Cornea is a very important component of the human eyeball wall.It maintains the physiological structure of eyeball and provides protection for eye content and it is an important part of refractive media.As human inhomogeneous viscoelastic material, the cornea possesses many biomechanical properties such as the elastic, viscosity and non linear elastic.Currently, ocular response an-alyzer and corneal visualization scheimpflug technology are often used in vivo measurement and analysis to assist in the diagnosis and treatment of clinical diseases such as keratoconus, and to assess the feasibility and prognosis of refractive surgery.The latest progress of corneal biomechanical measurement and its clinical application are reviewed in this paper.

Corneal endothelial transplantation has achieved good results in domestic and foreign clinical applications , which has become the preferred method for treatment of severe corneal endothelial lesion .Corneal endothelial transplantation retained the patients′autologous healthy corneal epithelum , Bowman′s membrane and the strooma , as far as possible to ensure the integrity of the ocular sur-face, reduce the astigmatism.It had some advantages such as small invasiveness , less rejection, and faster visual recovery .Descemet stripping endothelial keratoplasty is the mianstream mode of operation , then the advanced femtosecond laser Descemet′s membrane en-dothelial keratoplasty were developed .We review the development course , operation methods , and complications of corneal endothelial transplantation in this paper .

Background Herpes stromal keratitis (HSK) is a common infectious ocular surface disease,with a higher recurrent rate,especially in necrotizing HSK.The diagnosis of HSK primarily depends on signs and symptoms,and specific laboratory diagnostic is lack.Objective This study was to clarify the expression of herpes simplex virus (HSV) in the corneal epithelium scrapings and tears of necrotizing HSK patients.Methods Thirty eyes of 30 patients with necrotizing HSK were enrolled in Nanjing Hospital of Nanjing Medical Hospital from September 2012 to September 2013 under the patient's informed consent.The eyes were examined by slit lamp microscope and scored.HSK patients received local and systemic therapy for 8 weeks and then an oral maintenance dose for 6 months.Corneal epithelial scrapings and tears samples were collected for HSV DNA detection by real-time PCR before and the 1 st,2nd,4th,6th and 8th week after therapy respectively.The difference of HSV positive rate was compared between corneal epithelium scrapings and tears samples using Chi-square test.Multilevel mixed effective model was employed to evaluate HSV concentration change in the samples at various time points in the HSV-positive patients of initial visit.The correlation between HSV concentration and clinical score was analyzed by Spearman rank correlation.Results HSV-positive rate was 46.4％ (13/30) in the corneal epithelial scrapings and 13.3％(4/30) in the tear samples,showing a significant difference between them (P =0.006).HSV-positive rate was significantly lower in the corneal epithelial scrapings 1 week,2 weeks and 4 weeks after treatment than before (P =0.001,0.003,0.004),and no HSV was detected 6 weeks and 8 weeks after treatment.No significant change in HSV-positive rate in tear samples in 1 week and 2 weeks after treatment in comparison with before treatment (P =1.000,0.583),and no HSV was detected after 4 weeks following treatment.The HSV concentration was 2460 (2 165-636500)/ml in initial 13 HSV-positive eyes of corneal epithelial scrapings and 0 (0-1150)/ml in initial 13 HSV-positive eyes of tear samples.Multilevel mixed effective model determined that HSV concentration was significantly lower in corneal epithelial scraping than that in tear (P =0.005),and HSV concentration was reduced with the lapse of time (P =0.001),with the faster rate of decline in the corneal epithelial scrapings (P =0.049).A positive correlation was found between initial HSV concentration and clinical scores (rs =0.844,P =0.000).Conclusiors Real-time PCR appears to be a powerful molecular tool for the detection of HSV in the HSK,especially in corneal epithelial scrapings of lesion.The initial positive outcome of viral DNA in corneal epithelial scrapings predicts a severe clinical procedure.

