Purpose
To evaluate the progression of glaucomatous disc damage in patients who have undergone Boston Keratoprosthesis (KPro) implantation.
Methods
A total of 20 eyes of 19 patients who underwent KPro implantation between Feb 2007 and Aug 2012 were included in this retrospective study. Inclusion criteria limited patients to those with ≥ 1 year of post-operative follow-up and good quality optic disc photos. The following data were collected: demographics, ocular history, presence/absence of glaucoma, baseline intraocular pressure (IOP), best corrected visual acuity (BCVA), and number of glaucoma medications, and post-operative IOP, BCVA, and number of glaucoma medications at 1, 3, 6, 9, 12, 18, 24, 36, and 48 months or at last follow-up. Serial optic disc photographs were analyzed and the vertical and horizontal cup-to-disc ratios (C/D) were graded by an independent ophthalmologist. The percentage of patients who demonstrated progression of glaucomatous disc damage (C/D increase of ≥ 0.1 or ≥ 0.2) was calculated.
Results
The mean follow-up time was 48.4 months. The mean age at the time of KPro implantation was 48.6 years. There were 11 females (55%) and 9 males (45%). The three most common indications for KPro were chemical burn, herpetic keratitis, and aniridia. Glaucoma developed in 14/20 (70%) pre-KPro, 5/20 (25%) post-KPro, and did not develop in 1/20 (5%). Glaucoma drainage implants, cyclophotocoagulation, or trabeculotomy were performed in 15/20 (75%); concurrently with KPro (8/20), pre-KPro (4/20), or post-KPro (7/20). Pre-KPro, the mean BCVA, mean IOP, and mean number of glaucoma medications was 2.2 logMar, 20.2 mmHg, and 1.3, respectively. At last follow-up, the mean BCVA, mean IOP, and mean number of glaucoma medications was 0.5 logMar, 18.5 mmHg, and 1.15, respectively. A vertical or horizontal C/D increase of ≥ 0.1 or ≥ 0.2 was seen in 5/20 (25%) and 2/20 (10%), respectively. The mean vertical C/D among each patients' initial disc photographs was 0.51 and the mean vertical C/D among final disc photographs was 0.50.
Conclusions
Despite the high incidence of glaucoma in this patient population, close monitoring and aggressive treatment with possible early surgical intervention can be successful in minimizing development or progression of glaucomatous nerve damage.