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In this study, we investigated the use of porous silicon (PSi) fabricated using metal-assisted chemical etching (MACE) as a substrate for the deposition of Au nanoparticles (NPs) for the reduction of nitroaromatic compounds. PSi provides a high surface area for the deposition of Au NPs, and MACE allows for the fabrication of a well-defined porous structure in a single step. We used the reduction of p-nitroaniline as a model reaction to evaluate the catalytic activity of Au NPs on PSi. The results indicate that the Au NPs on the PSi exhibited excellent catalytic activity, which was affected by the etching time. Overall, our results highlighted the potential of PSi fabricated using MACE as a substrate for the deposition of metal NPs for catalytic applications.

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We evaluated the accuracy of an app for the iPad tablet computer (Eye Chart Pro) as a portable method of visual acuity (VA) testing. A total of 120 consecutive patients (240 eyes) underwent visual acuity test with an iPad 2 and a conventional light-box chart. The logMAR VA results from the iPad were significantly higher than those from the light-box (P < 0.001). Bland-Altman analysis revealed a mean difference (bias) of 0.02 logMAR units between the VA results from the iPad chart and the light-box chart, with 95% limits of agreement of -0.14 to 0.19. Two groups of patients were defined: in Group 1 there were 182 eyes with VA better than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 0.54 and by the light-box chart it was 0.52; there was no significant difference between them (P = 0.69). In Group 2 there were 58 eyes with VA equal to or worse than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 1.26 and was 1.10 by the light box; the result from the iPad was significantly lower (P < 0.001). The Eye Chart Pro app installed on the iPad is reliable for VA testing only when the Snellen VA is better than 0.1 (20/200).

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OBJECTIVE: To study the development of lymphatic vessels after keratoplasty and to explore the molecular mechanisms of corneal lymphangiogenesis in transplanted corneas. METHODS: Experimental research. The development of corneal lymphangiogenesis was examined by LYVE-1 immunohistochemistry and whole mount immunofluorescence 1, 3, 7, 10, 14, 30 and 60 days after corneal transplantation, then lymphatic vessels counting (LVC)was evaluated. The expression of vascular endothelial growth factor-C (VEGF-C) in transplanted corneas was examined by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and real time-PCR at same time. In addition, the inflammatory index (IF) was recorded at each time point. The association of VEGF-C and IF with LVC in transplanted corneas was examined. Analysis of the significance of differences between two groups was performed using paired Student's t-test. Pearson's analysis was used to analyze the correlation between VEGF-C, IF and LVC. RESULTS: Corneal lymphangiogenesis occurred in the stroma with LVC (1.8 ± 0.3) on Day 3, then developed and reached the peak with LVC (9.1 ± 1.5) on Day 14 after corneal transplantation. Both VEGF-C protein and mRNA up-regulated dramatically in rat transplanted corneas. The immunoreactivity reached the peak on the 3(rd) day and the 14(th) day after keratoplasty. Compared with the expression of VEGF-C mRNA (1.62 ± 0.08 copies/g) on Day 3, the expression of VEGF-C mRNA (2.48 ± 0.03 copies/g) significantly increased 14 days after the transplantation (t = 4.296, P = 0.02). LVC was strongly and positively correlated with IF (r = 0.55, P = 0.003) and the expression of VEGF-C mRNA (r = 0.51, P = 0.003). CONCLUSIONS: Corneal lymphangiogenesis correlates closely with corneal inflammation. The increased expression of VEGF-C in the cornea may be one of the important molecular mechanisms in the occurrence of corneal lymphangiogenesis after keratoplasty.

