Glaucoma Risk Factors

Background: Glaucoma is the second leading cause of blindness for over 70 million people worldwide. Bilateral blindness occurs with an estimated 10%. In Indonesia, the prevalence of glaucoma is 0,46%. That means, that 4 to 5 out of 1.000 people suffer from glaucoma. Content: The aim of this study was to analyze four risk factors that can affect the occurrence of glaucoma, namely age factor with diabetes and hypertension history, gender, family medical history, and race. This research used a literature review from 20 journals containing four risk factors for glaucoma. The results showed that diabetes and hypertension are often found in the elderly and that glaucoma symptoms can be exacerbated by increased intraocular pressure. Moreover, glaucoma patient with a positive family medical history of glaucoma has a higher value of intraocular pressure than glaucoma patients without the positive family medical history of glaucoma. Other results showed that men are more at risk because they have a different axial length than women, and Asians are considered riskier than Europeans because Asians’ awareness of eye health is very low. Conclusion: Based on the review, four risk factors could greatly affect the occurrence of glaucoma.


Introduction
Glaucoma is a progressive degeneration of eye nerve damage caused by blockage of the eye's fluid flow system (aqueous humor). Aqueous humor is a natural fluid that plays a role in protecting the shape of the eye, supplying nutrients, and sterilizing dirt in the eye. The pressure inside the eyeball will remain normal if the fluid in the eyeball is absorbed periodically to avoid accumulation. However, if there is a build-up of fluid, the pressure on the eyeball will increase and cause damage to the optic nerve fibers. The symptoms can include visual disturbances with reduced visual fields, pain in the eyes, to headaches. These symptoms are often not noticed by patients in the early stages because has no significant effect. However, the patient will realize it after experiencing severe visual disturbances or even blindness. Each glaucoma patient has a different disorder in pathoglaucos, risk factors, treatment, manifestations, non-specificity, and prognosis. (1;2;3) In general, glaucoma is classified into two types, namely primary and secondary glaucoma.
The most common primary glaucoma in the world is primary open-angle and angle-closure glaucoma. (4) The prevalence of glaucoma worldwide is estimated at 10% who are bilaterally blind. In Indonesia, the prevalence of glaucoma was 0,46%, which means that 4 to 5 people out of 1.000 Indonesians had glaucoma. Based on online hospital application information (SIRS online), the number of glaucoma visits has increased the incidence of glaucoma during the period 2015-2017. (2) The prevalence of glaucoma will increase if it is influenced by several factors, such as age, gender, race, family history, and history of comorbidities (diabetes mellitus and hypertension) and a history of the eye examination. (1)

Subheading 1
The method used a literature review, where the literature search was carried out on several databases using an electronic-based that is accredited/indexed by Sinta/Scopus, such as Science Direct, Pubmed, Ministry of Health Data Center, and other database sources. The inclusion criteria in the study include a minimum of 20 reference articles or journals with the last 10 years published, internationally and nationally accredited and relevant to the topic of this research, while the exclusion criteria include articles or journals that do not have an ISSN.
Research or case studies that relate to glaucoma risk factors were obtained as a result of data analysis in this study. There are 20 studies from international journals. Based on the 20 studies, consist of nine journals discussed the age factor with diabetes and hypertension so that it can affect the development glaucoma. The nine journals used several methods, such as systematic review and meta-analysis, crosssectional, imaging and clinical, retrospective case-control and longitudinal. The results from the nine journals showed that the elderly group is riskier of developing glaucoma because there are supporting risk Six other journals discussed family history and race, two journals discussed the effect of family history on glaucoma and four discussed the effect of race on glaucoma. Two journals discuss the effect of family history factors using cross-sectional methods and case reports of comparative studies. The results from these two journals showed that positive family history is strongly associated with the incidence of primary open-angle glaucoma and primary angle-closure, especially among first-degree relatives. Then, four journals that discussed the effect of race factors used prospective, cohort, cross-sectional observational and systematic review methods. The results from four journals showed that the incidence of glaucoma in Asia is higher than in Europe.

Subheading 2
Research related to glaucoma risk factors was obtained as a result of data analysis in this study. There were 20 related journals. The explanation for each journal can be seen in Table 1.

Crosssectional
The prevalence rates in diabetic, prediabetic, and non-diabetic patients with glaucoma at ≥ 40 years of 9.5%, 3.5% and 2.6% respectively. (7) Crosssectional and case control Diabetics were more often found to have glaucoma with an average age of 59.6 ± 8.11. 13 Prospective study Hypertension is a comorbid condition that generally affects the elderly, especially people with glaucoma. Researchers found that 56% of hypertensive patients with an average age of 58.7 had glaucoma. The investigators said that the association between hypertension and primary open angle glaucoma was 13.95%. (8) Retrospective case control Hypertension increased the risk of glaucoma severity by 31%. (9) Crosssectional observational There was a difference between the value of intraocular pressure in hypertensive patients and controls. The value showed 15.37 ± 2.01 mmHg and 13.41 ± 2.82 mmHg. (10) Longitudinal study The value of intraocular pressure in hypertensive patients of 15.4 ± 3.0 mmHg was strongly associated with the formation of glaucoma, cribrosa and axoplasmic flow disturbance. (11) Gender Case-control Men had about 1.64 times riskier of developing primary open angle glaucoma. (12) Crosssectional Men are riskier due to hormonal factors (not having estrogen) and health factors, as well as environmental conditions that allow them to experience an increase in intraocular pressure. (13) Retrospective Women can be riskier of developing glaucoma, with a percentage of 54.5% of 1,000 participants. (14) Retrospective longitudinal cohort Estrogen treatment was able to reduce the risk of developing primary open angle glaucoma in the long term until the woman experienced menopause. (15) Clinical study and observation Estrogen treatment was able to reduce intraocular pressure by 0.5 mmHg in elderly women, while pregnant women in the third trimester were able to reduce intraocular pressure by 10% due to an increase in estrogen and progesterone. (16) Family Medical

Cohort
The relationship between glaucoma and a positive family history of glaucoma is  (18) Comparative case report 25% of primary angle closure patients and 21.5% of primary open angle glaucoma patients got the disease from one family member. In other words, primary angle closure was found in the relationship with parents and primary open angle glaucoma was found in the relationship between siblings and offspring. (19) Race Prospective The incidence of glaucoma in Europe, especially acute angle closure occurred in Scotland with a percentage increase of 29% and 31% in 2012 and 2013. However, when compared with the prevalence in Asia (Singapore), Scotland has decreased prevalence of 46% (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012). In other words, the Chinese race had a higher prevalence of primary angle closure glaucoma. (20)

Cohort
The prevalence of glaucoma in Northern Ireland is similar to that of the rest of the European population, with an estimated prevalence of 2.83%. (21)

Crosssectional
The prevalence of glaucoma in Asia was higher than in Europe. It was found that nearly 10,000 Asian populations were affected by glaucoma. (22) Systematic review and metaanalysis The highest prevalence of glaucoma was found in East Asia and Central South Asia, which was 65.2%. This is caused by the increasing population and lack of awareness of eye health. In contrast to