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1.  Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis 
BMC Ophthalmology  2010;10:31.
Background
Age-related macular degeneration (AMD) is the leading cause of blindness in Western countries. Numerous risk factors have been reported but the evidence and strength of association is variable. We aimed to identify those risk factors with strong levels of evidence which could be easily assessed by physicians or ophthalmologists to implement preventive interventions or address current behaviours.
Methods
A systematic review identified 18 prospective and cross-sectional studies and 6 case control studies involving 113,780 persons with 17,236 cases of late AMD that included an estimate of the association between late AMD and at least one of 16 pre-selected risk factors. Fixed-effects meta-analyses were conducted for each factor to combine odds ratio (OR) and/or relative risk (RR) outcomes across studies by study design. Overall raw point estimates of each risk factor and associated 95% confidence intervals (CI) were calculated.
Results
Increasing age, current cigarette smoking, previous cataract surgery, and a family history of AMD showed strong and consistent associations with late AMD. Risk factors with moderate and consistent associations were higher body mass index, history of cardiovascular disease, hypertension, and higher plasma fibrinogen. Risk factors with weaker and inconsistent associations were gender, ethnicity, diabetes, iris colour, history of cerebrovascular disease, and serum total and HDL cholesterol and triglyceride levels.
Conclusions
Smoking, previous cataract surgery and a family history of AMD are consistent risk factors for AMD. Cardiovascular risk factors are also associated with AMD. Knowledge of these risk factors that may be easily assessed by physicians and general ophthalmologists may assist in identification and appropriate referral of persons at risk of AMD.
doi:10.1186/1471-2415-10-31
PMCID: PMC3009619  PMID: 21144031
2.  Peripheral capillary non-perfusion in asymptomatic Waldenström's macroglobulinemia 
BMC Ophthalmology  2010;10:30.
Background
To report the rare association of peripheral retinal ischemia in a patient with Waldenström's macroglobulinemia.
Case Presentation
A 39-year old man with a recent diagnosis of asymptomatic Waldenström's macroglobulinemia (WM) was referred from his physician for ocular evaluation. The fundus examination in his right eye (RE) revealed very mild central vein dilation, while retinal hemorrhages associated with microaneurismal alterations of the vascular plexus were detected at the temporal periphery. Fluoroscein angiography of his RE revealed an extended area of capillary dropout distal to the microaneurismal lesions. In our patient with WM an extensive area of capillary non-perfusion, in the absence of severe involvement of the posterior pole was documented; this association to the best of our knowledge has never been reported before.
Conclusion
Although the incidence of the disease is rare, meticulous examination of the retinal periphery should be performed in all patients with WM and vice versa the differential diagnosis of peripheral retinal ischemia of unknown origin should include an investigation to rule out asymptomatic Waldenström's macroglobulinemia.
doi:10.1186/1471-2415-10-30
PMCID: PMC3009618  PMID: 21126377
3.  Intraoperative fracture of phacoemulsification sleeve 
BMC Ophthalmology  2010;10:29.
Background
We describe a case of intraoperative fracture of phacoemulsification sleeve during phacoemulsification surgery.
Case presentation
Phacoemulsification surgery was performed in the left eye of a 58-year-old lady with grade II nuclear sclerosis & grade I cortical cataract. Towards the end of quadrant removal, there was anterior chamber instability with impaired followability of nuclear fragments. The distal part of the fractured sleeve remained inside the anterior chamber upon removal of the phacoemulsification probe. The retained sleeve was retrieved with a pair of forceps through the corneal incision site, which did not require widening. There was no missing fragments retained intraocularly and the patient had an uneventful recovery with vision of 20/25 at three months post-operatively.
Conclusion
Phacoemulsification sleeve fracture is an uncommon complication. With early identification of this condition and proper management, major complications can be avoided.
doi:10.1186/1471-2415-10-29
PMCID: PMC3009954  PMID: 21118542
4.  Goltz syndrome (focal dermal hypoplasia) with unilateral ocular, cutaneous and skeletal features: case report 
BMC Ophthalmology  2010;10:28.
Background
Goltz syndrome or focal dermal hypoplasia (FDH) is an uncommon multisystem disorder. Herein, we report a typical case of FDH with unilateral ocular, cutaneous and skeletal features.
Case Presentation
a 4-year-old girl presented with microphthalmos and iris coloboma of the left eye, facial asymmetry, and a low-set protruding ear. Cutaneous changes included hypopigmented atrophic macules on the left side of the face, chest, abdomen and limbs. Characteristic lobster claw deformity of left hand and oligodactyly and syndactyly of left foot were present.
Conclusions
FDH usually affects both sides of the body. This case represents the unusual unilateral manifestation of the syndrome.
doi:10.1186/1471-2415-10-28
PMCID: PMC2996349  PMID: 21092077
5.  Expression of connexin genes in the human retina 
BMC Ophthalmology  2010;10:27.
Background
Gap junction channels allow direct metabolically and electrical coupling between adjacent cells in various mammalian tissues. Each channel is composed of 12 protein subunits, termed connexins (Cx). In the mouse retina, Cx43 could be localized mostly between astroglial cells whereas expression of Cx36, Cx45 and Cx57 genes has been detected in different neuronal subtypes. In the human retina, however, the expression pattern of connexin genes is largely unknown.
