Partial Visual Rehabilitation Using a Toric Implantable Collamer Lens in a Patient with Keratoconus: A Case Report with 20 Months of Follow-up
A 37-year-old man with keratoconus () could not tolerate RGP lens-wearing and did not want to have a corneal transplant or other corneal surgeries. He had been using RGP contact lenses in both eyes for 10 years. He was diagnosed with unilateral keratoconus of the left eye. Stable keratoconus was confirmed with refraction and corneal topography for 7 years (). In the right eye, the UCVA was 0.04 and the BSCVA was 0.7 with -3.75 -3.00 × 155A. In the left eye, the UCVA was 0.02, and the BSCVA was 0.4 with -12.00 -3.50 × 30A. The corneal refractive power was 58.40 / 48.70 diopters × 117A in the left eye (). With manifest refraction, a BSCVA of 0.4 was achieved. He was told that the maximal possible visual correction would be 0.4 or less because irregular astigmatism could not be corrected with toric ICL implantation. With informed consent, toric ICL implantation was performed without any surgical complications. After surgery, the manifest refraction became -0.75 × 180A with a UCVA of 0.5 and BSCVA of 0.7 at 1 month, which then shifted to +2.25 -0.50 × 180A with a UCVA of 0.4 and BSCVA of 0.7 at 9 months, and to -1.75 × 180A with a UCVA of 0.2 and BSCVA of 0.5 at 20 months. The anterior chamber depth, from the endothelium to the ICL, decreased from 2.21 mm at 1 month to 2.13 mm at 9 months follow-up, corresponding with mild corneal flattening and transient hyperopic changes (), without any vault changes (). At the last follow-up, 20 months after surgery, the ICL vault was decreased, resulting in mild deepening of the ACD from 2.13 mm to 2.17 mm, and the manifest refraction results finally stabilized at mild myopic astigmatism (). The efficacy and safety index were 1.0 and 1.75 at 9 months and 0.5 and 1.25 at 20 months (). Postoperative contrast sensitivity was also enhanced ().