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Showing papers in "Clinical and Experimental Ophthalmology in 2014"


Journal ArticleDOI
TL;DR: A recent review as discussed by the authors outlines the current understanding of the genomic, genetic and epigenetic changes in retinoblastoma, highlighting recent genome-wide analyses that have identified exciting candidate genes worthy of further validation as potential prognostic and therapeutic targets.
Abstract: Retinoblastoma is a paediatric ocular tumour that continues to reveal much about the genetic basis of cancer development. Study of genomic aberrations in retinoblastoma tumours has exposed important mechanisms of cancer development and identified oncogenes and tumour suppressors that offer potential points of therapeutic intervention. The recent development of next-generation genomic technologies has allowed further refinement of the genomic landscape of retinoblastoma at high resolution. In a relatively short period of time, a wealth of genetic and epigenetic data has emerged on a small number of tumour samples. These data highlight the inherent molecular complexity of this cancer despite the fact that most retinoblastomas are initiated by the inactivation of a single tumour suppressor gene. This review outlines the current understanding of the genomic, genetic and epigenetic changes in retinoblastoma, highlighting recent genome-wide analyses that have identified exciting candidate genes worthy of further validation as potential prognostic and therapeutic targets.

139 citations


Journal ArticleDOI
TL;DR: The basic assumptions used in the LR model are presented and a simple methodology for checking if they are satisfied prior to its use is offered to increase the effectiveness and appropriateness of LR in clinical research.
Abstract: Linear regression (LR) is a powerful statistical model when used correctly. Because the model is an approximation of the long-term sequence of any event, it requires assumptions to be made about the data it represents in order to remain appropriate. However, these assumptions are often misunderstood. We present the basic assumptions used in the LR model and offer a simple methodology for checking if they are satisfied prior to its use. In doing so, we aim to increase the effectiveness and appropriateness of LR in clinical research.

134 citations


Journal ArticleDOI
TL;DR: To determine the prevalence of dry eye syndrome in the general 40‐ to 64‐year‐old population of Shahroud, Iran, a large sample of adults aged 40 to 64 years old was surveyed.
Abstract: Background To determine the prevalence of dry eye syndrome in the general 40- to 64-year-old population of Shahroud, Iran. Design Population-based cross-sectional study. Participants Through cluster sampling, 6311 people were selected and 5190 participated. Assessment of dry eye was done in a random subsample of 1008 people. Methods Subjective assessment for dry eye syndrome was performed using Ocular Surface Disease Index questionnaire. In addition, the following objective tests of dry eye syndrome were employed: Schirmer test, tear break-up time, and fluorescein and Rose Bengal staining using the Oxford grading scheme. Main Outcome Measures Those with an Ocular Surface Disease Index score ≥23 were considered symptomatic, and dry eye syndrome was defined as having symptoms and at least one positive objective sign. Results The prevalence of dry eye syndrome was 8.7% (95% confidence interval 6.9–10.6). Assessment of signs showed an abnormal Schirmer score in 17.8% (95% confidence interval 15.5–20.0), tear break-up time in 34.2% (95% confidence interval 29.5–38.8), corneal fluorescein staining (≥1) in 11.3% (95% confidence interval 8.5–14.1) and Rose Bengal staining (≥3 for cornea and/or conjunctiva) in 4.9% (95% confidence interval 3.4–6.5). According to the Ocular Surface Disease Index scores, 18.3% (95% confidence interval 15.9–20.6) had dry eye syndrome symptoms. The prevalence of dry eye syndrome was significantly higher in women (P = 0.010) and not significantly associated with age (P = 0.291). The objective dry eye syndrome signs significantly increased with age. Conclusions Based on the findings, the prevalence of dry eye syndrome in the studied population is in the mid-range. The prevalence is higher in women. Also, objective tests tend to turn abnormal at higher age. Pterygium is associated with dry eye syndrome and increased its symptoms.

100 citations


Journal ArticleDOI
TL;DR: To assess the prevalence of vision impairment and refractive error in school children 12–15 years of age in Ba Ria – Vung Tau province, Vietnam, a large number of children have suffered from vision impairment.
Abstract: Background To assess the prevalence of vision impairment and refractive error in school children 12–15 years of age in Ba Ria – Vung Tau province, Vietnam. Design Prospective, cross-sectional study. Participants 2238 secondary school children. Methods Subjects were selected based on stratified multistage cluster sampling of 13 secondary schools from urban, rural and semi-urban areas. The examination included visual acuity measurements, ocular motility evaluation, cycloplegic autorefraction, and examination of the external eye, anterior segment, media and fundus. Main Outcome Measures Visual acuity and principal cause of vision impairment. Results The prevalence of uncorrected and presenting visual acuity ≤6/12 in the better eye were 19.4% (95% confidence interval, 12.5–26.3) and 12.2% (95% confidence interval, 8.8–15.6), respectively. Refractive error was the cause of vision impairment in 92.7%, amblyopia in 2.2%, cataract in 0.7%, retinal disorders in 0.4%, other causes in 1.5% and unexplained causes in the remaining 2.6%. The prevalence of vision impairment due to myopia in either eye (–0.50 diopter or greater) was 20.4% (95% confidence interval, 12.8–28.0), hyperopia (≥2.00 D) was 0.4% (95% confidence interval, 0.0–0.7) and emmetropia with astigmatism (≥0.75 D) was 0.7% (95% confidence interval, 0.2–1.2). Vision impairment due to myopia was associated with higher school grade and increased time spent reading and working on a computer. Conclusions Uncorrected refractive error, particularly myopia, among secondary school children in Vietnam is a major public health problem. School-based eye health initiative such as refractive error screening is warranted to reduce vision impairment.

100 citations


Journal ArticleDOI
TL;DR: Genomic methods, such as genome‐wide association studies, are potentially an effective tool to understand anterior segment dysgenesis and the individual susceptibility to the development of glaucoma.
Abstract: Anterior segment dysgenesis refers to a spectrum of disorders affecting structures in the anterior segment of the eye including the iris, cornea and trabecular meshwork. Approximately 50% of patients with anterior segment dysgenesis develop glaucoma. Traditional genetic methods using linkage analysis and family-based studies have identified numerous disease-causing genes such as PAX6, FOXC1 and PITX2. Despite these advances, phenotypic and genotypic heterogeneity pose continuing challenges to understand the mechanisms underlying the complexity of anterior segment dysgenesis disorders. Genomic methods, such as genome-wide association studies, are potentially an effective tool to understand anterior segment dysgenesis and the individual susceptibility to the development of glaucoma. In this review, we provide the rationale, as well as the challenges, to utilizing genomic methods to examine anterior segment dysgenesis disorders.

95 citations


Journal ArticleDOI
TL;DR: To evaluate efficacy and safety of botulinum toxin A injections after more than 10 consecutive years of treatment for benign essential blepharospasm and hemifacial spasm.
Abstract: Background To evaluate efficacy and safety of botulinum toxin A injections after more than 10 consecutive years of treatment for benign essential blepharospasm and hemifacial spasm. Design Retrospective chart review at university-affiliated hospital. Participants Study consisted of 64 patients treated with botulinum toxin A injections between October 2005 and May 2006. Methods Inclusion criteria included patients treated with at least one annual botulinum toxin-A injection for more than 10 consecutive years. Data collected included diagnoses and patient characteristics, injection dates, doses administered at each visit, response scores, duration of effect, and adverse events. Main Outcome Measures Included changes in doses, response scores, duration of effects, and adverse events between the first and last botulinum toxin A injections. Results Thirty-two of 64 patients (mean age at first injection, 57.2 ± 12.4 years; 25 women) met the inclusion criteria. The mean duration of follow up was 14.1 ± 3.1 years (range 10–20 years; mean total visits 44.4 ± 19). A higher mean injection dose per visit was administered during the last year compared with the first year (26.8 ± 10.3 vs. 22.5 ± 7.5 units, respectively) (P = 0.003). The mean durations of effect during the first and last years were 12.4 ± 7.1 and 14.6 ± 7.0 weeks, respectively (P = 0.076). There were no significant differences between genders or between benign essential blepharospasm and hemifacial spasm subgroups. The most common adverse events were ptosis, lagophthalmos and dry eye. Conclusions Botulinum toxin A is an effective, safe, long-term treatment for patients with benign essential blepharospasm and hemifacial spasm. Sustained treatment efficacy required higher doses; however, fewer adverse reactions developed.

86 citations


Journal ArticleDOI
TL;DR: To investigate the frequency of prostaglandin‐associated periorbitopathy among bimatoprost, latanoprost and travoprost users, a large number of users were recruited.
Abstract: Background To investigate the frequency of prostaglandin-associated periorbitopathy among bimatoprost, latanoprost and travoprost users. Design Retrospective observational case series. Participants The study group included 105 patients who were using one of the drugs in one eye for more than 1 month, and the other eye was used as a control. Main Outcome Measures The frequency of prostaglandin-associated periorbitopathy. Methods Special care was taken to detect five prostaglandin-associated periorbitopathy findings. Hertel exophthalmometry measurements and colour pictures of the periocular area were taken. Results Statistically significant differences were found among the groups regarding the presence of all prostaglandin-associated periorbitopathy findings (P < 0.05). Periorbital fat loss was the most frequent and was observed in nearly all prostaglandin-associated periorbitopathy patients except those who were relatively young. The overall frequency of prostaglandin-associated periorbito pathy was 93.3% in the bimatoprost group, 41.4% in the latanoprost group and 70% in the travoprost group. The frequency of deepening of the upper lid sulcus was 80% in the bimatoprost group, 15.7% in the latanoprost group and 45% in the travoprost group. The frequency of milder changes (the presence of either only periorbital fat loss or dermatochalasis involution or the presence of both) was higher in the latanoprost group (62%) than in the travoprost (35.7%) and bimatoprost (7.1%) groups. Conclusions Prostaglandin-associated periorbitopathy is as common as other adverse effects when careful examinations are performed and is more frequent and more severe in bimatoprost users. The loss of the periorbital fat pad is the first sign to occur during the evolution of prostaglandin-associated periorbitopathy, especially in older patients.

82 citations


Journal ArticleDOI
TL;DR: A novel, ultra‐low energy nanosecond laser (retinal rejuvenation therapy) has been developed with the aim to slow progression of early age‐related macular degeneration (AMD).
Abstract: Background A novel, ultra-low energy nanosecond laser (retinal rejuvenation therapy) has been developed with the aim to slow progression of early age-related macular degeneration (AMD). The safety, changes in fundus characteristics and macular function in a cohort of participants with bilateral intermediate AMD are reported. Design Prospective non-randomised, pilot intervention study. Participants or Samples Subjects with bilateral intermediate AMD (n = 50, aged 50–75 years). Methods Ultra-low energy laser pulses applied in 12 spots around the macula of one eye (0.15–0.45 mJ), using 400 μm diameter spot, 3 nanosecond pulse length, 532 nm wavelength and energy titrated to each patient. Main Outcome Measures Best corrected visual acuity, drusen area and macular sensitivity (flicker perimetry) at baseline and at 3, 6 and 12 months post-laser. Results Treatment was painless with no clinically visible lesions. No participant developed choroidal neovascularization, while two with thin central retinal thickness at baseline developed atrophy at 12-month follow up. Drusen area was reduced in 44% of treated eyes and 22% of untreated fellow eyes, with changes in drusen and function not being coincident. Improvement in flicker threshold within the central 3° was observed in both the treated and untreated fellow eyes at 3 months post-laser. Of the 11 eyes at greatest risk of progression (flicker defect >15 dB), seven improved sufficiently to be taken out of this high-risk category. Conclusions A single unilateral application of nanosecond laser to the macula produced bilateral improvements in macula appearance and function. The nanosecond retinal rejuvenation therapy laser warrants ongoing evaluation as an early intervention for AMD.

