The Role of Diet in Glaucoma Hawaii Los Angeles – Hiroshima Study

In this cross-sectional study, we showed that cholesterol has a significant positive association with glaucoma. The data showed participants with cholesterol intake ?‰? 252 have risk 3 times higher than low intake cholesterol to have glaucoma (OR: 3.117; p=0.007).

Glaucoma is an insidious eye disease and about half of open angle glaucoma cases are undetected at a certain moment. (19) Oxidative stress has been proposed as an etiologic factor in the pathophysiology of glaucomatous retinal ganglion cells (RGCs) death, alongside elevated IOP, retinal ischemia and nutritional status.(5)(6) Neuro-degeneration due to oxidative stress may have role in deterioration in open angle glaucoma, its have been suggested to damage the trabecular meshwork, resulting in increase intraocular pressure.(5,20,21) It is also showed that in glaucoma, oxidative stress occurs mostly in mitochondria of the retinal ganglion cells and their axons.(4)

There are few common anti-oxidants such as carotenoids (present in fruits and vegetable), Vitamin B, C, E and polyphenolic flavanoids (present in tea, mostly in green tea, and coffee). Tanito et al. showed a low systemic antioxidant capacity is associated with more severe visual field damage in open angle glaucoma. (22) The Rotterdam study(8)showed a protective effect of vitamin B1 on open angle glaucoma (OAG patient has lower thiamine level than controls).

The other presumed mechanism was impaired blood flow. It has been showed that vascular dysregulation (regulation of the blood flow that is not adapted to the needs of the respective tissue) increased the risk of normotension glaucoma, optic nerve compartment syndrome, central serous choroidopathy, retinal artery and vein occlusion and anterior ischemic neuropathy without atherosclerosis.(4) Magnesium (Mg) involved in many metabolic processes in normal cell, its also acts as a natural physiologic calcium channel blocker, thus improve ocular blood flow, reduction of oxidative stress and neuro-protection. It was reviewed that Mg has potential and beneficial role in additional treatment of glaucoma.(23)

Rotterdam study (8) showed high intake of retinol equivalents and vitamin B1 were associated with decreased risk of OAG, whereas a high intake of magnesium was associated with an increase risk, they also found that vitamin A has no significant effect on open angle glaucoma. Nurses 'health study and Health Professionals Follow up study (10) were also could not find any relationship between vitamin A and glaucoma, despite vitamin A is one of the anti-oxidant. In this study we also cannot show any significant difference.

A few studies found a relationship between increase body mass index and elevated intra ocular pressure (24)(25,26), but in contrary to the Barbados study(27), they found low BMI is associated with POAG. In this study we found no association between BMI and glaucoma.

We found high cholesterol intake was positively significant related to glaucoma. There is a study by Pavljalsevic et al. found that higher cholesterol levels are related to POAG (28), a feasible explanation is that excess intraorbital fat and increase blood viscosity in obesity, usually related with lipid abnormality, may disturb the aqueous outflow capacity which cause increased intraocular pressure. Another study explained that prolonged disturbance of plasma lipids may cause to degenerative changes in the retinal and choroidal vessels, which may result in premature ischemic retino-neural angiopathy. This will create hypo perfusion causing microcirculations disorders related to ganglion cells, which may induce permanent visual disturbance. (29) In a case control study by Davari et al. found serum level of cholesterol and triglyceride significantly higher in POAG patient than control(30). Braakhuis et al. found that higher cholesterol intake may increase the risk of oxidative stress-related ocular disease such as cataract and age macular degeneration (AMD), but not for glaucoma (31). A meta analysis studies (32) found that hyperlipidemia did not increase the risk of glaucoma. There was a study about Statin (drug lowered cholesterol) and glaucoma, the result showed statin use was associated with a significant reduction in the risk of open angle glaucoma in-patient with hyperlipidemia.(33) There are few mechanisms to describe this event. Statins have been shown to increase cellular response of endothelial nitric oxide synthase.(34) This acts cause vasodilation and increase of retinal and choroidal blood flow; thus maintain the health of optic nerve and retinal fiber layer. Other mechanism is statins affect molecular intermediaries in the aqueous outflow pathway, including Rho Kinase activity and myosin II ATPase activity, which increase aqueous outflow facility thorough trabecular meshwork and produce a reduction of intraocular pressure(35).

In 2017, Williams et al. found that oral administration of vitamin B3 and/or gene therapy protects the retinal ganglion cell (RGCs) and axon from degeneration in aged mouse models. (36). They use DBA/2J(D2) mice that develop a form of chronic glaucoma with iris abnormalities, high intra ocular pressure, and retinal ganglion cell loss(37). The decrease of NAD+ (Nicotinamide adenine dinucleotide) induced mitochondrial dysfunctions and disturb redox metabolism. They found that a decline of NAD+, which have potential role in protecting mitochondrial metabolism and to protect against oxidative stress can be corrected by giving high dose oral NAM (Nicotinamide/ vitamin B3) as a biosynthetic precursor of NAD+. This study showed vitamin B3/ NAM could protects against both IOP elevation and neuronal susceptibility that has potential role for glaucoma treatment. Regarding to this evidence, human studies are needed in the future (36). In our study, we cannot found any significant relationship between vitamin B and glaucoma.

A possible limitation of our study is the limited number participants who diagnosed with glaucoma, and there were no other glaucoma examination except fundus photographs. This study uses a questioner with reference portion size color photograph; there might be possible errors in measurement of intake by participants. Another possible limitation this study is a cross sectional study, so we could not determine cause and effect between dietary nutrition's and glaucoma.

In conclusion, the current findings showed that high cholesterol intake have positive association to glaucoma in Japanese descent living in Hawaii and Los Angeles population. However, regarding the contradictory result a prospective study with large and general population and also measurement of nutrients serum in the future study is needed to determine weather there is a causal link between nutrition (Vitamin A, B, C, Magnesium, and cholesterol) and glaucoma.

Cite this page