Post-Approval Study of the Implantable Miniature Telescope

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The objective of the PAS-01 study is to assess the safety of the intraocular as measured by the cumulative incidence of patients who within 5 years after implantation experience persistent vision-impairing corneal edema (corneal edema leading to persistent loss of best corrected distance visual acuity >2 lines from pre-surgery baseline level). The study will test the null hypothesis that the percentage of patients who experience persistent vision-impairing corneal edema is >17% against the alternative that the percentage is <17%. The null hypothesis will be rejected if the upper bound of the two-sided 95% confidence integral for the observed percentage is <17%.

Device study
Any, age 65 years or older

Spectroscopic optical coherence tomography (OCT), to measure the oxygen saturation in retinal blood vessels

Can spectroscopic OCT improve the early diagnosis of diseases such as glaucoma,diabetic retinopathy, and age-related macular degeneration?

Patients with glaucoma are not aware that they have the disease, mainly because current screening methods detect cellular and axonal loss in the retina and optic nerve head after years of disease progression, often after significant and permanent vision loss. A period of metabolic stress, potentially reversible through treatments or interventions, is thought to precede neuronal death and vision loss in glaucoma, presenting a “window of opportunity” for appropriate treatments. Importantly, oxygen metabolism supports the energetic requirements of neuronal activity and active transport in the inner retina, which have been shown to be impaired in early glaucoma before structural changes occur. However, no current test can measure such metabolic dysfunction on an immediate time scale to adequately diagnose, monitor, or predict disease progression. The purpose of this research is to investigate a new noncontact optical method, called spectroscopic optical coherence tomography (OCT), to measure the oxygen saturation in retinal blood vessels. Spectroscopic OCT may enable the assessment of retinal vessel oxygenation which could improve the early diagnosis of diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD).

Other
Any, age 18-60 years

Study comparing vision restoration with collagen cross-linked donor cornea and standard donor cornea

Boston Keratoprosthesis surgery study (cornea transplant for patients not candidates for traditional corneal transplant)

The Boston Keratoprosthesis is used in patients who are not candidates for a traditional corneal transplant. This could be because they have had a previous failed corneal transplant or have high likelihood for transplant failure due to a large amount of blood vessels in the cornea. The Boston Keratoprosthesis is assembled using a donated cornea tissue. The donated tissue can thin out in certain patients. Studies have shown that cross-linked corneas are broken down more slowly than corneas that have not been cross-linked. In this study patient will either receive a cross-linked donor cornea before Boston Keratoprosthesis surgery or will receive a standard-of-care non-cross-linked donor cornea. Randomization is like flipping a coin – neither patient, nor physician will know which treatment was received. In either scenario, the donor cornea will be delivered to the surgeon by Tissue Bank International (TBI) at the time of the surgery. The cross-linking procedure has not yet been approved by the United States Food and Drug Administration (FDA) and is therefore considered experimental. The cornea contains a protein called collagen that normally provides stability to the cornea (like the steel beams within a tall building). In this study, we will attempt to form extra connections between the collagen strands to make the cornea tissue stronger before it is used for the Boston Keratoprosthesis implantation. The extra connections, called “cross-links,” are formed by treating the cornea tissue with a special Riboflavin (Vitamin B2) with dextran solution and then carefully exposing it to a measured amount of ultraviolet light. Our goal is to get an indication whether this cross-linking treatment may reduce the rate of cornea thinning or melting.

Drug study, Phase I/II
Any, age 18 to 100 years old