Age-related macular degeneration Lim, Laurence S, FRCSEd; Mitchell, Paul, Prof; Seddon, Johanna M, Prof ...
The Lancet (British edition),
05/2012, Letnik:
379, Številka:
9827
Journal Article
Recenzirano
Summary Age-related macular degeneration is a major cause of blindness worldwide. With ageing populations in many countries, more than 20% might have the disorder. Advanced age-related macular ...degeneration, including neovascular age-related macular degeneration (wet) and geographic atrophy (late dry), is associated with substantial, progressive visual impairment. Major risk factors include cigarette smoking, nutritional factors, cardiovascular diseases, and genetic markers, including genes regulating complement, lipid, angiogenic, and extracellular matrix pathways. Some studies have suggested a declining prevalence of age-related macular degeneration, perhaps due to reduced exposure to modifiable risk factors. Accurate diagnosis combines clinical examination and investigations, including retinal photography, angiography, and optical coherence tomography. Dietary anti-oxidant supplementation slows progression of the disease. Treatment for neovascular age-related macular degeneration incorporates intraocular injections of anti-VEGF agents, occasionally combined with other modalities. Evidence suggests that two commonly used anti-VEGF therapies, ranibizumab and bevacizumab, have similar efficacy, but possible differences in systemic safety are difficult to assess. Future treatments include inhibition of other angiogenic factors, and regenerative and topical therapies.
Abstract In the past 20 years, human amniotic membrane (AM) has become widely used as an ophthalmic surgical patch as well as a substrate for stem cell tissue equivalents for ocular surface ...reconstruction. AM reduces ocular surface scarring and inflammation, and enhances epithelialization. In addition, it shows limited immunogenicity and some anti-microbial properties. Before being applied clinically, the donor of AM is required to undergo a thorough health screening and the membrane has to undergo an accepted processing routine, which includes preservation, sterilization and de-epithelialization. There have been various articles describing methods in preserving, sterilizing and de-epithelializing AM. Each preparation technique has been reported to have differential effects on the physical and biological properties of the AM. Therefore, it is difficult to establish a standardized procedure. In this review, we discuss the present techniques and several novel, new approaches in the preparation of AM for use in ocular surface reconstruction, and their impact on AM structure and biological activity.
To analyze the associations between retinal vessel geometry and the 1-year incidence and progression of diabetic retinopathy (DR) in a Chinese population.
This was a prospective cohort study of adult ...subjects with diabetes mellitus. Retinal vascular geometry was quantified from fundus photographs using a semiautomated computer-assisted program. Diabetic retinopathy was graded from retinal photographs at baseline and 1 year. Incident DR and 2-step change in DR were analyzed.
In total, 249 subjects were included. Their mean age was 59.9 ± 8.9 years, 74% were male, and the mean glycated hemoglobin A1c (HbA1C) and duration of diabetes were 7.7 ± 1.4% and 14.3 ± 10.6 years, respectively. The distribution of DR severity at baseline was no DR in 35.7%, minimal nonproliferative diabetic retinopathy (NPDR) in 15.3%, mild NPDR in 14.6%, moderate NPDR in 23.1%, severe NPDR in 5.1%, and proliferative DR in 6.1% of eyes. In multivariate analyses adjusting for age, duration of diabetes, sex, smoking status, HbA1c, hypertension, and hyperlipidemia, subjects with higher venular fractal dimensions were more likely to have incident DR (odds ratio OR 0.38, 95% confidence interval (CI), 0.15-0.96, P = 0.032, per SD decrease). Lower venular tortuosity was associated with a lower likelihood of DR progression (OR 0.76, 95% CI, 0.59-0.97, P = 0.005, per SD decrease). Lower arteriolar tortuosity was associated with a greater likelihood of DR regression (OR 1.95, 95% CI 1.07-3.56, P = 0.037, per SD decrease).
Novel measures of retinal vascular geometry are associated with the incidence and progression of DR at 1 year. These geometric measures are likely to represent early dysfunction in the retinal microvasculature.
This study investigated the associations between the responses of retinal vessels to flickering light and the incidence and progression of diabetic retinopathy (DR).
A prospective cohort study of ...adult subjects with diabetes mellitus. The dynamic vessel analyser (DVA) was used to measure retinal vascular dilatation in response to diffuse illuminance flicker. Diabetic retinopathy was graded from retinal photography at baseline and at 1 year. Incident DR and two-step change in DR were analyzed.
