Purchase this article with an account.
Trucian A. Ostheimer, Jose de la Cruz, Maria S. Cortina; Corneal Graft Thinning in Boston Type 1 Keratoprosthesis Patients. Invest. Ophthalmol. Vis. Sci. 2011;52(14):346.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To characterize postoperative corneal graft thinning after receiving a Boston Type 1 keratoprosthesis (KPro) and evaluate associated risk factors at our institution.
A computerized database was used to retrospectively identify those patients with postoperative corneal graft thinning.
Seventy-six keratoprosthesis procedures were performed in 70 eyes from July 2007 to September 2010. Clinically evident graft thinning was observed in 10 eyes of 10 patients over this time period. Failed penetrating keratoplasty (PKP) was the primary indication in only 30% of these patients. The remaining 7 patients had corneal opacification related to aniridia (20%), chemical burns (20%), chronic ulcerative keratitis (10%), chronic atopic keratoconjunctivitis (10%), and radiation exposure (10%). Preoperative visual acuity was 20/200 or worse in all patients with 90% able to count fingers or worse. Best-corrected postoperative visual acuity was 20/70 or better in 40%, while 60% had 20/400 or worse with one patient eventually becoming NLP. The most common preoperative comorbidities included limbal stem cell deficiency (LSCD 90%), glaucoma (70%), cicatricial eyelid changes (40%), and floppy eyelid syndrome (20%). No intraoperative complications were described but combined procedures were common at the time of initial KPro placement: glaucoma shunt (30%), pars plana vitrectomy (30%), eyelid tightening procedures (20%), and amniotic membrane grafting (10%). Eighty percent of these patients had significant difficulty retaining bandage contact lenses postoperatively. Time to initial episode of corneal thinning averaged 9.5 months (range 1-23 months). Thirty percent developed thinning in the form of dellen (30%) or ulceration (10%) that eventually stabilized. Sixty percent of patients eventually had leakage or extrusion of their KPro requiring placement of a secondary KPro. Endophthalmitis was diagnosed in one patient. The average follow-up time from initial KPro placement was 19 months (range 2.5 - 36 months).
The retention rate of primary KPros at our institution was 92%, but attention must be paid to these 10 patients who suffered postoperative corneal graft thinning as 60% extruded. These patients were recognized as challenging surgical candidates preoperatively as evidenced by the fact that prior PKP was only performed in 30%. LSCD, eyelid abnormalities, or inability to retain contact lenses were observed in all patients. Further analysis is required to identify additional associations with graft thinning as KPro extrusion usually leads to adverse visual outcomes.
This PDF is available to Subscribers Only