A Proactive Approach for Glaucoma Suspects

Glaucoma is estimated to cost Australia $4.3 billion every year by 2025,¹ as a result of an ageing population. Approximately 10% of Australians over the age of 40 are considered to be at risk of glaucoma, or ‘glaucoma suspects’.² Of these, around 12.5% will go on to develop glaucoma within the standard two-year interval for routine eye examinations.³

The reason glaucoma suspects are labelled as such is because we are not certain who will remain stable and who will progress to develop vision loss from glaucoma. Thus, the current approach to managing glaucoma suspects is to monitor every six to 24 months depending on the intraocular pressure (IOP) and level of risk, and to intervene only when structural or functional progression has occurred.

This is a reactive approach, where we only act when there is progression. But is this the best approach when looking through the lens of a glaucoma suspect patient? The obvious question is: why do we wait until progression has occurred before we intervene?

Let’s take the example of age-related macular degeneration (AMD). When we see patients with drusen or early signs of AMD, do we just ask them to go away and come back for a review in 24 months? No. We proactively tell them to wear UV-protection sunglasses, stop smoking, and eat a healthy diet. We even give them an Amsler grid to monitor for distortion at home. The reason we do this? To reduce their risk of vision loss from AMD.

So why not do the same for our glaucoma suspect patients in addition to monitoring? Why do we not encourage them to cut down on smoking, eat a healthy balanced diet, and do more exercise and meditation? It is not as if evidence does not exist.

Population-based studies have confirmed that smoking is associated with higher IOP and increased risk of glaucoma.^4-6 There is similar compelling data for higher intake of vegetables and fruit significantly reducing the odds of glaucoma risk by 47% to 79%.^7-9 Increased moderate physical activity has been demonstrated to lower IOP¹⁰ and slow down the rate of glaucomatous field loss.¹¹ Mindfulness meditation 45 to 60 minutes daily reduces IOP and improves quality of life,¹² and is highly accepted by patients.¹³

My personal observation is that the overwhelming majority of glaucoma and glaucoma suspect patients want information on natural ways to reduce risk. We should therefore discuss these lifestyle changes with our glaucoma suspect (and glaucoma) patients given that there is a lot of upside and very little downside.

The role of nutritional supplements for neuroprotection is more controversial given the financial expense and the fact that the dosages are usually well above the recommended daily allowance. Among those that have been evaluated in human clinical studies for glaucoma, ginkgo biloba extract and nicotinamide, are probably the two that stand out the most.^14-16 At present, we do not know if consumption of these supplements will definitely reduce the risk of developing glaucoma over the long term, and we do not know what the ideal dosages should be. We also do not know if there are any adverse long-term effects, although the increased risk of bleeding with ginkgo biloba extract is probably overstated based on data from meta-analyses and systematic reviews.^17,18

However, the concept of taking supplements for neuroprotection makes sense to most glaucoma suspect patients, particularly those who are at higher risk. My personal opinion is that we should proactively discuss supplements with our patients if they are open to it. Encourage them to seek further advice from other healthcare professionals if they are considering supplements. Arm them with clear, unbiased information about the potential risks and benefits, and empower them to decide on the best option based on their circumstances.

Critics will say there is no evidence to support this proactive glaucoma approach. However, there is already enough evidence to warrant open two-way discussion with patients. Let’s not wait for the perfect evidence to be published first before we proactively educate patients about proactively managing their glaucoma risk.

Acting in the best interests of our patients should be at the core of our clinical practice. In my opinion as a glaucoma suspect myself, just waiting passively for glaucoma progression to occur is not good practice – proactive glaucoma management is.

This article has been republished courtesy of Insight Magazine. 

Note: Glaucoma Australia does not advise that complimentary medicines should replace prescribed glaucoma treatments. 

References: 

1. Dirani M, Crowston JG, Taylor PS, et al. Economic impact of primary open-angle glaucoma in Australia. Clin Exp Ophthalmol. 2011; 39(7):623-32.

2. Keel S, Xie J, Foreman J, et al. Prevalence of glaucoma in the Australian National Eye Health Survey. Br J Ophthalmol. 2019; 103(2):191-5. 

3. Miki A, Medeiros FA, Weinreb RN, et al. Rates of retinal nerve fiber layer thinning in glaucoma suspect eyes. 2014; 121(7):1350-8

4. Law SM, Lu X, Yu F, et al. Cigarette smoking and glaucoma in the United States population. Eye (Lond). 2018;32(4):716-725.

5. Perez-de-Arcelus M, Toledo E, Martinez-Gonzalez MA, et al. Smoking and incidence of glaucoma: The SUN Cohort. Medicine (Baltimore). 2017;96(1):e5761

6. Lee CS, Owen JP, Yanagihara RT, et al. Smoking is associated with higher intraocular pressure regardless of glaucoma: a retrospective study of 12.5 million patients using the Intelligent Research in Sight (IRIS) Registry. Ophthalmol Glaucoma. 2020;3(4):253-261.

7. Coleman AL, Stone KL, Kodjebacheva G, et al. Glaucoma risk and the consumption of fruits and vegetables among older women in the study of osteoporotic fractures. Am J Ophthalmol. 2008;145(6):1081-9.

8. Kang JH, Willett WC, Rosner BA, et al. Association of dietary nitrate intake with primary open-angle glaucoma: a prospective analysis from the Nurses’ Health Study and Health Professionals Follow-up Study. JAMA Ophthalmol. 2016;134(3):294-303.

9. Meier NF, Lee DC, Sui X, et al. Physical activity, cardiorespiratory fitness, and incident glaucoma. Med Sci Sports Exerc. 2018;50(11):2253-2258.

10. Schmidt KG, Mittag TW, Pavlovic, S, et al. Influence of physical exercise and nifedipine on ocular pulse amplitude. Graefes Arch Clin Exp Ophthalmol. 1996;234(8):527-32.

11. Lee MJ, Wang J, Friedman DS, et al. Greater physical activity is associated with slower visual field loss in glaucoma. Ophthalmology. 2019;126(7):958-964.

12. Dada T, Meetal D, Mohanty K, et al. Mindfulness meditation reduces intraocular pressure, lowers stress biomarkers and modulates gene expression in glaucoma: a randomized controlled trial. J Glaucoma. 2018;27(12):1061-1067.

13. Brogan K, Bigirimana D, Wightman A, et al. Daily meditation practice for managing glaucoma patients’ attitudes and acceptance. J Glaucoma. 2022;31(9):e75-e82.

14. Lee J, Sohn SW, Kee C. Effect of ginkgo biloba extract on visual field progression in normal tension glaucoma. J Glaucoma. 2013;22(9):780-4.

15. Quaranta L, Bettelli S, Uva MG, et al. Effect of Ginkgo biloba extract on preexisting visual field damage in normal tension glaucoma. 2003;110(2):359-62.

16. Hui F, Tang J, Williams PA, et al. Improvement in inner retinal function in glaucoma with nitocinamide (vitamin B3) supplementation: a crossover randomized clinical trial. Clin Exp Ophthalmol. 2020;48(7):903-914.

17. Kellermann AJ, Kloft C. Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis. Pharmacotherapy. 2011;31(5):490-502.

18. Yuan Q, Wang CW, Shi J, et al. Effects of Ginkgo biloba on dementia: an overview of systematic reviews. J Ethnopharmacol. 2017;195:1-9.