Methods
Northern blot hybridizations, RT-PCR as well as immunofluorescence analyses helped to explore at least partially the expression pattern of the following human connexin genes GJD2 (hCx36), GJC1 (hCx45), GJA9 (hCx59) and GJA10 (hCx62) in the human retina.
Results
Here we report that Northern blot hybridization signals of the orthologuous hCx36 and hCx45 were found in human retinal RNA. Immunofluorescence signals for both connexins could be located in both inner and outer plexiform layer (IPL, OPL). Expression of a third connexin gene denoted as GJA10 (Cx62) was also detected after Northern blot hybridization in the human retina. Interestingly, its gene structure is similar to that of Gja10 (mCx57) being expressed in mouse horizontal cells. RT-PCR analysis suggested that an additional exon of about 25 kb further downstream, coding for 12 amino acid residues, is spliced to the nearly complete reading frame on exon2 of GJA10 (Cx62). Cx59 mRNA, however, with high sequence identity to zebrafish Cx55.5 was only weakly detectable by RT-PCR in cDNA of human retina.
Conclusion
In contrast to the neuron-expressed connexin genes Gjd2 coding for mCx36, Gjc1 coding for mCx45 and Gja10 coding for mCx57 in the mouse, a subset of 4 connexin genes, including the unique GJA9 (Cx59) and GJA10 (Cx62), could be detected at least as transcript isoforms in the human retina. First immunofluorescence analyses revealed a staining pattern of hCx36 and hCx45 expression both in the IPL and OPL, partially reminiscent to that in the mouse, although additional post-mortem material is needed to further explore their sublamina-specific distribution. Appropriate antibodies against Cx59 and Cx62 protein will clarify expression of these proteins in future studies.
doi:10.1186/1471-2415-10-27
PMCID: PMC2984586  PMID: 20979653
6.  A case-control study: occupational cooking and the risk of uveal melanoma 
BMC Ophthalmology  2010;10:26.
Background
A European-wide population based case-control study (European rare cancer study) undertaken in nine European countries examined risk factors for uveal melanoma. They found a positive association between cooks and the risk of uveal melanoma. In our study we examine whether cooks or people who worked in cook related jobs have an increased uveal melanoma risk.
Methods
We conducted a case-control study during 2002 and 2005. Overall, 1653 eligible subjects (age range: 20-74 years, living in Germany) participated. Interviews were conducted with 459 incident uveal melanoma cases, 827 population controls, 180 ophthalmologist controls and 187 sibling controls. Data on occupational exposure were obtained from a self-administered postal questionnaire and a computer-assisted telephone interview. We used conditional logistic regression to estimate odds ratios adjusting for the matching factors.
Results
Overall, we did not observe an increased risk of uveal melanoma among people who worked as cooks or who worked in cook related jobs. When we restricted the source population of our study to the population of the Federal State of Northrhine-Westphalia, we observed an increased risk among subjects who were categorized as cooks in the cases-control analysis.
Conclusion
Our results are in conflict with former results of the European rare cancer study. Considering the rarity of the disease laboratory in vitro studies of human uveal melanoma cell lines should be done to analyze potential exposure risk factors like radiation from microwaves, strong light from incandescent ovens, or infrared radiation.
doi:10.1186/1471-2415-10-26
PMCID: PMC2978138  PMID: 20969762
7.  Non-viral siRNA delivery into the mouse retina in vivo 
BMC Ophthalmology  2010;10:25.
Background
Gene silencing in the retina using RNA interference could open broad possibilities for functional studies of genes in vivo and for therapeutic interventions in eye disorders. Therefore, there is a considerable demand for protocols to deliver siRNA into the vertebrate retina. In this work we explored a possibility to deliver synthetic 21 bp siRNA into the mouse retina after intravitreal application using a non-viral carrier.
Methods
Fluorescently labelled synthetic 21 bp siRNA duplex was combined with Transit-TKO transfection reagent and injected intravitreally into adult mice eyes. Eyes cryostat sections and whole mount retinas were prepared 24-48 h post-injection, stained with either Hoechst 33342 (cell nuclei) or immunostained with anti-GFAP antibody (astroglia cells marker). Distribution of fluorescent siRNA signal in the retina was investigated.
Results
Single intravitreal injection of as little as 5 ng of siRNA combined with Transit-TKO transfection reagent by a modified protocol provided robust and non-toxic delivery of the siRNA into the retina. However, siRNA accumulation was predominantly confined to ganglion cells layer as analysed 24 h post-injection. Furthermore, siRNA containing particles were localized along GFAP cytoskeleton of retinal astroglial cells hinting on intracellular localization of the siRNA
Conclusions
In this work we demonstrated that siRNA can be efficiently delivered into the vertebrate retina in vivo with low-toxicity using a non-viral carrier, specifically Transit-TKO transfection reagent. However, the capacity of siRNA delivered by our protocol to induce gene silencing in the retina has to be further evaluated. Our report could raise a closer look on Transit-TKO transfection reagent as a promising siRNA carrier in vivo and be of interest for the researchers and companies who work on development of ocular RNAi techniques.
doi:10.1186/1471-2415-10-25
PMCID: PMC2959040  PMID: 20920307
8.  Posterior migration of Ahmed glaucoma valve tube in a patient with Reiger anomaly: a case report 
BMC Ophthalmology  2010;10:23.
