Implantable Collamer Lens (ICL) Sizing in Advanced Keratoconus

This is the authors' abstract. We don't add key points for this paper.

A patient of advanced keratoconus underwent CXL followed by implantation of ICL. Pre-operative BCVA was 20/40 with mean refractive spherical equivalent (MRSE) of -12DS(OD) and -10DS(OS) respectively. Corneal refractive power was 56 D×13°/61.4D×103°(OD) and 55.3D×177°/61.5D×87°(OS). Anterior chamber depth from endothelium was 3.79 mm(OD) and 3.87mm(OS). Horizontal WTW measurement was 12.51mm (OD) and 12.72mm (OS). ICL of 13 mm, -22D (ICM130V4) was implanted in the right eye. Post operative BCVA was 20/60 with a high posterior vault which increased to 1.62 mm at 4 weeks. The ICL was replaced with an ICL of 12mm (2 sizes smaller), after which vault decreased to 636μ, UCVA was 20/30 with a well formed anterior chamber. Left eye was subsequently implanted with a 12 mm ICL and had an uneventful post operative course. Our experience suggests that WTW measurement in advanced keratoconus (57-60D) is fallacious possibly due to corneal and limbal stretching, resulting in difficulty in sizing of ICL. A modified nomogram for ICL size needs to be considered in cases of advanced keratoconus with K>55 D.