSIONS. Iris concavity was more prevalent in this cohort of schoolboys than 2 years earlier. The degree of concavity remains related to ACD and lens vault. The association between spur-to-spur distance and CH was similar at baseline and after 2 years.
Ophthalmology, 2007
Ophthalmology Clinics of North America, Volume 114, Issue 6, Pages 1235, June 2007, Authors:Saura... more Ophthalmology Clinics of North America, Volume 114, Issue 6, Pages 1235, June 2007, Authors:Saurabh Jain, MRCOphth; Ameet Shah, MRCOphth; James Deane, FRCOphth. ... Giant Cell Arteritis. Saurabh Jain, MRCOphth, Ameet Shah, MRCOphth, James Deane, FRCOphth. ...
Investigative Opthalmology & Visual Science, 2014
PURPOSE. Pigment dispersion syndrome is associated with iris concavity. This study investigated t... more PURPOSE. Pigment dispersion syndrome is associated with iris concavity. This study investigated the prevalence of iris concavity, defined as a measurement of À0.1 mm, in a cohort of 10-to 12-year-old boys, and explored the relationship between iris curvature and anterior segment biometry. Associations with corneal biomechanical parameters also were explored. METHODS. A cohort of school boys (n ¼ 96) was recruited from a local school. Anterior segment optical coherence tomography (AS-OCT) was performed under accommodative and nonaccommodative conditions, and iris curvature quantified. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with the ocular response analyzer (ORA). Noncontact axial biometry was performed using laser interferometry. RESULTS. The prevalence of iris concavity was 24% on distance fixation, increasing to 65% on accommodation. Variables significantly associated with nonaccommodating iris curvature were lens vault (P ¼ 0.02) and mean keratometry (P ¼ 0.02). For both variables acting jointly, R 2 ¼ 0.30. Variables associated significantly with accommodating iris curvature were anterior chamber depth (P ¼ 0.009), lens vault (P ¼ 0.049), and mean scleral spur angle (P < 0.0001). For these three variables acting jointly, R 2 ¼ 0.33. Significant association was found between CH and spur-to-spur distance (R 2 ¼ 0.07, P ¼ 0.025). CONCLUSIONS. Iris concavity was a common finding in this cohort and related to anterior segment biometric parameters. Further work is required to clarify whether anatomical differences exist between iris concavity seen in the adolescent eye and that found in adults with pigment dispersion syndrome.
British Journal of Ophthalmology, 2009
The technique of placing a second instrument between the posterior capsule and nuclear fragment i... more The technique of placing a second instrument between the posterior capsule and nuclear fragment is generally encouraged because it intuitively provides added protection against capsule aspiration and rupture by the phaco tip.1 2 This is especially so when the last segment is being phacoemulsified. However, it has been shown in our recent study3 that significant leakage occurs via a side-port incision when a second instrument is used through it. In fact the majority of fluid used during phaco appears to be lost through wound leakage, and a significant proportion of this is through the second instrument sideport. This inevitably contributes to chamber destabilisation and posterior capsule fluctuation, and it follows that the risk of capsule aspiration is likely to be increased. Logically, therefore, chamber fluctuations and the chance of posterior capsular damage should be reduced if …
Ophthalmology, 2022
- To identify genetic variants associated with pigment dispersion syndrome and pigmentary glaucom... more - To identify genetic variants associated with pigment dispersion syndrome and pigmentary glaucoma in unrelated patients, and to further understand the genetic and potentially causal relationships between pigment dispersion syndrome and associated risk factors. - A two-stage genome-wide association meta-analysis with replication and subsequent in-silico analyses including Mendelian randomisation. - A total of 574 cases with pigmentary glaucoma and/or pigment dispersion syndrome and 52,627 controls of European descent. - Genome-wide association analyses were performed in four cohorts and meta-analysed in three stages: first a discovery meta-analysis of three cohorts, secondly replication was performed in the fourth cohort, thirdly all four cohorts were meta-analysed to increase statistical power. Two-sample Mendelian randomisation was utilised to determine whether refractive error and intraocular pressure exert causal effects over pigment dispersion syndrome. - Significant association was present at two novel loci for pigment dispersion syndrome/pigmentary glaucoma. These loci and follow up analyses implicate the genes GSAP (lead SNP: rs9641220, p=6.0x10-10) and GRM5/TYR (lead SNP: rs661177, p=3.9x10-9) as important factors in disease risk. Mendelian randomisation showed significant evidence that negative refractive error (myopia) exerts a direct causal effect over pigment dispersion syndrome (p=8.9x10-7). A) The association of genetic variants with pigment dispersion syndrome and, B) whether myopia exerts causal effects over pigment dispersion syndrome. - Common SNPs relating to the GSAP and GRM5/TYR genes are associated risk factors for the development of pigment dispersion syndrome and pigmentary glaucoma. Although myopia is a known risk factor, this study is the first to use genetic data to demonstrate that myopia is, in part, a cause of pigment dispersion syndrome and pigmentary glaucoma.