Background
To describe, a yet non-documented complication of GDI surgery (glaucoma drainage incision surgery) - anterior to posterior segment migration of Ahmed Glaucoma Valve (AGV) tube.
Case Presentation
We report a young 9 year old boy, diagnosed with refractory glaucoma with Reiger anomaly. History included of poor vision in both eyes, left more than right with glare since childhood. He underwent GDI surgery with AGV implantation following which he developed posterior migration of AGV tube. The detailed ocular history, ophthalmic findings, clinical course, surgical management and development of the posterior tube migration is discussed.
Conclusion
Posterior Migration of AGV tube has yet not been described. Also there is a role of expectant management of the complication in this case as evidenced by the benign course of events.
doi:10.1186/1471-2415-10-23
PMCID: PMC2949731  PMID: 20849582
9.  Macular hole formation, progression, and surgical repair: case series of serial optical coherence tomography and time lapse morphing video study 
BMC Ophthalmology  2010;10:24.
Background
To use a new medium to dynamically visualize serial optical coherence tomography (OCT) scans in order to illustrate and elucidate the pathogenesis of idiopathic macular hole formation, progression, and surgical closure.
Case Presentations
Two patients at the onset of symptoms with early stage macular holes and one patient following repair were followed with serial OCTs. Images centered at the fovea and at the same orientation were digitally exported and morphed into an Audiovisual Interleaving (avi) movie format. Morphing videos from serial OCTs allowed the OCTs to be viewed dynamically. The videos supported anterior-posterior vitreofoveal traction as the initial event in macular hole formation. Progression of the macular hole occurred with increased cystic thickening of the fovea without evidence of further vitreofoveal traction. During cyst formation, the macular hole enlarged as the edges of the hole became elevated from the retinal pigment epithelium (RPE) with an increase in subretinal fluid. Surgical repair of a macular hole revealed initial closure of the macular hole with subsequent reabsorption of the sub-retinal fluid and restoration of the foveal contour.
Conclusions
Morphing videos from serial OCTs are a useful tool and helped illustrate and support anterior-posterior vitreofoveal traction with subsequent retinal hydration as the pathogenesis of idiopathic macular holes.
doi:10.1186/1471-2415-10-24
PMCID: PMC2954958  PMID: 20849638
10.  The oxysterol 27-hydroxycholesterol increases β-amyloid and oxidative stress in retinal pigment epithelial cells 
BMC Ophthalmology  2010;10:22.
Background
Alzheimer's disease (AD) and age-related macular degeneration (AMD) share several pathological features including β-amyloid (Aβ) peptide accumulation, oxidative damage, and cell death. The causes of AD and AMD are not known but several studies suggest disturbances in cholesterol metabolism as a culprit of these diseases. We have recently shown that the cholesterol oxidation metabolite 27-hydroxycholesterol (27-OHC) causes AD-like pathology in human neuroblastoma SH-SY5Y cells and in organotypic hippocampal slices. However, the extent to which and the mechanisms by which 27-OHC may also cause pathological hallmarks related to AMD are ill-defined. In this study, the effects of 27-OHC on AMD-related pathology were determined in ARPE-19 cells. These cells have structural and functional properties relevant to retinal pigmented epithelial cells, a target in the course of AMD.
Methods
ARPE-19 cells were treated with 0, 10 or 25 μM 27-OHC for 24 hours. Levels of Aβ peptide, mitochondrial and endoplasmic reticulum (ER) stress markers, Ca2+ homeostasis, glutathione depletion, reactive oxygen species (ROS) generation, inflammation and cell death were assessed using ELISA, Western blot, immunocytochemistry, and specific assays.
Results
27-OHC dose-dependently increased Aβ peptide production, increased levels of ER stress specific markers caspase 12 and gadd153 (also called CHOP), reduced mitochondrial membrane potential, triggered Ca2+ dyshomeostasis, increased levels of the nuclear factor κB (NFκB) and heme-oxygenase 1 (HO-1), two proteins activated by oxidative stress. Additionally, 27-OHC caused glutathione depletion, ROS generation, inflammation and apoptotic-mediated cell death.
Conclusions
The cholesterol metabolite 27-OHC is toxic to RPE cells. The deleterious effects of this oxysterol ranged from Aβ accumulation to oxidative cell damage. Our results suggest that high levels of 27-OHC may represent a common pathogenic factor for both AMD and AD.
doi:10.1186/1471-2415-10-22
PMCID: PMC2946278  PMID: 20836858
11.  Long-term effect of latanoprost/timolol fixed combination in patients with glaucoma or ocular hypertension: A prospective, observational, noninterventional study 
BMC Ophthalmology  2010;10:21.
Background
Prospective, observational studies that enroll large numbers of patients with few exclusion criteria may better reflect actual ongoing clinical experience than randomized clinical trials. Our purpose was to obtain efficacy and safety information from a cohort of subjects exposed to latanoprost/timolol fixed combination (FC) for ≥18 months using a prospective, observational design.
