Before discussing management, it would be helpful to perform corneal pachymetry and endothelial studies to determine possible future corneal decompensation. Also, although the patient's current optic nerve and visual status is favorable, it would help to know whether her optic nerve has changed since she initiated topical therapy. If progressive cupping was noted, one could conclude that IOP must be consistently lower to provide stability.
As surgical intervention is likely, it is important to review the options with the goal of minimizing intervention and maximizing outcome. Accordingly, one could consider the following:
- Cataract surgery alone, even by a clear corneal temporal approach, would be challenging in this eye because of possible difficulties associated with the iris and corneal endothelial abnormalities. Postoperative pressure fluctuation would also likely occur, precipitating further corneal compromise and potential glaucomatous change.
- A second option would be a combined cataract/glaucoma procedure using a 2-site (temporal clear corneal phacoemulsification with a superior filtration site) or a single phacotrabeculectomy site. Intraoperative antimetabolite therapy with mitomycin-C and possible postoperative supplemental 5-fluorouracil would help reduce an early postoperative IOP increase and possibly lessen the risk of future filtration bleb failure. Studies reporting long-term filtration function in eyes with iridocorneal endothelial dysgenesis are limited, particularly of combined surgical procedures.
- Finally, as the patient's cornea may be tenuous and long-term control of the glaucoma questionable, a third option should be considered; that is, combined penetrating keratoplasty (PKP), cataract extraction, and implantation of a posterior chamber IOL, as well as a tube/shunt drainage procedure.
The latter option may provide the best long-term prognosis. Many reports have shown the potential benefit of such combined surgery for optimizing long-term IOP control and visual rehabilitation (S.V.L. Brown, MD, and coauthors, “Combined Ahmed Valve Penetrating Keratoplasty,” poster presented at the annual meeting of the American Academy of Ophthalmology [AAO], Chicago, Illinois, USA, October 1996; A. Prywes, MD, and coauthors, “Graft Survival in Glaucoma/Valve Implant and Penetrating Keratoplasty,” poster presented at the annual meeting of AAO, Orlando, Florida, USA, October 1999). It is the last option I would advise.