This article was originally published in a sponsored newsletter.

Keratoconus is a bilateral and often asymmetric condition producing progressive corneal thinning, corneal steepening, and corneal protrusion, which results in irregular astigmatism and reduced visual acuity.¹ Keratoconus typically develops in the second and third decades of life. All ethnicities and sexes are affected.

In children, keratoconus is more aggressive than in adults. Since research on keratoconus in the pediatric population is restricted, a study aimed to determine the frequency of keratoconus by analyzing corneal tomography measurements in a minority (Black and Latinx), mainly underserved low-income (based on zip code) pediatric population. The study evaluated variations in corneal tomography measurements among the two races or differences among age groups in this population.

The corneal tomography delivered accurate and reliable data from both the anterior and posterior corneal surfaces. Additional indices are valuable for the diagnosis and monitoring of keratoconus.² The early diagnosis and detection of keratoconus is pertinent to preserve vision and prevent corneal transplantation. Additionally, the inability to identify, diagnose, and treat keratoconus may interfere with classroom performance.²

In this prospective study, 2,133 children aged 3 to 18 years in Chicago Public Schools were examined at a school-based vision clinic. The children were divided into three age groups: 3 to 6 years, 7 to 12 years, and 13 to 18 years. Analysis of four tomography measurements (Belin-Ambrósio enhanced ectasia display total deviation value [BAD] final D, maximum Ambrosio's relational thickness index [ART-Max], inferior-superior [I-S] ratio, and thinnest point asymmetry) were acquired.

In the study cohort, the mean astigmatism on the anterior cornea was −1.39D ± 1.45D. The mean tomography indices were 0.95 ± 0.74 for BAD Final D, 457.34 ± 94.83 for ART-Max, 0.01 ± 0.68 for I-S ratio, and 9.60 ± 25.55 for thinnest point asymmetry. Among age groups, there was a statistically significant difference for BAD final D (p< 0.001), ART-Max (p< 0.001), and thinnest point asymmetry (p= 0.006). The two indices used for screening for high risk of keratoconus were the BAD final D and ART-Max. The authors recommend that future analysis could be done to evaluate the diagnostic criteria against the study cohort data.

A challenge in the pediatric population is that normative data have not been well-defined with current tomography indices utilized for the early diagnosis and long-term monitoring of keratoconus. In the pediatric population, it is pertinent to not only detect individuals who have keratoconus but also keratoconus suspects for monitoring and early intervention. Mild to moderate cases of progressive keratoconus may be treated with corneal collagen cross-linking. In all severities of keratoconus, specialty contact lenses, including scleral lenses, may be employed to rehabilitate vision.

This is the first study in a pediatric population to provide a set of normative data on the four tomography measurements, offering a reference for the ability to diagnose keratoconus for Black and Latinx children. Future studies could examine different ethnicities and compare pediatric to adult data. This may offer guidance to evaluate the current keratoconus diagnosis criteria and assist with the early diagnosis of keratoconus in the pediatric population.

REFERENCES

1. Santodomingo-Rubido J, Carracedo G, Suzaki A, Villa-Collar C, Vincent SJ, Wolffsohn JS. Keratoconus: An updated review. Cont Lens Anterior Eye. 2022 Jun;45:101559.

2. Zhuang X, Harthan JS, Block SS, Tullo W, Barry Eiden S. Analysis of corneal tomography in select Black and LatinX children. Cont Lens Anterior Eye. 2022 Dec;45:101717.

Melissa Barnett, OD, FAAO, FSLS, is the Director of Optometry at the University of California, Davis, specializing in anterior segment disease and specialty contact lenses. She is the past president of the Scleral Lens Education Society and is past chair of American Optometric Association Contact Lens and Cornea Section. She is an advisor to and/or has received honoraria or travel expenses from AccuLens, Alcon, Allergan, Bausch + Lomb, Bruder, Contamac, CooperVision, Johnson & Johnson Vision, Ocusoft, ScienceBased Health, Shire, Tarsus, and Visus Therapeutics.