Investigative Ophthalmology & Visual Science, 2011
BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intrao... more BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intraocular pressure (IOP), yet there has been no previous placebo-controlled medical treatment trial assessing vision function preservation. Observation periods in previous (unmasked) trials assessing visual function have typically been at least 5 years. The aim of this study was to assess vision preservation by latanoprost treatment compared to placebo. METHODS In this randomised, triple-masked, placebo-controlled trial, patients with newly-diagnosed OAG were enrolled at 10 UK centres (tertiary referral centres, teaching hospitals, and district general hospitals) between Feb 2007 and Mar 2010. Eligible patients were randomly allocated (1:1) to receive either latanoprost 0·005% or placebo eye drops, provided in identical bottles, once daily to both eyes. Randomization was in permuted blocks stratified by participating centre. The primary hypothesis was that latanoprost treatment reduces incid...
BMC Ophthalmology, 2015
Mydriasert is an insoluble ophthalmic insert indicated for mydriasis prior to cataract surgery, w... more Mydriasert is an insoluble ophthalmic insert indicated for mydriasis prior to cataract surgery, which gradually releases the active ingredients: tropicamide (0.25 mg) and phenylephrine (5.38 mg). This study aimed to evaluate the cost of Mydriasert compared with conventional mydriatic eye drops to induce pupil dilation prior to cataract surgery using a budget impact model. A cohort-based, decision tree, budget impact model was developed to estimate the drug, consumable and staff costs for achieving mydriasis with Mydriasert compared to mydriatic eye drops (tropicamide [1%] plus phenylephrine [10%]). Insights from structured interviews with clinicians (n = 5) experienced in using both Mydriasert and mydriatic eye drops and results from the current clinical study of patients undergoing cataract surgery (n = 144) at a Greater London district general hospital were used to obtain key input parameters for the model, and to validate the model approach. The base case analysis in a cohort of 1763 patients undergoing cataract surgery showed that when Mydriasert substituted mydriatic eye drops, annual total costs decreased by 18% and annual total nurse time decreased from 235.1 hours to 44.1 hours over one year (2012-2013). This study demonstrated that despite its higher unit cost than mydriatic eye drops, Mydriasert resulted in overall savings in health-care costs, mainly associated with reduced nursing time. The economic model developed could assist National Health Service managers and local payers to estimate the budget impact of the introduction of Mydriasert into different clinical settings.
The exact pathogenesis of visual hallucinations in Parkinson&amp;amp;amp;amp;amp;amp;amp;... more The exact pathogenesis of visual hallucinations in Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s disease is not known but an integrated model has been proposed that includes impaired visual input and central visual processing, impaired brainstem regulation of sleep-wake cycle with fluctuating vigilance, intrusion of rapid eye movement dream imagery into wakefulness and emergence of internally generated imagery, cognitive dysfunction and influence of dopaminergic drugs. In a clinical study, we assessed motor and non-motor function, including sleep, mood, autonomic and global, frontal and visuoperceptive cognitive function in patients with and without visual hallucinations. A subgroup of patients underwent detailed ophthalmological assessment. In a separate pathological study, histological specimens were obtained from cases of pathologically proven Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s disease and a retrospective case notes review was made for reporting of persistent formed visual hallucinations. An assessment of Lewy body and Lewy neurite pathology…
British Journal of …, 2011
Lancet, Jan 18, 2014
Background Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intr... more Background Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intraocular pressure, but to our knowledge no placebo-controlled trials have assessed visual function preservation, and the observation periods of previous (unmasked) trials have typically been at least 5 years. We assessed vision preservation in patients given latanoprost compared with those given placebo.