Methods
In all, 577 office-based ophthalmologists in Germany switched 2339 patients with glaucoma or ocular hypertension to latanoprost/timolol FC for medical reasons. Follow-up visits were scheduled for every 6 months over 24 months; physicians followed usual care routines. Intraocular pressure (IOP), visual field status, optic nerve head findings, and adverse events were recorded. Efficacy parameters were evaluated for the per protocol (PP) population; the safety population included subjects receiving ≥1 drop of FC. Physicians rated efficacy, tolerability, and subject compliance at month 24.
Results
Of the 2339 subjects switched to latanoprost/timolol FC (safety population), the primary reasons for switching were inadequate IOP reduction (78.2%) and desire to simplify treatment with once-daily dosing (29.4%; multiple reasons possible). In all, 1317 (56.3%) subjects completed the study, and 1028 (44.0%) were included in the PP population. Most discontinuations were due to loss to follow-up. Change in mean IOP from baseline to month 6 was -4.0 ± 4.31 mmHg, a reduction that was maintained throughout (P < 0.05 for change at all time points). By investigator assessments, optic disc parameters and visual field were stable over 24 months, and there was no relationship between IOP reduction over 24 months and development of a visual field defect. More than 90% of physicians rated latanoprost/timolol FC as "very good" or "good" for efficacy (PP population), tolerability, and compliance. The FC was safe and well tolerated. No change in iris color was reported by most subjects (83.1%) at month 24.
Conclusions
Over 24 months, latanoprost/timolol FC effectively lowers IOP levels and is well tolerated in patients with glaucoma or ocular hypertension who change from their previous ocular hypotensive therapy for medical reasons. Investigator assessments found optic disc parameters and visual field to be stable throughout 24 months of follow-up.
doi:10.1186/1471-2415-10-21
PMCID: PMC2945977  PMID: 20825668
12.  Prediction error and accuracy of intraocular lens power calculation in pediatric patient comparing SRK II and Pediatric IOL Calculator 
BMC Ophthalmology  2010;10:20.
Background
Despite growing number of intraocular lens power calculation formulas, there is no evidence that these formulas have good predictive accuracy in pediatric, whose eyes are still undergoing rapid growth and refractive changes. This study is intended to compare the prediction error and the accuracy of predictability of intraocular lens power calculation in pediatric patients at 3 month post cataract surgery with primary implantation of an intraocular lens using SRK II versus Pediatric IOL Calculator for pediatric intraocular lens calculation. Pediatric IOL Calculator is a modification of SRK II using Holladay algorithm. This program attempts to predict the refraction of a pseudophakic child as he grows, using a Holladay algorithm model. This model is based on refraction measurements of pediatric aphakic eyes. Pediatric IOL Calculator uses computer software for intraocular lens calculation.
Methods
This comparative study consists of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below (range: 4 months to 12 years old). Patients were randomized into 2 groups; SRK II group and Pediatric IOL Calculator group using envelope technique sampling procedure. Intraocular lens power calculations were made using either SRK II or Pediatric IOL Calculator for pediatric intraocular lens calculation based on the printed technique selected for every patient. Thirteen patients were assigned for SRK II group and another 11 patients for Pediatric IOL Calculator group. For SRK II group, the predicted postoperative refraction is based on the patient's axial length and is aimed for emmetropic at the time of surgery. However for Pediatric IOL Calculator group, the predicted postoperative refraction is aimed for emmetropic spherical equivalent at age 2 years old. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The data were analysed to compare the mean prediction error and the accuracy of predictability of intraocular lens power calculation between SRK II and Pediatric IOL Calculator.
Results
There were 16 eyes in SRK II group and 15 eyes in Pediatric IOL Calculator group. The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Pediatric IOL Calculator group was 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Pediatric IOL Calculator group, but this was not statistically significant (p = 0.74). There were 3 eyes (18.75%) in SRK II group achieved acccurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Pediatric IOL Calculator group. However the difference of the accuracy of predictability of postoperative refraction between the two formulas was also not statistically significant (p = 0.097).
Conclusions
The prediction error and the accuracy of predictability of postoperative refraction in pediatric cataract surgery are comparable between SRK II and Pediatric IOL Calculator. The existence of the Pediatric IOL Calculator provides an alternative to the ophthalmologist for intraocular lens calculation in pediatric patients. Relatively small sample size and unequal distribution of patients especially the younger children (less than 3 years) with a short time follow-up (3 months), considering spherical equivalent only.
doi:10.1186/1471-2415-10-20
PMCID: PMC2936388  PMID: 20738840
13.  Intraocular pressure and aqueous humor flow during a euglycemic-hyperinsulinemic clamp in patients with type 1 diabetes and microvascular complications 
BMC Ophthalmology  2010;10:19.
Background
Microvascular complications, including retinopathy and nephropathy are seen with type 1 diabetes. It is unknown whether functional changes in aqueous humor flow or intraocular pressure (IOP) develop in parallel with these complications. This study was designed to test the hypothesis that clinical markers of microvascular complications coexist with the alteration in aqueous humor flow and IOP.
Methods
Ten patients with type 1 diabetes and ten healthy age- and weight-matched controls were studied. Aqueous flow was measured by fluorophotometry during a hyperinsulinemic-euglycemic clamp (insulin 2 mU/kg/min). Intraocular pressure was measured by tonometry at -10, 90 and 240 minutes from the start of the clamp, and outflow facility was measured by tonography at 240 minutes.
