Laser treatment in 341 patients with exudative agerelated macular degeneration

AIM:To document the prognosis of laser treatment in patients with exudative age-related macular degeneration(AMD).· METHODS:Efficacy of the intervention was evaluated using a before-after method.· RESULTS:A total of 392 eyes of 341 patients with exudative AMD were examined.77.6% had choroideal neovascularisation(CNV).Before the use of indocyanine green(ICG) angiography,occult CNV was detected in only 1.8% of the eyes,but after the use of ICG angiography,this increased to 19.5%(P<0.001).Of the 349 eyes which were followed up,visual acuity had remained stable in 68.2% of the eyes.There was a statistically significant relationship between localisation of lesion and visual acuity changes on pre-and post-laser treatment(P<0.001).Also there was a statistically significant relationship between localisation of lesion and recurrence(P<0.05).The recurrence was less in subfoveal lesions than that in juxtafoveal and extrafoveal lesions.· CONCLUSION:ICG angiography is highly important in the treatment of occult CNV.

Recent Developments in the Treatment of Wet Age-related Macular Degeneration

Age-related macular degeneration(AMD)is the most common cause of irreversible blindness and visual impairment in individuals over the age of 50 years in western societies.More than 25 million people currently suffer from this illness in the world,with an additional 500000 every year,approximately.It is a multifactorial ocular disease that affects the maculae due to a late-onset progressive neurodegeneration and dysfunction of photoreceptors and retinal pigment epithelium(RPE).There are many subtypes of AMD but basically two broad forms:the nonneovascular(dry,nonexudative)and neovascular(wet,exudative).Exudative AMD is the less common form(about 15%)but tends to progress more rapidly.At the moment,wet AMD is treated primarily on the basis of anti-vascular endothelial growth factor(VEGF)agents,which have led to massive improvement in the prognosis of the disease since they were first introduced.This article focuses on the latest treatment approaches to neovascular AMD.An extensive literature review was performed in order to illustrate the effectiveness of current and future anti-VEGF agents as well as the landmark clinical studies that have been carried out to establish these drugs as a gold standard in the therapy of wet AMD.

Novel mitochondrial therapies for the treatment of age-related macular degeneration

The purpose of this article is to review current literature and data regarding treatment options for age-related macular degeneration(AMD)related to mitochondrial therapy.This article considers the presence of flavoprotein fluorescence as a potential biomarker to test the effectiveness of the treatments.We focus primarily on two major mitochondrial targets,nuclear factor erythroid 2-related factor(NFE2L2)and PGC-1α,that function in controlling the production and effects of reactive oxidative species(ROS)directly in the mitochondria.PU-91 is an FDA approved drug that directly targets and upregulates PGC-1αin AMD cybrid cell lines.Although neither NFE2L2 nor PGC1-αhave yet been tested in clinical trials,their effects have been studied in rodent models and offer promising results.MTP-131,or elamipretide®,and metformin are two drugs in phase II clinical trials that focus on the treatment of advanced,non-exudative AMD.MTP-131 functions by associating with cardiolipin(CL)whereas metformin targets adenosine-monophosphate protein kinase(AMPK)in the mitochondria.The current results of their clinical trials are elucidated in this article.The molecular targets and drugs reviewed in this article show promising results in the treatment of AMD.These targets can be further pursued to improve and refine treatment practices of this diagnosis.

Genetic variants in three genes and smoking show strong associations with susceptibility to exudative age-related macular degeneration in a Chinese population

Background The present study was undertaken to replicate the associations of representative polymorphisms in three genes （complement factor H （CFH）, complement factor B （BF） and HtrA serine peptidase 1 （HTRA1）） with exudative age-related macular degeneration （AMD） in a Han Chinese population, and to test if the modifiable environmental factors affect AMD susceptibility associated with different type of genotype in these genes. Methods An age, gender and ethnicity matched case-control study was conducted to genotype the representative single neucleotide polymorphisms （SNPs） loci including rs1061170 and rs1410996 in CFH, rs641153 and rs4151667 in BF and rs11200638 in HTRA1 gene in 144 exudative AMD patients and 126 normal controls using PCR-RFLP and direct resequencing. The demographic characteristics and behavioral risk factors were also recorded. Allelic and genotypic associations for individual SNP and joint associations with two loci were performed. The gene-gene and gene-environment interactions were analyzed using multivariate non-conditional Logistic regression analysis. Results The C risk allele frequencies for CFH Y402H （rs1061170） in cases and controls were 12.5% and 5.4% respectively, which were much lower than those in Caucasians （P 〈0.001）. Compared with TT homozygous genotype, the CT heterozygous genotype was positively associated with AMD with odds ratio （OR） of 3.23 （1.36-5.07）. However, the population attributable risk （PAR） of C allele was only 3.3% （1.4%-4.3%）. rs1410996 was also associated with AMD independent of Y402H. The ORs of exudative AMD for individuals carrying one copy risk allele and two copy risk alleles were 2.57 （1.21-5.45） and 4.76 （2.15-10.55） respectively, with correspondent PARs of 28.3% （2.0%-40.5%） and 38.2% （21.8%-45.4%）. rs11200636 in HTRA1 was another susceptible locus for AMD and the risk homozygotes were significantly susceptible for exudutive AMD （OR=3.98, 1.88-8.43） with PAR of 38.9% （24.3%-45.8%）. Education status and cigarette smoking were also related to exudative AMD. After controlling for environmental risk factors, CFH and HTRA1 SNPs were independently associated with exudative AMD, with OR of 3.50 （1.45-8.45） for CT genotype in Y402H, 3.34 （1.33-8.36） for GG genotype in rs1410996 and 3.85 （1.58-9.42） for AA genotype in rs11200638 respectively. The interaction analysis between gene and environmental factors showed that smoking synergistically increased susceptibility of AMD for heterozygotes of rs1410996, with ORinteraction of 7.33 （Pinteraction=0.029）. Conclusions In a Han Chinese population, CFH and HTRA1 polymorphisms appear to be independently and possibly additively hereditary contributors to exudative AMD. Y402H polymorphism conferred a significant but relatively lower contribution in Chinese than in Caucasians with a low frequency of risk allele. The gene-environment interaction may be a best way to encourage those with a high genetic risk to prevent AMD by avoiding modifiable factors until there is effective treatment for AMD.