Penetration of topical and subconjunctival corticosteroids into human aqueous humour and its therapeutic significance

Topical and subconjunctival corticosteroids are some of the most effective and compelling treatment options in ocular inflammatory diseases. A systematic review of literature indexed by Ovid MEDLINE & EMBASE was performed up to December 2008. There are few studies on their aqueous penetration in human subjects. This review article discusses the penetration of different ocular corticosteroids into human aqueous humour along with the therapeutic implications on management of ocular surface diseases, immune-related corneal diseases, anterior uveitis and postoperative anti-inflammatory use. In the context of the paucity of well-constructed, prospective clinical trials comparing the efficacy of different corticosteroids, it provides guiding principles for the use of topical corticosteroids. Dexamethasone alcohol 0.1% and prednisolone acetate 1% are potent corticosteroids, but the latter achieves the highest aqueous concentration within 2 h and maintains higher levels for 24 h. Subconjunctival corticosteroids provide very high concentrations in the aqueous which maintain higher concentrations for longer periods

Current status and future prospects for cultured limbal tissue transplants in Australia and New Zealand

Cultured limbal tissue transplants have become widely used over the last decade as a treatment for limbal stem cell deficiency (LSCD). While the number of patients afflicted with LSCD in Australia and New Zealand is considered to be relatively low, the impact of this disease on quality of life is so severe that the potential efficacy of cultured transplants has necessitated investigation. We presently review the basic biology and experimental strategies associated with the use of cultured limbal tissue transplants in Australia and New Zealand. In doing so, we aim to encourage informed discussion on the issues required to advance the use of cultured limbal transplants in Australia and New Zealand. Moreover, we propose that a collaborative network could be established to maintain access to the technology in conjunction with a number of other existing and emerging treatments for eye diseases

Extreme Descemet's membrane rupture with hydrops in keratoconus: Clinical and histological manifestations

Purpose: To study the clinical and histological manifestations of an extreme Descemet's membrane rupture as a result of keratoconus. Observations: Using Periodic acid-Schiff assay to study a keratoconic cornea with an extreme rupture showed that the ruptured Descemet's membrane had retracted and folded into scrolls and ridges. The dimensions of the rupture were estimated to be 3.7mm2, and the central cornea was extremely thinned with a thickness of only 260μm. Stromal scarring and loosely packed lamellae were present anterior to the scrolls and ridges. Antibodies targetting the major components of Descemet's membrane, Laminin and type IV collagen, displayed intense labelling adjacent to the scrolls where the stroma was denuded and differential expression patterns lined the ridges. Environmental scanning electron microscopy showed possible collagen deposition at the site of rupture. Conclusions and importance: The specific staining patterns of laminin and type IV collagen suggest these components have an important role in re-endothelisation of the cornea. This is the first known report of spatial resolution of the topography of the Descemet's membrane rupture established by environmental scanning electron microscopic image montage. Keywords: Keratoconus, Descemet's membrane, Descemet's tear, Hydrops, Corneae, Histolog

Can penguins (Spheniscidae) see in the ultraviolet spectrum?

International audienceIt has been postulated that ultraviolet reflectance is important in mate choice in King Penguins Aptenodytes patagonicus, although not in other penguin species that do not have body parts that reflect UV light. However, this theory has been challenged. Here we aimed to determine the transmission of the ocular media in the large King Penguin as well as the smallest penguin, the Little Penguin Eudyptula minor, and a medium-sized penguin, the Gentoo Penguin Pygoscelis papua, to determine if the penguin eye is capable of seeing ultraviolet light. In all species the cornea absorbed the most damaging rays at 300 nm or below but it was the lens that predominantly determined the transmission of light between 300 and 400 nm. The lenses of a young King Penguin absorbed almost all light less than 370 nm and had 50% transmission at 406 nm, thus ultraviolet perception in the King Penguin is very limited. In contrast, 50% lenticular transmission was 329 nm in the Little Penguin and 367 nm in the Gentoo. Therefore, we suspect that ultraviolet light may be more important in the behaviour of smaller penguins than in the King Penguin, where it is unlikely to play a significant role

In vivo confocal microscopy images of representative affected family members

The right eye (virgin cornea) of the proband (frame size 400 µm x 400 µm) at the level of () basal epithelial layer illustrating focal deposition of homogeneous, reflective materials with rounded edges, and hyporeflective borders and () posterior stroma showing extensive scarring with arrow indicating “ghost” blood vessels. : Corresponding slit-lamp biomicroscopy photograph illustrating dense scarring. : In vivo confocal microscopy of the allograft in the right eye of subject II:1 at the level of Bowman’s layer which has been completely replaced by diffuse, homogeneous, reflective material (frame size 400 µm x 400 µm). : Corresponding slit-lamp biomicroscopy photograph illustrating recurrence of the dystrophy within the peripheral right corneal graft of subject II:1, 4 years following penetrating keratoplasty.<p><b>Copyright information:</b></p><p>Taken from "A novel phenotype-genotype relationship with a exon 14 mutation in a pedigree with a unique corneal dystrophy of Bowman’s layer"</p><p></p><p> 2008;14():1503-1512.</p><p>Published online 18 Aug 2008</p><p>PMCID:PMC2518171.</p><p></p