Active clinical trials for "Keratoconus"

To determine whether the Peschke PXL-330 is safe and effective in the treatment of corneal thinning conditions.

To evaluate the safety and effectiveness of the PXL Platinum 330 system for performing corneal cross-linking (CXL) for the treatment of ectatic disorders.

To evaluate the safety and effectiveness of the PXL Platinum 330 system for performing corneal cross-linking (CXL) for the treatment of ectatic disorders.

Optical Coherence Tomography (OCT) devices are non-contact instruments that can measure the depth of scars, other causes of cloudiness of the cornea, and degree of corneal thinning in patients with keratoconus. Laser Custom Corneal Collagen Cross-linking (CXL) significantly decreases corneal aberrations and improves vision. This study will use OCT-guided setting for the lasers used in the corneal smoothing portion of the laser custom CXL procedure to assess the affect on visual outcomes.

Corneal collagen crosslinking has been demonstrated as an effective method of reducing progression of both keratoconus and post-refractive corneal ectasia, as well as decreasing the steepness of the cornea in these pathologies. Performing an accelerated CXL procedure with pulsed UVA light may increase the oxygenation of the cornea, which may improve the crosslinking efficacy.

Corneal ectasia is characterized by irregularity and thinning of the cornea, causing the cornea to bulge forward and cause distorted vision and impaired visual acuity. Corneal ectasia is a complication after refractive (LASIK) surgery. It is also the primary problem in keratoconus, a gradually progressive inherited condition that typically is manifested in young adulthood, more commonly in women. Treatment approaches to stabilize the cornea's shape include rigid contact lenses, surgical implantation of stiff plastic intrastromal corneal ring segments, a collagen cross-linking procedure and, in severe cases, cornea transplantation. The collagen cross-linking procedure involves topical application of a concentrated riboflavin (vitamin B2) solution after the corneal epithelium is scraped, followed by ultraviolet (UV) light exposure. UV light stimulates riboflavin to form new bonds (cross links) between the cornea's connective tissue, giving the cornea additional strength to maintain its shape and prevent the need for transplantation. The cost of one treatment using this system is $2,500 to $3,500. A small prospective study including 7 patients with keratoconus was started on a trial of oral riboflavin and 15 minutes of natural sunlight exposure daily. These patients reported no adverse effects and preliminary results showed corneal stabilization and/or corneal flattening in all 7 patients It is hypothesized that dietary riboflavin and natural sunlight is as effective in corneal crosslinking as the currently FDA approved Avedro therapy. If the clinical study confirms the investigators' early observations of the benefits of this approach, coupled with animal studies that document corneal cross-linking, the investigators will have data to pursue funding for larger clinical and animal studies. This has the potential to save millions of dollars in health care costs and ease the burden of treatment in patients who require therapy to induce corneal cross-linking to stabilize the cornea's shape.

The standard or Dresden protocol was established in 2003 and treats the entire cornea. However, recent ultra-structural research showed that keratoconus is localized. Therefore, treating only the affected zone and minimalizing the risk of damaging surrounding tissues would be beneficial. The objective of this study is to evaluate whether the effectiveness of customized cross-linking (cCXL) is non-inferior to standard accelerated cross-linking (sCXL) in terms of flattening of the cornea and halting keratoconus progression.

Aberrations are the spreading of light from a point focus. Aberrations of the eyes can be objectively evaluated with a wavefront aberrometer. Lower order aberrations such as defocus and astigmatism can be corrected with glasses and traditional/disposable soft contact lenses. Patients with ectatic corneal disease, such as keratoconus, or irregular astigmatism cause by surgery, trauma or disease, experience vision that is unlikely to be adequately corrected with glasses or disposable soft contact lenses due to higher order aberrations (HOA). HOA's cause halos, flare, glare, starbursts, doubling, smearing or ghosting of vision. Specialty contact lenses, such as scleral lenses, can be used to mask the irregularity of the cornea, reducing HOA's and improving vision. In many patients the resultant vision, though improved, still has some level of residual HOA's affecting the quality of vision. Custom scleral lenses with customized wavefront guided optics can be used to reduce residual HOA's and improve vision further. These lenses have been referred to as higher order aberration correcting scleral lenses or HOA correcting sclerals and wavefront guided scleral lenses or WFG sclerals.

The study objective is to compare accelerated and standard corneal crosslinking for treatment of progressive keratoconus or corneal ectasia.

The mechanism by which vision loss in glaucoma occurs is still unknown, but it is clear that increased Intraocular Pressure (IOP) is a major risk factor. It is also thought that the lamina cribrosa (LC) is a site of primary damage during the pathogenesis of the disease. The changes caused by intraocular pressure (IOP) modulation at the level of the optic nerve head and LC will be evaluated in the present study. Subjects with keratoconus exhibit abnormal collagen properties that can impair their LC behavior. By evaluating their lamina biomechanical response we can advance our understanding on the role of the lamina in glaucoma pathogenesis. A better understanding of the process will ultimately lead to improved detection and management of glaucoma. It is hypothesized that subjects with keratoconus have an abnormal biomechanical response of the lamina cribrosa in response to IOP modulation.