Visual Performance in Eyes Undergoing Femtosecond Laser-Assisted Keratoplasty for Advanced Keratoconus

Current approaches in the management of patients with keratoconus

Keratoconus is a relatively frequent eye disease, especially in young patients, in which the cornea gradually thins and deforms in a cone shape. In the past, it could be treated only with glasses, rigid contact lenses or, for advanced cases, penetrating corneal transplant. Nowadays, corneal cross-linking, intracorneal ring segments implantation or deep anterior lamellar keratoplasty are available options of treatment, along with the above mentioned ones. Several studies focused on this disease and its management attempted to establish the applicability of these treatment methods in current practice. In the early stages, glasses or soft toric contact lenses are able to correct the astigmatism, but, as the disease progresses, rigid contact lenses are indicated. Corneal cross-linking is done in order to slow down or even stop the progression of the disease. Implanting intracorneal ring segments helps improve visual acuity in patients with low vision that cannot be corrected otherwise. Advanced stages need corneal transplant, either penetrating or anterior lamellar, depending on each patient's ocular characteristics. Thus, keratoconus treatment is individualized for every patient, according to the stage of the disease. Moreover, because of the new developed technology, keratoconus patients can benefit from efficient treatment, in much safer conditions.

Synergic Effect of Novel WS2 Carriers Holding Spherical Cobalt Ferrite @cubic Fe3O4 (WS2/s-CoFe2O4@c-Fe3O4) Nanocomposites in Magnetic Resonance Imaging and Photothermal Therapy for Ocular Treatments and Investigation of Corneal Endothelial Cell Migration

The design of novel materials to use simultaneously in an ocular system for driven therapeutics and wound healing is still challenging. Here, we produced nanocomposites of tungsten disulfide carriers with spherical cobalt ferrite nanoparticles (NPs) as core inside a cubic iron oxide NPs shell (WS2/s-CoFe2O4@c-Fe3O4). Transmission electron microscopy (TEM) confirmed that 10 nm s-CoFe2O4@c-Fe3O4 NPs were attached on the WS2 sheet surfaces. The cytotoxicity of the WS2 sheets and nanocomposites were evaluated on bovine cornea endothelial cells (BCECs) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for a duration of three days. The MTT assay results showed low toxicity of the WS2 sheets on BCECs by 67% cell viability at 100 μg/mL in 24 h, while the nanocomposites show 50% cell viability in the same conditions. The magnetic resonance imaging (MRI) of nanocomposites revealed the excellent T2-weighted imaging with an r2 contrast of 108 mM-1 S-1. The in vitro photothermal therapy based on WS2 sheets and WS2/s-CoFe2O4 @c-Fe3O4 nanocomposites using 808 nm laser showed that the maximum thermal energy dispatched in medium at different applied power densities (1200 mw, 1800, 2200, 2600 mW) was for 0.1 mg/mL of the sample solution. The migration assay of BCECs showed that the wound healing was approximately 20% slower for the cell exposed by nanocomposites compared with the control (no exposed BCECs). We believe that WS2/s-CoFe2O4@c-Fe3O4 nanocomposites have a synergic effect as photothermal therapy agents for eye diseases and could be a target in an ocular system using MRI.