71 citations


Journal ArticleDOI
TL;DR: To assess the association between refractive errors and the 10‐year incidence of cataracts and cataract surgery, a large number of patients were diagnosed with refractive error before or after surgery.
Abstract: Background To assess the association between refractive errors and the 10-year incidence of cataract and cataract surgery. Design Population-based prospective study. Participants Three thousand six hundred fifty-four persons aged 49+ years living in a well-defined geographical region were examined at baseline; 2564 were re-examined after 5 and/or 10 years. Methods Baseline refractive error was measured using autorefraction with subjective refinement. Lens photographs were taken at each visit and assessed using the Wisconsin Cataract Grading System. Main Outcome Measures Long-term incidence of cataract and cataract surgery. Results Compared with emmetropia, high myopia was associated with increased incidence of nuclear cataract (adjusted odds ratio 3.01, 95% confidence intervals 1.35–6.71). Low (odds ratio 1.86, confidence interval 1.03–3.35) and high myopia (odds ratio 7.80, confidence interval 3.51–17.35) were significantly associated with higher incidence of posterior subcapsular cataract. Low, moderate and high myopia were associated with increased incidence of cataract surgery (odds ratio 2.54, confidence interval 1.76–3.68; odds ratio 2.61, confidence interval 1.45–4.69; and odds ratio 4.81, confidence interval 2.33–9.93, respectively). Either any (odds ratio 1.35, confidence interval 1.08–1.69) or moderate hyperopia (odds ratio 1.76, confidence interval 1.32–2.34) was associated with increased incidence of nuclear cataract. Conclusion Our longitudinal study confirms the association between myopia and an increased risk of nuclear and posterior subcapsular cataract. It also suggests that hyperopia may increase the risk of nuclear cataract.

64 citations


Journal ArticleDOI
TL;DR: Findings from a large, population-based study of visual impairment in rural Heilong-Jiang province, China show that the majority of corneal blindness in this sample was acquired in childhood, and trauma is reported as the second most common cause in their population.
Abstract: Corneal blindness is an important, yet underreported cause of avoidable visual impairment worldwide, especially in developing countries. The World Health Organisation (WHO) estimates that corneal opacities (including trachoma) accounted for 7% of the world’s blind population in 2010, making it the 3rd most common cause of blindness. Although cataracts and glaucoma (in the elderly) are more common causes of visual impairment, corneal blindness affects all age groups and is a leading cause of irreversible visual impairment. An eye blind from scarring and vascularisation of the cornea, usually remains blind for life. In this issue of Clinical and Experimental Ophthalmology, Wang et al. present findings on corneal blindness from a large, population-based study of visual impairment in rural Heilong-Jiang province, China. Although there are numerous population-based studies detailing the major causes of blindness and low vision in both the developed and developing world, few published reports have thus far attempted to detail the different causes of corneal blindness. Rapoza et al. reported corneal infections (including trachoma) to be the leading cause of unilateral and bilateral corneal blindness in Central Tanzania, followed by vitamin A deficiency and measles. Unilateral corneal opacification had similar causes, with the important addition of trauma. Bowman et al. replicated these results in a population-based study in Gambia. Wang et al. here present findings on a large sample of 10 384 participants, representative of the rural Northern Chinese population, with a high overall response rate of 88.1%. Blindness was defined according to WHO criteria as a visual acuity of less than 3/60. All respondents underwent a screening examination, including measurement of best-corrected visual acuity (BCVA). Those achieving BCVA < 6/18 were subsequently referred for a more detailed examination. Although anterior segment examination was performed with a slit-lamp biomicroscope, fundus examination was carried with a hand-held ophthalmoscope only, without pupillary dilatation. This may have resulted in misclassification of the cause of blindness in a proportion of patients. Despite this shortcoming, the study presents some important findings. First, the majority (40%) of corneal blindness in this sample was acquired in childhood. Second, trauma (an entirely avoidable) cause of corneal blindness accounted for a third of all cases. Corneal opacification is the 3rd commonest cause of childhood blindness worldwide, after non-corneal causes such as congenital cataract and glaucoma. Unlike trachomatous corneal opacification, which results from repeated episodes of trachoma infection, corneal blindness in childhood is often due to a single episode of infection, such as ophthalmia neonatarum resulting from Neisseria gonorrhoea and Chlamydia trachomatis infections acquired from the mother’s genital tract at birth. During infancy and childhood, measles is another important cause of corneal blindness in the developing world, the impact of which is mediated through multiple mechanisms, including induction of acute vitamin A deficiency, measles keratitis, secondary bacterial or herpetic keratitis as well as the use of harmful traditional medicines. The WHO has ranked trachoma, corneal opacities, as well as childhood blindness, as priority eye diseases. Blind children have a lifetime of increased morbidity ahead of them. In addition, that lifetime can be very short, with up to 60% of blind children dying within 1 year of becoming blind. In this issue, Wang et al. report trauma as the second most common cause of corneal blindness in their population. In fact, corneal ulceration in developing countries is now considered a ‘silent epidemic’. Superficial corneal injuries from agriculture or domestic incidents led to blinding corneal ulceration due to delayed presentation and treatment. Indeed, in the developing world the majority of corneal ulcerations are the result of minor trauma and foreign bodies. This highlights the importance of public health education programs, targeting highrisk populations such as males, farmers and people with lower education. These programmes need to emphasize the importance of workplace safety, and timely hospitalization for corneal ulceration. In a previous study, also from China, Zhang and Wu demonstrated a lack of knowledge and awareness

62 citations


Journal ArticleDOI
TL;DR: The evidence behind several potential biological and mechanical mechanisms of selective laser trabeculoplasty, including cytokine secretion, matrix metalloproteinase induction, increased cell division, repopulation of burn sites and macrophage recruitment were reviewed.
Abstract: Selective laser trabeculoplasty is a safe and effective treatment for glaucoma, with greater cost effectiveness than its pharmacological and surgical alternatives. Nevertheless, although the basic science literature on selective laser trabeculoplasty continues to grow, there remains uncertainty over the mechanism by which laser trabeculoplasty reduces intraocular pressure. To address this uncertainty, the evidence behind several potential biological and mechanical mechanisms of selective laser trabeculoplasty were reviewed. In particular, cytokine secretion, matrix metalloproteinase induction, increased cell division, repopulation of burn sites and macrophage recruitment were discussed. Refining our understanding of these mechanisms is essential both to understanding the pathophysiology of ocular hypertension and developing improved therapies to treat the condition.

