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PMCID: PMC1771901
2.  Corrections for vol. 85, p. 822, and vol. 85, p. 921 
PMCID: PMC1723811
PMCID: PMC1722596
PMCID: PMC1722491
5.  Pro-inflammatory and anti-angiogenic effects of bisphosphonates on human cultured retinal pigment epithelial cells 
The British journal of ophthalmology  2013;97(8):1074-1078.
Bisphosphonates have been shown to induce ocular inflammatory diseases such as uveitis and scleritis, while being protective against angiogenic diseases like neovascular age-related macular degeneration (AMD). Therefore, we studied the effects of bisphosphonates on primary culture of human fetal retinal pigment epithelium (hRPE), a cell type known to secrete both inflammatory and angiogenic factors. Alendronate and etidronate were selected for this experiment as they are members of the two structurally different classes of bisphosphonates.
Primary cultures of hRPE were serum-starved for 24 h and then treated for 24 h with alendronate (0.0001, 0.1, 100 μM) or etidronate (0.01, 1 μM). Cell viability was measured using the MTT assay. Investigation of secreted cytokines induced by bisphosphonates was performed using a human cytokine 29-Plex Panel (Bio-Plex) array and the results were analysed with an analysis of variance (ANOVA).
Etidronate, at the lower concentration, significantly increased the expression of interleukin (IL)-6 (p=0.03) and IL-8 (p=0.04). At the higher concentration, etidronate significantly decreased the expression of granulocyte macrophage colony-stimulating factor (p=0.02) and basic fibroblast growth factor (bFGF) (p=0.02). Alendronate, at the highest concentration, significantly increased the expression of IL-8 (p=0.02) and decreased the expression of eotaxin (p=0.02). Alendronate also significantly decreased the expression of bFGF at all concentrations (p<0.05) and demonstrated a trend towards decreasing vascular endothelial growth factor expression at low concentration.
Alendronate and etidronate display dose dependent effects in hRPE cells. Alendronate and etidronate administration resulted in concentration dependent elevations in inflammatory cytokines. Furthermore, alendronate and etidronate administration resulted in reduced expression of a number of angiogenic factors. These findings may explain the increased incidence of ocular inflammation as well as the therapeutic effect on neovascular AMD which have been described with bisphosphonates.
PMCID: PMC3947383  PMID: 23766431 CAMSID: cams4155
6.  Association Between Retinal Thickness Measured by Spectral-Domain OCT and Rod-Mediated Dark Adaptation in Non-exudative Age-Related Maculopathy 
The British journal of ophthalmology  2011;95(10):10.1136/bjo.2010.190355.
To examine associations between retinal thickness and rod-mediated dark adaptation in older adults with non-exudative age-related maculopathy (ARM) or normal macular health.
A cross-sectional study was conducted with 74 adults ≥ 50 years old from the comprehensive ophthalmology and retina services of an academic eye center. ARM presence and disease severity in the enrollment eye was defined by the masked grading of stereofundus photos using the Clinical Age-Related Maculopathy (CARMS) grading system. High-definition, spectral-domain optical coherence tomography was used to estimate retinal thickness in a grid of regions in the macula. Rod-mediated dark adaptation, recovery of light sensitivity after a photo-bleach, was measured over a 20-minute period for a 500 nm target presented at 5° on the inferior vertical meridian. Main outcomes of interest were retinal thickness in the macula (μm) and parameters of rod-mediated dark adaptation (second slope, third slope, average sensitivity, final sensitivity).
In non-exudative disease retinal thickness was decreased in greater disease severity; thinner retina was associated with reductions in average and final rod-mediated sensitivity even after adjustment for age and visual acuity.
Impairment in rod-mediated dark adaptation in non-exudative ARM is associated with macular thinning.
PMCID: PMC3882115  PMID: 21289019
age-related maculopathy; dark adaptation; rod photoreceptors; optical coherence tomography
7.  Detection of retinal Nerve Fiber Layer Progression: Comparison of the Fast and Extended Modes of GDx Guided Progression Analysis 
The British journal of ophthalmology  2011;95(12):10.1136/bjophthalmol-2011-300354.
To compare detection of retinal nerve fiber layer (RNFL) changes using GDx Guided Progression Analysis (GPA) fast mode (which assumes fixed variability of a reference population) and extended mode (which measures individual variability) and to determine how they compare to photography and visual field based conventional methods for identifying glaucoma progression.
