Originally published in NKCF Update (June 2024).

A groundbreaking study on the state of pediatric keratoconus in the US was conducted by the Illinois College of Optometry (ICO). The results were recently published in the journal Eye & Contact Lens.

In response to several international papers demonstrating the incidence of keratoconus varies by geographic region and among certain ethnic groups, members of the International Keratoconus Academy (IKA) joined forces with ICO to conduct a large-scale pediatric screening in the United States.

Using an existing eye clinic staged by ICO as the study center, eye care professionals who conduct eye exams also performed tomographic scans on students who volunteered to participate in the study. The clinic serves students from the Chicago Public Schools. Study participants were largely low-income; ethnicity recorded for subjects was Black (60.7%) followed by Hispanic (34.5%), Asian (1.95), Mixed (1.4%), White (1.2%), and Middle Eastern (0.2%).

2,007 students were enrolled over a 2-year period. Keratoconus (KC) was diagnosed in six, and KC was suspected in another three subjects.

With nine KC or possible-KC subjects, the prevalence is 1 in 223, almost 10 times higher than the outdated but often quoted estimate of 1:2000.

Even if the KC-suspected subjects were excluded, the six students diagnosed with keratoconus computes to 1 in 334 for this urban population. This study demonstrates with certainty that keratoconus is not a rare disease in the U.S.

Investigators were able to include subjects as young as 4 years old; the average participant was 11 years old. Other research has shown that when keratoconus is found in pediatric patients, it can be more aggressive than when corneal changes begin in the late teen or adult years. When children are affected, KC tends to progress faster and is often more advanced when it is finally diagnosed.

Dr. Jennifer Harthan, OD, first author of the paper and Professor at the Illinois College of Optometry, remarked on the importance of the findings, “These updated prevalence findings can be used to help educate patients, caregivers, and pediatric health workers (optometrists, ophthalmologists, pediatricians, and school nurses) to ensure that we aren’t missing pediatric keratoconus.”

The authors of the Chicago study noted that tomographic scans are typically not included in a comprehensive eye exam, but eye doctors should consider performing scans, particularly in young patients who have risk factors such as high astigmatism or a family history of KC.

Dr. Harthan added, “It is important for industry to develop affordable instruments for early screening and for practitioners to implement them for timely diagnosis, monitoring, and treatment.”

The authors observed that until the American Medical Association generates a CPT code (Current Procedural Terminology) for pediatric keratoconus screening, insurers will not cover the costs of a tomographic scan. This discourages many doctors from investing in the technology or asking families to pay for the test out-of-pocket, which can result in delayed diagnosis for children at risk.

This paper’s authors included several key advisors to the National Keratoconus Foundation, including first author, Dr. Jennifer Harthan OD; Dr. John Gelles OD, Dr. Steven Greenstein MD and Dr. Peter Harsh MD of the Cornea and Laser Eye Institute in New Jersey and co-founders of the International Keratoconus Academy, Dr. Andrew Morgenstern OD and Dr. Barry Eiden OD.

Reference:  Harthan JS, Gelles JD, et al, Prevalence of Keratoconus Based on Scheimpflug Corneal Tomography Metrics in a Pediatric Population from a Chicago-Based School Age Vision Clinic, Eye Contact Lens, 50:121-125, 2024.