Impression cytology refers to the application of a cellulose acetate filter to the ocular surface to remove the superficial layers of the ocular surface epithelium. These cells can then be subjected to histological, immunohistological, or molecular analysis. Proper technique is essential as the number of cells sampled can vary considerably. Generally two to three layers of cells are removed in one application but deeper cells can be accessed by repeat application over the same site. Applications for impression cytology include diagnosing a wide range of ocular surface disorders, documenting sequential changes in the conjunctival and corneal surface over time, staging conjunctival squamous metaplasia, and monitoring effects of treatment. It is also a useful investigational tool for analysing ocular surface disease with immunostaining and DNA analysis. It is non-invasive, relatively easy to perform, and yields reliable information about the area sampled with minimal discomfort to the patient. Major ophthalmic centres should develop and introduce this technique into routine clinical practice. This is best achieved with a team approach including the ophthalmologist, pathologist, microbiologist, and the immunologist.

Bi-canalicular stenting achieved excellent cosmetic results in eyelid avulsion injuries, by facilitating adequate tissue realignment without the need for a posterior lacrimal crest fixation suture. Good functional results were achieved and were comparable with previous studies.

Our study showed that IOP was significantly lower in women taking HT than in those who had never taken HT, even after removing other possible influences on IOP. The IOP-lowering effect of HT deserves further investigation to explore whether it may represent a possible new therapeutic modality for glaucoma.

The amniotic membrane (AM) is considered as a natural cell culture substrate and has occasionally been exploited in regenerative medicine especially for ocular surface reconstruction and dermal wound healing applications. However, its limited use infers from its relatively weak mechanical strength, difficulty during manual handling and susceptibility to proteolytic degradation in vivo. Therefore, in this study we aimed to enhance the mechanical and biological characteristics of the AM by enzymatic cross--linking it using tissue transglutaminase (TG): a calcium--dependent enzyme capable of forming stable ε(γ--glutamyl)lysine cross--linkages. Using a biological catalyst such as TG should not only prevent denaturation during sample preparation but also minimise the potential of residual chemical cross--linking agents compared to alternative methodologies. Methods: Human AM, sourced from elective caesarean sectioning, were treated with TG, BSA and/or a no--treatment control. Samples were then compared in terms of their physical characteristics (SEM, transparency, mechanical strength, susceptibility to proteolytic degradation), biological characteristics (in vitro cell culture, activation of dendritic cells) and its in vivo biocompatibility/angiogenic capacity (chick chorioallantoic membrane (CAM) assay).Results: Transglutaminase--treated AM exhibited enhanced mechanical strength and greater resistance to proteolytic/collagenase degradation compared to the control(s). SEM imaging of the TG--treated membrane summarised a significantly closer association and greater interconnectivity of individual collagen fibres yet it had no effect on the overall transparency of the AM. In vitro cell culture demonstrated no detrimental effect of TG--treatment on the AM in terms of cell attachment, spreading, proliferation and differentiation. Moreover, an "immune response" was not elicited based on extended in vitro culture with human monocyte--derived dendritic cells (mDC). Interestingly, the TG--treated AM still allowed angiogenesis to occur and in some instances, demonstrated an enhancement compared to the control (n = 5). Conclusion:We hereby demonstrate that treating the AM with the cross--linking enzyme, transglutaminase, results in a novel biomaterial with enhanced mechanical and biological characteristics. Above all, this modified membrane demonstrates greater strength, maintains in vitro cell growth, retains optical transparency and allows angiogenesis to occur without inducing an immune response. Taken together, this study demonstrates the feasibility of transglutaminase as an alternate cross--linking treatment for the production of novel biomaterials and suggests that TG--treated AM may now be more commonly exploited as a therapeutic dressing for ocular or wound applications.