There are many challenges individuals can face when they are diagnosed with keratoconus. However, things can be even more difficult for someone with special needs. More than half of people with Down syndrome experience an eye disease, such as keratoconus, at some point in their lives so caregivers and doctors should monitor their vision closely. In fact, what many people don’t know is that research shows that an estimated 5-30% of people with Down syndrome are also affected by keratoconus[10][11], even though it is considered a rare disease. That’s why it’s extremely important to raise awareness of keratoconus in this community and to be aware of the potential signs and symptoms.
With an increased prevalence of keratoconus in the Down syndrome community, physicians and caregivers play a crucial role in communicating, educating, and advocating for people with special needs. People with Down syndrome may not be able to communicate or express any difficulties they are having with their eyes, which can cause many challenges if their condition goes undiagnosed and continues to progress. This is where physicians can really help to educate caregivers about progressive keratoconus and the importance of routine eye exams, in addition to available treatment options, such as iLink® FDA-approved cross-linking.
Hear from a Keratoconus Expert
As you continue to read, Dr. Ostrovsky will answer questions, offer tips and advice to caregivers of Down syndrome loved ones, as well as discuss the importance of early detection and treatment of keratoconus.
What are some tips you would offer to parents/caregivers of those with Down syndrome around monitoring for keratoconus and other vision issues? Are there any specific signs or behaviors to watch for that may indicate a vision issue?
Parents know their child best and are usually the best source for identifying changes in their child’s visual functioning. Children and adults with Down syndrome may not actively voice concerns about declining vision. Because of this, parents can frequently pick up on non-verbal cues about declining vision – such as bringing reading materials closer or further from the face, squinting, tilting of the head, and having difficulty carrying out tasks that were previously easily accomplished.
Certain behaviors can also be clues of underlying medical conditions or can lead to the development or worsening of certain eye conditions if left unchecked. For example, rubbing of the eyes can be a sign of underlying allergic eye disease or inflammatory conditions of the eyelids (such as rosacea or blepharitis). Eye rubbing in certain individuals predisposed to KC, in turn, can lead to the development of keratoconus, which can cause progressive vision loss. Treating the underlying allergic or inflammatory condition can in turn relieve itching and prevent the eye rubbing behavior.
How common is keratoconus in the Down syndrome community? Why is there a higher prevalence of keratoconus in people with Down syndrome?
Compared to estimates that 1 in 2,000 individuals in the US are living with keratoconus, the prevalence in people with Down syndrome has been cited to be 10 times that of the typical population[1][2][3]. A recent study from Norway national registry quoted a prevalence of keratoconus of 1:18[4] in people with Down syndrome. The increased prevalence of keratoconus in patients with Down syndrome is likely due to the following:
- Chromosome 21: This chromosome is responsible for the production of collagen in the body. Collagen anomalies are seen in the various organ systems in patients with Down syndrome in the eye, corneal collagen abnormalities can result in weakening, thinning and deformity of the cornea called keratoconus.[5][6][7]
- Allergies and Eye Rubbing: Patients with Down syndrome tend to have a higher prevalence of atopy (the genetic tendency to develop allergic diseases) and eye rubbing behavior, both of which have been associated with the development of keratoconus.[8][9]
Why is early detection and treatment of progressive keratoconus so important? How can it impact someone’s quality of life?
Untreated keratoconus will often progress and can cause loss of vision. Vision loss can be profound and people with advanced forms of this condition can be legally blind. Treating advanced stages of the disease can only be accomplished with corneal transplant surgery. Patients with Down Syndrome have worse outcomes with this surgery than neurotypical patients with keratoconus, so catching the disease in its early stages allows doctors to undertake a stabilizing treatment called corneal collagen cross-linking. This FDA-approved treatment can only be done before the corneal thinning becomes severe. iLink® FDA-approved cross-linking can strengthen the cornea and prevent further progressive deformation and vision loss, allowing the patient to maintain good vision with contact lenses and avoid corneal transplantation.
What treatment options would you recommend for people with Down syndrome who are diagnosed with progressive keratoconus?