Journal ArticleDOI
TL;DR: To compare the in vitro optical quality of two new trifocal intraocular lenses at different focal points as a function of pupil size, a comparison of the quality of these lenses is presented.
Abstract: Background To compare the in vitro optical quality of two new trifocal intraocular lenses at different focal points as a function of pupil size. Methods Two intraocular lenses having different design approaches were evaluated: the AT LISA tri 839MP with a trifocal diffractive design, and the FineVision, which combines two distinct apodized bifocal diffractive profiles resulting in three foci. A PMTF optical bench was used to assess the intraocular lenses' performance, and as optical quality metrics, the through-focus modulation transfer function was selected; that is, it was measured at 10 focal points and for four different apertures (2.0, 3.0, 3.75 and 4.5 mm). Results For both lenses, the through-focus curve showed three peaks, corresponding to far, intermediate and near focal point. At the 0.0 D focal point, the FineVision yielded better results for larger pupils. At the −1.5 D focal point, both lenses performed worse for larger pupils. At the −3.0 D, the FineVision provided better results for all apertures. However, at the −3.5 D focal point, it was the AT LISA tri 839MP that outperformed the FineVision for larger pupils. Conclusions The two trifocal intraocular lenses under analysis have modulation transfer function peaks that correspond to the far, intermediate and near focal points. For larger pupil sizes, the FineVision seems to provide better results at far focal points, while the AT LISA tri 839MP not only provides better results at the intermediate and near focal points, but is also less pupil size-dependent.

Journal ArticleDOI
TL;DR: In this study, a series of compounds – miltefosine, polyhexamethylene biguanide, chlorhexidine and propamidine isethionate – and combinations of the latter three agents were prepared and used in a rat model for the topical treatment of Acanthamoeba keratitis.
Abstract: Background In this study, a series of compounds – miltefosine, polyhexamethylene biguanide, chlorhexidine and propamidine isethionate – and combinations of the latter three agents with miltefosine were prepared and used in a rat model for the topical treatment of Acanthamoeba keratitis. Methods The corneas of rats were infected with Acanthamoeba hatchetti. On the fifth day, all corneas were microscopically examined in order to determine the grade of infections. Nine groups were then prepared: miltefosine (65.12 μg/mL); chlorhexidine (0.02%); polyhexamethylene biguanide (0.02%), propamidine isethionate (0.1%), miltefosine plus chlorhexidine, miltefosine plus polyhexamethylene biguanide; miltefosine plus propamidine isethionate; infected control; and a non-infected control group. The treatment was continued for 28 days. After the treatment, the corneas were excised and used for Acanthamoeba culture to investigate the presence of Acanthamoeba growth. For the determination of cytotoxicity of the drugs on L929 cells, colorimetric assays were performed. Results The best treatment results were obtained from the polyhexamethylene biguanide plus miltefosine group; the ratio of fully recovered eyes was 28.4%. It was proven that the miltefosine–polyhexamethylene biguanide combination yielded the highest anti-acanthamoebal activity in that approximately 86% of the eyes were cleared from amoebae. The cytotoxicity values of the miltefosine and the control groups were compared with other groups and found to be statistically different (P < 0.05). Conclusion This in vivo study demonstrates that a miltefosine–polyhexamethylene biguanide combination is highly effective for the treatment of Acanthamoeba keratitis.

Journal ArticleDOI
TL;DR: Current surgical techniques for retinal prosthetic implantation require long and complicated surgery, which can increase the risk of complications and adverse outcomes.
Abstract: Background Current surgical techniques for retinal prosthetic implantation require long and complicated surgery, which can increase the risk of complications and adverse outcomes. Method The suprachoroidal position is known to be an easier location to access surgically, and so this study aimed to develop a surgical procedure for implanting a prototype suprachoroidal retinal prosthesis. The array implantation procedure was developed in 14 enucleated eyes. A full-thickness scleral incision was made parallel to the intermuscular septum and superotemporal to the lateral rectus muscle. A pocket was created in the suprachoroidal space, and the moulded electrode array was inserted. The scleral incision was closed and scleral anchor point sutured. In 9 of the 14 eyes examined, the device insertion was obstructed by the posterior ciliary neurovascular bundle. Subsequently, the position of this neurovascular bundle in 10 eyes was characterized. Implantation and lead routing procedure was then developed in six human cadavers. The array was tunnelled forward from behind the pinna to the orbit. Next, a lateral canthotomy was made. Lead fixation was established by creating an orbitotomy drilled in the frontal process of the zygomatic bone. The lateral rectus muscle was detached, and implantation was carried out. Finally, pinna to lateral canthus measurements were taken on 61 patients in order to determine optimal lead length. Results These results identified potential anatomical obstructions and informed the anatomical fitting of the suprachoroidal retinal prosthesis. Conclusion As a result of this work, a straightforward surgical approach for accurate anatomical suprachoroidal array and lead placement was developed for clinical application.

