Re-evaluate target pressure after disc hemorrhage

New Orleans-Optic disc hemorrhage, a rare event in non-glaucomatous eyes, is a strong predictor of glaucoma as well as glaucoma progression. Clinicians might consider re-evaluating the patient's target IOP after this finding, said Jost B. Jonas, MD, at the American Academy of Ophthalmology's glaucoma subspecialty day meeting.

Disc hemorrhages have been detected in about 4% to 7% of glaucomatous eyes but are rarely seen in eyes without glaucoma.

Klein in 1992 and Healey and Mitchell in 1998 reported about 1% of non-glaucomatous eyes presented with optic disc hemorrhages.

In 1970, Stephen Drance, MD, was one of the first to report that optic disc hemorrhage can be followed by acute disc change in eyes with glaucoma. "The disc hemorrhages were described to be more prevalent in eyes with manifest glaucoma than in eyes with ocular hypertension, and to occur more often in the lower IOP range than in glaucomatous eyes with high IOP," Dr. Jonas said.

The stage of glaucoma influences the location and frequency of optic disc hemorrhages. In the early stage of the disease, disc hemorrhages are found in the inferotemporal disc region. As the disease progresses to a medium-advanced stage, bleeding can also occur in the temporal superior and temporal horizontal disc regions. "Disc hemorrhages are usually not found in disc regions or eyes without detectable neuroretinal rim," he said.

As far as frequency is concerned, optic disc hemorrhage can be seen in the early part of the disease and then increases in frequency at the medium-advanced stage of glaucoma. In the far-advanced stage, bleeding decreases because there is little detectable neuroretinal rim, Dr. Jonas said.

Disc hemorrhages are present for 8 days to 12 weeks after the initial event, according to a 1986 report by Anders Heijl, MD. The largest and most-often detected disc hemorrhages have been found in eyes with normal-pressure glaucoma. A possible reason is that "the transmural pressure difference across the blood vessel wall is higher in eyes with normal-pressure glaucoma than in eyes with high-pressure glaucoma," Dr. Jonas noted.

Risk factors for bleeding Dr. Jonas and colleagues reported in 2002 that small neuroretinal rim size and a large beta zone of parapapillary atrophy are risk factors for optic disc hemorrhages. Factors that did not differ between the hemorrhagic group and non-hemorrhagic group were optic disc size and shape, optic disc depth, alpha zone of parapapillary atrophy, and retinal vessel diameter, Dr. Jonas said.

Some studies have indicated that a retinal nerve fiber layer defect can occur as early as 2 months after bleeding. "It may, however, have occurred already at the time of the hemorrhage. It may have taken 2 months for it to become ophthalmoscopically detectable," he said.

Numerous studies have indicated that optic disc hemorrhages put patients at risk for glaucoma or glaucoma progression. In the Ocular Hypertension Treatment Study (OHTS), Budenz and colleagues studied optic disc hemorrhages as a predictor of the development of glaucoma. They found that 20% of the 152 eyes with detected disc hemorrhages developed glaucoma during follow-up. In these eyes, glaucoma was detected at a median of 16.3 months, Dr. Jonas said.

"The OHTS offers convincing evidence that the target pressure should be reconsidered," he said. "It is yet open whether the target pressure should be re-adjusted."

When Dr. Jonas counsels patients with disc hemorrhage, he explains that the disc bleeding "may be the equivalent of a worsening of the situation, and that one should intensify the treatment."