Constructal law analysis of Cl- transport in eyes aqueous humor.

Progressive loss-of-vision related to any intraocular disorder is known as glaucoma. Secretion of aqueous humor is physiologically important to provide nutrients and oxygen to the avascular anterior segment and ensuring normal visual function, even if, nowadays reducing the secretory rate to lower intraocular pressure is a major strategy in treating glaucomatous patients. Understanding the mechanisms and regulation of aqueous humor formation is very important to develop possible new approaches to lower intraocular pressure,but today there isn't any comprehensive model of the regulation of these component in forming aqueous humor. In this paper Construcal law is used to suggest how the Cl- fluxes can determine the water inflow and outflow, and, consequently, how the intraocular pressure is controlled by these fluxes.

Constructal approach to bio-engineering: the ocular anterior chamber temperature.

The aim of this work was to analyse the pressure inside the eyes anterior chamber, namedintraocular pressure (IOP), in relation to the biomechanical properties of corneas. The approach used was based on the constructal law, recently introduced in vision analysis. Results were expressed as the relation between the temperature of the ocular anterior chamber and the biomechanical properties of the cornea. The IOP, the elastic properties of the cornea, and the related refractive properties of the eye were demonstrated to be dependent on the temperature of the ocular anterior chamber. These results could lead to new perspectives for experimental analysis of the IOP in relation to the properties of the cornea.

A Single-Center Pilot Prospective Study of Topical Application of Platelet-Derived Eye Drops for Patients with Ocular Chronic Graft-versus-Host Disease.

Ocular involvement of chronic graft-versus-host disease (cGVHD) is a complication that occurs in up to 60% of patients after allogeneic hematopoietic stem cell transplantation. Conventional therapeutic options include medical and surgical procedures that are administered depending on the severity of the condition, but most of them have provided unsatisfactory results and, to date, there is no consensus about treatment. We considered that topical application of a platelet lysate, administered as eye drops, might be considered an alternative worthwhile of investigation to treat ocular surface disorders in patients suffering from cGVHD. Therefore, we conducted a single-center prospective pilot study to assess the efficacy and safety of using eye drops made from reconstituted lysed platelet concentrate. Twenty-six patients with ocular cGVHD were eligible for the study; all but 2 completed their scheduled 1-year treatment and complied with the hematologic and ophthalmic regimen. At their first assessment interviews, after 30 days of treatment, 91% of patients reported an improvement in their symptoms and for 32%, substantive objective differences were measured. Remission of corneal damage was seen for 86% of our cohort, and improved National Institutes of Health scores for 73%, of whom 8% achieved the best score of 0 (ie, non-dry eye). Similar results were seen at later time points. Comparing outcomes for our patient cohort to those determined retrospectively for patients in our institutional database revealed a 5-year overall survival (OS) of 65%. This OS is comparable to patients with limited cGVHD (75%) and is superior to that of patients with nonocular extensive cGVHD or without cGVHD (30% and 59%, respectively) (P = .013). Our results suggest that platelet-derived eye drops are a safe, practical, and well-tolerated therapeutic option that offers substantial benefits for most patients affected by ocular cGVHD at onset. The favorable OS of our patient cohort suggests that this topical therapy, rather than systemic immunosuppression, may be the treatment of choice.