Journal ArticleDOI
TL;DR: The aim of this study was to elucidate the effects of the aqueous humour monocyte chemotactic protein‐1 level on the surgical outcome of trabeculectomy in cases of phakic glaucoma.
Abstract: Background The aim of this study was to elucidate the effects of the aqueous humour monocyte chemotactic protein-1 level on the surgical outcome of trabeculectomy in cases of phakic glaucoma. Design Retrospective study. Participants Fifty-three cases of open-angle glaucoma. Methods At the time of trabeculectomy, aqueous humour samples were collected before any incisions were made. The monocyte chemotactic protein-1 level was then determined by immunoassay. The Cox proportional hazards test was used to analyse the clinical factors related to failure of trabeculectomy. Subsequently, the success probability was calculated by Kaplan–Meier analysis and cumulative success probabilities were analysed by the log-rank test. Main Outcome Measures Probability of success. Results In 30 phakic glaucoma and 23 pseudophakic glaucoma cases, the mean monocyte chemotactic protein-1 levels in aqueous humour were 1165.2 and 2152.9 pg/mL, respectively; the difference was statistically significant (P < 0.0001). Univariate analysis showed that the outcomes of surgery were correlated with the monocyte chemotactic protein-1 level, but not with age, gender, diagnosis of exfoliation glaucoma, pseudophakic status or pretrabeculectomy intraocular pressure. Subsequent multivariate analysis revealed that only the aqueous humour monocyte chemotactic protein-1 level was significantly correlated with the outcomes of trabeculectomy (P = 0.043). Among the 30 phakic glaucoma eyes, the success probabilities after trabeculectomy were significantly different between the high and low monocyte chemotactic protein-1 groups (P = 0.018). Conclusion In open-angle glaucoma patients, the monocyte chemotactic protein-1 level is a prognostic factor for the results of trabeculectomy.

Journal ArticleDOI
TL;DR: The study aimed to estimate the prevalence and associated factors of refractive error in school‐aged children in a rural area of northern China.
Abstract: Background The prevalence of refractive error in the north of China is unknown. The study aimed to estimate the prevalence and associated factors of refractive error in school-aged children in a rural area of northern China. Design Cross-sectional study. Participants or Samples The cluster random sampling method was used to select the sample. Methods A total of 1700 subjects of 5 to 18 years of age were examined. All participants underwent ophthalmic evaluation. Refraction was performed under cycloplegia. Association of refractive errors with age, sex, and education was analysed. Main Outcome Measures The main outcome measure was prevalence rates of refractive error among school-aged children. Results Of the 1700 responders, 1675 were eligible. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye was 6.3%, 3.0% and 1.2%, respectively. The prevalence of myopia was 5.0% (84/1675, 95% CI, 4.8%–5.4%) and of hyperopia was 1.6% (27/1675, 95% CI, 1.0%–2.2%). Astigmatism was evident in 2.0% of the subjects. Myopia increased with increasing age, whereas hyperopia and astigmatism were associated with younger age. Myopia, hyperopia and astigmatism were more common in females. We also found that prevalence of refractive error were associated with education. Myopia and astigmatism were more common in those with higher degrees of education. Conclusion This report has provided details of the refractive status in a rural school-aged population. Although the prevalence of refractive errors is lower in the population, the unmet need for spectacle correction remains a significant challenge for refractive eye-care services.

Journal ArticleDOI
TL;DR: The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population and found that blindness is more common in rural areas than in urban areas.
Abstract: Background The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. Design Cross-sectional study. Participants or Samples The cluster random sampling method was used to select the sample. Methods This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was <9/18 because of corneal diseases. Main Outcome Measures The main outcome measure was prevalence rates of corneal blindness and low vision. Results Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2–0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. Conclusion Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention.

Journal ArticleDOI
TL;DR: To evaluate different mechanisms of acute angle closure and to compare it with unaffected fellow eyes and primary angle closure suspects using anterior segment optical coherence tomography.
Abstract: Background To evaluate different mechanisms of acute angle closure and to compare it with unaffected fellow eyes and primary angle closure suspects using anterior segment optical coherence tomography. Design Prospective, cross-sectional. Participants 116 eyes (76 patients) with angle closure disease were included. Methods Eyes were categorized into three groups: (i) acute angle closure (40 eyes); (ii) fellow eyes of acute angle closure (40 eyes); and (iii) primary angle closure suspect (36 eyes). Complete ophthalmic examinations including gonioscopy, A-scan biometry and anterior segment optical coherence tomography were performed. Main Outcome Measure Based on the anterior segment optical coherence tomography images, four mechanisms of primary angle closure including pupil block, plateau iris configuration, thick peripheral iris roll and exaggerated lens vault were evaluated among the three subtypes of angle closure disease. Results There was a statistically significant difference in the mechanism of angle closure disease among the three groups (P < 0.001). Although the majority of fellow and primary angle closure suspect eyes had pupil block mechanism (77.5% and 75%, respectively), only 37.5% of acute angle closure eyes had dominant pupil block mechanism. The percentage because of exaggerated lens vault was greatest in acute angle closure eyes (50%). Acute angle closure eyes had the shallowest anterior chamber depth (P < 0.001), least iris curvature (P < 0.001) and greatest lens vault (P = 0.003) compared with the other two groups. Conclusions A statistically significant difference in the underlying primary angle closure mechanisms among acute angle closure eyes as compared with their fellow eyes and primary angle closure suspect may exist.