Survey of Ophthalmology, 2013
We review the inheritance patterns and recent genetic advances in the study of pigment dispersion... more We review the inheritance patterns and recent genetic advances in the study of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). Both conditions may result from combinations of mutations in more than one gene or from common variants in many genes, each contributing small effects. We discuss the currently known genetic loci that may be related with PDS/PG in humans, the role of animal models in expanding our understanding of the genetic basis of PDS, the genetic factors underlying the risk for conversion from PDS to PG and the relationship between genetic and environmental--as well as anatomical--risk factors.
Strabismus, 2007
Amyloidosis is a multi-system disease characterised by the intracellular deposition of beta-pleat... more Amyloidosis is a multi-system disease characterised by the intracellular deposition of beta-pleated sheets of amyloid. It can involve the eye, orbit and ocular adnexae. We describe a case of a 58-year-old woman presenting to the eye department with external ophthalmoplegia, including the findings of various investigations. The spectrum of ocular amyloidosis is discussed. Amyloidosis may be the underlying diagnosis in some cases of external ophthalmoplegia with findings atypical to other systemic disease.
Retinal Cases & Brief Reports, 2008
To report a patient presenting with a symptomatic retinal pigment epithelial detachment (RPED) th... more To report a patient presenting with a symptomatic retinal pigment epithelial detachment (RPED) that resolved after successful treatment of a slow flow dural carotid cavernous fistula (CCF). Possible pathophysiological mechanisms are discussed. Interventional case report. A 69-year-old female presented with left uniocular distortion, confirmed on fluorescein and indocyanine green angiography to be secondary to a non-vascularised serous RPED. Further examination revealed a long standing left VI nerve palsy, mild proptosis and conjunctival injection. Magnetic resonance and cranial angiography confirmed the presence of a dural CCF. Surgical closure of the CCF resulted in a rapid resolution of the clinical signs and improvement in visual symptoms. Patients with serous RPED and other signs or symptoms of a CCF may warrant neuroimaging of the orbit and/or angiography to evaluate for CCF, as correct diagnosis may lead to an excellent visual outcome.
Ophthalmology, 2013
Objective: The United Kingdom Glaucoma Treatment Study (UKGTS) tests the hypothesis that treatmen... more Objective: The United Kingdom Glaucoma Treatment Study (UKGTS) tests the hypothesis that treatment with a topical prostaglandin analog, compared with placebo, reduces the frequency of visual field (VF) deterioration events in patients with open-angle glaucoma (OAG) by 50% over a 2-year period. Additional goals are to evaluate study power with novel clinical trial outcomes: (1) VF deterioration velocity and (2) VF and quantitative imaging measurements modeled as joint outcomes.
Cochrane Database of Systematic Reviews, 2020
PLOS Genetics, 2020
Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure ... more Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure glaucoma (PACG) but the causative gene is not known. We used genetic linkage and whole genome sequencing to identify Spermatogenesis Associated Protein 13, SPATA13 (NM_001166271; NP_001159743, SPATA13 isoform I), also known as ASEF2 (Adenomatous polyposis coli-stimulated guanine nucleotide exchange factor 2), as the causal gene for PACG in a large seven-generation white British family showing variable expression and incomplete penetrance. The 9 bp deletion, c.1432_1440del; p.478_480del was present in all affected individuals with angle-closure disease. We show ubiquitous expression of this transcript in cell lines derived from human tissues and in iris, retina, retinal pigment and ciliary epithelia, cornea and lens. We also identified eight additional mutations in SPATA13 in a cohort of 189 unrelated PACS/PAC/PACG samples. This gene encodes a 1277 residue protein which localises to the nucleus with partial co-localisation with nuclear speckles. In cells undergoing mitosis SPATA13 isoform I becomes part of the kinetochore complex co-localising with two kinetochore markers, polo like kinase 1 (PLK-1) and centrosome-associated protein E (CENP-E). The 9 bp deletion reported in this study increases the RAC1-dependent guanine nucleotide exchange factors (GEF) activity. The increase in GEF activity was also observed in three other variants identified in this study. Taken together, our data suggest that SPATA13 is involved in the regulation of mitosis and the mutations
