American Journal of Ophthalmology, September 2018
In a recent case series, corneal ectasia was an incidental finding in patients with Stevens-Johnson syndrome (SJS), an inflammatory disease affecting skin and mucous membranes. Subsequently, Maharana et al. assessed topographic changes in patients with chronic SJS and concluded that corneal ectasia is a common but often-missed contributor to poor visual acuity.
This prospective observational study included 30 eyes of 15 consecutive patients (median age, 26 years; 11 males) with chronic SJS who were referred to a cornea clinic. In all cases, SJS was caused by medication-induced hypersensitivity reaction. The median time from disease onset to assessment was7 years (range, 1-27 years).
The authors used a Scheimpflug system (Pentacam-HR, Oculus) for enhanced detection of corneal ectasia. Repeat imaging was performed until a good scan was obtained. Primary outcomes were best-corrected distance visual acuity (BCDVA), maximum corneal curvature (Kmax), anterior and posterior elevations, thinnest pachymetry, and Sotozono severity score. Final analyses were performed on 21 eyes.
At presentation, median BCDVA was 0.8 logMAR units, Schirmer score was 0 mm, and Sotozono score was 11. Tomography revealed corneal ectasia (Kmax >48 D) in 76.2% of eyes (mean Kmax, 58.37 ± 14.89 D). Front and back elevations on Belin/Ambrósio ectasia display were 42 µm (range, 10-176 µm) and 267 µm (range, 15-2,392 µm), respectively. Mean pachymetry was 377.76 ± 165.05 µm (range, 133-448 µm). The point of maximum ectasia was peripheral in 57.1% of eyes, central in 23.8%, and both peripheral and central in 19.1%. Spearman correlations indicated that deterioration of BCDVA and elevation of Kmax were linked to higher Sotozono severity scores. Associations between disease severity and presentation time, thinnest pachymetry, or anterior/posterior elevations were not significant.
According to the authors, their findings suggest that higher Sotozono scores denote more severe ectasia and that posterior elevation ≥15 µm signals early ectasia. However, validation is needed.
To properly manage SJS and its long-term effects, they advocate checking for corneal ectasia in all patients with the syndrome, especially if reduced visual acuity seems disproportionate to disease severity.
The original article can be found here.