A 1 in 10,000 Chance: A Case of Congenital Glaucoma
By Samantha Herrera
It was a warm spring evening in a small Mexican town in 1988 when Aaron Mendoza was born. His family was very happy with their newest little bundle of joy. His three siblings were especially happy to have another playmate. Aaron and his mother were released from the hospital, both with a clean bill of health, and the Mendoza family settled into a new routine with the new baby.
However, the story didn’t end there. The Mendozas didn’t know what to make of Aaron’s condition. In the short three months Aaron had been alive, he was constantly crying. While it’s perfectly normal, even expected, for babies to cry, this wasn’t your average baby crying. It was always one eye that cried, the left one. The right one seemed perfectly unaffected, while the left one just constantly produced a steady stream of tears. Aaron also cried all the time: when sad, when happy, when playing, when eating. They considered this strange but weren’t entirely convinced something was wrong until a family member, Aaron’s aunt (who was a nurse), pointed out that this continuous tearing up wasn’t common or normal, and that the affected eye was enlarged compared to the non-affected eye.
While no parent wants to believe that there could be something wrong with their child, much less their child that isn’t even half a year old yet, the Mendozas didn’t want to take any chances. They took their child to the local hospital where he was examined by a pediatrician. The pediatrician concluded that there did appear to be something wrong with Aaron, but they couldn’t give an exact diagnosis. With this new information, the pediatrician gave the Mendozas a referral to a doctor specializing in treatment of pediatric visual conditions. This vision specialist was in Guadalajara, Mexico, five hours from their home.
The Mendozas took some time off work to go visit the specialist in Guadalajara. He was a kind, older gentleman who examined Aaron and gently gave his official diagnosis to the boy’s worried family. Aaron had congenital glaucoma. The Mendozas were confused. They knew people who suffered from glaucoma, but they had never met or heard of anyone who had any experience of congenital glaucoma. The doctor explained that this was a rare disease. In fact, congenital glaucoma only affects 1 in every 10,000 newborns. (Ocular Microsurgery Institute, 2018). Congenital glaucoma is a disease that affects babies’ vision, characterized by symptoms like enlarged eyes, sensitivity to light, and excessive tearing up of the affected eye or eyes. Problems cause damage to the optic nerve, caused by increased intraocular pressure. If the pressure is not relieved, the optic nerve might become irreparably damaged, and the child will become blind.
To understand what caused this, we must understand the development of the eye in the first place. As soon as conception occurs, the human embryo is growing and changing. The eyes begin to develop right around the third week of gestation and will continue to do so until the end of the tenth week of gestation (Ludwig et al. 2020). Spurred onward by the embryo’s genes, the embryo’s brain grows out in two places to form optic vesicles, which will eventually make contact with the surface in front of it and continue development (Ludwig et al. 2020). The optic cup develops from the optic vesicles, and gives rise to the retina, the iris, and the ciliary body (Ludwig et al. 2020). This layered cup will continue to change, eventually gaining a lens, blood vessels, and a sophisticated drainage system to move fluids out of the eye. The ciliary body and the drainage system are the most pertinent to congenital glaucoma. The ciliary body is an extension of the iris. It is constantly producing aqueous humor, the jelly-like, viscous substance that fills the inner chamber of the eye. As fresh aqueous humor is produced, the eye needs to get rid of the older aqueous humor, which it does by passing it through the drainage system. Think of this as if you were filling a bathtub with water. You open the tap, and fresh water comes flowing out into the bathtub. The water then moves out through the drain, in order to allow new water to come in without causing the whole bathtub to overflow. But what if you plugged up the drain and left the water running? The tub would fill up higher and higher with water, but the water would have nowhere to go, and eventually the whole system would simply run over.
The same thing can happen in the eye. If something is obstructing the eye’s drainage system or the system was not formed properly during embryonic development, then the aqueous humor cannot flow out of the eye. However, unlike the bathtub scenario, the aqueous humor cannot just all overflow from the eye. Some of it can leak out, in the form of the eye constantly tearing up, but the vast majority of the humor remains trapped within the eye. The amount of humor in the eye increases as more aqueous humor is created and is added to the eye. This creates a higher than normal intraocular pressure, which crushes the optic nerve until it is no longer able to send any signals to the brain and the individual becomes blind.