There were 276 subjects in total, with a mean age of 59.8 ± 8.9 years. The majority were male (73%) and the mean glycated hemoglobin A1c (HbA1c) level and mean duration of diabetes were 7.7 ± 1.4% and 14.0 ± 10.5 years, respectively. After adjustments for age, sex, smoking, duration of diabetes, HbA1c, hypertension, and hyperlipidemia, the responses of retinal arterioles to flicker stimulation were lower in subjects with incident DR (P = 0.048). Subjects with greater arteriolar dilatory responses were less likely to have DR progression (odds ratio OR 1.85, 95% confidence interval CI 1.33-2.56, P = 0.012, per SD decrease). Subjects with greater venular dilatory responses were also less likely to have DR progression (OR 1.89, 95% CI 1.35-2.63, P = 0.003, per SD decrease). There were no significant associations between arteriolar or venular dilation response and incident proliferative DR (PDR) and DR regression.
Reduced retinal arteriolar and venular dilatory responses to flickering light are associated with risk of DR progression at 1 year in adult patients with diabetes.
To evaluate the possible associations between dietary factors and myopia.
Cross-sectional study.
Eight hundred fifty-one Chinese schoolchildren from the Singapore Cohort Study of Risk Factors for ...Myopia.
Diet was assessed using a semiquantitative food-frequency questionnaire. Spherical equivalent (SE) refraction was assessed with an autorefractometer, and axial length (AL) by contact ultrasound A-scan biometry.
Myopia was defined as SE< or =-0.5 diopters (D). Spherical equivalent and AL were analyzed by quartile groups.
The mean age (+/-standard deviation) was 12.81+/-0.83 years, approximately half were male (422 children 49.6%), and 653 (73.8%) children had myopia. In multivariate models, AL was longest in the highest quartile group of total cholesterol intake compared with the lowest (adjusted mean 95% confidence interval, 24.66 24.62-24.71 mm vs. 24.32 24.27-24.36 mm; P = 0.026, for trend) and was longest in the highest quartile group of saturated fat intake compared with the lowest (24.65 24.60-24.70 vs. 24.36 24.32-24.41 mm; P = 0.039, for trend). None of the nutrients was associated with SE or a diagnosis of myopia.
Higher saturated fat and cholesterol intake are associated with longer AL in otherwise healthy Singapore Chinese schoolchildren.
Intraocular injections of anti-vascular endothelial growth factor (VEGF) agents have yielded dramatic improvements in the management of a wide variety of neovascular ocular diseases including ...age-related macular degeneration (AMD),1 diabetic retinopathy (DR),2 retinal vein occlusion,3 and now even retinopathy of prematurity.4 These agents have thus become one of the most commonly employed treatments, with 824 525 anti-VEGF intraocular injections given in 2008 in the United States.5 There are currently 2 widely used agents: ranibizumab (Lucentis), which is FDA-approved, and bevacizumab (Avastin),5 given off-label. ...it is becoming apparent that intraocular injections of bevacizumab can significantly suppress systemic VEGF levels.
Background
Swept source optical coherence tomography (SS‐OCT, Topcon Medical System, Japan) is known to have longer wavelength than spectral domain OCT (SD‐OCT, Spectralis, Heidelberg Engineering, ...Germany), allowing a deeper penetration into retina and choroidal layers. This objective of this study was to compare the visibility of retinal and choroidal features in polypoidal choroidal vasculopathy (PCV) using SS‐OCT and SD‐OCT.
Design
This study employs prospective comparative observational case series in Singapore National Eye Center.
Participants
There were 20 eyes (20 patients) with PCV confirmed with indocyanine green angiogram.
Methods
Six pre‐specified OCT parameters (presence of polyps, sharp pigment epithelial detachment PED peak, notched PED and visibility of full maximum height of PED, inner segment/outer segment IS/OS line and choroid‐scleral interface CSI) were graded using SS‐OCT and SD‐OCT.
Main Outcome Measures
The Kappa statistics between the two imaging modalities were calculated.
Results
Both SS‐OCT and SD‐OCT were able to detect polypoidal lesions in the majority of eyes (90% and 85%, respectively). However, SS‐OCT had better detection for CSI and IS/OS lines (CSI: 80% vs 45%, P = 0.05; IS/OS line: 65% vs 45%, P = 0.34). For sharp PED peak, notched PED, ability to visualize the full PED height and retinal pigment epithelial line, both OCT machines were able to detect in ≥80% of the eyes.