Journal ArticleDOI
TL;DR: Both drugs provided effective best corrected visual acuity improvements and central subfield thickness reductions that showed no statistically significant difference between the two groups.
Abstract: Background To compare the efficiency of dexamethasone implants to bevacizumab injections in macular oedema secondary to central retinal vein occlusion. Design Randomized clinical trial at Cairo University Hospitals. Participants Sixty eyes of 60 newly diagnosed patients with macular oedema secondary to central retinal vein occlusion with best corrected visual acuity 0.3 logMAR (6/12) to counting fingers, no evidence of retinal ischaemia and/or neovascularization on fluorescein angiography and central subfield thickness ≥300 μm on ocular coherence tomography. Methods Patients were randomly assigned (30 eyes each group) to either intravitreal dexamethasone implant or bevacizumab injections repeated whenever needed. Best corrected visual acuity and ocular coherence tomography were done at baseline and monthly for 6 months. Main Outcome Measures Comparing best corrected visual acuity and central foveal subfield thickness between both groups during the 6-month period. Results There was no significant difference in best corrected visual acuity between the two groups during the 6 months (P-values > 0.05). The bevacizumab group had a statistically significant thinner central subfield thickness at 1 month (P-value 0.006) and no statistically significant difference for the rest of the 6 months (P-values > 0.05). There was a statistically significant higher intraocular pressure for dexamethasone implant group (compared with bevacizumab) at 3–6 months (P-values < 0.05), respectively. Conclusion Both drugs provided effective best corrected visual acuity improvements and central subfield thickness reductions that showed no statistically significant difference between the two groups.

Journal ArticleDOI
TL;DR: A review of the chromosome 9p21 susceptibility locus as a risk factor for primary open‐angle glaucoma is provided.
Abstract: Primary open-angle glaucoma (POAG) is a genetically complex disease. Genome-wide association study (GWAS) is a particularly useful tool in the search for genetic contributions to glaucoma. Recently, chromosome 9p21 has become a major focus of research endeavour, with multiple genome-wide association studies suggesting associations to POAG. Herein, we provide a review of the chromosome 9p21 susceptibility locus as a risk factor for POAG.

Journal ArticleDOI
TL;DR: To assess the reproducibility and repeatability of cone imaging in healthy human eyes, using the RTx‐1 Adaptive Optics Retinal Camera and its proprietary cone‐counting software.
Abstract: Background To assess the reproducibility and repeatability of cone imaging in healthy human eyes, using the RTx-1 Adaptive Optics Retinal Camera and its proprietary cone-counting software. Design Single-centre, prospective study. Participants Ten healthy adults. Methods Macular cones were imaged. Intrasession repeatability was assessed by comparing 10 consecutive acquisitions obtained by the same operator from each subject. For the intersession study, each subject was imaged five consecutive days. Interoperator reproducibility was also evaluated by comparing the images obtained from 10 different subjects by two independent operators. Finally, intergrader agreement was evaluated by comparing the cone counts measured by two masked graders. Main Outcome Measures Mean cone density (cells/mm2), spacing between cells (μm) and percentage of cones with six neighbours calculated on Voronoi diagrams were measured. Correlation coefficients, intraclass correlation coefficients, and coefficients of variation were calculated. Results Correlation coefficient and intraclass correlation coefficient were respectively 0.81 and 0.96 between operators, and 0.97 and 0.98 between the two graders. The intrasession and intersession coefficients of variation were under 7%. The percentage of cells with six neighbours and the spacing between cones varied in the same proportion (coefficients of variation ranged from 1.66 to 10.05%). Conclusions Overall, the test–retest variability of RTx-1 and its software was good in normal human eyes. Further studies in the normal clinical setting are mandatory.

Journal ArticleDOI
TL;DR: To report rates of recurrence and complications of localized ocular surface squamous neoplasia treated with 5‐fluorouracil or mitomycin C as adjunctive treatment to surgical excision.
Abstract: Background To report rates of recurrence and complications of localized ocular surface squamous neoplasia treated with 5-fluorouracil or mitomycin C as adjunctive treatment to surgical excision. Design Long-term follow up of two prospective, non-comparative interventional case series. Participants One hundred fifty-three eyes with histologically confirmed localized, non-invasive ocular surface squamous neoplasia. 89 eyes were treated with adjuvant 5-fluorouracil and 64 eyes were treated with adjuvant mitomycin C. Methods Following surgical excision±cryotherapy patients received topical 5-fluorouracil 1% four times daily for two weeks or topical mitomycin C 0.04% four times daily for two to three 1-week cycles. Main Outcome Measures Ocular surface squamous neoplasia recurrence, complications of therapy and compliance. Results Median follow up was 33.6 (range 12–84) months and 57.9 (range 12–160) months in 5-fluorouracil and mitomycin C groups, respectively. There was one recurrence in the 5-fluorouracil group and no recurrences in the mitomycin C group. Side-effects occurred in 69% of 5-fluorouracil patients and 41% of mitomycin C patients. Five patients (6%) required intervention for treatment-related side-effects in the 5-fluorouracil group versus 11 (17%) in the mitomycin C group. No vision-threatening complications were noted. Conclusions Long-term recurrence of localised ocular surface squamous neoplasia is rare when topical 5-fluorouracil or mitomycin C are used as adjunctive treatment to surgical excision. While side-effects are common, the majority are transient and rarely limit compliance.

Journal ArticleDOI
TL;DR: The study aims to investigate whether retinal nerve fibre layer (RNFL) abnormalities can be detected in patients with obstructive sleep apnoea/hypopNoea syndrome with normally appearing optic disc.
Abstract: Background The study aims to investigate whether retinal nerve fibre layer (RNFL) abnormalities can be detected in patients with obstructive sleep apnoea/hypopnoea syndrome with normally appearing optic disc. Design This is an observational case-control study. Participants One hundred and eight consecutive patients with moderate or severe obstructive sleep apnoea/hypopnoea syndrome (OSAHS) as determined by overnight polysomnography and normal looking discs and 108 age-matched healthy controls were included in the study. Methods All patients underwent RNFL examinations by optical coherence tomography using fast retinal nerve fibre layer thickness scan. Main Outcome Measures The main outcome measure was RNFL thickness. Results Multivariate regression analysis results showed that the RNFL was thinner for a patient with OSAHS than that of a normal control in the average by 4.20 μm (P < 0.003), in the superior quadrant by 4.83 μm (P = 0.028) and in the inferior quadrant by 5.19 μm (P = 0.016). RNFL thickness did not correlate with the severity of the disease. Conclusions RNFL thinning was detected in normal-looking discs of patients with advanced OSAHS, but the extent of this thinning did not correlate with the severity of the disease. Longitudinal follow-up is needed to clarify whether RNFL thinning in OSAHS patients with normal clinically appearing optic nerves will eventually lead to glaucoma.

