Genetic mutations and molecular mechanisms of Fuchs endothelial corneal dystrophy

Background:Fuchs endothelial corneal dystrophy is a hereditary disease and the most frequent cause of corneal transplantation in the worldwide.Its main clinical signs are an accelerated decrease in the number of endothelial cells,thickening of Descemet’s membrane and formation of guttae in the extracellular matrix.The cornea’s ability to maintain stromal dehydration is impaired,causing painful epithelial bullae and loss of vision at the point when the amount of corneal endothelial cells cannot be compensated.At present,apart from corneal transplantation,there is no other effective treatment that prevents blindness.Main text:In this review,we first summarized the mutations of COL8A2,TCF4,TCF8,SLC4A11 and AGBL1 genes in Fuchs endothelial corneal dystrophy.The molecular mechanisms associated with Fuchs endothelial corneal dystrophy,such as endoplasmic reticulum stress and unfolded protein response pathway,oxidative stress,mitochondrial dysregulation pathway,apoptosis pathway,mitophagy,epithelial-mesenchymal transition pathway,RNA toxicity and repeat-associated non-ATG translation,and other pathogenesis,were then explored.Finally,we discussed several potential treatments related to the pathogenesis of Fuchs endothelial corneal dystrophy,which may be the focus of future research.Conclusions:The pathogenesis of Fuchs endothelial corneal dystrophy is very complicated.Currently,corneal transplantation is an important method in the treatment of Fuchs endothelial corneal dystrophy.It is necessary to continuously explore the pathogenesis of Fuchs endothelial corneal dystrophy and establish the scientific foundations for the development of next-generation corneal therapeutics.

AB027.Varying pattern of proteases secretion in Fuchs corneal endothelial dystrophy

Background:The goal of this project was to analyze the relationship between cell morphology and proteases/proteases inhibitors(PIs)secretion profile in fuchs endothelial corneal dystrophy(FECD)corneal endothelial cells(CECs).Methods:Cell morphology was determined using a circularity index(4π×area/perimeter2)for each CECs population extracted from surgical FECD specimens(N=2)and healthy Eye bank corneas(N=3).CECs were cultured 28 days post-confluency.Supernatant was collected and analysed using Proteome Profiler Array detecting 35 proteases and 32 PIs(R&D Systems).Proteome signal was analyzed using Image Studio Lite and correlated with the population’s circularity index.Results:Calculation of circularity index reported different morphologies among FECD populations(0.59±0.18 and 0.64±0.17)and healthy populations(0.44±0.18,0.66±0.13 and 0.71±0.11).Proteome arrays revealed the presence of 10 proteases(ADAMTS1,Cathepsin A,B,D,and X/Z/P,DPPIV/CD26,MMP-2,3 and 12,uPA/Urokinase)and 10 PIs(Protease Nexin II,Cystatin B and C,EMMPRIN/CD147,Latexin,Lipocalin-1,Serpin E1,TFPI,TFPI-2,TIMP-1,2 and 4).Healthy and FECD specimens showed similar variation patterns according to morphology for secretion of ADAMTS1,MMP-3 and 12.However,opposing patterns between healthy and FECD populations were observed for Cathepsin B and D.Moreover,some proteins did not show variation according to phenotype in healthy CECs,but did in FECD CECs:Cathepsin A,Cystatin C,TFPI-2 and total TIMPs.For the other proteins,secretion did not vary according to morphology or no specific pattern was distinguishable.Conclusions:To conclude,our results suggest that cell phenotype is linked to the secretion of certain proteases/PIs in both groups.However,there seems to be differences in secretion of particular proteases and PIs between FECD and healthy specimens as morphology did not have a similar influence.These differences might initiate an imbalance between proteases and PIs explaining the irregular thickening of the Descemet membrane seen in FECD.

Phacoemulsification in a rare case of keratoconus with Fuch's endothelial corneal dystrophy

Dear Sir,Iam Dr.Jaya Kaushik from the Department of Ophthalmology of the Post Graduate Institute of Medical Education and Research,Chandigarh,India.I write to present a case report of phacoemulsification in a rare case of cataract associated with keratoconus and Fuch’s endothelial corneal