Semaphorin 7a participants in pterygium by regulating vascular endothelial growth factor

AIM: To investigate the relationship between semaphorin 7a expression and cell proliferation and migration in pterygium fibroblasts. METHODS: Twenty-six patients with surgically diagnosed pterygium were enrolled, including 15 cases of primary pterygium and 11 cases of recurrent pterygium. In addition, 12 cases of normal conjunctival tissue were collected. The expression of semaphorin 7a in normal conjunctival tissue, primary pterygium and recurrent pterygium was detected by real-time polymerase chain reaction. Recurrent pterygium fibroblasts were isolated and cultured, and the expression of semaphorin 7a was silenced by small interfering RNA(siRNA) interference technique. Furthermore, the effects of si-semaphorin 7a interference on the mRNA and protein levels of β1-integrin, vascular endothelial growth factor A(VEGFA) and vascular endothelial growth factor receptor(VEGFR), and on fibroblast proliferation were analyzed. Transwell assay was used to detect the effect of semaphorin 7a interference on fibroblast migration. RESULTS: Semaphorin 7a was highly expressed in the primary pterygium and recurrent pterygium samples than that of the normal conjunctival tissue. Compared with the primary pterygium, the expression of semaphoring 7a in the recurrent pterygium samples was significantly increased(P<0.05). The mRNA and protein expression levels of β1-integrin, VEGFA and VEGFR were decreased after si-semaphorin 7a transfection, and as well as the cell proliferation and migration. CONCLUSION: Semaphorin 7a might play important roles in the pathogenesis of pterygium by affecting the expression of β1-integrin, VEGFA and VEGFR.

Comparative study of visual acuity and aberrations after intralase femtosecond LASIK:small corneal flap versus big corneal flap

AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

A short-term study of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas

AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure.RESULTS: The mean thinnest thickness of the cornea was 408.5 ±29.0 μm before treatment and reduced to369.8 ±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0 ±26.5 μm before CXL and recover to 412.5 ±22.7 μm at 3mo after treatment, P =0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6 ±4.0 diopters, and slightly decreased(54.7±4.9 diopters) after surgery(P =0.085). Mean best-corrected visual acuity was 0.55 ±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery(P =0.879).The endothelial cell density was 2706.4 ±201.6 cells/mm2 before treatment, and slightly decreased( 2641. 2 ±218.2 cells/mm2) at last fellow up(P =0.002).CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.

Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani

AIMTo evaluate the antimicrobial properties of ultraviolet A (UVA) (365 nm)/riboflavin against Candida albicans and Fusarium solani.

Therapeutic and inducing effect of corneal crosslinking on infectious keratitis

The corneal crosslinking （CXL） with riboflavin and ultraviolet-A （UVA） is a new therapy method to successfully treat infectious keratitis in clinical practice. However, there are rare reports on the complications of CXL such as the secondary keratitis. The diverse clinical outcomes on keratitis have highlighted the necessity to further evaluate the efficacy and complications of CXL. We reviewed the positive and negative reports on UVA/riboflavin related with keratitis and provided our opinion on the therapeutic and side effect of UVA/riboflavin crosslinking on keratitis.

Inhibitory effect of polysulfated heparin endostatin on alkali burn induced corneal neovascularization in rabbits

AIM: To investigate anti-angiogenic effects of polysulfated heparin endostatin(PSH-ES) on alkali burn induced corneal neovascularization(NV) in rabbits.METHODS: An alkali burn was made on rabbit corneas to induce corneal NV in the right eye of 24 rabbits. One day after burn creation, a 0.2 m L subconjunctival injection of 50 μg/m L PSH-ES, 50 μg/m L recombinant endostatin(ES), or normal saline was administered every other day for a total of 14d(7 injections). Histology and immunohistochemisty were used to examine corneas.Corneal NV growth was evaluated as microvessel quantity and corneal vascular endothelial growth factor(VEGF)expression was measured by immunohistochemical assay.RESULTS: Subconjunctival injection of ES and PSHES resulted in significant corneal NV suppression, but PSH-ES had a more powerful anti-angiogenic effect than ES. Mean VEGF concentration in PSH-ES treated corneas was significantly lower than in ES treated and saline treated corneas. Histological examination showed that corneas treated with either PSH-ES or ES had significantly fewer microvessels than eyes treated with saline. Additionally corneas treated with PSH-ES had significantly fewer microvessels than corneas treated with ES.CONCLUSION: Both PSH-ES and recombinant ES effectively inhibit corneal NV induced by alkali burn.However, PSH-ES is a more powerful anti-angiogenic agent than ES. This research has the potential to provide a new treatment option for preventing and treating corneal NV.

Evaluation of corneal endothelium after UVA/riboflavin cross-linking in thin keratoconic corneas

Dear Sir,UVA/riboflavin cross-linking （CXL） has been used clinically applied for the treatment of keratoconus and corneal edema via enhancement of corneal stiffness The safety of the corneal endothelium is of prime importance during CXL treatment. In clinical practice, a corneal thickness （CT） of 400um has traditionally been regarded as the minimum treatable thickness, thereby avoiding damage to the corneal endothelium Although CXL has been applied to thinner corneas, using a hypoosmotic solution onto cornea and inducing edema . CXL safety still needs further evaluation because of lower relative concentration of collagen in the hydrated stroma . This study aims to evaluate the changes of corneal endothelial density （ECD） in cases where the CT is 〈400 um before iatrogenic corneal swelling and CXL treatment.