Acta Ophthalmologica, 2019
Investigative Opthalmology & Visual Science, 2014
PURPOSE. To explore changes in iris curvature over a 2-year period. To investigate associations b... more PURPOSE. To explore changes in iris curvature over a 2-year period. To investigate associations between iris curvature and ocular biometric parameters. To explore relationships between a number of nonocular measurements and ocular biometric parameters. METHODS. Schoolboys enrolled 2 years previously were invited to return for anterior segment optical coherence tomography, corneal hysteresis (CH), corneal resistance factor (CRF), and axial biometric measurements. Refractive error was assessed and measures of height, weight, waist circumference, digit ratio, and percentage body fat taken. RESULTS. Mean spherical equivalent refraction reduced by 0.76 diopters and mean iris concavity, defined as a measurement of less than or equal to À0.1 mm, increased by 0.018 mm at distance fixation and 0.04 mm on accommodation. Compared with 2 years previously, the prevalence of iris concavity increased from 24% to 32% on distance fixation and from 65% to 84% on accommodation. Variables significantly associated with nonaccommodating iris curvature were anterior chamber depth (ACD, P ¼ 0.029) and mean scleral spur angle (P ¼ 0.0001). Variables significantly associated with accommodating iris curvature were ACD (P ¼ 0.02), lens vault (P ¼ 0.047), and scleral spur angle (P < 0.0001). Significant association was again found between CH and accommodating spur-to-spur distance (R 2 ¼ 0.13, P ¼ 0.007). CONCLUSIONS. Iris concavity was more prevalent in this cohort of schoolboys than 2 years earlier. The degree of concavity remains related to ACD and lens vault. The association between spur-to-spur distance and CH was similar at baseline and after 2 years.
Ophthalmology, 2007
Ophthalmology Clinics of North America, Volume 114, Issue 6, Pages 1235, June 2007, Authors:Saura... more Ophthalmology Clinics of North America, Volume 114, Issue 6, Pages 1235, June 2007, Authors:Saurabh Jain, MRCOphth; Ameet Shah, MRCOphth; James Deane, FRCOphth. ... Giant Cell Arteritis. Saurabh Jain, MRCOphth, Ameet Shah, MRCOphth, James Deane, FRCOphth. ...
Investigative Opthalmology & Visual Science, 2014
PURPOSE. Pigment dispersion syndrome is associated with iris concavity. This study investigated t... more PURPOSE. Pigment dispersion syndrome is associated with iris concavity. This study investigated the prevalence of iris concavity, defined as a measurement of À0.1 mm, in a cohort of 10-to 12-year-old boys, and explored the relationship between iris curvature and anterior segment biometry. Associations with corneal biomechanical parameters also were explored. METHODS. A cohort of school boys (n ¼ 96) was recruited from a local school. Anterior segment optical coherence tomography (AS-OCT) was performed under accommodative and nonaccommodative conditions, and iris curvature quantified. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with the ocular response analyzer (ORA). Noncontact axial biometry was performed using laser interferometry. RESULTS. The prevalence of iris concavity was 24% on distance fixation, increasing to 65% on accommodation. Variables significantly associated with nonaccommodating iris curvature were lens vault (P ¼ 0.02) and mean keratometry (P ¼ 0.02). For both variables acting jointly, R 2 ¼ 0.30. Variables associated significantly with accommodating iris curvature were anterior chamber depth (P ¼ 0.009), lens vault (P ¼ 0.049), and mean scleral spur angle (P < 0.0001). For these three variables acting jointly, R 2 ¼ 0.33. Significant association was found between CH and spur-to-spur distance (R 2 ¼ 0.07, P ¼ 0.025). CONCLUSIONS. Iris concavity was a common finding in this cohort and related to anterior segment biometric parameters. Further work is required to clarify whether anatomical differences exist between iris concavity seen in the adolescent eye and that found in adults with pigment dispersion syndrome.
