• Cataract/Anterior Segment, Comprehensive Ophthalmology, Glaucoma

    Richard L. Lindstrom, MD, gave this year's Charles D. Kelman Lecture, making the case that the lens plays a more significant role in the development of glaucoma than previously recognized. He's so convinced that he rarely performs combined cataract and glaucoma procedures on patients with both conditions.

    "Cataract extraction alone may be the most appropriate procedure for patients with controlled or mostly controlled glaucoma," Dr. Lindstrom said.

    This is particularly relevant since 300,000 to 400,000 patients with both glaucoma and cataract are seen by American surgeons each year and about 10 percent of cataract patients have glaucomatous visual impairments. Advances that have been made in the surgical management of cataract and the medical management of glaucoma significantly influence the treatment of these patients, Dr. Lindstrom said.

    He presented the results of a retrospective review of 588 patients with IOP ranging from 9 mm Hg to 31 mm Hg who underwent combined phacoemulsification-IOL implantation procedures. Drops in IOP were greatest among those with higher initial IOPs. Dr. Lindstrom's study, co-authored with Drs. Brooks J. Poley and Thomas W. Samuelson, appeared in the May 2008 issue of the Journal of Cataract and Refractive Surgery. http://www.jcrsjournal.org/article/S0886-3350(08)00204-6/abstract

    He also discussed the results of a second chart review of 124 eyes with glaucoma who underwent phaco-IOL procedures. Their preoperative IOPs ranged from 5 mm Hg to 29 mm Hg, and they had previously been treated with glaucoma drops, iridectomy, trabeculectomy or laser trabeculectomy or had visual field or optic nerve defects.

    The glaucoma patients experienced greater drops in IOP compared with patients without glaucoma. Other studies confirm the same results if you break out the findings, Dr. Lindstrom said. The results also demonstrated that IOP reduction following phaco-IOL procedures both in eyes with and without glaucoma was proportional to preoperative IOP.

    Authors have postulated that the lens becomes a major source of ocular hypertension as it ages, Dr. Lindstrom said. Cataract extraction reestablishes normal tension in many ocular hypertensive eyes by replacing the growing lens with an artificial lens. Two images from the JCRS study illustrate this point:

    Image courtesy of the Journal of Cataract & Refractive Surgery
    Poley 5A.JPG

    The MR images of the 25-year-old patient (right eye) and 49-year-old patient (left eye) show how continuous lens growth shallows the anterior chamber, repositions the anterior lens capsule forward of the canal of Schlemm, creates forward traction by the zonules on the anterior ciliary body, displaces the uveal tract anteriorly, and thereby compresses the trabecular meshwork and canal of Schlemm.

    Image courtesy of the Journal of Cataract & Refractive Surgery
    Poley 5B.JPG

    The MR images of the 74-year-old's left eye with IOL implantation and the fellow unoperated right eye show how, after phacoemulsification and IOL implantation, the anterior chamber deepens, the anterior lens capsule is repositioned well behind the canal of Schlemm, and the zonules now exert rearward traction on the anterior ciliary body. Compression of the trabecular meshwork and canal of Schlemm is thereby relieved. Now, aqueous has easier egress from the eye. Intraocular pressure of most eyes with ocular hypertension reestablishes at lower levels.