Current understanding of the treatment and outcome of acute primary angle-closure glaucoma: an Asian perspective

<p><b>INTRODUCTION</b>Primary angle-closure glaucoma (PACG) is a major cause of blindness among Asians. A better understanding of the disease will improve the treatment and outcome of this condition.</p><p><b>METHODS</b>A literature review of all recent publications on PACG was carried out. Articles were retrieved using a key word search of MEDLINE, PubMed and Science Citation Index databases.</p><p><b>RESULTS</b>Following laser peripheral iritodomy for acute angle-closure, Asians were found to have a higher tendency to develop a subsequent rise in intraocular pressure compared to Caucasians. Furthermore, the extent and severity of visual field damage was more severe in Asians than Caucasians, particularly in eyes that presented insidiously with chronic PACG. Prophylactic laser iridotomy in the contralateral eye was found to be highly effective in preventing acute angle-closure attacks.</p><p><b>CONCLUSION</b>PACG is more difficult to manage and is associated with more severe long-term visual morbidity in Asians than Caucasians. Regular follow-up of patients with PACG is important for the early detection of progression of the disease and visual field deterioration.</p>

Enhancement of the mechanical and biological properties of a biomembrane for tissue engineering the ocular surface

<p><b>INTRODUCTION</b>In this study, we have developed and optimised a novel gelatin-chitosan (GC) substrate for use as a cellular carrier for tissue-engineered conjunctival epithelium.</p><p><b>MATERIALS AND METHODS</b>The substrate was fabricated by casting and the mechanical properties of the substrate, including tensile strength and elongation, were measured. Using the MTT, cell proliferation assay with rabbit conjunctival fibroblasts, we optimised the G:C ratio to enhance cytocompatibility. Rabbit conjunctival epithelial cells were immunostained using monoclonal antibodies for keratin 4 and pancytokeratin to investigate the biological effects of the GC substrate on the proliferation and differentiation of epithelial cells.</p><p><b>RESULTS</b>We found that increasing the amount of gelatin resulted in an increase in elasticity (from 1:9 to 1:1 ratio), reaching a maximum (101.89% +/- 7.13%) at a ratio of 1:1. The MTT assay showed that the proliferation of conjunctival fibroblasts significantly increased from 0.068 +/- 0.017 to 0.177 +/- 0.011 (P = 0.014) as the gelatin was increased from 20% (1:4) to 50% (1:1). Additional studies using tissue-cultured conjunctiva explants showed that these explants grew well on the substrate, forming a multilayered epithelium. Cell morphology on this substrate was similar to that of cells grown on culture dishes alone. Positive staining of keratin 4 and pancytokeratin indicated that the substrate supported normal differentiation of conjunctival epithelial cells.</p><p><b>CONCLUSION</b>By enhancing the proportion of gelatin, both the mechanical and biological properties of the chitosan substrate were improved. The results also suggest that this GC biomembrane may be a useful candidate for reconstructive tissue engineering of the conjunctiva.</p>

Characterisation of human tear proteins using high-resolution mass spectrometry

<p><b>INTRODUCTION</b>The proteins found in tears play an important role in maintaining the ocular surface and changes in tear protein components may reflect changes in the health of the ocular surface. Proteomics provides a comprehensive approach for cataloguing all the proteins of the tear proteome, which will help to elucidate disease pathogenesis, make clinical diagnoses and evaluate the influence of medications on the structure, composition and secretion of tear proteins. In this study, an alternative proteomic strategy was investigated to explore the human tear proteome.</p><p><b>MATERIALS AND METHODS</b>Tear samples were obtained from patients who had pterygium and were collected on the first day and third day after pterygium surgery. Tears pooled from 6 patients were used in the analysis. Reverse-phase high-pressure liquid chromatograph (RPHPLC) was used as the first step to separate intact proteins into 21 peaks. Each fraction was then tryptic-digested and analysed by nanoLC-nano-ESI-MS/MS to characterise the protein components in each fraction.</p><p><b>RESULTS</b>In total, 60 tear proteins were identified with high confidence, including well-known abundant tear proteins, and tear-specific proteins such as lacritin and proline-rich proteins. Among them, proline-rich protein 5 was found for the first time in tear fluid. A large number of plasma proteins were also observed in tear fluid.</p><p><b>CONCLUSIONS</b>The results showed that the proteomic strategy used in this study was successfully applied to analyse tear proteome.</p>