Corneal blindness,second only to cataracts as a cause of blindness in China,is inflicting an increasing number of patients because of the extreme shortage of corneal donor tissue.Unlike the developed WeStern countries,the primary indications for corneal transplants in China are comprised of severe infectious keratitis, ocular acid burn, thermal burn, and bullous keratopathy caused by various complications from intraocular surgeries.Preventing corneal blindness in China is complicated by multiple challenges such as late-stage corneal diseases, poor compliance, affordability and a critical shortage of tissue for transplants.In recent years,because of these especially difficult conditions,China's corneal specialists have developed and innovated a series of new techniques that include deep anterior lamellar keratoplasty, endothelial keratoplasty, keratoprosthesis and corneal xenotransplantation.These have significantly improved donor utilization and reduced rejection rates for high-risk keratoplasties.However,the unsolved shortage of donor corneas is still the main bottleneck in preventing corneal blindness,which has resulted in fewer opportunities to cultivate novice corneal surgeons. In order to quickly reduce the amount of corneal blindness, it is urgent to promote legislation for corneal donation, support research in corneal eugineering xenotransplantation, and strengthen the international cooperation in eye banks.The innovation and training of new surgical techniques is still a long and arduous task in China.

Objective To evaluate the clinical efficacy of conjunctival flap transplantation for the treatment of scleral necrosis after eye burns or ocular surgeries.Methods It was a retrospective case series study.A total of 13 cases of scleral necrosis, including 10 patients with eye burns and 3 cases with post-pterygium excision,received conjunctival flap transplants in Shandong Eye Hospital from January 2007 to March 2012.Four patients received conjunctival flap transplants only,2 patients had combined lamellar keratoplasty (LK),6 patients received combined amniotic membrane transplants (AMT),and 1 patient had combined LK and AMT.The follow-up period ranged from 3 to 24 months after the surgery and during this time scleral necrosis status, conjunctival flap survival, et al,were monitored. Results The transplanted conjunctival flap appeared pale within 1 week after the surgery, and congestion developed after 1 week with conjunctival flap healing. The congestion gradually disappeared when the suture was removed after 2 weeks.The conjunctival flaps hcaled with the sclera and necrosis was controlled in all patients. At the final follow-up evaluation, corneal transparency was observed in 2 patients,clear graft in 3 patients,corneal macula in 1 patient,and corneal vascularization in 7 patients.Conclusion Conjunctival flap transplantation (or combined LK and/or AMT) is a safe and effective method for the clinical treatment of scleral necrosis.This method can prevent the risk of scleral necrosis and perforation and establishes a stable ocular surface for further treatment.

Objective To evaluate the contribution of different degrees of astigmatism on the latency and amplitude of pattern visual evoked potentials (PVEPs).The effect of astigmatism on the transmission and response intensity of visual signals in the visual cortex was evaluated.Methods It was a random designed study.PVEPs were measured in subjects with normal or normal corrected visual acuity using a checkerboard pattern stimulus under varying conditions using different astigmatic trial lens powers in succession (0-5 D).Paired samples t test,analysis of variance and Pearson correlation was performed.Results When a lower spatial frequency (60' checkerboards stimulus) was used,there was little change in the latency of P100 (F=0.290,P＞0.05).However,when a higher spatial frequency (15' checkerboards stimulus) was used,VEP latency increased with a greater degree of astigmatism (F=10.850,P＜0.01; r=0.647,P＜0.01).There was a gradual reduction of amplitudes of P100 as convex cylindrical lens power increased (when 60' checkerboards were used, F=3.947,P＜0.01; r=-0.470,P＜0.01; when 15' checkerboards were used,F=14.280,P＜0.01; r=-0.699,P＜0.01).Conclusion The transmission of visual signals depends on the quality of the visual image formed on the retina.Visual signal transmission time and response intensity in the visual cortex are affected not only by the defocus of the retinal image but also by the spatial frequency of the pattern stimulus.With a high spatial frequency,the transmission of visual signals is faster and the response intensity of the visual cortex is greater if the visual image formed on the retina is clear.

Objective To study the difference in the prevalence of conjunctivochalasis (CCh)when using two different diagnostic and inclusion standards.Methods It was a cross-sectional study.The prevalence of CCh based on the diagnostic standards of H(o)h and Zhang was conducted in people over 60 years of age in Shanghai's CaoYangXinCun community.The people underwent interview and ocular examination.Pre- test was maded before formal investigation,and the quality of investigations was guaranteed.Data were analyzed using an independent samples t test and a chi-square test.Results Two hundred and forty-six people (492 eyes) were included in this study.One hundred and ninety-three cases (377 eyes) (78.4％) were diagnosed with CCh using the H(o)h's standard,whereas 96 cases (191 eyes) (39.0％) were diagnosed using the Zhang standard.When they were subdivided into different age groups,60-65,66-70,71-75,76-80,and over 80 years of age,the respective prevalences of CCh with H(o)h's standard were 69.3％,72.1％,76.0％,82.1％,89.3％ and 100％ while respective prevalences were 31.6％, 36.5％,42.3％,42.9％ and 44.6％ with Zhang's standard.There was a statistical difference in the prevalence of CCh with the two standards (x2=78.91,P＜0.01).Despite the difference,the prevalence of CCh with both standards increased with age.Conclusion The prevalence of CCh with H(o)h's standard is higher than that with Zhang's yet it is also reasonable to use Zhang's standard to diagnose CCh.

Objective To design a subjective aniseikonia test using the synoptophore and to evaluate the validity and repeatability of the tests for further use in clinical practice.Methods It was a repeat measurement design.Two graphs were designed based on the ratio of similar triangles.The differences in size,between subjective images for each eye were measured with the synoptophore.The validity of the test was evaluated by comparing the difference between the measured aniseikonia and the theoretical aniseikonia simulated by different power lenses, and the repeatability was evaluated by comparing the results obtained at two different time points with an interval of 24 hours.The data were analyzed by linear regression analysis and analysis of covariance. Results The regression coefficient of the overall regression equation was 0.908 for tbe two different time points,which was lower than the theoretical value (the theoretical value is 1).There was no statistically significant difference between the results of the two different time points.Conclusion The validity and repeatability of this aniseikonia test is relatively high.However,further clinical study should be carried out to test its use in the clinic.

Polypoidal choroidal vasculopathies share some clinical presentations with neovascular age-related macular degeneration,but differ in epidemiology and prognosis as well as in the response to treatments.Diagnosis requires the use of indocyanine green angiography.Optical coherence tomography provides more information about the pathophysiology of this disorder. Treatments, including laser photocoagulation, transpupillary thermotherapy,anti-VEGF drug injection and glucocorticoid injection have various degrees of effectiveness.This review highlights advances in the diagnosis and treatment of polypoidal choroidal vasculopathy.