Results
During conditions of identical glucose and insulin concentrations, mean aqueous flow was lower by 0.58 μl/min in the diabetes group compared to controls (2.58 ± 0.65 versus 3.16 ± 0.66 μl/min, respectively, mean ± SD, p = 0.07) but statistical significance was not reached. Before the clamp, IOP was higher in the diabetes group (22.6 ± 3.0 mm Hg) than in the control group (19.3 ± 1.8 mm Hg, p = 0.01) but at 90 minutes into the clamp, and for the remainder of the study, IOP was reduced in the diabetes group to the level of the control group. Ocular pulse amplitude and outflow facility were not different between groups. Systolic blood pressure was significantly higher in the diabetes group, but diastolic and mean arterial pressures were not different.
Conclusions
We conclude that compared to healthy participants, patients with type 1 diabetes having microalbuminuria and retinopathy have higher IOPs that are normalized by hyperinsulinemia. During the clamp, a reduction in aqueous flow was not statistically significant.
doi:10.1186/1471-2415-10-19
PMCID: PMC2908568  PMID: 20573241
14.  Candida glabrata endophthalmitis following penetrating keratoplasty in a patient with negative donor rim culture 
BMC Ophthalmology  2010;10:18.
Background
Candida glabrata endophthalmitis following keratoplasty is rare and almost always associated with positive donor rim culture.
Case presentation
A 63-year-old patient, diagnosed Fuch's endothelial dystrophy in both eyes underwent a penetrating keratoplasty in his right eye. He had multiple underlying medical problems, which included diabetes mellitus, hypertension, hypoadrenalism on oral dexamethasone and fatty liver secondary to hypertrigliseridemia. He developed multiple suture abscesses, corneal haziness, retrocorneal white plaques and a level of hypopyon two weeks after an uneventful penetrating keratoplasty in his right eye. Cultures of the donor button and the transport media culture were negative. Candida glabrata was isolated successfully from the aqueous and vitreous taps. He was treated with a combination of topical, intracameral, intravitreal and intravenous Amphotericin B. His final visual acuity remained poor due to the haziness of the corneal button.
Conclusion
Candida glabrata endophthalmitis following penetrating keratoplasty can occur in negative donor rim and transport media cultures. The growth of the organism is facilitated by the patient's immunocompromised status. Awareness by the ophthalmologists and appropriate choice of antibiotics are mandatory in this challenging condition.
doi:10.1186/1471-2415-10-18
PMCID: PMC2891680  PMID: 20537193
15.  Glaucoma awareness among people attending ophthalmic outreach services in Southwestern Ethiopia 
BMC Ophthalmology  2010;10:17.
Background
Individuals may need to be aware of glaucoma and seek assessment regularly in order to diagnose the condition early. Awareness of glaucoma has not been previously documented in an Ethiopian setting.
Objective
The main aim of this study was to assess the level of awareness of glaucoma among people attending outreach ophthalmic services.
Methods
We conducted a cross-sectional survey in April 2009 of all people 40 years of age or older who presented during a two-week outreach service period in Agaro town, southwestern Ethiopia. Data on demographics and awareness of glaucoma were collected through face to face interview using a pretested structured questionnaire.
Results
340 people participated in the study. Their mean age was 54.5 (SD 10.6) years. About 43% were illiterates and 37.6% were farmers. Only eight people (2.4%) were aware of glaucoma. The association between awareness and attaining high school or better education was statistically significant (p < 0.0001).
Conclusion
Awareness of glaucoma in this population is very low. An efficient information, education and communication (IEC) strategy needs to be designed to increase knowledge of the community about glaucoma so that early diagnosis and treatment of individuals with this condition may be possible.
doi:10.1186/1471-2415-10-17
PMCID: PMC2889880  PMID: 20509877
16.  A survey of visual function in an Austrian population of school-age children with reading and writing difficulties 
BMC Ophthalmology  2010;10:16.
Background
To describe and compare visual function measures of two groups of school age children (6-14 years of age) attending a specialist eyecare practice in Austria; one group referred to the practice from educational assessment centres diagnosed with reading and writing difficulties and the other, a clinical age-matched control group.
Methods
Retrospective clinical data from one group of subjects with reading difficulties (n = 825) and a clinical control group of subjects (n = 328) were examined.
Statistical analysis was performed to determine whether any differences existed between visual function measures from each group (refractive error, visual acuity, binocular status, accommodative function and reading speed and accuracy).
Results
Statistical analysis using one way ANOVA demonstrated no differences between the two groups in terms of refractive error and the size or direction of heterophoria at distance (p > 0.05). Using predominately one way ANOVA and chi-square analyses, those subjects in the referred group were statistically more likely to have poorer distance visual acuity, an exophoric deviation at near, a lower amplitude of accommodation, reduced accommodative facility, reduced vergence facility, a reduced near point of convergence, a lower AC/A ratio and a slower reading speed than those in the clinical control group (p < 0.05).
Conclusions
This study highlights the high proportions of visual function anomalies in a group of children with reading difficulties in an Austrian population. It confirms the importance of a full assessment of binocular visual status in order to detect and remedy these deficits in order to prevent the visual problems continuing to impact upon educational development.
doi:10.1186/1471-2415-10-16
PMCID: PMC2887790  PMID: 20500851
17.  Measuring benefits and patients' satisfaction when glasses are not needed after cataract and presbyopia surgery: scoring and psychometric validation of the Freedom from Glasses Value Scale (FGVS©) 
BMC Ophthalmology  2010;10:15.
