Ocular motility defects in patients with the Krupin valve implant

To determine the prevalence of ocular motility defects following placement of a Krupin valve with disk and adjunctive mitomycin-C in glaucoma patients, a retrospective case series of all patients receiving a Krupin valve with disk and intraoperative mitomycin-C in a university-based referral practice was conducted. Each of the seven consecutive patients undergoing placement of a Krupin valve with disk in one eye because of uncontrolled glaucoma, developed significant primary position heterotropia or limitation of ocular rotations. One patient had significant postoperative diplopia. We conclude that the Krupin valve with disk used with intraoperative mitomycin-C can be associated with the development of ocular motility defects. The limitation of rotations appears to relate to the combined mechanisms of implant and cyst bulk and the displacement of the oculorotary muscles by the encapsulating cyst.