Luckily, Aaron Mendoza’s glaucoma wasn’t that far along. He was very young, and they were able to catch the condition when it was in its first stages. The doctor informed the family that it appeared that the boy’s drainage system had failed to form properly, so Aaron would have to have surgery in order to create a new, artificial drainage system. This type of surgery is known as a filtering surgery, or a microsurgery (Stanford, 2021). Major types of this surgery are trabeculectomies, surgeries that cut away part of the trabecular meshwork drainage system to allow the eye to drain properly, and iridotomies, surgeries that make small holes in the iris to allow for easier fluid movement in the eye (Stanford, 2021). More recently, laser surgery has also been used to correct congenital glaucoma. In these surgeries, doctors utilize a laser to cut away at the tissue of the eye and create a new opening to allow the successful draining of the aqueous humor (Stanford, 2021).
Aaron Mendoza had his microsurgery at the young age of 8 months, and it was successful in making a new drainage system. He would have to return several times to the Guadalajara hospital for post-operative care and check-ups on the progression of his vision. During each of these visits, Mr. Mendoza would stay home to work and take care of their three other children, while Mrs. Mendoza made the long trip into the city with Aaron for his appointments. The new drainage system worked perfectly, and the intraocular pressure was relieved. Since the disease was caught and treated early, Aaron suffered no vision loss. Today, he sees perfectly fine, and has never required any kind of visual aid. He remembers nothing of his eye problems. Indeed, the only remnants of the ordeal are stories, pictures from the time, and a single small scar on his nose next to an ever-so-slightly enlarged eye.
About the Author
Samantha Herrera is a junior at Harvard College concentrating in Neuroscience.
References
IMO. 2018. Congenital glaucoma. [online] Available at: https://www.imo.es/en/congenital-glaucoma [Accessed 2 April 2021].
Ludwig, P., Lopez, M. and Czyz, C., 2021. Embryology, Eye Malformations. [online]
Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK482496/#:~:text=Eye%20development%20occurs
%20in%20the,of%20mesodermal%20and%20ectodermal%20origin [Accessed 1 April 2021].
Stanfordchildrens.org. 2021. Stanford Children's Health. [online] Available at: https://www.stanfordchildrens.org/en/topic/default?id=childhood-glaucoma-90-P02106 [Accessed 2 April 2021].
However, the story didn’t end there. The Mendozas didn’t know what to make of Aaron’s condition. In the short three months Aaron had been alive, he was constantly crying. While it’s perfectly normal, even expected, for babies to cry, this wasn’t your average baby crying. It was always one eye that cried, the left one. The right one seemed perfectly unaffected, while the left one just constantly produced a steady stream of tears. Aaron also cried all the time: when sad, when happy, when playing, when eating. They considered this strange but weren’t entirely convinced something was wrong until a family member, Aaron’s aunt (who was a nurse), pointed out that this continuous tearing up wasn’t common or normal, and that the affected eye was enlarged compared to the non-affected eye.
While no parent wants to believe that there could be something wrong with their child, much less their child that isn’t even half a year old yet, the Mendozas didn’t want to take any chances. They took their child to the local hospital where he was examined by a pediatrician. The pediatrician concluded that there did appear to be something wrong with Aaron, but they couldn’t give an exact diagnosis. With this new information, the pediatrician gave the Mendozas a referral to a doctor specializing in treatment of pediatric visual conditions. This vision specialist was in Guadalajara, Mexico, five hours from their home.
The Mendozas took some time off work to go visit the specialist in Guadalajara. He was a kind, older gentleman who examined Aaron and gently gave his official diagnosis to the boy’s worried family. Aaron had congenital glaucoma. The Mendozas were confused. They knew people who suffered from glaucoma, but they had never met or heard of anyone who had any experience of congenital glaucoma. The doctor explained that this was a rare disease. In fact, congenital glaucoma only affects 1 in every 10,000 newborns. (Ocular Microsurgery Institute, 2018). Congenital glaucoma is a disease that affects babies’ vision, characterized by symptoms like enlarged eyes, sensitivity to light, and excessive tearing up of the affected eye or eyes. Problems cause damage to the optic nerve, caused by increased intraocular pressure. If the pressure is not relieved, the optic nerve might become irreparably damaged, and the child will become blind.