Background
The purpose of this study was to reduce the number of items, create a scoring method and assess the psychometric properties of the Freedom from Glasses Value Scale (FGVS), which measures benefits of freedom from glasses perceived by cataract and presbyopic patients after multifocal intraocular lens (IOL) surgery.
Methods
The 21-item FGVS, developed simultaneously in French and Spanish, was administered by phone during an observational study to 152 French and 152 Spanish patients who had undergone cataract or presbyopia surgery at least 1 year before the study. Reduction of items and creation of the scoring method employed statistical methods (principal component analysis, multitrait analysis) and content analysis. Psychometric properties (validation of the structure, internal consistency reliability, and known-group validity) of the resulting version were assessed in the pooled population and per country.
Results
One item was deleted and 3 were kept but not aggregated in a dimension. The other 17 items were grouped into 2 dimensions ('global evaluation', 9 items; 'advantages', 8 items) and divided into 5 sub-dimensions, with higher scores indicating higher benefit of surgery. The structure was validated (good item convergent and discriminant validity). Internal consistency reliability was good for all dimensions and sub-dimensions (Cronbach's alphas above 0.70). The FGVS was able to discriminate between patients wearing glasses or not after surgery (higher scores for patients not wearing glasses). FGVS scores were significantly higher in Spain than France; however, the measure had similar psychometric performances in both countries.
Conclusions
The FGVS is a valid and reliable instrument measuring benefits of freedom from glasses perceived by cataract and presbyopic patients after multifocal IOL surgery.
doi:10.1186/1471-2415-10-15
PMCID: PMC2881904  PMID: 20497555
18.  Traumatic vertebral artery dissection presenting with incomplete congruous homonymous quadrantanopia 
BMC Ophthalmology  2010;10:14.
Background
To describe a rare presentation of vertebral artery dissection (VAD) as a small but congruous incomplete homonymous hemianopia demonstrating use of visual field testing in the diagnosis.
Case presentation
A 30 year old woman had been unwell for 4 months with difficulty focusing, vertigo, dizziness and a feeling of falling to the right. A small but congruous right inferior homonymous quadrantanopia was found on examination leading to further investigation that uncovered a vertebral artery dissection and multiple posterior circulation infarctions including a left occipital stroke matching the field defect.
Conclusions
We describe an atypical case of VAD presenting with a small congruous quadrantanopia. This is a rare but significant condition that predisposes to multiple thromboembolic infarction that may be easily misdiagnosed and a high index of suspicion is required to make the diagnosis.
doi:10.1186/1471-2415-10-14
PMCID: PMC2885997  PMID: 20482837
19.  Macular thickness measurements in healthy Norwegian volunteers: an optical coherence tomography study 
BMC Ophthalmology  2010;10:13.
Background
Ethnic, intersubject, interoperator and intermachine differences in measured macular thickness seem to exist. Our purpose was to collect normative macular thickness data in Norwegians and to evaluate the association between macular thickness and age, gender, parity, and contraception status.
Methods
Retinal thickness was measured by Stratus Optical Coherence Tomography in healthy subjects. Mean macular thickness (MMT) was analyzed by repeated measures ANOVA with three dependent regional MMT-variables for interaction with age, gender, parity and oral contraception use. Exploratory correlation with age by the Pearson correlation test, both before and after stratification by gender was performed. Differences in MMT between older and younger subjects, between oral contraception users and non-users, as well as parous and nulliparous women were studied by post-hoc Student's t-tests.
Results
Central MMT in Norwegians was similar to values earlier reported in whites. MMT in central areas of 1 and 2.25 mm in diameter were higher in males than in females. In younger subjects (≤43 years) differences in MMT between genders were larger than in the mixed age group, whereas in older subjects (>43 years) the small differences did not reach the set significance level. No differences were found in minimal foveolar thickness (MMFT) between the genders in any age group.
Mean foveal thickness (1 mm in diameter) was positively associated with age in females (r = 0.28, p = 0.03). MMFT was positively associated with age in all groups and reached significance both in females and in mixed gender group (r = 0.20, p = 0.041 and r = 0.26, p = 0.044 respectively).
Mean foveal thickness and MMFT were significantly higher in parous than in nulliparous women, and age-adjusted ANOVA for MMFT revealed a borderline effect of parity.
Conclusions
Age and gender should be taken into consideration when establishing normal ranges for MMT in younger subjects. The gender difference in retinal thickness in young, but not older adults suggests a gonadal hormonal influence. The possible association between parity and retinal structure and its clinical relevance, should be studied further.
doi:10.1186/1471-2415-10-13
PMCID: PMC2885325  PMID: 20465801
20.  Refractive ocular conditions and reasons for spectacles renewal in a resource-limited economy 
BMC Ophthalmology  2010;10:12.
Background
Although a leading cause of visual impairment and a treatable cause of blindness globally, the pattern of refractive errors in many populations is unknown. This study determined the pattern of refractive ocular conditions, reasons for spectacles renewal and the effect of correction on refractive errors in a resource-limited community.
Methods
A retrospective review of case records of 1,413 consecutive patients seen in a private optometry practice, Nigeria between January 2006 and July 2007.
