Developmental and intellectual delays are the main feature of Down Syndrome, but this genetic condition is associated with diverse other disorders including a heightened risk for keratoconus. Nearly 15 percent of all people born with Down Syndrome have keratoconus, and this cornea disorder can lead to progressively-worsening myopia and astigmatism. Meanwhile, around 50 percent of Down Syndrome newborns have a congenital heart defect requiring corrective surgery to reduce the risk of premature death in childhood. Described below are some common symptoms of keratoconus and usual management, as well as a minimally-invasive surgery that can halt progressive vision loss in some people afflicted with keratoconus.
Keratoconus’ Impact on Eyesight
An abnormality of a cone-shaped cornea occurs in keratoconus, which causes light to be refracted onto the retina at an incorrect angle. Depending upon the severity of the incorrect angle of refraction, the keratoconus-afflicted person can have both myopia and astigmatism. Over time, the progressive bulging of the cornea causes thinning and stiffening of the corneal fibers which can lead to persistent “dry eyes” and cornea pain (as well as a heightened risk for corneal ulceration).
While keratoconus is typically not diagnosed until adolescence, experiencing this cornea disorder in childhood is linked to more severe vision impairment by adulthood due to increased amount of time for progression. Besides progressively worsening eyesight, people living with keratoconus often experience a heightened sensitivity to sunlight (and glare), along with intermittent blurry vision.
Vision Correction utilizing Rigid Gas Permeable (RGP) Contact Lenses
Wearing eyeglasses may not be able to enable a keratoconus-afflicted person to see distant objects clearly if the astigmatism is severe. For this reason, the most common corrective eyewear prescribed are Rigid Gas Permeable (RGP) contact lenses (which are often called “hard” lenses). Since “soft” contact lenses do not correct astigmatism, these are only suitable in people who have myopia without astigmatism.
While learning to insert RGP contact lenses can be difficult for a person with Down Syndrome, the benefit of enabling 20/20 vision may outweigh the many hours needed to train your Down Syndrome teenager or young adult in how to correctly insert a RGP contact lens. (Removing RGP contact lenses correctly is also necessary, and may be aided by use of a contact lens insertion/removal tool.)
Other Frequent Health Problems in People with Down Syndrome
The following are three other frequent health problems in people born with Down Syndrome:
- Hearing loss;
- Obstructive sleep apnea;
- Higher risk for dental cavities and periodontal disease
In addition, people with Down Syndrome are at increased risk of developing gastroesophageal reflux and celiac disease, and around 15 percent of all people with Down Syndrome have hypothyroidism.
Three Variants of Down Syndrome
According to the Mayo Clinic, the following are the three genetic variants causing Down Syndrome:
- Trisomy 21 –This is the genetic cause in 95 percent of people with Down Syndrome, and the genetic causal factor is three copies of chromosome 21 instead of the usual two copies of chromosome 21 in all of the body’s cells.
- Mosaic Down Syndrome – In this rare form of Down Syndrome, the afflicted person has only some cells with an extra copy of chromosome 21.
- Translocation Down Syndrome – This genetic variant occurs when only a portion of chromosome 21 becomes attached onto another chromosome before (or at) conception (and the genetic material most often attaches to chromosome 14 or to another copy of chromosome 21).
Intracorneal Ring Segments (ICRS) for the Treatment of Keratoconus
One minimally-invasive surgery to improve vision in keratoconus-afflicted people is the surgical placement of intracorneal ring segments. An article in Eye and Vision in 2016 noted that ICRS implantation occurs within the corneal stroma in order to induce a positive change in the cornea’s refractive geometry and refractive power with resulting improved visual acuity. However, an article in Ophthalmology and Therapy specifies that good candidates for this surgery are at least 18 years old, and show alignment of refractive and keratometric axes (with corneal scarring as a contraindication for this surgical procedure).
By scheduling an appointment at the Precision Keratoconus Center nearest your residence, you can learn more about keratoconus treatment options.