Optimum | Tangible Hydra-PEG™ – Gaining Momentum in the Industry

The issue of hydrophilicity of the surface of gas permeable contact lenses remains one of the persistent problems. Tangible Hydra-PEG™ surface coating is applied to gas permeable contact lenses to significantly improve wettability and wearing comfort. Although it is mainly used to alleviate dry eye symptoms in scleral and corneal lens users, particularly for those patients with corneal ectasia and/or Ocular Surface Disease (OSD), it can be used in other modalities. This article describes the development of the product and describes the benefits of its use in a clinical case.

Clinical significance of detecting organ-specificsensitization in patients with long-term chronic posttraumatic uveitis

Purpose: to assess the clinical significance of detecting organ-specific sensitization in chronic posttraumatic uveitis (CPTU) based on a comparative analysis of data from the leukocyte migration inhibition test (LMIT) and histological examination.Materials and methods. We examined 54 patients aged 17-82 with CPTU who underwent surgical removal of the eyeball (by enucleation/evisceration). To detect organ-specific sensitization, the LMIT in whole blood with extracts of corneal, lens, and uvearetinal tissue antigens was used. The eyes were subjected to histological examination after removal.Results. A positive response in LMIT was detected in 35.2 % of patients with CPTU. Pathomorphological signs of immune inflammation were found in 55.5 % of cases (30 eyes). In 23 eyes (42.6 %), the morphological picture was characterized by atrophic, fibrous and dystrophic changes in tissues. Based on the data from a comparative analysis of LMIT results and histological studies, we showed that in 16 cases out of 30 (53.3 %), morphologically confirmed immune inflammation was accompanied by sensitization to antigens of eye shells.Conclusions. In half of the cases, a productive inflammation, detected in CPTU during histological examination, was associated with the development of specific sensitization to eye tissue antigens. This result is important and should be considered when choosing how the patient should be managed, including targeted diagnostics and immunotropic therapy. The negative organ-specific response of LMIT in patients with chronic CPTU and intraocular inflammation confirmed by pathomorphological signs suggests a possible involvement of additional mechanisms of the inflammatory process, which requires further research.

Current Trends in Treating Acanthamoeba Keratitis: A Brief Narrative Review

The Author, after examining the historical evolution of scientific knowledge and treatment of severe Acanthamoebic keratitis, presents this brief review on the treatment of this serious eye disease, relatively frequent in patients with corneal contact lenses. Therapy of Acanthamoeba keratitis is always very long and demanding. Its management requires adequate experience because it is not always easy to evaluate the response to treatment and complications can be very serious and difficult to manage. Resistance to therapy can also occur during treatment and must be distinguished from drug-induced toxicity. In cases where no improvement is obtained with maximum medical therapy, it is advisable to repeat the corneal sampling and proceed to new laboratory tests for Acanthamoeba, bacteria and fungi. Prevention, which always remains of fundamental importance, is practically based on avoiding contact of the corneal lens with contaminated water, since this Acanthamoeba has a ubiquitous diffusion. It is therefore recommended to always avoid the use of corneal contact lenses in the pool or in the shower, not to wash them under running tap water and to frequently replace the relative container of these lenses. Key Words: Acanthamoeba Keratitis, Corneal ulcer, Contact lenses.

Hybrid contact lenses for the correction of primary and induced ametropias

The review presents the data on the use of hybrid contact lenses (HCL), a modern method of contact correction of ametropias of diverse origins. A HCL has a central rigid optical zone made of highly gas-permeable material and a flexible peripheral part made of hydrophilic material. These lenses combine the optical effect of gas-permeable corneal lens with the comfort and stable fitting of soft contact lenses. Compared with the corneal (RGP) lenses, HCLs are more comfortable, often are better centrated and more stably fit on the eye. HCLs are successfully used in various refractive disorders: ametropias (with regular cornea), irregular astigmatism, presbyopia, including that combined with astigmatism. This type of lens is a good option of contact correction for patients who have high requirements to the quality of vision.

Stem Cell Therapies for Blindness due to Corneal, Lens, and Retinal Diseases: A Review

Stem cell therapies are continuing to be researched and implemented to treat a wide range of disorders that result in blindness. Major structures of the eye most prevalently tied to blindness are the cornea, lens, and retina, and specific conditions resulting in blindness includes corneal disease, stromal scarring, cataracts, age-related macular degeneration, retinitis pigmentosa, glaucoma, and diabetic retinopathy. This review covers a detailed description of the structures of the eye, the causes and corresponding disease pathways of each form of corneal, lens, and retinal dysfunction that results in blindness, and the current stem cell sources being researched and implemented, through animal models and clinical trials, to treat blindness. The review evaluates the progress of stem cell research and trials and presents the obstacles that remain to be overcome before stem cell sources to treat blindness can become standard clinical practice.

Grain boundaries and coincidence site lattices in the corneal nanonipple structure of the Mourning Cloak butterfly

In this study the highly ordered corneal nanonipple structure observed on the Mourning Cloak butterfly (Nymphalis antiopa) is analyzed with a particular emphasis on the high-angle grain-boundary-like defects that are observed between individual nanonipple crystals. It is shown that these grain boundaries are generated by rows of topological coordination defects, which create very specific misorientations between adjacent crystals. These specific orientations form coincidence site lattices, which (i) have unit cells larger than the unit cell in each individual crystal and (ii) extend from one crystal to the next, effectively creating order over areas larger than the individual crystals. A comparison to similar coincidence site lattices in engineering materials is made and the importance of such arrangements in terms of nipple packing density, corneal lens curvature and potential optical properties is discussed.