172 eyes from 117 participants in the Diagnostic Innovations in Glaucoma Study (DIGS) (12 healthy, 108 glaucoma suspect and 52 glaucoma eyes) with ≥4 GDx VCC visits and ≥3 good quality GDx VCC scans at each visit were included. Results: Agreement between the GDx GPA fast mode and GDx GPA extended mode was limited. The GDx fast mode and extended mode detected 15 and 18 eyes, respectively as “likely progression” but only 7 of them agreed. The conventional reference standard (stereophotograph based optic disc and/or visual field progression) identified 9 eyes as progressing of which 2 eyes were also identified by the GDx fast and 3 eyes by the extended mode. In the GDx fast mode, we found that the progression detection varies depending on which 2 scans are included in the baseline and follow-up images. Conclusion: There was limited agreement between the GDx fast mode and the GDx extended mode for progression detection, and between different scans included in the GDx fast mode progression analysis. Longer follow-up is needed to determine the proportion of eyes classified as “likely progression” by the GDx analysis that are early change and the proportion that are false positive results.
PMCID: PMC3855018  PMID: 21979898
glaucoma; imaging; diagnostic tests/investigation
12.  Change in function and spectacle-use 2 months after providing presbyopic spectacles in rural Tanzania 
The British journal of ophthalmology  2010;94(6):10.1136/bjo.2008.145607.
To examine near vision spectacle retention and use, and changes in self-reported and performance-based near vision, 2 months after the provision of near vision spectacles.
We conducted a 2-month follow-up of a population-based cohort of persons in rural Tanzania with near vision impairment who had received spectacles. Previously, residents age ≥40 years were examined for distance and near vision acuity. Those with presbyopia and hyperopia (‘functional presbyopia’) were given near vision spectacles. At baseline, subjects were asked to thread a needle; they were also asked questions on the perception of their near vision, ability to be independent and general health. At 2 months, subjects were again queried. Questions on the perceived affordability of replacement spectacles were also asked.
Of the 866 people provided with spectacles, 89% were seen at 2 months. Ninety-two per cent were still using the spectacles. Users were more likely to have any education (51.8%) than non-users (28.3%) (p<0.001). Only 31% had successfully threaded a needle at baseline, increasing to 91% at follow-up (p<0.001). Spectacle-users showed a significant improvement in satisfaction with near vision and ability to be independent, but no change in perception of general health, from baseline to follow-up. Men were more likely than women to be able to afford spectacles and to know where to get them.
Our cohort maintained their spectacles and reported tangible improvements associated with their use. The value of simple reading spectacles for those with near vision impairment suggests that a greater emphasis on near vision is needed in the Vision 2020 agenda.
PMCID: PMC3820013  PMID: 20508042
13.  Lithium treatment increases endothelial cell survival and autophagy in a mouse model of Fuchs endothelial corneal dystrophy 
The British journal of ophthalmology  2013;97(8):1068-1073.
Lithium previously has been shown to reduce both endoplasmic reticulum (ER) and oxidative stress in other in vitro and in vivo model systems. We investigated lithium’s effects on cultured corneal endothelial cells (CECs) exposed to these types of stress and in a mouse model of Fuchs endothelial corneal dystrophy (FECD).
Viability of cultured bovine CECs was determined by CellTiter-Glo. 2-month-old Col8a2Q455K/Q455K mutant (Q455K) and C57/Bl6 wild type animals were divided into two groups of 15 mice. Group I received 0.2% lithium carbonate-containing chow and Group II received control chow for 7 months. Confocal microscopy, transmission electron microscopy, real-time PCR (RT-PCR) and western blot were performed.
Pretreatment with lithium increased viability of cultured CECs after H2O2 and thapsigargin exposure compared with untreated controls (p<0.05). In vivo analysis of mouse corneal endothelium showed the following: endothelial cell density of lithium treated Q455K was higher than for untreated Q455K (p<0.01). transmission electron microscopy of lithium treated Q455K showed normal endothelium with enlarged autophagosomes, but untreated Q455K showed dilated ER and guttae. Compared with untreated Q455K endothelium, lithium treated Q455K showed significant upregulation of P62, Tmem74, Tm9sf1 and Tmem 166 by RT-PCR and of Atg5-12 conjugate by western blotting indicating that lithium treatment increased autophagy. Although RT-PCR unexpectedly showed increased levels of lithium response genes, caspase 12, Gsk3β, Arrβ2 and Impa1, western blotting showed the expected downregulation of Arrβ2 and Impa1 proteins in response to lithium treatment.
