Topographic corneal changes in children with moderate to severe blepharokeratoconjunctivitis

To determine the corneal topographic characteristics of children with blepharokeratoconjunctivitis (BKC), a chronic inflammatory ocular surface disease involving the lid margin, conjunctiva, and cornea.

The corneal topography of 21 children diagnosed with BKC between March 2008 and June 2019 at a single institution were reviewed retrospectively. Pachymetry and asymmetry indices were also analyzed.

Mean flat keratometry (K1), steep keratometry (K2), maximum keratometry (K_max), and topographic astigmatism (TA) were 42.61 ± 2.63 D, 46.00 ± 3.17 D, 51.00 ± 5.29 D, and 3.39 ± 2.60 D, respectively. Mean central corneal thickness (CCT) was 528.8 ± 72.2 μm; mean thinnest point (TP) was 487.00 ± 88.28 μm; 47% of eyes had a TP of <500 μm. Compared with previously published pediatric normative values, K2, K_max, and TA were significantly higher (46.00 ± 3.17 vs 45.16 ± 0.27, 51.00 ± 5.29 vs 45.76 ± 0.28, and 3.38 ± 2.48 vs 2.81 ± 0.19 [P < 0.0001]), whereas mean CCT and TP were significantly lower in the BKC group. 72.2% of cases fulfilled the Rabinowitz diagnostic criteria for ectasia: 67% had a K_max >47.2 D and 31% had an inferior-superior asymmetry value >1.2 D. Using topography-derived indices comparing the superior and inferior corneal characteristics, the index of height decentration, index of surface variance, and index of vertical asymmetry were found to be abnormal in 83%, 69%, and 64% of cases, respectively.

Children with moderate-to-severe BKC may present with significant topographic corneal changes that can mimic corneal ectasia. Corneal topography could be an important tool in evaluating corneal involvement and explaining reduced visual function due to refractive changes.