Iridectomies in extracapsular cataract surgery

Phacotrabeculectomy: peripheral iridectomy or no peripheral iridectomy?

PURPOSE

To study the effect of peripheral iridectomy (PI) in phacotrabeculectomy.

SETTING

Academic private glaucoma practice with a primarily white patient population.

METHODS

This retrospective study comprised 126 eyes of 117 patients randomized for PI or no PI during phacotrabeculectomy who were followed for 12 months. Postoperative parameters in both groups included intraocular pressure (IOP), bleb development, visual acuity, and complications.

RESULTS

There were no statistically significant differences between the 2 groups in visual acuity or IOP. Bleb development required significantly more 5-fluorouracil therapy in the no-PI group than in the PI group; however, bleb failure and the need for laser suture lysis were not significantly different between groups. Complications were rare in both groups.

CONCLUSION

Phacotrabeculectomy without PI may be an acceptable alternative to the surgical management of co-existing cataract and glaucoma.

The glaucomas in aphakia and pseudophakia

Intraocular pressure may become temporarily or permanently elevated at various intervals following cataract surgery. There are several mechanisms by which glaucoma develops as a complication of the cataract extraction itself. The presence of a pseudophakos may or may not contribute to the pathogenesis. Important diagnostic clues include the anterior chamber depth, the presence or absence of an iridectomy, gonioscopic findings, and the appearance of the optic nerve head. Life-long medical treatment is frequently justified, as alternative laser or surgical modalities may not be successful. The exact causes for high failure of filtration surgery in aphakic eyes is not clearly understood; scarring of the conjunctiva, the vitreous, and altered characteristics of the aqueous humor have all been incriminated. Current research to improve surgical success includes the development of effective artificial drainage implants or the use of pharmacologic modulators of wound healing, which promote filtration by preventing scar formation.

Pseudophakic pupillary block with angle-closure glaucoma in diabetic patients

Six diabetic patients (five women and one man, 63 to 79 years old) developed pseudophakic pupillary block with angle-closure glaucoma two days to one year after undergoing extracapsular cataract extraction. None of the six had had a peripheral iridectomy during the procedure. Symptoms included pain and visual loss. Corneal edema and intraocular pressures as high as 80 mm Hg were also present. Laser iridotomies decreased the intraocular pressure in three cases but failed in a fourth. In one case corneal edema prevented laser treatment but a surgical peripheral iridectomy was successful. One eye with central retinal vein occlusion was treated with panretinal photocoagulation and trabeculectomy.

Complications of extracapsular cataract surgery. The indications and risks of peripheral iridectomy

With the increased popularity of extracapsular cataract surgery, the need for a peripheral iridectomy has been questioned. Some surgeons feel that the risks involved in performing the iridectomy are greater than when leaving the iris untouched. The indications and risks of iridectomy with cataract surgery are discussed. Four case reports are presented. In three cases, iridectomy was not performed with cataract surgery, and a pupillary block developed. In one of these three, a congenital cataract, secondary angle closure, developed requiring filtering surgery. In the fourth case, an iridectomy prevented serious complications from an unusual degree of postoperative inflammation with complete posterior synechia following uneventful cataract surgery.