The ICE syndrome represents a spectrum of disease presentations caused by abnormalities of contact inhibition of the corneal endothelial cells.1 As such, endothelial cell bands migrate freely across the anterior chamber angle and on the iris to form broad, band-like, contractile PAS and cause glaucoma by physical segmental angle closure. Displacement of the pupil (corectopia) toward the area of activity with contralateral shredding of the iris into strand-like openings leads to polycoria and ensuing visual disturbance.
Treatment of this patient should be focused on relieving iris-induced visual symptoms, removing the visually significant cataract, and controlling the glaucoma.
The first stage in this treatment can be to create a central pseudopupillary opening in the iris using a neodymium:YAG laser. This is done after the pupil is constricted with a miotic because the pupillary sphincter muscle is largely intact. In this example, by opening the bridge of iris tissue between the corectopic pupil and the area of iris atrophy, such treatment may yield an adequate central opening; subsequent fitting with a Narcissus-type masking contact lens can provide relief from the polycoria.
At this point, the best corrected visual acuity can be assessed and if the cataract is visually significant, cataract surgery performed. If the patient has adequate vision, however, consideration should be given to deferring intraocular surgery because these patients are at high risk for corneal decompensation and progressive glaucoma.
If surgery is required, a Rasch-Rosenthal iris diaphragm ring or a pair of Rasch iris coloboma rings can be used (Morcher GMbH). The former consists of a pair of poly(methyl methacrylate) (PMMA) rings that have been dyed black and can be inserted into the capsular bag at the time of cataract removal. The rings have intermittent tongues of PMMA that will interdigitate to create a continuous iris diaphragm with a 6.0 mm diameter.
One advantage of this modular design of iris–lens replacement is that cataract surgery, ring insertion, and foldable IOL implantation can be performed through a 4.0 mm scleral tunnel. The central iris opening can be extended or perfected if needed using an intraocular long-handled scissors or a mechanical vitrector. After phacoemulsification, the iris diaphragm rings are dialed into the capsular bag, directly or by first insertion into the anterior chamber. The latter approach may be desirable because the rings are extremely brittle and may easily fracture if flexed excessively, particularly at the fulcrum created by the incision. It is absolutely necessary to have extra rings at hand if a break occurs. A similar technique can be done using coloboma rings.
It would be reasonable to perform a glaucoma filtering procedure at the time of cataract surgery with the use of mitomycin. Despite the use of antimetabolites, however, filters in ICE patients frequently fail because of continued corneal endothelial cell invasion of the fistula.
The patient should be apprised of the increased likelihood of failure, particularly with respect to corneal decompensation and glaucoma failure, which may require corneal transplantation in conjunction with valve implantation.
1. Shields MB. Iridocorneal endothelial syndrome. In: Principles and Practice of Ophthalmology. New York, NY, WB Saunders, 1994; 1448-1454