Glaucoma and intraocular pressure (IOP) are closely linked, as it is well known that elevated IOP can damage the optic nerve and lead to the onset of glaucoma. In the absence of appropriate treatment, glaucoma progresses and causes damage to the optic nerve, resulting in a gradual narrowing of the visual field and ultimately irreversible vision loss.
Glaucoma is a multifactorial disease, and its onset depends not only on intraocular pressure but also on various other factors, such as age, family history, and ocular anatomy. However, intraocular pressure is the only controllable factor, which is why it is considered the cornerstone in the management of glaucoma. All existing therapies—both pharmacological and surgical—aim to lower IOP.
Given the importance of intraocular pressure in the diagnosis and treatment of glaucoma, the scientific community has begun to question whether it is truly appropriate to make clinical decisions based solely on IOP values measured during the few seconds of a routine eye exam—while ignoring the rest of the year, which contains a total of 31,536,000 seconds.
Recent studies using an innovative investigative technique known as continuous intraocular pressure telemetry have shown that IOP can vary significantly over a 24-hour period, depending on circadian rhythms, season, temperature, body position, physical activity, alcohol consumption, and more. Psychological stress, meditation, and wearing FFP2 face masks during physical exertion can also influence IOP levels.
Several studies have shown that intraocular pressure increases during sleep and in the lying-down position—especially in older individuals and those already affected by glaucoma. Sleeping on one’s side or stomach, extending or flexing the neck, and other sleeping postures also influence IOP. This is supported by evidence that in cases of asymmetric glaucoma, IOP is often higher in the eye on the side the person sleeps. Furthermore, fluctuations in IOP may play an important role in the pathophysiology of glaucoma, comparable to average IOP levels.
Although this theory is not yet universally accepted, research suggests that monitoring IOP continuously over 24 hours in real-life conditions plays a far more important role in the effective management of glaucoma than the two or three isolated measurements typically taken during ophthalmologic check-ups. This theory is supported by the existence of many glaucoma cases in patients whose IOP values appear normal during clinical visits.
In recent years, researchers have developed various types of contact lenses equipped with integrated sensors capable of detecting IOP fluctuations while being worn like standard contact lenses. All the smart lenses designed and built to date are based on highly advanced technologies, and several have already been tested in preclinical and clinical studies. It is hoped that these smart lenses will soon be introduced into clinical practice as an innovative method for continuous 24-hour IOP monitoring, allowing for a more effective and comprehensive management of glaucoma than what is currently possible.
Improving glaucoma management is highly desirable, considering that this condition is among the leading causes of irreversible vision loss worldwide, with over one million people affected in Italy alone.
Dr. Jung Hee Levialdi Ghiron
Responsabile comunicazione scientifica Rome Vision Clinic
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