Keratoconus prevalence: Much more common than previously thought

Previously, the frequency of keratoconus was most commonly reported to be 1 in 2,000, a value based on a registration study in Olmsted County, Minnesota, conducted 1935-1982; the study reported a prevalence of 54.5 per 100,000 cases. As advancement in technologies such as corneal topography led the way for earlier detection of subclinical cases, the prevalence of keratoconus was then found to be much, much more common. An epidemiological study conducted via data extraction from the largest health insurance provider in the Netherlands concluded that keratoconus among the age group of 10-40 years, the annual incidence of the disease was 1:7500 (13.3 cases per 100,000) and the estimated prevalence was 1:375 (265 cases per 100,000). These values are 5 to 10-fold higher than previously documented. Wow!

We know that the progressed unilateral and even more so bilateral form of the disease can be very visually significant and even life-altering. If caught early, you can change the outcome of someone’s life before keratoconus has had a chance to functionally impact it, but the key is early diagnosis, close monitoring, and intervention when necessary. So, are you asking the right questions? Are you screening your patients, if so, whom? Are you connected with the right team of professionals to help you manage your patients comprehensively?

A family history of keratoconus – when to screen

Keratoconus affects all countries and races, yet it has become clear that the prevalence distribution is not uniform throughout the world. Differences in prevalence and age of onset among ethnic populations point at strong genetic influences in the presentation, course, and outcome of the disease. Patients with any indication of a family history of keratoconus must be screened and closely monitored. Patients with an ocular history of keratoconus should be educated to have family members screened – children, siblings, etc. Early detection can dramatically alter the outcome. Although the natural history and pattern of progression of keratoconus are variable, the process typically begins around the age of puberty and progresses over the course of one to two decades, after which point it eventually stops. The severity of the disease at the time the progression stops can vary from mild unilateral or bilateral irregular astigmatism, to severely ectatic, scarred corneas in need of high-risk surgical intervention. Early diagnosis is crucial in the hopes of preventing any visually significant and often debilitating effects.

Screening tools

Diagnosis of keratoconus happens at, “hello.” Asking the right questions and weeding out the pertinent answers sets a path for proper management. Having the right screening tools in a primary eye care setting using new advanced technologies can profoundly impact the course of a life destined for severe visual hurdles. Technologies such as Scheimpflug imaging tomography assess the corneal surface layers for early signs of abnormal elevation or thinning. Wavefront aberrometry identifies higher-order aberration, seen not only in severe cases but also in subclinical forms of keratoconus. Anterior segment OCT can pick up irregular corneal epithelial thinning next to areas of thickening, raising a red flag. Technologies used to assess corneal biomechanics, currently being explored for future implementation, will eventually be used to detect abnormalities diagnostic of keratoconus at even earlier stages. Having access to all of the right instruments is crucial in properly identifying the disease in a comprehensive manner. If these instruments are unavailable in your setting, you should be very familiar with someone in the vicinity of your practice who can offer these tools to screen the patients in question.

Treatment options

Your role in the care of each patient, no matter the type of disease presented, is to EDUCATE. Break down the findings, clearly explain what they mean and the potential prognosis if 1) ignored, 2) closely monitored by experienced professionals, 3) treated. Do not force the patient’s hand (or eye in this case!) in selecting their wellness management, but do stress the importance. Offer a referral for a second opinion, provide resources to seek proper management if you do not manage this condition in your setting, partner with colleagues to co-manage the patient along their journey.

With the development of corneal cross-linking, as eye health professionals, we now have the ability to impact the natural history of the disease, patients, and their family members can have a chance at normal visual function and a normal life. Studies have shown that crosslinking is highly effective in controlling progression, which offers great hope when considering the management of keratoconus.

Parting words…

New and developing technologies are allowing us to screen for and diagnose keratoconus at very early stages in the disease process, showing us that keratoconus is far more prevalent than previously thought. The treatment options that enable us to halt disease progression are becoming more effective and safer. With that in mind, it is becoming crucial that eye care professionals provide access for patients to these technologies, with the goal of preserving vision for many who in the past would have suffered from progressive keratoconus.