Abstract
Purpose:
To evaluate the preexisting diagnosis, the subsequent development, treatment and characteristics of glaucoma in patients with Boston Type 1 keratoprosthesis.
Methods:
We retrospectively analyzed the clinical records of all the patients with Boston Type I keratoprosthesis implantation in a single-center ophthalmologic institution. All the variables related to glaucoma were examined. The main outcome measures included: previous diagnosis of glaucoma and related surgeries, drainage procedures concomitant to keratoprosthesis, postoperative management and final glaucoma status.
Results:
21 patients (22 eyes) were included with a median age of 49.5 years. Nine patients (42.8%) had glaucoma previous to keratoprosthesis, 3 of them with diagnosis of congenital glaucoma. Six patients (28.5%) had glaucoma surgery previous keratoprosthesis implantation, four with more than one surgery per eye. In 13 patients (61.9%), the clinical characteristics of the optic nerve could not be analyzed before keratoprosthesis surgery due to corneal opacity. The decision for a newer glaucoma valve surgery in the same surgical time of the keratoprosthesis implantation was taken in 6 patients (28.5%) for intraocular hypertension or advanced glaucoma. Postoperative procedures related to glaucoma were: one patient required Ahmed glaucoma valve surgery, one a replacement of the tube into pars plana, one an scleral patch for valve extrusion, another patient had extrusion of the glaucoma valve and it had to be removed, and one required endocyclophotocoagulation. At the end of the follow-up (median 14 months, range 3 to 124 months after the surgery), 14 patients (66.6%) required long-term use of hypotensive medication, 12 (57.1%) had advanced structural glaucoma (cup to disc ratio above 0.9) and 15 eyes (68.1%) had glaucoma either before or after keratoprosthesis implantation.
Conclusions:
Glaucoma was a common disease previous the implantation of Boston Type I keratoprosthesis in this group of patients. It becomes an important complication as most of the patients develop the necessity of a drainage implant device or long-term use of hypotensive medication, as the majority of patients had glaucoma because either preexisting condition or postoperative development.