Clarifying the clinical conundrums in glaucoma

Seattle-When caring for patients with glaucoma, clinicians sometimes encounter clinical issues that are challenging and controversial.

The first “conundrum” that clinicians must consider is whether the patient really has glaucoma, said Joseph Sowka, OD, professor of optometry at Nova Southeastern University College of Optometry in Florida.

Various insults can afflict the optic nerve and manifest ophthalmoscopically as pallor, atrophy, cupping and notching, and the most common underlying condition is glaucoma.

“But we still need to be aware of what else is going on,” said Dr. Sowka during the annual meeting of the American Academy of Optometry.

A diagnosis of glaucoma without risk factors is suspicious. However, it can be difficult to separate glaucoma from other disorders when there are risk factors present, he said.

One rule of thumb is that “nothing notches a nerve like glaucoma,” and tumors and inflammations do not notch a nerve. The fields and nerve should match, and disc pallor usually indicates something other than glaucoma.

Dr. Sowka pointed to a 1998 study in which it was found that patients with glaucoma tended to be older, had better visual acuity, more frequent disc hemorrhages, and less neuroretinal rim pallor. He noted that these results have held up since that time.

Another conundrum faced by clinicians is what to do when diagnostic imaging does not agree with the diagnosis. Dr. Sowka explained that “things have to make sense” and clinicians need to use their own knowledge.

“If the imaging doesn’t make sense, don’t let it lead you down the path of misdiagnosis,” he said. “No current technology is better than the human eye, common sense, and the skilled clinician . . . and know the limitations of the technology.”

Clinicians often face the conundrum of patient compliance with medications. Two of the main reasons for non-compliance are cost, and irritation to the ocular surface.

For cost, Dr. Sowka explained there are patient assistant programs for branded drugs, and there are also generic options that may be much less expensive.

Rim Makhlouf, OD, a clinical instructor who is also at Nova Southeastern, discussed the options for less irritating medications.

For optimal patient compliance, comfort is a very important factor.

“The irritation can be caused by preservatives, and some studies have shown that non-preserved drugs are less irritating to the ocular surface,” she said.

There are both preservative-free options, as well as those with low or attenuated preservatives.

Zioptan is preservative-free, as is Cosopt PF.

Another drug, Travatan has a preservative system called Sofzia, which has similar antimicrobial activity to the commonly used BAK, but it becomes inactive once in contact with the eye and causes less irritation.

Finally, Simbrinza is preserved with BAK, but the concentrations are very low.