British Journal of Ophthalmology, 2009
The technique of placing a second instrument between the posterior capsule and nuclear fragment i... more The technique of placing a second instrument between the posterior capsule and nuclear fragment is generally encouraged because it intuitively provides added protection against capsule aspiration and rupture by the phaco tip.1 2 This is especially so when the last segment is being phacoemulsified. However, it has been shown in our recent study3 that significant leakage occurs via a side-port incision when a second instrument is used through it. In fact the majority of fluid used during phaco appears to be lost through wound leakage, and a significant proportion of this is through the second instrument sideport. This inevitably contributes to chamber destabilisation and posterior capsule fluctuation, and it follows that the risk of capsule aspiration is likely to be increased. Logically, therefore, chamber fluctuations and the chance of posterior capsular damage should be reduced if …
Ophthalmology, 2022
- To identify genetic variants associated with pigment dispersion syndrome and pigmentary glaucom... more - To identify genetic variants associated with pigment dispersion syndrome and pigmentary glaucoma in unrelated patients, and to further understand the genetic and potentially causal relationships between pigment dispersion syndrome and associated risk factors. - A two-stage genome-wide association meta-analysis with replication and subsequent in-silico analyses including Mendelian randomisation. - A total of 574 cases with pigmentary glaucoma and/or pigment dispersion syndrome and 52,627 controls of European descent. - Genome-wide association analyses were performed in four cohorts and meta-analysed in three stages: first a discovery meta-analysis of three cohorts, secondly replication was performed in the fourth cohort, thirdly all four cohorts were meta-analysed to increase statistical power. Two-sample Mendelian randomisation was utilised to determine whether refractive error and intraocular pressure exert causal effects over pigment dispersion syndrome. - Significant association was present at two novel loci for pigment dispersion syndrome/pigmentary glaucoma. These loci and follow up analyses implicate the genes GSAP (lead SNP: rs9641220, p=6.0x10-10) and GRM5/TYR (lead SNP: rs661177, p=3.9x10-9) as important factors in disease risk. Mendelian randomisation showed significant evidence that negative refractive error (myopia) exerts a direct causal effect over pigment dispersion syndrome (p=8.9x10-7). A) The association of genetic variants with pigment dispersion syndrome and, B) whether myopia exerts causal effects over pigment dispersion syndrome. - Common SNPs relating to the GSAP and GRM5/TYR genes are associated risk factors for the development of pigment dispersion syndrome and pigmentary glaucoma. Although myopia is a known risk factor, this study is the first to use genetic data to demonstrate that myopia is, in part, a cause of pigment dispersion syndrome and pigmentary glaucoma.
Investigative Ophthalmology & Visual Science, 2011
BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intrao... more BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intraocular pressure (IOP), yet there has been no previous placebo-controlled medical treatment trial assessing vision function preservation. Observation periods in previous (unmasked) trials assessing visual function have typically been at least 5 years. The aim of this study was to assess vision preservation by latanoprost treatment compared to placebo. METHODS In this randomised, triple-masked, placebo-controlled trial, patients with newly-diagnosed OAG were enrolled at 10 UK centres (tertiary referral centres, teaching hospitals, and district general hospitals) between Feb 2007 and Mar 2010. Eligible patients were randomly allocated (1:1) to receive either latanoprost 0·005% or placebo eye drops, provided in identical bottles, once daily to both eyes. Randomization was in permuted blocks stratified by participating centre. The primary hypothesis was that latanoprost treatment reduces incid...
BMC Ophthalmology, 2015
Mydriasert is an insoluble ophthalmic insert indicated for mydriasis prior to cataract surgery, w... more Mydriasert is an insoluble ophthalmic insert indicated for mydriasis prior to cataract surgery, which gradually releases the active ingredients: tropicamide (0.25 mg) and phenylephrine (5.38 mg). This study aimed to evaluate the cost of Mydriasert compared with conventional mydriatic eye drops to induce pupil dilation prior to cataract surgery using a budget impact model. A cohort-based, decision tree, budget impact model was developed to estimate the drug, consumable and staff costs for achieving mydriasis with Mydriasert compared to mydriatic eye drops (tropicamide [1%] plus phenylephrine [10%]). Insights from structured interviews with clinicians (n = 5) experienced in using both Mydriasert and mydriatic eye drops and results from the current clinical study of patients undergoing cataract surgery (n = 144) at a Greater London district general hospital were used to obtain key input parameters for the model, and to validate the model approach. The base case analysis in a cohort of 1763 patients undergoing cataract surgery showed that when Mydriasert substituted mydriatic eye drops, annual total costs decreased by 18% and annual total nurse time decreased from 235.1 hours to 44.1 hours over one year (2012-2013). This study demonstrated that despite its higher unit cost than mydriatic eye drops, Mydriasert resulted in overall savings in health-care costs, mainly associated with reduced nursing time. The economic model developed could assist National Health Service managers and local payers to estimate the budget impact of the introduction of Mydriasert into different clinical settings.
