Chen Bo has suffered from coronary heart disease, angina for many years, always have nitroglycerin tablets at home. Whenever chest discomfort strikes, as long as the tongue on a piece of this “life-saving drugs”, it works very well.
However, a few days ago, Chen appeared red pain in his right eye, blurred vision, was diagnosed as glaucoma. He underwent glaucoma surgery and his condition was controlled.
Glaucoma in the elderly is mostly primary closed-angle type
Glaucoma is a group of eye diseases that seriously threaten visual function, due to high pressure in the eye, more than the limit of the retinal nerve can withstand, resulting in visual impairment and eventual blindness. The disease is divided into three types: primary glaucoma, secondary glaucoma and developmental glaucoma. Among them, primary glaucoma is the most common and is divided into two categories: primary open-angle glaucoma and primary closed-angle glaucoma (the so-called closed-angle and open-angle depends on whether the atrial angle, the channel through which the water flows out of the atrium in the eye, is blocked).
Closed-angle glaucoma has a rapid onset, with painful eye swelling and vision loss, while open-angle glaucoma has an insidious onset, with no obvious eye symptoms, and the patient only develops vision abnormalities in the late stages. In China, primary closed-angle glaucoma is the most common in the elderly.
Is nitroglycerin the culprit of glaucoma?
Once we understand the causes of glaucoma, we know that any drug that may cause an increase in intraocular pressure or induce an acute attack of glaucoma is a contraindicated drug for glaucoma patients.
And what about nitroglycerin?
As early as the 20th century, in animal experiments, nitroglycerin was found to dilate blood vessels and subsequently cause an increase in cerebrospinal fluid pressure and intraocular pressure, which was thought to aggravate glaucoma; later, there were also reports of acute closed-angle glaucoma when nitroglycerin was applied to treat heart disease. Therefore, “glaucoma” is listed as a contraindication in the drug instructions of nitroglycerin.
However, there are reports that nitroglycerin can lower intraocular pressure, especially in a study that found that patients with coronary artery disease experienced a decrease in intraocular pressure after nitroglycerin treatment. This leads to the question of whether nitroglycerin is a “curse” or a “blessing”.
In fact, it is very rare for glaucoma to be induced by the use of nitroglycerin. Although there are some patients who have had acute closed-angle glaucoma attacks when using nitroglycerin to treat heart disease, this does not prove that nitroglycerin is the “killer”.
We can think about the reason why there is the name “primary glaucoma”, because the exact cause of it is not completely clear, may be related to genetics, psychological factors, autonomic nervous system, narrowing of the anterior segment structure; and heart attack, patient tension and fear, autonomic nervous system disorders, etc., is also an important cause of glaucoma attack. It is difficult to say that nitroglycerin is the “murderer” that triggers glaucoma. Moreover, nitroglycerin has the effect of dilating the blood vessels of the optic nerve, improving blood supply and microcirculation, and has a potential protective effect on the optic nerve. In this way, it should be very beneficial for glaucoma.
Glaucoma, with or without nitroglycerin
At present, due to the controversy between glaucoma and nitroglycerin, we still list glaucoma as a contraindication to the use of nitroglycerin for safety reasons. However, this does not mean that it should not be used at all.
If you really want to use nitroglycerin, you should tell your doctor in advance that you or someone else in your family has glaucoma, and also go to the ophthalmology department to check for signs such as high intraocular pressure, atrial angle narrowing, and glaucomatous changes in the optic nerve in the fundus of the eye.
If the diagnosis of glaucoma is clear, different follow-up and preventive measures can be taken according to different types. If primary closed-angle glaucoma is not surgically treated, the IOP and ocular symptoms should be closely monitored (both before and every day after medication), because nitroglycerin causes mostly acute closed-angle glaucoma.
For patients with closed-angle glaucoma who have been treated surgically, or for patients with open-angle glaucoma who are well controlled with medication, regular ophthalmologic follow-up and monitoring of IOP is all that is needed.
It is important to note that the majority of primary glaucoma is bilateral, and those with one eye only and the other eye “normal” should also be monitored closely for changes in IOP in both eyes.
For people without a history of glaucoma, nitroglycerin is safe to use if the IOP is not higher than 21 mm Hg or fluctuates no more than 8 mm Hg. However, for people with a history of glaucoma, the IOP level should not exceed the “target IOP” set in previous treatments. Moreover, if blurred vision, iris vision, nasal swelling, eye distention with headache, nausea, eye redness, photophobia and tearing occur after using the medication, you should immediately visit an ophthalmologist to clarify whether the glaucoma attack has occurred.
Conclusion: It should be noted that when an acute heart attack may be life-threatening, if there are no other drug options, the primary and secondary conflicts should be distinguished, and saving life is the most important, and you can go to the ophthalmology department after the medication has been relieved, so as not to delay the rescue time.