Lithium increases cultured CEC survival against ER and oxidative stress. Increased autophagy in lithium treated endothelium in a mouse model of FECD suggests autophagy may contribute to increased endothelial cell survival.
PMCID: PMC3793892  PMID: 23759441
14.  Penetrating keratoplasty using femtosecond laser-enabled keratoplasty with zig-zag incisions versus a mechanical trephine in patients with keratoconus 
The British journal of ophthalmology  2012;96(9):1195-1199.
This paper will compare the visual outcomes of two different penetrating keratoplasty (PKP) techniques in patients with keratoconus. It is a retrospective comparative surgical case series of 116 keratoconus patients (137 eyes) who had PKP at the Cornea Eye Institute, Beverly Hills, California, USA.
56 keratoconus patients (66 eyes) underwent femtosecond laser-enabled keratoplasty (FLEK) with a zig-zag incision configuration. Their visual parameters were compared with those of 60 patients (71 eyes) who had traditional blade mechanical trephination PKP. The range of follow-up was between 3 and 6 months. The main outcome measures included uncorrected visual acuity and best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent and topographically determined astigmatism.
BSCVA was significantly better as early as 3 months postoperatively (p=0.001) in the FLEK group. Visual recovery to 20/40 after 3 months was significantly better in the FLEK group (p<0.001). Topographic astigmatism was lower in the FLEK group, but the difference between the two groups reached significance only at 3 months of follow-up (p=0.001). Postoperative complications noted were not different between the two groups.
Faster visual recovery and better long-term outcomes were observed in keratoconus patients who had FLEK compared with those who had the mechanical PKP procedure with 6 months of postoperative follow-up.
PMCID: PMC3598602  PMID: 22790433
16.  Intraobserver variability of Confocal Scanning Laser Ophthalmoscopy with and without Stereo photographs 
The British journal of ophthalmology  2009;93(11):1552-1553.
PMCID: PMC3747839  PMID: 19854740
Glaucoma; confocal scanning laser ophthalmoscopy; screening; stereo photographs; intraobserver variability
17.  Comparison of two probe designs for determining intraocular oxygen distribution 
Alterations in intraocular oxygen levels are important contributors to, or indications of ocular disease. Polarographic electrodes and fiberoptic sensors (optodes) have been used to measure oxygen and to map the distribution of oxygen in animal models and in human eyes. A recent study reported the use of a commercial electrode to compare oxygen distribution in the vitreous of patients undergoing vitrectomy related to central retinal vein occlusion, macular hole or preretinal membrane. The results of this study were at variance with previous measures of oxygen distribution in the human vitreous using polarographic or optical sensors. To resolve this discrepancy, the present study compared measurements made in vitro or in animal eyes, using the electrode employed in the previous study or a fiberoptic sensor of different design.
Study design
Comparative in vitro and in vivo measurements.
In vitro, the two devices reported similar levels of oxygen, although the electrode consistently detected levels above the calculated values. In rabbit eyes, the electrode had a slow response time and was unable to detect oxygen gradients that were readily measured by the smaller optode. When the electrode was inserted into an eye of similar size to the human eye, the reference thermistor measured the temperature outside the eye, not in the vitreous.
The design of the electrode used in the previous study makes it unsuitable for measurements of oxygen distribution in the eye.
PMCID: PMC3736552  PMID: 20870641
18.  Glaucoma Discrimination of Segmented Cirrus Spectral Domain Optical Coherence Tomography (SD-OCT) Macular Scans 
The British journal of ophthalmology  2012;96(11):1420-1425.
To evaluate the glaucoma discriminating ability of macular retinal layers as measured by spectral-domain optical coherence tomography (SD-OCT).
Healthy, glaucoma suspect and glaucomatous subjects had a comprehensive ocular examination, visual field testing and SD-OCT imaging (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA) in the macular and optic nerve head regions. OCT macular scans were segmented into macular nerve fiber layer (mNFL), ganglion cell layer with inner plexiform layer (GCIP), ganglion cell complex (GCC) (composed of mNFL and GCIP), outer retinal complex (ORC) and total retina (TR). Glaucoma discriminating ability was assessed using the area under the receiver operator characteristic curve (AUC) for all macular parameters and mean circumpapillary (cp) RNFL. Glaucoma suspects and glaucoma subjects were grouped together for the calculation of AUCs.
