Tomographic and Refractive Characteristics of Pediatric First-Degree Relatives of Keratoconus Patients

To evaluate the tomographic and refractive characteristics of pediatric first-degree relatives of patients with keratoconus.

Cross-sectional study.

Setting: Department of Ophthalmology at the American University of Beirut Medical, Beirut, Lebanon.

Pediatric first-degree relatives of patients with keratoconus. Both eyes of all participants aged between 6 and 18 years were included and studied.

Soft contact lens use in the past 2 weeks or rigid gas-permeable lens wear within 4 weeks, history of prior ocular surgery or infectious keratitis, and unreliable corneal tomography. Masking and Randomization: Two masked cornea and refractive surgeons of different training backgrounds independently evaluated the participants' tomographic outputs. Additionally, the tomographic data were analyzed using Smadja's decision tree.

Scheimpflug tomography, manifest refraction, and slit-lamp examination.

Anterior curvature indices, posterior elevation values, thinnest pachymetry, and subjective and objective tomographic interpretation.

One hundred eighty-three subjects were recruited. Tomographic evaluation after Cohen's kappa coefficient analysis revealed 32 patients as having keratoconus (17.5%), while 35 patients (19.1%) were labeled as keratoconus by objective analysis. There were 11.5%-15.5% of patients with keratoconus aged less than 11 years, 18.0% aged 12-15 years, and 25.5% aged 16-18 years. Their respective steepest anterior curvature and thinnest pachymetry are 44.8 ± 6.5 diopters (D) and 515.9 ± 39.2 μm, 47.34 ± 3.4 D and 496.1 ± 37.9 μm, and 49.7 ± 6.1 D and 486.0 ± 66.5 μm. A total of 37.5% of the keratoconus patients were unilateral as evaluated by tomography alone.

The prevalence of keratoconus in pediatric first-degree relatives of diagnosed keratoconus patients is high. Screening in this high-risk group is warranted.