Each patient’s case needs to be taken on with an individualized approach, but if possible, every attempt should be made to perform FDA-approved cross-linking to help slow or halt the progression of keratoconus. You should discuss the risks with your doctor to consider whether you or a loved one are candidates for this procedure. It is also essential for the patient to stop rubbing his/her eyes. Increased risk of progression of the disease, even in cross-linked corneas, exists in people who continue to rub their eyes.
How do you prepare someone with Down syndrome for a vision exam or other procedure, such as iLink® FDA-approved cross-linking?
I get to know all of my patients closely. My office staff is also specially trained to work with patients with Down syndrome. Repetition is often the key to getting patients comfortable with diagnostic testing. With time, the reproducibility and accuracy of the testing improve. When I prepare patients for cross-linking, we practice the postoperative regimen for weeks before the procedure. I ask the patient and their family to instill artificial tear drops in preparation for having to use post-operative medications.
I also ask the patients to practice wearing protective goggles and masks around the house and while sleeping in the weeks before the procedure. With some people who I feel would be able to tolerate a procedure in the office, we practice placing the eye speculum into the eye for several visits before the procedure visit. The speculum appears to be the most anxiety-provoking step for many patients and “practicing” placing the speculum ahead of time helps alleviate some of this anxiety. That said, many will need sedation or general anesthesia in order to tolerate the procedure.
Why do you think it’s important to raise awareness of keratoconus in the Down syndrome community?
Patients with Down syndrome are less likely to complain about their visual decline and so diagnosis can be missed or delayed. The sharpness of vision is decreased at baseline in some patients and diagnostic testing (even measuring vision) can be challenging. Additionally, there are currently no formal established screening guidelines for keratoconus in patients with Down syndrome. Awareness of this condition and routine screening should be established in order to be able to catch this condition early. This will allow us to stabilize the condition before significant vision loss occurs and hopefully be able to avoid corneal transplantation.
Stay on Top of It
While keratoconus can be a challenging condition, staying on top of your loved one’s diagnosis and routine checkups is very important. Be alert and keep a watchful eye on their behavior as well as any signs that their vision may be deteriorating. For more information on keratoconus and available treatment options or to hear from members within the Living with KC and Down syndrome community, visit our blog.
Follow #KCExperts and #LivingWithKC on our social channels (Facebook, Twitter, and Instagram) for more information.
[1] Millodot et al. A prevalence and associated factors of keratoconus in Jerusalem. Ophthalmic Epidem. 2011; 560747
[2] Sugar et al. What causes Keratoconus? Cornea 2012; 31: (6) 716-9
[3] Edwards et al. The genetics of keratoconus. Clin Exp Ophthalmology. 2001; 29:(6)245-51
[4] Prevalence of Keratoconus in Persons With Down Syndrome in a National Registry in Norway. JAMA Network Open (IF8.483), Pub Date: 2021-03-01
[5] Nielsen et al. Incidence and prevalence of keratoconus in Denmark. Acta Ophthalmologica Scand. 2007; 85: (8) 890-2
[6] Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998;42:297–319. 10.1016/S0039-6257(97)00119-7
[7] Edwards M, McGhee CNJ, Dean S. The genetics of keratoconus. Clin Exp Ophthalmol 2001;29:345–51
[8] Shapiro et al. The ocular features of Down Syndrome. Am J Ophthalmology. 1985; 99; 659-63
[9] Haugen OH, Høvding G, Eide GE. Biometric measurements of the eyes in teenagers and young adults with Down syndrome. Acta Ophthalmol Scand 2001;79:616–25
[10] Alio, J. L., Vega-Estrada, A., Sanz, P., Osman, A. A., Kamal, A. M., Mamoon, A., & Soliman, H. (2018). Corneal morphologic characteristics in patients with down syndrome. JAMA Ophthalmology, 136(9), 971. https://doi.org/10.1001/jamaophthalmol.2018.2373
[11] Kristianslund, O., & Drolsum, L. (2021). Prevalence of keratoconus in persons with Down Syndrome: A Review. BMJ Open Ophthalmology, 6(1). https://doi.org/10.1136/bmjophth-2021-000754
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