The ARGOS-IO pressure sensor is intended to be implanted in the human eye in combination with Boston Keratoprosthesis (BKPro) surgery and to remain in place indefinitely. It is intended to be used together with the hand-held Mesograph reading device to telemetrically measure the intraocular pressure (IOP) of patients with a BKPro.

The purpose of this study is to evaluate the safety and performance of the ARGOS-IO system in patients undergoing concomitant implantation of a BKPro and an ARGOS-IO sensor over the 12 month period beginning at implantation.

(see above)

Inclusion Criteria:

1. Male or female aged ≥ 18 and ≤ 80 years on the day of screening
2. Keratoprosthesis surgery indicated, defined as having a severely opaque and vascularized cornea AND either a verifiable history of two or more prior failed corneal transplant procedures or a medical condition such as alkali burns or autoimmune disease that makes the success of a traditional corneal transplant procedure unlikely. Potential study subjects will be solicited for participation in the clinical trial only after they have consented to the keratoprosthesis operation.
3. Axial length > 21 mm
4. Ability and willingness to attend all scheduled visits and comply with all study procedures

Exclusion Criteria:

1. Reasonable chance of success with traditional keratoplasty
2. Current retinal detachment
3. Connective tissue diseases
4. History or evidence of severe inflammatory eye diseases (i.e. uveitis, retinitis, scleritis) in one or both eyes within 6 months prior to ARGOS-IO implantation
5. History of ocular or periocular malignancy
6. History of extensive keloid formation
7. Any known intolerance or hypersensitivity to topical anesthetics, mydriatics, or silicone (component of the device)
8. Presence of another active medical eye implant and/or other active medical implants in the head/neck region
9. Signs of current infection, including fever and current treatment with antibiotics
10. Severe generalized disease that results in a life expectancy shorter than a year
11. Any clinical evidence that the investigator feels would place the subject at increased risk with the placement of the device
12. Currently pregnant or breastfeeding
13. Participation in any study involving an investigational drug or device within the past 30 days or ongoing participation in a study with an investigational drug or device
14. Intraoperative complication that would preclude implantation of the study device
15. Subject and/or an immediate family member is an employee of the investigational site directly affiliated with this study, the sponsor or the contract research organization.

Previous or concurrent enrollment of the contralateral eye in this clinical study.