Iris retraction associated with rhegmatogenous retinal detachment syndrome and hypotony. A new explanation.

Eyes with rhegmatogenous retinal detachment can occasionally be seen with hypotony and a peculiar retraction of the peripheral iris. Herein I report the following new observations in this syndrome: (1) seclusion of the pupil, (2) resolution of the retraction configuration after disruption of the seclusion, (3) the initial manifestation as angle closure secondary to iris bombé interchangeable with the iris retraction configuration with the addition (to bombé) and the withdrawal (from retraction) of pharmacologic aqueous suppressants, and (4) the rapid cataract formation. The theory that vitreous traction or retraction is the cause of the retrodisplacement of the iris was disproved. A hydrodynamic theory is presented. A lowering of pressure behind the iris, at least partially, due to posterior removal of fluid, presumably from the subretinal space, was shown to be the cause of the iris retraction. The iris retrodisplacement occurred when posterior aqueous removal exceeded aqueous formation. This removal of fluid may be an important factor in the understanding of proliferative vitreoretinopathy as the fluid flow involved may draw cells posteriorly.