Results
A total number of 1,216 (86.1%) patients comprising of (486, 40%) males and (730, 60%) females with a mean age of 41.02 years SD 14.19 were analyzed. The age distribution peaked at peri-adolescent and the middle age years. The main ocular complaints were spectacles loss and discomfort (412, 33.9%), blurred near vision (399, 32.8%) and asthenopia (255, 20.9%). The mean duration of ocular symptoms before consultation was 2.05 years SD 1.92. The most common refractive errors include presbyopia (431, 35.3%), hyperopic astigmatism (240, 19.7%) and presbyopia with hyperopia (276, 22.7%). Only (59, 4.9%) had myopia. Following correction, there were reductions in magnitudes of the blind (VA<3/60) and visually impaired (VA<6/18-3/60) patients by (18, 58.1%) and (89, 81.7%) respectively. The main reasons for renewal of spectacles were broken lenses/frame/scratched lenses/lenses' falling off (47, 63.4%).
Conclusions
Adequate correction of refractive errors reduces visual impairment and avoidable blindness and to achieve optimal control of refractive errors in the community, services should be targeted at individuals in the peri-adolescent and the middle age years.
doi:10.1186/1471-2415-10-12
PMCID: PMC2885324  PMID: 20459676
21.  Visual acuity and foveal thickness after vitrectomy for macular edema associated with branch retinal vein occlusion: a case series 
BMC Ophthalmology  2010;10:11.
Background
The mechanism by which vitrectomy improves macular edema in patients with branch retinal vein occlusion remains unclear, although intraocular levels of vascular endothelial growth factor have been suggested to influence the visual prognosis and macular edema.
Methods
A series of 54 consecutive patients (54 eyes) with branch retinal vein occlusion was studied prospectively. All patients underwent pars plana vitrectomy for treatment of macular edema. Best corrected visual acuity and retinal thickness (examined by optical coherence tomography) were assessed before and after surgery. The level of vascular endothelial growth factor in vitreous fluid harvested at operation was determined. Patients were followed for at least 6 months postoperatively.
Results
Both the visual acuity and the retinal thickness showed significant improvement at 6 months postoperatively (P = 0.0002 and P < 0.0001, respectively). The vitreous level of vascular endothelial growth factor was significantly higher in patients who showed less improvement of visual acuity compared with those who had a better visual prognosis (p = 0.0135). In contrast, a high vitreous level of vascular endothelial growth factor was associated with greater improvement of macular edema (p = 0.0064).
Conclusions
These results suggest that the vitreous level of vascular endothelial growth factor might influence the visual prognosis and the response of macular edema to vitrectomy in patients with branch retinal vein occlusion.
doi:10.1186/1471-2415-10-11
PMCID: PMC2873510  PMID: 20429890
22.  Predictors of additional intraocular pressure reduction in patients changed to latanoprost/timolol fixed combination 
BMC Ophthalmology  2010;10:10.
Background
Given the growing number of ocular hypotensive medications available, it is important to be able to predict a positive response to therapy. The purpose of the present study was to identify predictors of an additional 10% intraocular pressure (IOP) reduction after 12 weeks of treatment with latanoprost/timolol fixed combination (FC) in patients requiring a change in their previous ocular hypotensive medication.
Methods
This multicenter, open-label, prospective, phase IIIb study included subjects ≥18 years of age with open-angle glaucoma (OAG) or ocular hypertension (OHT). Eligible subjects had baseline IOP ≥21 mmHg and insufficient response to current beta-blocker monotherapy. The primary efficacy analysis (logistic regression) identified predictors of a positive response after 12 weeks of latanoprost/timolol FC.
Results
The intent-to-treat (ITT) population included 383 subjects treated with ≥1 drop of FC and having ≥1 follow-up IOP assessment. Mean IOP was 22.19 ± 2.16 mmHg at baseline and was reduced by 5.42 ± 2.71 mmHg at study end. In all, 325 (84.9%) subjects had a positive response to latanoprost/timolol FC; the response rate was similar across groups: OAG (n = 208; 82.7%); OHT (n = 161; 87.6%); OAG+OHT (n = 14; 85.7%). Higher baseline IOP (odds ratio: 1.284; 95% confidence interval [CI]: 1.101, 1.497; p = 0.0014) and absence of adverse events (odds ratio: 0.318; 95% CI: 0.161, 0.629; p = 0.0010) were significant predictors of positive response. Age, gender, ethnic origin, diagnosis, family history of OAG/OHT, corneal thickness, and concomitant systemic beta-blocker were not significant predictors of a positive response in the ITT analysis. The FC was well tolerated. The most common adverse events were related to the eye and were consistent with known adverse events associated with latanoprost and timolol.
Conclusions
These results support the use of latanoprost/timolol FC in patients whose IOP is insufficiently controlled on beta-blocker monotherapy. Patients with higher baseline IOP levels and who do not experience adverse events while on therapy are most likely to achieve a positive response to latanoprost/timolol FC.
Trial Registration
Study registration number: NCT00230763
doi:10.1186/1471-2415-10-10
PMCID: PMC2861019  PMID: 20346127
23.  Evaluation of alternate outreach models for cataract services in rural Nepal 
BMC Ophthalmology  2010;10:9.