Journal ArticleDOI
TL;DR: To identify risk factors associated with open‐angle glaucoma with normal baseline intraocular pressure in a young Korean population, a large number of subjects were recruited from the under-18s to 30-year-old population.
Abstract: Background To identify risk factors associated with open-angle glaucoma with normal baseline intraocular pressure in a young Korean population. Design Retrospective, population-based, case-control study. Participants Between 2009 and 2010, among participants from the Korea National Health and Nutrition Examination Survey (n = 17 901), subjects between 19 and 39 years of age were included. Methods Participants had structured interviews systemic and ophthalmic examination. Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology criteria. Main Outcome Measures The risk factors for open-angle glaucoma with normal baseline intraocular pressure were analyzed using univariate and multivariate comparisons. Results Eighty open-angle glaucoma with normal baseline intraocular pressure patients and 4015 controls were included. In the univariate analysis, the patient group was more likely to have higher fasting plasma glucose (98.04 ± 33.16 vs. 89.74 ± 12.65, P < 0.001) and higher proportion of fasting capillary glucose ≥200 mg/dL (P < 0.001) than the control. Multivariate analysis found that high myopia (odds ratio, 3.54 [95% confidence interval, 1.34–9.39], P = 0.011), fasting capillary glucose ≥200 mg/dL (odds ratio, 12.65 [95% confidence interval, 2.63–60.94], P = 0.002) and low high-density lipoprotein cholesterol (odds ratio, 0.96 [95% confidence interval, 0.94–0.99], P = 0.015) were associated with an increased risk of having open-angle glaucoma with normal baseline intraocular pressure. Conclusions High myopia, fasting capillary glucose level ≥200 mmol/L and high-density lipoprotein cholesterol level were significant risk factors for open-angle glaucoma with normal baseline intraocular pressure in a young Korean population.

Journal ArticleDOI
TL;DR: The purpose of the study was to evaluate the safety and selectivity of the retinal pigment epithelium lesions by using automatic energy ramping and dosimetry technique for selective retina therapy and to investigate the healing response.
Abstract: Background The purpose of the study was to evaluate the safety and selectivity of the retinal pigment epithelium lesions by using automatic energy ramping and dosimetry technique for selective retina therapy and to investigate the healing response. Methods Ten eyes of Chinchilla Bastard rabbits were treated with an automatic dosage controlled selective retina therapy laser (frequency doubled Q-switched Nd:YLF, wavelength: 527 nm, pulse duration: 1.7 μs, repetition rate: 100 Hz, pulse energy: linear increasing from pulse to pulse up to shut down – maximal 110 μJ, max. number of pulses in a burst: 30, retinal spot diameter: 133 μm). After treatment, fundus photography, optical coherence tomography and fluorescein angiography were performed at three time points from 1 h to 3 weeks. Histological analysis was performed. Results A total of 381 selective retina therapy laser spots were tested (range 13–104 μJ).Typical fundus photographs obtained at 1 h after irradiation showed that 379 out of 381 lesions produced by selective retina therapy were not visible ophthalmoscopically and the lesions could be detected by angiography only. Optical coherence tomography images revealed that the structure of photoreceptors was preserved, but a disrupted retinal pigment epithelium layer was observed as was expected. By 3 weeks, histology showed selective retinal pigment epithelium damage without any effect on the inner retina and focal proliferation of the retinal pigment epithelium layer. Conclusions Automatically controlled selective retina therapy is a significant improvement in this innovative treatment. It could be demonstrated that the non-contact, reflectometric technique with a controlled pulse energy ramp is safe and selective.

Journal ArticleDOI
TL;DR: To elucidate the biological effects of blocking fluorescent light on the retina using specific blocking materials using specificblocking materials.
Abstract: Background To elucidate the biological effects of blocking fluorescent light on the retina using specific blocking materials. Methods Seven- to 8-week-old BALB/c mice were divided into three groups and placed in one of the three boxes: one blocked ultraviolet and violet wavelengths of light (violet blockade), one blocked ultraviolet, violet, blue and some other visible wavelengths (blue-plus blockade), and one allowed most visible light to pass through (control). They were then exposed to a white fluorescent lamp for 1 h at 5.65E-05 mW/cm2/s. After treatment, the electroretinogram, retinal outer nuclear layer thickness and retinal outer segment length were measured. In addition, retinal apoptotic cells were quantified by TdT-mediated dUTP nick-end labelling assay and c-Fos messenger RNA, and protein levels were measured by real-time reverse-transcription polymerase chain reaction and immunoblot analyses, respectively. Results The blue-plus blockade group retained a significantly better electroretinogram response following light exposure than the control or violet blockade groups. The blue-plus blockade group also exhibited greater outer nuclear layer thickness and greater outer-segment length, and fewer apoptotic cells after light exposure than the other groups. The c-Fos messenger RNA and protein levels were substantially reduced in the blue-plus blockade group and reduced to a lesser extent in the violet blockade group. Conclusions The blockade of blue plus additional visible wavelengths of light was most effective in protecting the retina from light-induced damage. The blockade of violet light alone was also effective in reducing intracellular molecular responses, but these effects were not sufficient for attenuating retinal degeneration.