Conclusion
In conclusion, SS‐OCT and SD‐OCT appeared to be similarly effective at detecting most features associated with PCV. However, SS‐OCT is more superior in detecting the CSI.
Purpose To determine postoperative risk factors that influence long-term corneal graft survival. Design Prospective cohort study. Methods Nine-hundred one consecutive penetrating keratoplasty ...procedures for optical, therapeutic, or tectonic indications from the Singapore Corneal Transplant Study. Univariate and multivariate analysis was performed for postoperative risk factors; Cox proportional hazards regression with a time-dependent covariate was used for preoperative, intraoperative, donor, and postoperative risk factors in a combined model. Results Raised intraocular pressure (20.7%) was the most common complication, followed by rejection (18.2%), whereas glaucoma surgery (7.9%) and repeat grafting (7.3%) were the most common procedures after penetrating keratoplasty. The primary graft failure rate was 1.4%, and late failure was seen in 9.4% of eyes. In the combined regression model, rejection (hazard ratio HR, 3.4; P = .00), microbial keratitis (HR, 3.6; P = .00), endophthalmitis (HR, 7.7; P = .00), primary disease recurrence (HR, 73.9; P = .00), wound dehiscence (HR, 2.8; P = .02), lid surgery (HR, 2.3; P = .02), glaucoma surgery (HR, 2.46; P = .02), and repeat grafting (HR, 3.2; P = .00) were the significant postoperative failure predictors; the significant preoperative and intraoperative factors identified were female gender, graft size of less than 7 mm and more than 9 mm, primary diagnosis, preoperative inflammation, and preexisting perforation. Conclusions Postoperative complications and operative procedures after grafting have an adverse effect on graft survival.
Lipids and diabetic retinopathy Lim, Laurence S; Wong, Tien Y
Expert opinion on biological therapy,
2012-January, 1/1/2012, 2012-Jan, 2012-01-00, 20120101, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Introduction:
Diabetic retinopathy (DR) is a significant cause of visual impairment worldwide. The association between hyperlipidemia or dyslipidemia and DR has been investigated extensively, but a ...conclusive link remains elusive. This review summarizes the current knowledge regarding lipids and DR.
Areas covered:
The clinical literature on the associations between the 'traditional' lipid markers and DR will be critically evaluated, along with some of the postulated biological mechanisms underlying the associations. The emergence of several novel 'non-traditional' lipid fractions as possible biomarkers for DR will also be discussed. The review will conclude by evaluating current lipid-lowering therapies in DR and also give an overview of other novel treatments targeting lipid pathways.
Expert opinion:
Future studies need to address three important issues. First, the role of novel lipid biomarkers needs to be clarified in light of the persistent failure of epidemiological studies to demonstrate a clear association between traditional lipids and DR. Second, the pathways by which lipid-lowering therapies act in preventing the retinal complications of diabetes need to be elucidated. Last, identifying the patient profile that would benefit most from treatment is essential.
This study investigated the responses of retinal vessels to flickering light in diabetic patients with various stages of diabetic retinopathy (DR).
This cross-sectional observational study evaluated ...adult subjects with diabetes mellitus. The Dynamic Vessel Analyzer (DVA) was used to measure retinal vascular dilatation in response to diffuse illuminance flicker. Diabetic retinopathy was graded from retinal photography.
There were 279 subjects in total, with a mean age of 59.9 ± 9.2 years. The majority were male (73%) and the mean HbA1c level and mean duration of diabetes were 7.7% ± 1.4% and 13.9 ± 10.4 years, respectively. After adjustments for age, sex, smoking, duration of diabetes, HbA1c, hypertension, and hyperlipidemia, the responses of both retinal arterioles and venules to flicker stimulation decreased continuously with increasing stages of diabetic retinopathy (P = 0.008 and <0.001, respectively). Subjects with reduced arteriolar dilation responses were more likely to have any DR (odds ratio, OR, 1.20, 95% confidence interval (CI), 1.01-1.45, P = 0.045, per SD decrease). Subjects with reduced venular dilation responses were more likely to have any DR, moderate DR, or vision-threatening DR (OR: 1.27 1.04-1.53, P = 0.02; OR: 1.27 (1.06-1.49), P = 0.007; and OR: 1.51 (1.14-1.50), P = 0.002; per SD decrease, respectively).
The responses of retinal arterioles and venules to flickering light are reduced in subjects with DR, and decrease progressively with more severe stages of DR.
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