Glaucoma update: Sorting through the nuts and bolts of a glaucoma practice

Optometric Management, Sep 2002 by Bowling, Ernest L

Glaucoma Update

Prepare yourself for a challenging and rewarding specialty.

Diagnosing and treating glaucoma within a primary care practice is one of the most challenging and rewarding aspects of optometry. Forty-six states plus the District of Columbia currently allow optometrists to manage the disease, yet many O.D.s still refer their patients to other providers for this important service.

These next few accounts will explain how to assemble the nuts and bolts of a glaucoma practice within your current operation so you don't have to send patients away. I'll give you the basic information that you need to get yourself started.

Prepping yourself

Before launching your own glaucoma practice, take as much continuing education on glaucoma as you can, from as many different lecturers as possible. Visit a glaucoma practice and pick the specialist's brain; see how folks who do this for a living handle the disease. Then look into equipment.

Prepping your office

If you're going to treat glaucoma, you'll need a sphygmomanometer and stethoscope for monitoring patients' blood pressures. You also must invest in the following:

* An applanation tonometer. This is the standard of care for glaucoma, so the instrument is vital for managing the disease.

Some form of threshold visual field testing device is critical, and several are available. Once thought the most sensitive way to detect glaucoma, visual field testing is now considered more of a tool for tracking the disease than for detecting it.

* A gonioscopy lens. This lens is necessary for evaluating the anterior chamber angle. Several types are commercially available, but the type isn't nearly as important as your ability to use it and be comfortable with what you're seeing.

* Some means of evaluating the optic nerve head. The direct ophthalmoscope forces you to use color differences to estimate the edge of the cup and can lead you to underestimate the true cup size. Slit lamp ophthalmoscopy with a condensing lens is probably the best way to assess cup-to-disk (C/D) ratio. While many O.D.s prefer the 90D-- condensing lens, a better option for glaucoma patients is the clear 78D or 60D lens.

m Some means of quantifying the optic nerve. Stereoscopic fundus photos have long been used, but with the advent of optic nerve and nerve fiber layer imaging technologies, we now have a variety of optic nerve and nerve fiber layer imaging technologies.

Co-manage a big investment

Purchasing these devices may be cost prohibitive for your practice. If so, consider co-managing these patients with your glaucoma specialist. We send our patients out to co-managing glaucoma specialists for retinal tomography and unbundle the procedure code - the specialist's office bills for the technical component and our office bills for the professional component.

Making the diagnosis

If you suspect glaucoma, you'll need to establish baseline values for the patient before initiating therapy. Perform a comprehensive ocular examination, including the following:

* Complete history with review of symptoms. The first, and perhaps most important, step in the exam is a thorough case history, which should include questions about these issues:

* Demographics. Both age and race are risk factors for glaucoma, with elderly AfricanAmericans having the highest incidence, according to the Baltimore Eye Survey of August 1991.

* Heredity. A family history of glaucoma, especially on the maternal side, is considered a risk factor.

* Past trauma. A past history of trauma may contribute to elevated intraocular pressure (IOP) later in life.

* Medication use. Past or current use of topical or oral steroids may cause elevations in IOP levels. Medications commonly used to control hypertension, such as oral beta-blockers, can lower IOP.

* Refractive status. Low-tomoderate amounts of myopia are often associated with pigmentary dispersion syndrome, and high myopia in particular has been associated with a higher incidence of glaucoma.

* Physical exam with IOP assessment. The first hands-on step in any glaucoma work-up is biomicroscopy, which yields a wealth of information about the eye's efficiency in draining aqueous. Be sure to look for:

* Pigmentary deposits. Usually in the form of a Krukenberg's spindle, these deposits indicate pigmentary dispersion syndrome (PDS). Small white flakes at the edge of the pupil and large sheets on the lens capsule indicate pseudoexfoliation syndrome (PXS). The debris from either condition can temporarily clog the trabecular meshwork, causing episodic rises or "spikes" in IOP.

* Uveitis. Active anterior segment inflammation can cause an increase in IOP. Patients who have active uveitis may have increased IOP, which usually returns to normal once the uveitis resolves.

* Pupil or lens abnormalities. Look closely for evidence of trauma. An afferent pupillary defect may also mean that the glaucoma is more advanced in one eye than in the other.

* Narrow angles. Most optometrists routinely screen all patients for narrow angles using von Herrick's technique. However, any time you suspect glaucoma you should perform: