CLINICAL CHALLENGES
A Sudden Rise in Pressure
Sometimes avoiding surgery to treat glaucoma is possible; in this case it wasn't.

The standard protocol for following well-controlled glaucoma patients is to see them at least once every three months. It's also the standard to repeat visual field testing and optic nerve imaging at least yearly.

Sometimes this practice seems a bit of an overkill. But as the following case illustrates, these regular three-month checks prove critical -- more so with some cases than with others.

Suddenly Sadie

Sadie has been my patient for a long time and over the years we've developed a love-hate relationship (I love seeing her but she absolutely hates coming to my office). Although Sadie always speaks her mind, she's really a sweet person. She also has moderate glaucoma and despite my exhortations and pleas, won't routinely return for her follow-up appointments and stops using her drops when she feels she doesn't need them anymore.

Sadie was 62 years old when she first came to see me. Her main complaint was that she had episodes where her eyes hurt and she saw rainbows around lights. Despite these episodes, she said that her vision was pretty good. I noticed on her medication list that she was taking an antibiotic for chronic congestion, alprazolam (Xanax) for depression and using an inhaler p.r.n. for asthma. She was also using ketorolac tromethamine 0.5% (Acular) that her medical doctor had given her to manage the ocular pain.

Optic disk photographs showing large c/d ratios OS.

At first glimpse . . .

At this first visit, Sadie's visual acuity (VA) in each eye was 20/40 but improved to 20/25 with an increase in her already hyperopic prescription. Her slit lamp examination was normal with the exception of small posterior subcapsular cataracts OU. Her IOP was 24 mmHg OD and 27 mmHg OS at 10:20 a.m. Gonioscopy revealed a deep Grade 4 anterior chamber angles, 360š in each eye and free of iris processes or peripheral anterior synechiae (PAS), which ruled out angle closure as the cause of her pain and "rainbows."

A classic glaucoma case

After dilation, I examined Sadie's optic nerves with a 78.00D lens. They looked classically glaucomatous. Sadie was a +4.00D hyperope and she had small optic nerve heads (ONH), yet her cup-to-disc ratio (c/d) was large and asymmetrical. I estimated her c/d ratio at .55 OD and .7/.7 OS (see photo at left). In addition, the cupping was deep and the lamina was visible in the base of the cup.

I discussed with Sadie the great likelihood that she had glaucoma but that I wanted to run a few more tests before initiating therapy. She reluctantly agreed to come back in 10 days. At that visit, her IOP had risen to 31 mmHg OD and 34 mmHg OS. A visual field test revealed that she already had moderate double arcuate field defects OU (Fig 2). Sadie had a clear-cut case of glaucoma for which I prescribe latanoprost 0.005% (Xalatan) OU q.h.s.

Fast forward

At first Sadie did well using her drops and returning for her exams. When she used the latanoprost, her IOP stayed in the 14 mmHg to 18 mmHg range, which is well within the 40% drop in IOP that I targeted. But after two years, Sadie would neglect to refill her prescription when it ran out and would come back every four to five months instead of at the intervals that I asked her to return. Over these 18 months her c/d began to increase -- more so in her right eye than in her left -- and her VF showed decreasing mean sensitivity OU. I suggested to Sadie that we perform a laser treatment and hopefully get her off the drops, but she said that she didn't want any "surgery."

I added another drop, hoping to illustrate how her condition was worsening. That strategy seemed to work, as Sadie became more compliant with the drops and in returning for her scheduled progress checks. On latanoprost OU q.h.s. and brimonidine (Alphagan) OU b.i.d., her IOPs returned to the mid-teens.

From good to not-so-great

This treatment success continued for about one year until Sadie appeared at my office one month ahead of her scheduled appointment, which was unlike her. She was worried about her pressure because she was seeing the rainbows again. Sadie assured me that she hadn't stopped using the drops but that the rainbows had reappeared about two weeks previously.

Indeed, when I checked Sadie's IOPs they were 48 mmHg OD and 39 mmHg OS. There was no afferent pupil defect and the angles were open OU judging by both the Von-Herrick method with the slit lamp and with a gonioscopy lens. There was no iris pigment released and she denied trauma.

I questioned her again about her medications and she informed me that her medical doctor had changed her asthma regimen because the condition was getting worse and she now also had chronic bronchitis. Sadie was now using ipratropium bromide (Atrovent) at least b.i.d. and 10 mg to 20 mg of predni-sone daily. Most likely these steroids caused the IOP to rise. The question now was how to get the IOP normalized.

Resorting to surgery

A call to Sadie's internist confirmed that she couldn't discontinue the ipratropium bromide. Her breathing condition had deteriorated such that this specialist felt that the prednisone was also an absolute necessity for the time being.

I couldn't add a beta blocker because of Sadie's respiratory dysfunction, but I added brinzolamide 1% (Azopt) OU b.i.d. and increased the brimonidine to t.i.d. I also scheduled her for an argon laser trabeculoplasy (ALT).

Two days later, Sadie's IOP was better but still quite elevated at 39 mmHg OD and 32 mmHg OS. Again, her angles were wide open, so a surgeon performed ALT in the temporal 180š of each eye. One month later, the surgeon treated the remaining 180š of each angle with the argon laser.

And so it goes

Our course of treatment has worked well for Sadie thus far. Her IOPs have remained in the mid-teens for the past two years. On her current regimen of bimatoprost 0.03% (Lumigan) OU q.h.s. and brimonidine tartrate 0.15% (Alphagan P) OU t.i.d., her last IOP measurements were 14 mmHg OD and 15 mmHg OS. She's still using her ipratropium bromide and montelukast (Singulair) and her asthma is doing "fairly well."

Sadie's neuroretinal rim did thin during the time of her elevated IOPs, which have since stabilized at .85/.85 in each eye. Her VF likewise showed some deterioration but it, along with her retinal thickness, is now stable. She also complies and shows up for her scheduled exams.

From glaucoma to cataracts

Sadie's VA has decreased to 20/50 OU over the past six months because of increased nuclear sclerotic and posterior subcapsular cataracts. She's now complaining about dimming vision. A cataract extraction would benefit her, but should we perform a combined trabeculectomy and cataract extraction? And what should I do with the inevitable steroid response? These are questions for another day!

Contributing Editor Eric Schmidt, O.D., is director of the Bladen Eye Center in Elizabethtown, N.C. E-mail him at kenziekate@aol.com.