Objective　To study the value of comprehensive examination of visual electrophysiology in prognosis of visual function after cataract operation.Methods　315 patients with cataract(408 eyes) underwent preoperative routine examination with pattern reversal visual evoked potential(PVEP), red and blue flicker electroretinogram(ERG) and oscillatory potential (OPs). Normal control group included 162 cases (266 eyes). All of the ocular fundi were examined postoperatively and corrected visual acuities were obtained 3 months after operation. Results　Postoperative corrected visions ≥0.5(Ⅰ) and ＜0.5(Ⅱ) in case group compared with that in control group, amplitudes of PVEP P100-wave decreased significantly and PVEP P100-wave latency times prolonged significantly in group Ⅰ and Ⅱ. There was much more prominent changes in P100-wave of group Ⅱ due to other factors influencing visual function. There wasn't significant difference of the amplitudes and the latency times of a-wave and b-wave of Red-Blue ERG in group Ⅰ and the control group preoperatively. The amplitudes of a-wave and b-wave of Red ERG decreased, the latency times of a-wave and b-wave of Red ERG prolonged, the amplitudes of a-wave and b-wave of Blue ERG decreased but latency times didn' t prolong in group Ⅱ. The value of OPs decreased in groupⅡ compared with that of the control group, which was related to the retinopathy due to blood circulation obstruction.Conclusion　Combined examination of visual electrophysiology can estimate visual function thoroughly. The prognosis will be good if various examinations are normal before operation, but will not be good if PVEP P100 latency time prolong, the amplitudes of a-wave and b-wave of Red ERG decrease and the latency time prolong, the amplitudes of a-wave and b-wave of Blue ERG decrease and the value of OPs decrease.

BACKGROUNDHerpes simplex keratitis (HSK) caused by herpes simplex virus 1 (HSV-1), which has high recurrent rate and incidence of severe vision loss, is the leading cause of infectious blindness in the world. The aim was to explore the clinical efficacy of oral ganciclovir (GCV) in the prevention of recurrent HSK.

METHODSA multicenter, prospective, randomized, single-blind, and controlled clinical trial was conducted from April 2010 to June 2013. One hundred seventy-three patients (173 eyes involved) who were diagnosed as recurrent HSK definitely, including stromal keratitis and corneal endotheliitis, were divided into three groups randomly: negative control (placebo) group was topically administered with 0.15% GCV ophthalmic gel, 4 times per day and 0.1% fluorometholone eye drops, 3 times per day until resolution of HSK; positive control acyclovir (ACV) group was topically adopted the same ophthalmic gel and eye drops and additionally received oral ACV 400 mg 5 times a day for 10 weeks and followed by 400 mg 2 times per day for 6 months; test GCV group was topically adopted the same treatment as negative control group and additionally received oral GCV 1000 mg 3 times per day for 8 weeks. The symptoms and signs were evaluated before and after the therapy 1 st week, 2 nd week and then followed up every 2 weeks until recovery. Furthermore, we followed up recurrence of HSK for every 3 months after recovery and then assessed the cure time, recurrent rate and adverse reactions.

RESULTSOne hundred and seventy-three patients were followed up 7-48 months (mean 32.1 ± 12.3 months), but 34 patients were failed to follow-up. The cure time was 12.1 ± 4.3, 11.9 ± 4.0 weeks in negative control (placebo) group and positive control ACV group respectively (P = 0.991), which was longer than that in test GCV group (8.6 ± 2.8 weeks) and there was a significant difference between test GCV group and negative control (placebo) group or positive control ACV group (P = 0.000). Furthermore, the recurrent rate was higher in negative control (placebo) group (47.3%) than that in positive control group ACV (26.7%) and test GCV group (17.2%), and there was a great significant difference among the three groups (P = 0.007), but there was no significant difference between positive control ACV group and test GCV group (P = 0.358). In addition, there was no obvious adverse reaction expect neutropenia (only one patient in test GCV group).

CONCLUSIONShort-term oral GCV could cure recurrent HSK and endotheliitis, shorten the course, reduce recurrent rate of HSK and have confirmed safety.

