Laser iridotomy for aphakic pupillary block

D. R. Anderson, R. K. Forster and M. L. Lewis

In six patients with aphakic pupillary block, argon laser produced full-thickness iridotomies that succeeded in restoring anterior chamber and intraocular pressure to normal. In one case, it was shown that location of iridotomy is important in determining whether or not iridotomy will succeed in relieving aphakic pupillary block. In two cases, pupillary block had resulted in shallowing of the anterior chamber without pressure elevation. Cases reported here show that continuous laser energy, such as from an argon laser, can produce a full-thickness opening, in contrast to the short duration pulse of the ruby, which will destroy only pigmented structures without producing a full-thickness iris opening. This need to produce some degree of spread of damage to unpigmented tissue elements in order to achieve and iris opening is a problem in phakic patients where injury to the lens must be avoided.