Protect, Prevent, Preserve Your Eyes Podcast: EPISODE 4
Elizabeth Nystrom & Olivia Mohney
Elizabeth: Hi again, welcome back to Protect, Prevent, Preserve Your Eyes. Once again, my name is Elizabeth Nystrom, a Master of Public Health Student at Michigan State University, and this is Olivia Mohney, a public relations student at Baylor University.
Olivia: We will be your guides for this educational podcast which will look at various eye conditions, risk factors for developing these conditions, and what you can do to aid in preventing some of these conditions.
E: We both work for Association for the Blind and Visually Impaired (ABVI), a nonprofit organization focused on helping those with vision loss thrive in a sighted world. More background information on ABVI, the services offered, and ways to donate or get involved can be found on the website abvimichigan.org.
O: For this final episode, we will be discussing how genetics can influence the development of eye disease and we’ll have a very special interview to help elaborate on life with vision loss. With that, let’s get started!
O: Throughout this podcast we have been discussing various external, controllable lifestyle factors. These factors such as, smoking and diet can be modified to help protect you against eye disease and vision loss. For this segment of the episode, we will be discussing the uncontrollable factor, genetics!
E: In terms of cataracts, there is a form that can be inherited, and these are referred to as congenital cataracts and are classified based on the location and appearance of the opacification (or cloudiness) of the lens. Most inherited cataracts are autosomal dominant, yet some cataracts can be autosomal recessive or X-linked.
E (continued): When talking about genetics, autosomal dominant traits are relatively easy to pass on, because only one copy of the gene is necessary. A common autosomal dominant trait would be Huntington’s disease, if you’ve ever heard of that. Autosomal recessive inheritance requires two copies of the gene to be passed on, one from the father and one from the mother. The parents who carry one copy of this gene will not show symptoms. A common autosomal recessive trait would be sickle cell disease. Finally, X-liked inheritance primarily occurs in women, because we have two X chromosomes, while men have an X and a Y.
O: Flash back to cataracts! The remaining percentage of cataracts are sporadically inherited with no direct family history. Interestingly, there are 115 genes that have been identified as being associated with inherited cataracts. For reference, the human genome is over 3 billion!
O (continued): There have been several variants in genes that have demonstrated an association with increased risk for age-related macular degeneration (AMD). However, a variant in a very specific gene, the Complement Factor H gene, has been shown to increase the risk of AMD by 2.45 to 5.57 times. For reference, Complement Factor H influences the blood clotting pathway. Additionally, age and a positive family history for AMD are the two most influential risk factors for developing AMD. Studies have shown that an individual with a primary relative, such as a mother or father, with AMD is 12 to 27 times more likely to develop AMD than someone without a family history of it.
E: Wow, Olivia, that is sort of scary. My dad’s mother had AMD and I always worry about him getting it, especially because he doesn’t get regular eye care!
O: We can’t stress that enough! Even if you aren’t experiencing changes in your vision, it’s always best to see the regular eye doctor annually.
E: On another note, retinitis pigmentosa accounts for nearly half of all inherited retinal diseases in the United States. RP is a progressive disease of the retina which typically begins with symptoms such as night blindness and progressive loss of peripheral vision, which can lead to loss of central vision and eventually blindness. These symptoms usually begin in adolescence and progress into adulthood.
E (continued): There are several forms of RP including non-syndromic and syndromic forms, which include Usher syndrome and Bardet-Biedl syndrome. Usher syndrome is what Helen Keller suffered from, RP and deafness. 12 specific genes have been found to be associated with Usher syndrome, 17 with Bardet-Biedl and over 50 are associated with various forms of RP.
O: Interestingly enough, ABVI has a volunteer, Doug, who has retinitis pigmentosa. If you’re interested in learning more about what life is like with RP, reach out to us through social media and we would be happy to interview Doug in a potential future episode.
O (continued): Now, there are heritable components to both early-onset glaucoma and adult-onset glaucoma, yet, one follows more complex pathways than the other. Early-onset glaucoma occurs prior to age 40 and is more likely to be inherited via single genes, whereas adult-onset glaucoma follows a more complex pattern involving multiple genetic factors.
E: Three single genes (we will pass on educating you on the names of these genes because it is out of the scope of this podcast) have been found to cause glaucoma without influence from other genes or external factors. Additionally, greater than 20 genes have been determined to be associated with increased risk for primary open-angle glaucoma and primary angle-closure glaucoma when found in combination with other genes or external factors. For a refresher on the difference between these two types of glaucoma, pop back over to our first episode of the podcast where we review these in detail.
E (continued): Finally, familial normal tension glaucoma, the form of glaucoma that has a normal intraocular pressure, is associated with two rare genetic mutations. This form of glaucoma is typically inherited in an autosomal dominant fashion, meaning only one copy of the gene is required. These types of mutations account for approximately 2-3% of normal tension glaucoma cases.
O: In terms of populations that are most at risk for glaucoma, Asian, African, and Hispanic populations have significant prevalence rates for glaucoma, such that the risk of developing it is 3 to 5 times higher among individuals of African ancestry than among individuals of other backgrounds. Additionally, individuals of African ancestry have an increased likelihood of having a severe form of glaucoma and suffer from eventual blindness.
E: If you have questions about your risk of glaucoma or any of the other genetic eye diseases, talk with your doctor first to see if you may be at risk. Still have questions? Contact ABVI and we would be happy to answer any questions you may have.
O: We will now shift into the Q and A portion of our podcast. For this first interview, we will be talking with Charis Austin, ABVI’s client advocate and a member of the legally blind community. Charis, welcome to the Triple P podcast, we are so happy to have you for this episode. Would you care to introduce yourself and let us know a little bit about you?
E: Well, thank you for joining us today, Charis. Let’s dive in! How long have you been a member of the blind community?
O: Can you elaborate a little on which type of vision loss you have?
O: So, it sounds like you had to adjust to life without vision at a pretty young age. At which time in your life did you become involved with ABVI and how did that come to be?
E: As ABVI’s long-time client advocate and support group leader, Charis has quite a bit of experience and advice to offer for those who are new to vision loss and blindness, or those who just may be struggling with acceptance. Charis, do you have any quick advice that you’d like to share with our podcast listeners?
E: Let’s say for a scenario, a sighted individual was meeting you for the first time. To be respectful and indicate their presence, how would you like to be approached by a sighted person?
E: Well, thank you for joining us today, Charis. We really appreciate you providing such valuable insight.
O: And thank you all for joining us once more today and listening to our podcast. This will be the last episode of the Triple P podcast, for the time being. You may hear from us again in the future.
E: As with all of our episodes, the references from this episode will be uploaded to ABVI website should any of the studies interest you, I will admit though, they are quite technical in their reporting. Thanks so much for listening to the Triple P Podcast if you would like to connect with us make sure to follow us on Instagram and Facebook, @abvimichigan and thanks for listening to the Prevent, Protect and Preserve Podcast.
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