Glaucoma Case Studies

Case One
Monitoring Progression in First Eye Can Guide Treatment of Second

Patient history/presentation: This 75-year-old white female first presented in our office in 1985. She had a strong family history of glaucoma. Her mother, sister and brother were each afflicted with the disease. She had been diagnosed with glaucoma in 1979 and previously had argon laser trabeculoplasty (ALT) in each eye. The patient was using Timoptic 0.5% b.i.d, Pilocarpine 6% q.i.d., and Epifrin 2% b.i.d. OU.

The patient confirmed that she was taking her prescribed medication, but her IOP, measured using Goldmann tonometry, was 20 mm Hg in each eye. Fundoscopy revealed 0.4 cupping in her right eye with an intact neuroretinal rim. In contrast, her left eye exhibited a loss of the inferior rim at the 5 o'clock position, giving a vertical cupping that was greater than the horizontal. Visual field examination on the Humphrey Field Analyzer showed normal fields in each eye.

However, within a couple of months, repeat visual field tests revealed that she had developed a superior arcuate scotoma in the left eye, in the area corresponding to the disc damage.

During her next examination in 1986, the patient was again noted to have a normal optic nerve and a full visual field in her right eye, but a persistent notch in the optic nerve in her left eye with a corresponding superior visual field loss. The patient was receiving maximum medical therapy, and her IOP measured in the high teens to the low twenties in each eye.

Between 1980 and 1986, photos of the patient's right eye showed no change. However, images of her left eye during that period revealed two hemorrhages and notching. Pictured above are the left eye in 1984 and in 1988.

A review of disc photos taken between 1980 and 1986 supported these findings. Photos of the right eye showed no change. However, the image of her left eye revealed a small hemorrhage at 6 o'clock in 1980. Notching was noted in 1981, followed by evidence of another hemorrhage in 1983, and then more stable findings in 1985 and 1986. (See disc photos.)

The patient had a posterior vitreous detachment in the left eye in 1988, but no other clinical signs of pathology. She was followed closely in the next several years, with repeated eye and visual field examinations and IOP measurements.

By 1992, the visual field in the right eye had become slightly unstable with equivocal findings in the superior arcuate area, but the left eye remained stable with a superior arcuate scotoma. The patient's IOPs remained elevated in the low- to mid-twenties, despite maximum tolerable medical therapy.

Treatment: As new medications became available during the 1990s, they were prescribed to this patient for a monocular therapeutic trial. These included Iopidine (apraclonidine), Trusopt (dorzolamide), and Xalatan (latanoprost). However, in each case the medication either proved ineffective or the patient developed an allergic reaction to it. Epifrin was no longer tolerated and was discontinued in 1992.

In January 1995, the patient's IOP had risen to the mid- to high-twenties OU despite the 6% Pilocarpine and 0.5% Timoptic, which were the only tolerable medications. In an effort to reduce IOP further, the patient underwent ALT for the second time in her right eye. There was a reasonable response to the procedure, so it was also performed in her left eye 6 months later. Her visual fields remained stable.

In 1997, Alphagan 0.2% b.i.d. (brimonidine) was introduced to her left eye in a monocular trial. This medication successfully lowered her IOP, and was maintained.

A review of the Heidelberg Retina Tomograph (HRT) scans taken of the optic nerve head and adjacent nerve fiber layer in her left eye between 1994 and 1997 (See images on the next page.) showed increased cupping in the inferior temporal quadrant, even though the visual field in the superior arcuate area remained stable. The progressive cupping continued in 1998 and 1999. The patient finally agreed to surgery in Sept. 1999. A trabeculectomy was performed on her left eye with an excellent result; IOP was lowered to the low teens without additional medication.

Discussion: This case shows evidence of damage to the optic nerve occurring in an area that was preceded by disc hemorrhage. A corresponding superior arcuate scotoma developed. The superior arcuate scotoma remained stable over time, even though IOP control was less than ideal and the cupping became worse, as demonstrated on the HRT.

The patient's right eye, which originally had a normal cup and a normal visual field, has started to show deterioration in the superior arcuate bundle with a small paracentral scotoma, very reminiscent of the original changes in the left eye. Given the clinical course of the left eye, we have been more aggressive in treating the right eye to lower its IOP. Unfortunately, medical therapy also proved unsuccessful in the right eye, so a trabeculectomy was performed, which succeeded in lowering the IOP to the low teens.

This case further demonstrates that while glaucoma is asymmetrical, with one eye often preceding the other in terms of manifestations of damage and visual field change, the changes are often similar in the second eye. Cupping may be more impressive than field loss in some patients, and may in fact precede, by a significant time frame, the changes that will be seen in the visual field.

Case One was submitted by Raymond P. LeBlanc, M.D., head of the Department of Ophthalmology at Dalhousie University, Halifax, Nova Scotia. If you would like to comment on this case, e-mail Ophthalmology Management at ifftda@boucher1.com.

Case Two
Therapy in Patients with Ocular Surface Disease

Patient history/presentation: A 50-year-old white female with a history of equivocal optic nerve changes was referred for evaluation of glaucoma. The patient could not wear contact lenses due to dry eyes. She also suffered from fybromyalgia, Sjögren's Syndrome and migraines.

Examination/findings: The anterior segment exam showed extremely dry eyes. Stereo disc photos showed early notching of the optic nerves. Ocular medications included Xalatan q.h.s and Timolol maleate b.i.d. OU for 5 years, and generic artificial tears q1 hour WA. Her IOPs measured 15 mm Hg OD and 16 mm Hg OS, with a historical range of 16 mm Hg to 19 mm Hg OU on therapy. The patient said that some days she does not use her nighttime drops because her eyes burn so badly.

Treatment: Initially, we discontinued Timolol and changed to Refresh Plus artificial tears. One month later, the patient's IOPs were 16 mm Hg OD and 17 mm Hg OS. Then we discontinued Xalatan in order to establish baseline. Six weeks later, her IOP levels were 19 mm Hg OD and 20 mm Hg OS, and she noted that since stopping Xalatan her eyes burned less and she had fewer headaches.

Once baseline was reached, the initial target pressure was reset to less than or equal to 15 mm Hg. The patient was switched to Alphagan P OS and 3 weeks later, her IOPs were 18 mm Hg OD and 15 mm Hg OS. Therapy then advanced to OU and 3 months later, the patient's IOP levels were 14 OD and 15 OS. The only complaint the patient had was a dry mouth.

Discussion: Dry, burning eyes are a common side effect for many glaucoma patients. If a certain drop is causing irritation, many patients will discontinue use, allowing glaucoma to progress. For this reason, it's important to continue monitoring progress and to work to find a therapy that works well for them.

Continued management: The patient's IOP has remained at its target level for the past year, and the dry mouth has lessened. The ocular surface has improved with decreased staining.

Case Two was submitted by Robert Noecker, M.D., from the University of Arizona. If you would like to comment on this case, e-mail Ophthalmology Management at ifftda@boucher1.com.