The exact pathogenesis of visual hallucinations in Parkinson&amp;amp;amp;amp;amp;amp;amp;... more The exact pathogenesis of visual hallucinations in Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s disease is not known but an integrated model has been proposed that includes impaired visual input and central visual processing, impaired brainstem regulation of sleep-wake cycle with fluctuating vigilance, intrusion of rapid eye movement dream imagery into wakefulness and emergence of internally generated imagery, cognitive dysfunction and influence of dopaminergic drugs. In a clinical study, we assessed motor and non-motor function, including sleep, mood, autonomic and global, frontal and visuoperceptive cognitive function in patients with and without visual hallucinations. A subgroup of patients underwent detailed ophthalmological assessment. In a separate pathological study, histological specimens were obtained from cases of pathologically proven Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s disease and a retrospective case notes review was made for reporting of persistent formed visual hallucinations. An assessment of Lewy body and Lewy neurite pathology…
British Journal of …, 2011
Lancet, Jan 18, 2014
Background Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intr... more Background Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intraocular pressure, but to our knowledge no placebo-controlled trials have assessed visual function preservation, and the observation periods of previous (unmasked) trials have typically been at least 5 years. We assessed vision preservation in patients given latanoprost compared with those given placebo.
Survey of Ophthalmology, 2013
We review the inheritance patterns and recent genetic advances in the study of pigment dispersion... more We review the inheritance patterns and recent genetic advances in the study of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). Both conditions may result from combinations of mutations in more than one gene or from common variants in many genes, each contributing small effects. We discuss the currently known genetic loci that may be related with PDS/PG in humans, the role of animal models in expanding our understanding of the genetic basis of PDS, the genetic factors underlying the risk for conversion from PDS to PG and the relationship between genetic and environmental--as well as anatomical--risk factors.
Strabismus, 2007
Amyloidosis is a multi-system disease characterised by the intracellular deposition of beta-pleat... more Amyloidosis is a multi-system disease characterised by the intracellular deposition of beta-pleated sheets of amyloid. It can involve the eye, orbit and ocular adnexae. We describe a case of a 58-year-old woman presenting to the eye department with external ophthalmoplegia, including the findings of various investigations. The spectrum of ocular amyloidosis is discussed. Amyloidosis may be the underlying diagnosis in some cases of external ophthalmoplegia with findings atypical to other systemic disease.
Retinal Cases & Brief Reports, 2008
To report a patient presenting with a symptomatic retinal pigment epithelial detachment (RPED) th... more To report a patient presenting with a symptomatic retinal pigment epithelial detachment (RPED) that resolved after successful treatment of a slow flow dural carotid cavernous fistula (CCF). Possible pathophysiological mechanisms are discussed. Interventional case report. A 69-year-old female presented with left uniocular distortion, confirmed on fluorescein and indocyanine green angiography to be secondary to a non-vascularised serous RPED. Further examination revealed a long standing left VI nerve palsy, mild proptosis and conjunctival injection. Magnetic resonance and cranial angiography confirmed the presence of a dural CCF. Surgical closure of the CCF resulted in a rapid resolution of the clinical signs and improvement in visual symptoms. Patients with serous RPED and other signs or symptoms of a CCF may warrant neuroimaging of the orbit and/or angiography to evaluate for CCF, as correct diagnosis may lead to an excellent visual outcome.
Ophthalmology, 2013
Objective: The United Kingdom Glaucoma Treatment Study (UKGTS) tests the hypothesis that treatmen... more Objective: The United Kingdom Glaucoma Treatment Study (UKGTS) tests the hypothesis that treatment with a topical prostaglandin analog, compared with placebo, reduces the frequency of visual field (VF) deterioration events in patients with open-angle glaucoma (OAG) by 50% over a 2-year period. Additional goals are to evaluate study power with novel clinical trial outcomes: (1) VF deterioration velocity and (2) VF and quantitative imaging measurements modeled as joint outcomes.