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Silent Thief of Sight and It’s Inheritance

by | Feb 1, 2022 | Manuscripts | 0 comments

Alok Ranjan, B.Optometry

Fellow optometrist, Dr. Shroff’s Charity Eye Hospital, New Delhi, India

 

Glaucoma is a progressive optic neuropathy that causes permanent loss of vision by damaging the optic nerve and peripheral visual field. The prevalence of glaucoma is higher in elderly population. The worldwide prevalence of glaucoma in 2010 was 60.5 million which increased up to 79.6 million in 2020 in which Open Angle Glaucoma (OAG) cases were 74%.(1) The most common type of glaucoma (OAG) often have no symptoms other than slow vision loss.

Angle closure glaucoma (ACG) is a rare, but a medical emergency condition and its symptoms include ocular pain with nausea and sudden visual disturbances. The purpose of this article is to discuss the hereditary factors associated with glaucoma.

Positive family history is associated with increased risk of developing glaucoma. Other factors which contributed to the prevalence are older age, female sex, systemic illness, and their medication such as usage of steroid and prior history of glaucoma surgery.(2)  Systemic conditions like hypertension and diabetes plays important role in maintaining intraocular pressure. Hypertension medication such as systemic B- blockers lowers the Intra Ocular Pressure (IOP) but other components in that medication such as the angiotensin-converting enzyme inhibitor and angiotensin receptor blocker increases the IOP. Hypoglycaemic agents such as sulfonylureas increases the IOP up to 1mm of Hg. (3)

Family history act as a key factor in glaucoma diagnosis in which the risk of OAG for the first line of relatives of the patient is ten times greater than people with no family history of glaucoma.(4)Many genetics studies have proved that more than 50 % of glaucoma cases are associated with family history which indicates that glaucoma is strongly hereditary.(5)

A valid positive bloodline of glaucoma is a precious information.(6) In another condition, when the patient with glaucoma fails to inform their family members about the disease, the unreliability of negative bloodline is increased.(6)

Primary open angle glaucoma occurrence ratio is equal in male and female population and the prevalence of positive bloodline of primary open angle glaucoma is 6-7 times higher in maternal side than the paternal side. (7)Multiple genes are considered as causative factors of primary open angle glaucoma. Much of the primary open angle glaucoma genetics and pathological effects have yet to be explained. (8) Primary open angle glaucoma links to at least 29 genetic loci but there are only 2 genes identified among those, Myocilin and Optineurin. These two are identified as well-defined glaucoma causing genes whereas the role of other loci, genes and variants involved in development of primary open angle glaucoma is controversial and under study.(9)

In primary open angle criteria, positive bloodline case frequency decreased significantly with age(10):

  • 8% in patients younger than50 years.
  • 25% in patients with 51-70 years.
  • 7% in patients older than 70 years.

To conclude, few tips to protect the eyesight from glaucoma “The silent thief of sight” recommended by American academy of ophthalmology(11)

  • Inform your consultant about your systemic illness status and medications
  • Avoid steroid medication for long term and in higher doses; discuss it with your ophthalmologist
  • Avoid breath holding exercises and weightlifting
  • Eat well and see well
  • Avoid any types of ocular injury
  • Sleep at the right position
  • Schedule regular eye examination
  • Follow the treatment plan properly
  • If you have a family history, family screening is a very important aspect

 

References:

  1. Quigley, H. A., & Broman, A. T. (2006). The number of people with glaucoma worldwide in 2010 and 2020. The British journal of ophthalmology, 90(3), 262–267. https://doi.org/10.1136/bjo.2005.081224
  2. O’Brien, J. M., Salowe, R. J., Fertig, R., Salinas, J., Pistilli, M., Sankar, P. S., Miller-Ellis, E., Lehman, A., Murphy, W., Homsher, M., Gordon, K., & Ying, G. S. (2018). Family History in the Primary Open-Angle African American Glaucoma Genetics Study Cohort. American journal of ophthalmology, 192, 239–247. https://doi.org/10.1016/j.ajo.2018.03 HYPERLINK “https://doi.org/10.1016/j.ajo.2018.03.014”.014
  3. Henrietta Ho, FRCOphth1; Yuan Shi, PhD1; Jacqueline Chua, PhD1,2; et al(2017) Association of Systemic Medication Use With Intraocular Pressure in a Multiethnic Asian Population.
  4. Richard H C Zegers, Erik F Reinders and Marc D de Smet Med J Aust 2008; 188 (5): 312-313. || doi:10.5694/j.1326-5377.2008.tb01630.x
  5. Wolfs, R. C., Klaver, C. C., Ramrattan, R. S., van Duijn, C. M., Hofman, A., & de Jong, P. T. (1998). Genetic risk of primary open-angle glaucoma. Population-based familial aggregation study. Archives of ophthalmology (Chicago, Ill. : 1960), 116(12), 1640–1645.https://doi.org/10.1001/archopht.116.12.1640
  6. https://www.fleyedocs.com/tips-to-protect-your-eyesight-from-glaucoma/

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