This audio article is from VisualFieldTest.com.

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Excerpt:

Vasospasm, Cold Hands, and Normal-Tension Glaucoma: The Raynaud’s ConnectionGlaucoma is usually linked to high eye pressure, but in normal-tension glaucoma (NTG) the optic nerve is damaged even when eye pressure is normal. Researchers have long suspected that blood flow problems play a role in NTG. In fact, many NTG patients have symptoms of vascular dysregulation (abnormal control of blood vessels), such as Raynaud’s phenomenon, migraines, or low blood pressure () (). Raynaud’s phenomenon is a condition where cold or stress causes the small arteries in the fingers and toes to spasm and shut down blood flow (turning the skin white then blue) (). This exaggerated vasoconstriction is a clear example of vascular dysregulation. Interestingly, studies show that people with NTG are more likely to have cold hands (Raynaud’s) than those without glaucoma () (). In one study of 246 NTG patients and over 1,100 controls, symptoms like cold hands or feet were significantly more common in the NTG group (). Likewise, a review on NTG noted that “Raynaud’s phenomenon, migraine, [and] nocturnal systemic hypotension” are among the main associated factors for NTG (). These findings suggest that the optic nerve damage in NTG may come from inadequate blood supply rather than pressure. When blood vessels in the body (and eye) over-react to cold or stress, the optic nerve can suffer from repeated mild ischemia (low oxygen) and ‘reperfusion injury’ (damage when blood returns) () (). In short, NTG may in part be a vascular glaucoma, and Raynaud’s is one visible sign of that vascular trouble.How Cold Tests Reveal Vascular ProblemsTo study this connection, researchers use cold provocation tests and blood-flow measurements. A common test is the cold pressor test: a patient immerses a hand in ice water for about a minute, and doctors measure how much the finger temperature drops. In healthy people, the drop is modest; in someone with Raynaud’s or vasospasm it is large. For example, a 2021 study had 113 NTG patients (with well-controlled low eye pressure) dip a hand in ice water and then measured finger temperature () (). NTG patients showed a significantly larger temperature drop than normal controls (about 31.8% vs. 27.0% after one minute, P=0.042) (). Moreover, within the NTG group, those with greater finger cooling progressed faster: they lost visual field (vision) more rapidly than those with milder cooling (). In other words, “an excessive drop in finger temperature after ice water was significantly associated with faster visual field progression” in NTG (). This suggests that strong peripheral vasospasm predicts worse glaucoma, presumably because it reflects similar constriction in the eye’s blood vessels.Another study directly imaged the eye’s blood flow during a cold test (). Using laser flowmetry on the optic nerve head (ONH) and video capillaroscopy on fingernails, Takahashi et al. compared 14 NTG patients to 15 healthy controls (). They found that in NTG the optic nerve head vessels and finger capillaries showed abnormally large constrictions after cold stress, while facial vessels actually dilated (widened) more than normal (). In plain terms, NTG patients’ eye blood flow and finger blood flow drop much more in response to cold than in healthy people. This abnormal vasoreactivity (vessel response) is a hallmark of vascular dysregulation () (). Many older studies have likewise found nailfold capillary abnormalities in NTG and glaucoma patients (). For instance, combi

This audio article is from VisualFieldTest.com.

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Introduction Lifestyle exercise is great for overall health – including eye health. In fact, moderate aerobic exercise (like walking, jogging, or cycling) tends to lower intraocular pressure (IOP), while intense straining (especially with breath-holding) can push IOP way up. For people at risk of glaucoma or optic nerve damage, it’s important to get heart-pumping cardiovascular benefits without dangerous eye-pressure spikes. Here we compare steady cardio versus heavy lifting (weightlifting) and breath-holding (Valsalva maneuver), and explain how smart modifications (breathing out on exertion, lighter resistance) can keep IOP in check. We also discuss which yoga and Pilates poses raise eye pressure, and suggest safer alternatives so you can protect your optic nerves while staying fit.Aerobic Exercise Is Good for Eye Pressure Regular cardio workouts generally lower IOP. Many studies show that after a bout of dynamic exercise, eye pressure falls. For example, a BMC Ophthalmology study found a statistically significant decrease in IOP during jogging (). Longer or more intense activity can drop it even more – one report found IOP fell by about 2.25 mmHg after running a marathon, and by 4.1 mmHg (about 26%) after a 110 km march (). Even a brisk walk produces a significant pressure drop (). Over time, a regular exercise program can keep baseline IOP lower (though it will return up if you stop training) (). These drops occur because exercise shunts blood flow to muscles, alters body-fluid balance, and may accelerate eye fluid drainage. (Minor dehydration during hard workouts can also slightly reduce fluid production ().) The upshot is that aerobic exercise is safe and often beneficial for people with glaucoma risk. It boosts optic nerve blood flow and may even lower glaucoma risk: one large survey found people who walked or did moderate activity had markedly lower glaucoma incidence (). In plain terms, daily moderate workouts (like 30 minutes of brisk walking, cycling, swimming, or similar) are recommended: they strengthen the heart and actually help keep eye pressure down () (). Heavy Lifting and IOP Spikes By contrast, resistance training – especially heavy, isometric lifts – can cause short-lived IOP spikes. Lifting very heavy weights tends to raise blood pressure and venous pressure in the head, which squeezes the eye. Studies have recorded sharp jumps in IOP during heavy lifts. For example, doing a bench press can raise IOP significantly, and holding the breath (the Valsalva maneuver) makes it worse (). In concrete numbers, one study found IOP jumped about 23% above baseline when breath-holding was used, versus only 12% without it (). In maximal static efforts, average IOP rose by 115% above normal – one subject even spiked as high as 46 mmHg (normally in the high 20s) during an all-out lift (). A sustained squat (thighs at right angles) caused about a 37% mean increase in IOP (). Essentially, any time you push hard against a heavy weight and especially hold your breath to “brace,” eye pressure can double or more. These spikes matter because sudden high IOP can strain the optic nerve and blood vessels in the eye. In fact, heavy straining has been linked to eye problems (like retina hemorrhages or detachment) in rare cases (). The bottom line: strenuous lifts can be risky for a vulnerable eye unless you modify them. Breathing Tips: Exhale on Exertion To avoid these dangerous spikes, use proper breathing during lifts. A fundamental tip is to ex