Adult ; Aged ; Antiviral Agents ; administration & dosage ; therapeutic use ; Female ; Ganciclovir ; administration & dosage ; therapeutic use ; Humans ; Keratitis, Herpetic ; drug therapy ; Male ; Middle Aged ; Single-Blind Method ; Treatment Outcome

Background The instability of tear film in dry eye often affects the visual quality after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK).The prediction for visual quality following FS-LASIK was difficult in the past because of the limiting of examination method.OQAS-Ⅱ is a quantitative checking system of visual quality,which is helpful for the evaluation of the relationship between tear stability and visual quality following FS-LASIK.Objective This study was to investigate the predicting effects of the quality of tear film on visual quality after LASIK.Methods A prospective cohort study was performed.One hundred and twenty eyes of 120 myopic patients who wanted to receive FS-LASIK were enrolled in Nanjing First Hospital from August to December 2015 after informed consent.The objective scattering index (OSI) was 1.2 in the patients.The patients were divided into mild dry eye group (71 eyes) and non-dry eye group (49 eyes) based on the Expert Consensus on Clinical Diagnosis and Treatment of Dry Eye(2013).FS-LASIK was performed in the non-dry eye group,and 0.1％ sodium hyaluronate eye drops was topically administered for 1 month firstly and then the operation was carried out in the same way in the mild dry eye group.Slit lamp microscope,uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),spherical equivalent (SE) were examined,and the safety index and availability index were assessed.OQASTM Ⅱ analysis system was employed for the defection of Schirmer Ⅰ test (S Ⅰ t),breakup time of tear film (BUT),modulation transfer function cut-off frequency (MTF cut off) and mean OSI before and after surgery.Results The safety index was 1.05 ±0.11 and 1.03 ±0.09,and the availability index was 1.02±0.14 and 1.01 ± 0.12 in the non-dry eye group and mild dry eye group,respectively,showing significant differences between the two groups (t =0.391,0.147,both at P＞0.05).The BUT was evidently shortened 1 month and 3 months after surgery in comparison with before surgery in both non-dry eye group and mild dry eye group,and BUT in the mild dry eye group was shorter than that in the non-dry eye group in postoperative 3 months,with a significant differences between them (P＜0.05).The mean OSI was increased and MTF cutoff was reduced 1 month,3 months and 6 months after surgery in comparison with before surgery in both mild dry eye group and none-dry eye group,and mean OSI was higher and MTF cutoff was lower in the mild dry eye group than that in the non-dry eye group,with significant differences between them (all at P＜0.05).In postoperative 12 months,BUT,mean OSI and MTF cutoff were near normal in both groups.Conclusions FS-LASIK can improve objective visual quality,and preoperative tear film quality is associated with objective visual quality after FS-LASIK.The unstable tear film affects visual quality after FS-LASIK.OQASTM Ⅱ system can diagnose and monitor tear change of dry eyes,which is helpful for the screening of indicator of FS-LASIK and rational prediction of postoperative visual quality.

Objective To compare the clinical efficacy and safety following the topical application of pazufloxacin mesylate eye drops with levofloxacin eye drops (LOFX) for bacterial conjunctivitis.Methods A multicenter,randomized,investigator-masked,parallel-controlled clinical trial was performed.Five hundred and twenty eyes of 520 patients with bacterial conjunctivitis were enrolled from March to October 2008 in seven ophthalmic centers in China.The patients were randomized into trial group and control group in 3 ∶ 1 ratio with the 390 eyes in the trial group and 130 eyes in the control group.Pazufloxacin mesylate eye drops was topically used 4 times per day for consecutively 7-14 days in the trial group,and levofloxacin eye drops was used in the same way in the control group.Microbiological cultures for conjunctiva sac secretions and drug sensitive test were carried out before and at the end of the administration of eye drops.The signs and symptoms were observed and scored before treatment and 0,3,7 and 14days after treatment.The adverse events following the administration of the eye drops were evaluated and compared.Results The intention to treat analysis (ITT) showed that the cure rate was 59.38％ in the trial group and 60.47％ in the control group,with the effective rate 88.80％ and 86.05％,respectively,with an insignificant difference between the two groups (x2 =0.12,P =0.72).The clinically evaluable analysis (CE) exhibited that the cure rates were 63.48％ in the trial group and 63.87％ in the control group,with the effective rate 92.46％ and 88.24％,whichwas not significantly different between them (x2 =0.54,P=0.46).The modified-ITT analysis (mITT) showed that the cure rates were 60.57％ in the trial group and 62.07％ in the control group,with the effective rate 90.32％ and 88.51％,without significant difference between the two groups (P＞0.05).Based on microbiologically evaluable analysis (ME),the clinical cure rates were 63.71％ and 63.41％ in the trial group and control group,and the effective rates were 93.44％ and 90.24％,respectively.There was no significantly difference between the both groups (P＞0.05).In the trial group and control group,the bacterial eradication rate was 89.42％ and 90.80％ based on ITT,90.11％ and 92.77％ based on CE,respectively.There was no significant difference in incidences of adverse events following the administration of the drug between the trial group and control group,including ocular tolerance,burning sensation,pricking and itching (P =0.34).Conclusions The effectiveness and adverse response were resemble between Pazufloxacin mesylate eye drops and LOFV following the topical application for bacterial conjunctivitis,which indicate that Pazufloxacin mesylate eye drops is effective and safe.