Background
Bharatpur Eye Hospital in Chitwan District, a primarily agrarian setting in south-central Nepal, reduced the number of diagnostic screening and treatment (DST) camps by one half (151 to 75) in an attempt to increase both the efficiency of its outreach program and the number of people that go directly to the hospital for service. The Hospital evaluated the two program models in terms of program costs, cataract surgical utilization, hospital direct payment and patient equity.
Methods
The study is a prospective, before and after, study of the impact of an alternate outreach model on cataract service utilization patterns and cost per outreach camp and cost per cataract surgery at Bharatpur Eye Hospital, comparing the service years July 2006 to June 2007, with July 2007 to June 2008. Study findings were based on routinely gathered hospital and outreach administrative data.
Results
The total cost of the DST camps decreased by approximately US$2000. The cost per camp increased from US$52 to $78 and the cost per cataract surgery decreased from US$ 3.80 to $3.20. The number of patients who went directly to the hospital, and paid for cataract surgery, increased from 432 (17%) to 623 (25%). The total number of cataract surgical procedures at Bharatpur Eye Hospital remained very similar between the two service years (2501 and 2449, respectively). The presenting visual acuity and sex of the two cataract surgical populations were very similar (favouring women, 53 and 55% in the two years, respectively). A shift toward younger men and women occurred with a 245 (64%) increase in people age 50-59 years, and shift away from people age 70 years and older with a 236 (22%) reduction. The age and sex distribution of the direct paying patients were very similar in the two years.
Conclusion
The new, more concentrated, more rural DST model of service delivery reduced overall outreach program costs, cost per cataract surgery transported, while increasing direct payments to the hospital, with a significant decrease in the number of people age 70 and older in the first year.
doi:10.1186/1471-2415-10-9
PMCID: PMC2860345  PMID: 20334695
24.  Comparison of the biometric values obtained by two different A-mode ultrasound devices (Eye Cubed vs. PalmScan): A Transversal, descriptive, and comparative study 
BMC Ophthalmology  2010;10:8.
Background
To assess the reliability of the measurements obtained with the PalmScan™, when compared with another standardized A-mode ultrasound device, and assess the consistency and correlation between the two methods.
Methods
Transversal, descriptive, and comparative study. We recorded the axial length (AL), anterior chamber depth (ACD) and lens thickness (LT) obtained with two A-mode ultrasounds (PalmScan™ A2000 and Eye Cubed™) using an immersion technique. We compared the measurements with a two-sample t-test. Agreement between the two devices was assessed with Bland-Altman plots and 95% limits of agreement.
Results
70 eyes of 70 patients were enrolled in this study. The measurements with the Eye Cubed™ of AL and ACD were shorter than the measurements taken by the PalmScan™. The differences were not statistically significant regarding AL (p < 0.4) but significant regarding ACD (p < 0.001). The highest agreement between the two devices was obtained during LT measurement. The PalmScan™ measurements were shorter, but not statistically significantly (p < 0.2).
Conclusions
The values of AL and LT, obtained with both devices are not identical, but within the limits of agreement. The agreement is not affected by the magnitude of the ocular dimensions (but only between range of 20 mm to 27 mm of AL and 3.5 mm to 5.7 mm of LT). A correction of about 0.5 D could be considered if an intraocular lens is being calculated. However due to the large variability of the results, the authors recommend discretion in using this conversion factor, and to adjust the power of the intraocular lenses based upon the personal experience of the surgeon.
doi:10.1186/1471-2415-10-8
PMCID: PMC2856532  PMID: 20334670
25.  Patients' knowledge and perception on optic neuritis management before and after an information session 
BMC Ophthalmology  2010;10:7.
Background
Patients' understanding of their condition affect the choice of treatment. The aim of this study is to evaluate patients' understanding and treatment preferences before and after an information session on the treatment of acute optic neuritis.
Methods
Participants were asked to complete a questionnaire consisting of 14 questions before and after an information session presented by a neuro-ophthalmologist. The information session highlighted the treatment options and the treatment effects based on the Optic Neuritis Treatment Trial in plain patient language. The information session stressed the finding that high dose intravenous steroid therapy accelerated visual recovery but does not change final vision and that treatment with oral prednisone alone resulted in a higher incidence of recurrent optic neuritis.
Results
Before the information session, 23 (85%) participants knew that there was treatment available for ON and this increased to 27 (100%) after the information session. There were no significantly change in patients knowledge of symptoms of ON and purpose of treatment before and after the information session. Before the information session, 4 (14%) respondents reported they would like to be treated by oral steroid alone in the event of an optic neuritis and 5 (19%) did not respond. After the education session, only 1 patient (4%) indicated they would undergo treatment with oral steroid alone but 25 (92%) indicated they would undergo treatment with intravenous steroid treatment, alone or in combination with oral treatment. Results indicated that there were significant differences in the numbers of participants selecting that they would undergo treatment with a steroid injection (n = 22, p = 0.016).
Conclusions
In this study, patients have shown good understanding of the symptoms and signs of optic neuritis. The finding that significant increases in the likelihood of patients engaging in best practice can be achieved with an information session is very important. This suggests that patient knowledge of available treatments and outcomes can play an important role in implementing and adopting guideline recommendations.
doi:10.1186/1471-2415-10-7
PMCID: PMC2854102  PMID: 20302669

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