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OBJECTIVE: To explore the lymphangiogenesis process in alkali burned human cornea and to discuss factors modulating this process. METHODS: It was a retrospective case series study. Twenty-two cases (22 eyes) of hospitalized patients suffering from alkali burned cornea and requiring keratoplasty from January to December 2005 were analyzed retrospectively. Before surgery, injury time (IT) and injury degree (ID) were recorded. Furthermore, inflammation index (II) and relative area of new blood vessels (BVA) were measured. Cornea specimens were assessed for lymphatic vessel counting (LVC) and blood vessel counting (BVC) via immunohistochemical staining and transmission electronic microscopy. Meanwhile, HE staining was also performed to observe infiltration of polymorphonuclear (PMN) leucocytes in corneal tissues. Student t-test, Pearson correlation test and Stepwise regression analysis were used to investigate the influencing factors. RESULTS: In these 22 cases, IT was (57.62 +/- 31.72) months; ID was (12.00 +/- 2.76) scores; II was (2.32 +/- 2.63) scores; BVA was (29.79% +/- 18.61%); BVC was (14.45 +/- 9.29) units; LVC was (2.73 +/- 4.57) units and PMN was (13.45 +/- 13.09) units. In 7 patients with IT more than 64 months (accounted for 32% of 22 cases), lymphangiogenesis [(8.6 +/- 3.8) units] and hemangiogenesis [(22.3 +/- 11.1) units] were both present. In these 7 patients, the whole number of LVC was 60 units, constituting 16% of all vessels (BVC+LVC = 378 units). The correlation coefficient of LVC with IT, ID, BVA, PMN and II was -0.673, 0.604, 0.755, 0.806 and 0.873, respectively. P value of all these correlations was less than 0.05. Further regression analysis revealed that LVC could be approximately calculated from II and BVA multiplying certain constant coefficients separately (resulting in lymphatic index, LI). Lymphatic vessels with characteristic ultrastructures and inflammatory cells were identified by transmission electronic microscopy. CONCLUSIONS: Lymphatic vessels exist in part of alkali burned human corneas and may be estimated through II and BVA indirectly. Lymphatic index may be a convenient and useful clinical index for evaluating lymphangiogenesis in corneal alkali burn.

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OBJECTIVE: To evaluate the efficacy and safety of keratoplasty combined with corneal foci resection in the treatment of Terrien's marginal degeneration (TMD). METHODS: In this nonrandomized retrospective case series, the records of 48 eyes from 40 patients with TMD who received keratoplasty from January 1995 to December 2005 in Zhongshan Ophthalmic Center were reviewed retrospectively. Orbscan topography examination was undertaken in 8 eyes of 8 patients and the refractive error of 9 eyes from 9 patients was tested before and after the operation. RESULTS: The mean age of the patients was (30 +/- 6) years old. The mean follow up period was (7 +/- 6) years. It took (3 +/- 1) months postoperatively to obtain a stable visual acuity. Before operation, the naked eye and best corrected visual acuity (VA) (Q25,Q75) were (0.05,0.4), and (0.1,0.5), respectively, while improved to (0.2,0.6) and (0.4,0.7) after operation, respectively (Z = 4.63, 3.85, both P<0.01). VA was improved in 39 eyes (81.3%), remained at the same level in 4 eyes (8.3%), decreased 1-2 lines in 3 eyes (6.3%), and decreased more than 2 lines in 2 eyes (4.1%) after the operation. The median spherical diopter and cylinder diopter were (-2.00 D, -8.50 D) and (2.50 D,12.00 D) before operation, while decreased to ( -1.25 D, -4.75 D) and (0.75 D, 4.25 D) after operation (Z= 2. 49, 2.54, P = 0.01, 0.01). The improvement in Sim K's astigmatism, astigmatism in 3 mm zone and mean power in 3 mm and 5 mm zone were reduced statistically significant after the operation (P <0.05); with the exception of astigmatism in the 5 mm zone, which was not reduced significantly after the operation (Z = 1.86, P = 0.06) . The operative complications included corneal perforation during operation in 5 eyes (10.4%), hydrops between graft and recipient interface in 8 eyes (16.7%), epithelial in-growth in 4 eyes (8.3%), choroidal detachment in 1 eye (2.1%), graft rejection in 7 eyes (14.6%), and recurrence in 3 eyes (6.3%). Secondary surgery was required in 5 eyes (10.4%) for interface hydrops, epithelial in-growth and recurrence of TMD. CONCLUSIONS: Keratoplasty combined with foci resection is effective and safe in the treatment of TMD. This procedure can preserve and improve the visual activity.

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