The optometrist leaned back in his chair. To Chuck, it looked like a position in which to deliver bad news.
“Chuck, take a look these results of your visual field test.”
“Yeah, I noticed that you took longer on this test than the last time. I thought the test would never be over,” Chuck commented, his mouth dry with worry.
“Yes, I did the longer test,” Dr. Tim said. “This time I wanted to make sure we got a good look, especially at your left eye.” Chuck looked down at the two small charts that Dr. Tim held in his hand. “You’ll notice that the right eye shows good responses all around. No places are blacked out. You have excellent perception in all four quadrants.” Then Dr. Tim pointed to the left-hand chart. “But here on the nasal side of your left eye. This blacked out space. You consistently missed seeing any of the squiggly lines right here.”
Chuck sat back. “It’s the glaucoma, isn’t it?”
Dr. Tim nodded his head. “We thought you might not be developing it, but it’s here.” He looked up seriously. “I’ve been following you for more than four years now. You have a longer than normal eye – that’s why you have myopia, uh . . . near-sightedness.” Chuck nodded. He’d worn thick glassed for most of his life. “And I know that you have a thicker than normal cornea – the clear outside layer over the front of your eye where the light gets in.” Chuck nodded again. “We’ve talked about this before. I thought that might be why you had somewhat higher than normal pressures some time back.”
“But the pressures started to coming down about two years ago,” Chuck responded with irritation. “They were normal just six months ago.”
“It’s true, they were.” Dr. Tim pressed on with the bad news. “But here’s the evidence I was afraid I might find,” he said, holding up the charts. Dr. Tim moved his rolling chair more squarely in front of Chuck.
“There are two common types of glaucoma: one where the eye angles are open and one where the eye angles are closed. Both types have high pressure inside the eye. Both types can be treated with medicines and, sometimes, with surgery. But in the recent past we have had a rise in a third type of glaucoma that has normal pressure in the eye, but still has the same loss of nerves in the back of the eye – in the retina. It’s still glaucoma.” Dr. Tim rolled back slightly. “You don’t look like someone who has it . . . but . . . has anyone ever told you that you have sleep apnea?”
Chuck glanced at his wife in the far corner. “I got my sleep apnea machine about a year ago. But I thought sleep apnea caused high blood pressure and heart disease . . . and other things.”
“True enough,” Dr. Tim said, “there’s a myriad of diseases that are made worse by the lack of oxygen caused by sleep apnea. But in my field of optometry normal pressure glaucoma has shown a relationship to sleep apnea. We don’t know that exact relationship. We don’t know the exact cause and effect. But the association is there between sleep apnea and normal pressure glaucoma.”
“It’s a good thing I started on that machine, huh?”
“Yes, it’s a good thing.” Dr. Tim nodded. “What we don’t know is if the glaucoma will be arrested by using the machine . . . or if the glaucoma with continue to progress. I don’t want you to lose anymore vision. We should treat you with the glaucoma drops now.”
“Can we wait a while? See if the glaucoma will stabilize with the machine?”
“Three months. Let’s see you in three months. And we’ll hope for the best.”