Analysis was performed on 51 healthy, 49 glaucoma suspect and 63 glaucomatous eyes. The median visual field MD was −2.21dB (interquartile range (IQR): −6.92 to −0.35) for the glaucoma group, −0.32dB (IQR: −1.22 to 0.73) for the suspect group and −0.18dB (IQR: −0.92 to 0.71) for the healthy group. Highest age adjusted AUCs for discriminating between healthy and glaucomatous eyes were found for average GCC and GCIP (AUC=0.901 and 0.900, respectively), and their sectoral measurements: infero-temporal (0.922 and 0.913), inferior (0.904 and 0.912) and supero-temporal (0.910 and 0.897). These values were similar to the discriminating ability of the mean cpRNFL (AUC=0.913). Comparison of these AUCs did not yield any statistically significant difference (all p>0.05). Similar discrimination performance but with slight reduction in AUCs was achieved for comparison between healthy and the combination of glaucoma and glaucoma suspect eyes.
SD-OCT GCIP and GCC measurements showed similar glaucoma diagnostic ability and was comparable with that of cpRNFL.
PMCID: PMC3721629  PMID: 22914498
19.  Detection of Glaucoma Progression by Population and Individual Derived Variability Criteria 
Ocular imaging devices provide quantitative structural information that might improve glaucoma progression detection. This study examined scanning laser polarimetry (SLP) population-derived versus individual-derived cut-off criteria for detecting progression.
Forty-eight healthy, glaucoma suspect and glaucoma subjects, providing 76 eyes were used. All subjects had reliable visual field (VF) and SLP scans acquired at the same visits from ≥ 4 visits. VF progression was defined by guided progression analysis (GPA) and by the VF index (VFI). SLP measurements were analyzed by fast mode (FM) GPA, compared to the population rate of progression, and extended mode (EM) GPA, compared to the individual variability. The agreement between progression detection methods was measured.
Poor agreement was observed between progression defined by VF and FM and EM. The difference in TSNIT average rate of change between VF defined progressors and non-progressors for both FM (p=0.010) and EM (p=0.015) was statistically significant.
There is poor agreement between VF and SLP progression regardless of the use of population derived or individual variability criteria. The best SLP progression detection method could not be ascertained, therefore, acquiring three SLP scans per visit is recommended.
PMCID: PMC3721630  PMID: 23203702
Scanning laser polarimetry; glaucoma progression
20.  Macula assessment using optical coherence tomography for glaucoma diagnosis 
The British journal of ophthalmology  2012;96(12):1452-1455.
Optical coherence tomography (OCT) is an interferometry-based imaging modality that generates high-resolution cross-sectional images of the retina. Circumpapillary retinal nerve fiber layer (cpRNFL) and optic nerve head assessments are the mainstay of glaucomatous structural measurements in OCT. However, because these measurements are not always available or precise, it would be useful to have another reliable indicator. The macula has been suggested as an alternative scanning location for glaucoma diagnosis. Using time-domain (TD-) OCT, macular measurements have shown to provide good glaucoma diagnostic capabilities. With the adoption of spectral-domain OCT, which allows a higher image resolution than TD-OCT, segmentation of inner macular layers becomes possible. These layers are specifically prone to glaucomatous damage and thickness measurements show a comparable performance to that of glaucomatous cpRNFL measurements. The role of macular measurements for detection of glaucoma progression is still under investigation. More sophisticated measurement and analysis tools that can amplify the advantages of macular measurements are expected. For example, improvement of image quality would allow better visualization, development of various scanning modes would optimize macular measurements, and further refining of the analytical algorithm would provide more accurate segmentation. With these achievements, macular measurement can be an important surrogate for glaucomatous structural assessment.
PMCID: PMC3718015  PMID: 23018425
21.  Inflammatory Response to Intravitreal Injection of Gold Nanorods 
The British journal of ophthalmology  2012;96(12):1522-1529.
To evaluate the utility of gold nanorods (AuNRs) as a contrast agent for ocular optical coherence tomography (OCT).
Mice were intravitreally injected with sterile AuNRs coated with either poly(strenesulfate) (PSS-AuNRs) or anti-CD90.2 antibodies (Ab-AuNRs), and imaged using OCT. After 24 hours, eyes were processed for transmission electron microscopy or rendered into single cell suspensions for flow cytometric analysis to determine absolute numbers of CD45+ leukocytes and subsets (T cells, myeloid cells, macrophages, neutrophils). Generalized estimation equations were used to compare cell counts between groups.