This audio article is from VisualFieldTest.com.

Read the full article here: https://visualfieldtest.com/en/sleep-posture-hacks-head-elevation-and-side-sleeping-effects-on-eye-pressure

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Excerpt:

Sleep Posture Hacks: Head Elevation and Side-Sleeping Effects on Eye PressureHigh intraocular pressure (IOP) – the fluid pressure inside the eye – is a key factor in glaucoma and other eye diseases. Notably, IOP can change with sleep position. Studies show that simply lying down tends to raise IOP compared to sitting (). For example, one experiment found the average IOP was significantly higher when healthy subjects lay flat than when they sat up (). Over the course of the night, side-lying or stomach-lying positions can further affect pressure. In this article we explain how sleeping at a 20–30° head-up angle can lower nighttime eye pressure, why the “down-side” eye often has higher pressure when you sleep on your side, and how practical aids (wedges, adjustable beds, pillow stacks) compare. We also discuss comfort and adherence issues, caution about tight eye masks, and give a simple step-by-step plan for trying new sleep postures and checking the effect (for example with a home tonometer if you have one).Side-Sleeping and the Dependent EyeWhen you lie on your side, gravity and blood flow tend to increase pressure in the dependent eye – the one on the pillow side. In other words, your lower eye usually has higher IOP than your upper eye. Multiple studies confirm this dependent-eye effect. For instance, experiments with healthy volunteers and glaucoma patients show that the eye you lie on (the dependent eye) experiences a significantly greater IOP rise than the higher eye (). Even in people with one worse (more damaged) eye, that worse eye tended to have higher pressure if it happened to be on the pillow side (). Another study of glaucoma patients who habitually slept on one side found that the down-side eye’s IOP climbed about +1.6 mmHg after 30 minutes in that position (). (In eyes that were deteriorating on that side, the increase was even larger, around +2.5 mmHg ().) Over time such repeated pressure spikes on one eye could contribute to worsening glaucoma in that eye.The takeaway: if you sleep on your side, the eye on that side will typically show higher pressure overnight. Experts often recommend that glaucoma patients try to avoid lying on the “bad” eye side. Sleeping on the back (with head raised) keeps both eyes level and may help limit these asymmetric pressure bursts ().Why flat lying raises IOP tooIt’s worth noting that even flat supine sleep (lying on the back or stomach) raises IOP compared to sitting up. In the same head-elevation study mentioned above, investigators found standing/sitting IOP was lower than flat-lying IOP in all subjects (). This happens partly because lying down increases blood pressure in the head and heart, and this in turn raises eye pressure. The lay-flat effect is why simply elevating the head can lower IOP somewhat – as we will see next.Head Elevation and IOP ReductionSleeping on an incline (head up) has been shown to lower IOP a modest amount. A clinical experiment with patients sleeping in a lab found that a 20° head-up tilt (achieved with a wedge pillow) reduced average nighttime IOP by about 1.5 mmHg (around 9–10%) compared to lying fully flat (). In that study, 25 of 30 patients (over 80%) had lower mean IOP at 20°, and 36.7% had reductions of over 10% (). In real numbers the average drop was about 1.56 mmHg for glaucoma patients (from ~15–16 down to ~14 mmHg) and 1.47 mmHg in non-glaucoma people (). In plain terms, elevating the head by 20°–30° lowered nighttime eye pressure b