ANGLE-CLOSURE GLAUCOMA 169

that have narrow and potentially occludable angles until a prophylactic laser iridotomy is performed. These medications are not contraindicated in patients with eyes that have narrow b

out this possibility. If the angles do become significantly narrower, then one must consi

KEY P OINTS: LONG-TERM SEQUELAE OF A CUTE ANGLE-CLOSURE GLAUCO MA ATTACK

1. Corneal endothelial cell loss, endothelial pigment.

2. Permanently mid-dilated and unreactive pupil.

3. Iris sector atrophy, posterior synechiae.

4. Peripheral anterior synechiae in the angle.

5. Glaucomflecken, other cataractous changes.

6. Occasionally, lens zonular weakness.

7. Optic nerve pallor out of proportion to cupping.

27. List some possible causes for persistent or recurrent IOP elevation after successful PI.

&Peripheral anterior synechiae formation and/or undetected injury to the TM during the period of angle closure

&Nonpupillary block angle closure (see question 9, classification, B.I.b.–d.)

&Incomplete iridotomy will result in persistent IOP elevation. Occlusion of the iridotomy with debris or a membrane may cause a recurrent episode of pupillary block angle closure. Remember that transillumination does not equal patency.

&Underlying or residual open-angle glaucoma component

PLATEAU IRIS

28.Describe the epidemiology of plateau iris.

These patients are usually younger (typically fourth and fifth decades) and less hyperopic than patients with primary angle closure; they may even be myopic.

29.How does it present clinically?

It may be noted on routine examination or present as an acute or chronic angle-closure glaucoma.

30.What is plateau iris configuration (PIC)?

Anteriorly positioned (and sometimes larger than normal) ciliary processes push the peripheral iris more anteriorly than normal (Fig. 16-7). The central AC is usually slightly

170 ANGLE-CLOSURE GLAUCOMA

to open and does not open as widely as

a typical narrow angle. A ‘‘hills and valleys’’ profile may be seen when looking at the angle. In addition, indentation gonioscopy reveals the almost pathognomonic ‘‘double hump sign,’’ characterized by posterior displacement of the midperipheral iris but a persistently anterior position of the peripheral iris. Persistence of the plateau iris appearance despite a patent iridotomy confirms the diagnosis clinically. High-resolution ultrasound biomicroscopy can also confirm the diagnosis.

32.What is plateau iris syndrome?

Acute or chronic angle closure that develops with dilation, or even spontaneously, in an eye with plateau iris configuration and a patent PI.

33.How is plateau iris treated?

The primary procedure of choice in an eye with (or at risk for) angle closure is laser peripheral iridotomy, to eliminate any component of pupillary block that may be present. In general, the older the patient, the more the pupillary block contributes, as a percentage, to the mechanism of angle closure. However, laser iridotomy is not adequate treatment in such cases; it is merely the necessary first step.

Laser peripheral iridoplasty may be necessary in patients whose angle approach remains very narrow despite a patent PI. This technique uses the argon laser to apply burns circumferentially to the peripheral iris, which cause it to contract and pull away from the angle. Although the green wavelength is usually used, use of the yellow-green wavelength may improve absorption of laser energy in more lightly colored irides. One important potential complication that should always be discussed with the patient is the risk of a permanently larger pupil size postoperatively, and its attendant potential to increase problems with glare.

Chronic miotic therapy can also be a useful alternative or adjunct to iridoplasty in eyes with a narrow approach despite a patent PI. With either method of therapy, the angle should be