PSS-AuNRs and Ab-AuNRs were visualized in the vitreous 30min and 24h post- injection with OCT. At 24h, a statistically significant increase in leukocytes, comprised primarily of neutrophils, was observed in eyes that received either AuNR in comparison to eyes that received saline. The accumulation of leukocytes was equal in eyes given PSS-AuNR or Ab- AuNR. Endotoxin-resistant C3H/HeJ mice also showed ocular inflammation after injection with AuNRs, indicating that the inflammatory response was not due to lipopolysaccharide contamination of AuNRs.
Although AuNRs can be visualized in the eye using OCT they can induce ocular inflammation, which limits their use as a contrast agent.
PMCID: PMC3718482  PMID: 23087415
gold nanoparticles; optical coherence tomography; contrast enhancement; immune response
22.  Lipid metabolites in the pathogenesis and treatment of neovascular eye disease 
The British journal of ophthalmology  2011;95(11):1496-1501.
Lipids and lipid metabolites have long been known to play biological roles that go beyond energy storage and membrane structure. In age-related macular degeneration and diabetes, for example, dysregulation of lipid metabolism is closely associated with disease onset and progression. At the same time, some lipids and their metabolites can exert beneficial effects in the same disorders. This review summarises our current knowledge of the contributions of lipids to both the pathogenesis and treatment of neovascular eye disease. The clinical entities covered are exudative age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity, with a special emphasis on the potential therapeutic effects of ω3-(also known as n-3) polyunsaturated fatty acids.
PMCID: PMC3711020  PMID: 21421650
23.  Telemedical Diagnosis of Retinopathy of Prematurity: Accuracy of Expert vs. Non-expert Graders 
To assess accuracy of telemedical retinopathy of prematurity (ROP) diagnosis by trained non-expert graders compared to expert graders.
248 eye examinations from 67 consecutive infants were captured using wide-angle retinal photography (RetCam-II, Clarity Medical Systems, Pleasanton, CA). Non-expert graders attended two hour-long training sessions on image-based ROP diagnosis. Using a web-based telemedicine system, 14 non-expert and 3 expert graders provided a diagnosis for each eye: no ROP, mild ROP, type-2 prethreshold ROP, or treatment-requiring ROP. All diagnoses were compared to a reference standard of dilated indirect ophthalmoscopy by an experienced pediatric ophthalmologist.
For detection of type-2 or worse ROP, the mean (range) sensitivities and specificities were 0.95 (0.94–0.97) and 0.93 (0.91–0.96) for experts, 0.87 (0.71–0.97) and 0.73 (0.39–0.95) for resident non-experts, and 0.73 (0.41–0.88) and 0.91 (0.84–0.96) for student non-experts. For detection of treatment-requiring ROP, the mean (range) sensitivities and specificities were 1.00 (1.00-1.00) and 0.93 (0.88–0.96) for experts, 0.88 (0.50–1.00) and 0.84 (0.71–0.98) for resident non-experts, and 0.82 (0.42–1.00) and 0.92 (0.83–0.97) for student non-experts.
Mean sensitivity and specificity of trained non-experts are lower than that of experts, although several non-experts had high accuracy. Development of methods for training non-expert graders may help support telemedical ROP evaluation.
PMCID: PMC3711625  PMID: 19955195
retinopathy of prematurity; pediatric ophthalmology; telemedicine; medical informatics; retina
24.  Normative optical coherence tomography measurements in children 
PMCID: PMC3417148  PMID: 22426801
25.  Spectral-domain OCT peripapillary retinal nerve fibre layer thickness measurements in patients with stargardt disease 
To evaluate the presence of peripapillary retinal nerve fibre layer (RNFL) defects in patients with Stargardt disease by using spectral-domain optical coherence tomography (SD-OCT).
Fifty-two eyes of 27 patients with Stargardt disease underwent peripapillary RNFL thickness measurements using SD-OCT.
Twenty-seven patients with Stargardt disease were enrolled. Their mean (±SD) age was 38.3 (14.7) years. Fourteen patients (51.9%) showed a thinning of the peripapillary RNFL in one or more quadrants in at least one eye, and four patients (14.8%) in both eyes. Five patients (18.5%) showed a thickening of the peripapillary RNFL in at least one eye, and four patients (14.8%) in both eyes.
This study demonstrated the presence of defects in the peripapillary RNFL thickness in patients with Stargardt disease by using SD-OCT. It would be clinically prudent that Stargardt patients considered for various treatment options be considered for RNFL thickness measurements.
PMCID: PMC3697128  PMID: 20935302

Results 1-25 (21756)