Corneal collagen cross-linking (CXL) has been proved to be a very safe and effective technique to halt the progression of many cornea diseases, such as ectasia disease, infectious keratitis and ametropia.CXL techniques include conventional CXL, accelerated CXL, transepithelial CXL and photochemical CXL.CXL can prevent the progression of dilated keratopathy, postpone or avoid corneal transplant surgery, and has an auxiliary function in the treatment of bullous keratopathy, infectious keratitis except herpes virus infection, and ametropia.CXL is not effective for patients with ocular herpes virus infection and patients with thin cornea and may even worsen the development of the disease.This review summarized the advantages and disadvantages of common CXL techniques, indications, contraindications, and complications, which may help enhancing the clinical application of CXL and reducing its complications.

Objective:To evaluate the effect of mushroom-like pattern femtosecond laser enabled penetrating keratoplasty with different laser energies on the ring incision and corneal endothelial cells, and compare with conventional penetrating keratoplasty.Methods:According to the point/line separation and blasting energy, 48 porcine corneas were randomly divided into 6 groups by using a random number table.In group A, B, C, D and E, the point/line separation was 4/4, 4/4, 8/8, 8/8 and 4/2 μm, and the blasting energy was 1.5, 2.0, 1.5, 2.0 and 2.0 μJ; In group F, a negative pressure ring drill was used to make penetrating incisions.There were 8 porcine corneas in each group.Femtosecond laser of 200 kHz was used to make corresponding mushroom-shaped penetrating incisions on the porcine corneas, and compared with porcine corneas incisions with a ring drill.The optical and scanning electron microscope images were used to evaluate the glossiness of ring incisions.Four human corneas used femtosecond laser for mushroom-like penetrating incisions with point/line separation 8/8 μm, and blasting energy 2.0 μJ as the experimental group; three human corneas received a negative pressure ring drill for penetrating incisions as the control group.The loss rate of corneal endothelial cells was observed and compared between experimental group and control group.The donor guardians agreed to the acquisition and use of the donors' cornea and signed informed consents.This study protocol was approved by the Ethics Committee of Nanjing First Hospital.Results:Femtosecond laser mushroom penetrating ring incision completion rate was 100%.The corneal ring incision in each group was stepped, and sections of ring incisions in group A and group E were glossiest by the light microscope.Sections of ring incisions in group E were glossiest by the laser scanning electron microscope.The overall glossiness scores of the corneal ring incisions among various groups were statistically significantly different by the light microscopy ( F=22.75, P<0.01). Among them, the glossiness scores in the group A were higher than those in the group B, and the glossiness scores in the group C were higher than those in the group D, with statistically significant differences (both P<0.05). The overall glossiness scores of corneal ring incisions among various groups were statistically significantly different by laser scanning electron microscopey ( F=122.33, P<0.01). Among them, the glossiness scores in the group A were higher than those in the group B, and the the glossiness scores in the group C were higher than those in the group D, with statistically significant differences (both P<0.05). The corneal endothelial cells showed regular shape and tight arrangement in the experimental group, and irregular shape and loose connections were seen in the control group.The average corneal endothelial cell loss rate in the experimental group was (2.2±1.3)%, lower than (6.7±2.1)% of the control group, with a significant difference between them ( t=3.569, P<0.05). Conclusions:Femtosecond laser can produce perfect mushroom configuration, and the ring incision glossiness is better in comparison with trephine cutting.Femtosecond laser ring cut can lessen corneal endothelial loss.