To understand what caused this, we must understand the development of the eye in the first place. As soon as conception occurs, the human embryo is growing and changing. The eyes begin to develop right around the third week of gestation and will continue to do so until the end of the tenth week of gestation (Ludwig et al. 2020). Spurred onward by the embryo’s genes, the embryo’s brain grows out in two places to form optic vesicles, which will eventually make contact with the surface in front of it and continue development (Ludwig et al. 2020). The optic cup develops from the optic vesicles, and gives rise to the retina, the iris, and the ciliary body (Ludwig et al. 2020). This layered cup will continue to change, eventually gaining a lens, blood vessels, and a sophisticated drainage system to move fluids out of the eye. The ciliary body and the drainage system are the most pertinent to congenital glaucoma. The ciliary body is an extension of the iris. It is constantly producing aqueous humor, the jelly-like, viscous substance that fills the inner chamber of the eye. As fresh aqueous humor is produced, the eye needs to get rid of the older aqueous humor, which it does by passing it through the drainage system. Think of this as if you were filling a bathtub with water. You open the tap, and fresh water comes flowing out into the bathtub. The water then moves out through the drain, in order to allow new water to come in without causing the whole bathtub to overflow. But what if you plugged up the drain and left the water running? The tub would fill up higher and higher with water, but the water would have nowhere to go, and eventually the whole system would simply run over.
The same thing can happen in the eye. If something is obstructing the eye’s drainage system or the system was not formed properly during embryonic development, then the aqueous humor cannot flow out of the eye. However, unlike the bathtub scenario, the aqueous humor cannot just all overflow from the eye. Some of it can leak out, in the form of the eye constantly tearing up, but the vast majority of the humor remains trapped within the eye. The amount of humor in the eye increases as more aqueous humor is created and is added to the eye. This creates a higher than normal intraocular pressure, which crushes the optic nerve until it is no longer able to send any signals to the brain and the individual becomes blind.
Luckily, Aaron Mendoza’s glaucoma wasn’t that far along. He was very young, and they were able to catch the condition when it was in its first stages. The doctor informed the family that it appeared that the boy’s drainage system had failed to form properly, so Aaron would have to have surgery in order to create a new, artificial drainage system. This type of surgery is known as a filtering surgery, or a microsurgery (Stanford, 2021). Major types of this surgery are trabeculectomies, surgeries that cut away part of the trabecular meshwork drainage system to allow the eye to drain properly, and iridotomies, surgeries that make small holes in the iris to allow for easier fluid movement in the eye (Stanford, 2021). More recently, laser surgery has also been used to correct congenital glaucoma. In these surgeries, doctors utilize a laser to cut away at the tissue of the eye and create a new opening to allow the successful draining of the aqueous humor (Stanford, 2021).
Aaron Mendoza had his microsurgery at the young age of 8 months, and it was successful in making a new drainage system. He would have to return several times to the Guadalajara hospital for post-operative care and check-ups on the progression of his vision. During each of these visits, Mr. Mendoza would stay home to work and take care of their three other children, while Mrs. Mendoza made the long trip into the city with Aaron for his appointments. The new drainage system worked perfectly, and the intraocular pressure was relieved. Since the disease was caught and treated early, Aaron suffered no vision loss. Today, he sees perfectly fine, and has never required any kind of visual aid. He remembers nothing of his eye problems. Indeed, the only remnants of the ordeal are stories, pictures from the time, and a single small scar on his nose next to an ever-so-slightly enlarged eye.
About the Author
Samantha Herrera is a junior at Harvard College concentrating in Neuroscience.
References
IMO. 2018. Congenital glaucoma. [online] Available at: https://www.imo.es/en/congenital-glaucoma [Accessed 2 April 2021].
Ludwig, P., Lopez, M. and Czyz, C., 2021. Embryology, Eye Malformations. [online]
Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK482496/#:~:text=Eye%20development%20occurs
%20in%20the,of%20mesodermal%20and%20ectodermal%20origin [Accessed 1 April 2021].
Stanfordchildrens.org. 2021. Stanford Children's Health. [online] Available at: https://www.stanfordchildrens.org/en/topic/default?id=childhood-glaucoma-90-P02106 [Accessed 2 April 2021].