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TL;DR: To evaluate changes of choroidal circulation quantitatively using laser speckle flowgraphy in patients with acute zonal occult outer retinopathy, lasers are used for the first time in a clinical trial.
Abstract: Background To evaluate changes of choroidal circulation quantitatively using laser speckle flowgraphy in patients with acute zonal occult outer retinopathy. Design Retrospective observational case series. Participants Sixteen eyes of 11 acute zonal occult outer retinopathy patients: seven non-treated eyes with good visual acuity and nine systemic corticosteroid-treated eyes with progressive visual acuity loss. Six eyes with thyroid-associated ophthalmopathy receiving systemic corticosteroid therapy served as controls. Methods The mean blur rate, an index of quantitative relative blood flow velocity, in the affected area was measured by laser speckle flowgraphy. The changes of mean blur rate, best-corrected visual acuity and the average threshold at the affected area on Humphrey perimetry during 24-week follow up were analysed. Main Outcome Measures Mean blur rate, best-corrected visual acuity, and the average threshold. Results In non-treated eyes, the average mean blur rate significantly increased at 24 weeks, with a significant increase of the average threshold. In corticosteroid-treated eyes, the mean blur rates at 1, 4, 12 and 24 weeks were significantly higher than the pretreatment value, with significant improvement of best-corrected visual acuity and the average threshold. The increase in mean blur rate at 4 weeks in corticosteroid-treated acute zonal occult outer retinopathy eyes was significantly higher than that in corticosteroid-treated control eyes. Conclusions In eyes with acute zonal occult outer retinopathy, the mean blur rate at the affected area significantly increases along with improvement of visual functions. These results suggest that impaired choroidal circulation is involved in the pathogenesis of acute zonal occult outer retinopathy.

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TL;DR: Limiting the total cumulative dose of methylprednisolone, careful patient selection and monitoring the condition of patients during treatment are necessary.
Abstract: A meta-analysis was performed to evaluate the efficacy of methylprednisolone pulse therapy for Graves' ophthalmopathy. Eight studies involving 376 patients were included. A higher effective rate was found for patients treated with intravenous glucocorticoids (IVGC) over oral glucocorticoids (OGC) (risk ratio [RR] = 1.48; 95% confidence interval [CI] = 1.18−1.86). The combined IVGC and orbital radiotherapy (OR) was markedly more effective than OGC+OR (RR = 1.40; 95% CI = 1.11−1.77). IVGC resulted in an obvious reduction of clinical activity score (CAS) compared with OGC, with a weighted mean difference (WMD) of 0.86 (95% CI = 0.53−1.18). The WMD for the reduction of the CAS between IVGC+OR and OGC+OR was 0.66 (95% CI = 0.30−1.02). IVGC is an effective treatment and cause fewer adverse events. Limiting the total cumulative dose of methylprednisolone, careful patient selection and monitoring the condition of patients during treatment are necessary.

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TL;DR: The novel application of an infrared anterior segment camera to observation of the condition of the iris that is masked by the corneal opacity because of stromal oedema in patients with Peters’ anomaly is demonstrated.
Abstract: not have a high resolution. The quality of the images was sufficient to visualize the iris abnormalities in the present cases, however. For cases in which more detailed images might be required, an infrared slit-lamp biomicroscope might prove more appropriate. The flexibility of the mobile camera allowed us to observe an infant and a small child, for whom slit-lamp microscopy and slit-lamp photography are more problematic. This system is also likely to prove beneficial for the observation of pupil shape before keratoplasty in bullous keratopathy patients with an unknown clinical history. Such observation may facilitate identification of a peaked pupil because of vitreous prolapse into the side port or the corneal or sclerocorneal tunnel. On the other hand, we found that although the shape of the pupil of patients with a scarred cornea was visible with the Meibopen camera, it was not as clear as that for individuals with an oedematous cornea (data not shown). Unlike the case of corneal oedema, the corneal opacity associated with a scarred cornea is not due to disorganization of collagen fibres but rather is the result either of abnormal collagen fibres secreted by fibroblasts or myofibroblasts, or of the loss of transparency of corneal stromal cells. The benefits of infrared observation are thus likely to be restricted to oedematous corneas. We have thus demonstrated the novel application of an infrared anterior segment camera to observation of the condition of the iris that is masked by the corneal opacity because of stromal oedema in patients with Peters’ anomaly. This non-invasive approach provides valuable clinical information and should prove applicable to other conditions characterized by corneal stromal oedema.

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TL;DR: The efficacy of topical application of the opioid antagonist naltrexone (NTX) in reversing diabetic‐related ocular surface complications in mice was examined.
Abstract: Background Ocular surface complications of type 2 diabetes are associated with reductions in tear production, increased corneal surface sensitivity, and delayed corneal re-epithelialization. This study examined the efficacy of topical application of the opioid antagonist naltrexone (NTX) in reversing these diabetic-related ocular surface complications in mice. Methods The genetic db/db mouse model of type 2 diabetes, along with C57Bl/6 wild-type mice were investigated. Tear production was assessed by phenol red impregnated threads, and ocular surface sensitivity was measured using Von Frey filaments. Centrally located, circular corneal abrasions were created in mice and residual epithelial defects measured by fluorescein photography. Animals in each group received topical applications of drops of 10−5 M NTX in sterile Vigamox (Vigamox, Alcon Laboratories, Fort Worth, Texas, USA) or sterile Vigamox alone, and tear production, corneal sensitivity, and reepithelialization were monitored. Results In comparison to diabetic mice receiving vehicle only, db/db mice treated with one drop of NTX demonstrated a marked reversal in dry eye and ocular surface hypersensitivity within 1 h of one drop of NTX. Reversal of the complications in db/db mice usually lasted for 48–90 h. Corneal epithelial repair in db/db mice was enhanced following a regimen of three drops of NTX daily such that by 72 h, residual wounds were one third the size in db/db mice receiving NTX relative to diabetic mice receiving vehicle. Application of Vigamox alone had no effect. No adverse effects of NTX administration were noted in the cornea. Conclusions This is the first report of the efficacy of topical NTX in reversing corneal surface complications in type 2 diabetic mice.