ICLs

Implantable collamer lenses (ICLs) are a type of phakic intraocular lens implanted to correct refractive errors. The lens is placed in the posterior chamber between the iris and the natural crystalline lens. Made from collamer, a biocompatible material, ICLs can correct moderate to high myopia and myopic astigmatism, with toric designs addressing astigmatic error. They are often considered when corneal refractive procedures are unsuitable or insufficient.

Indications for ICLs include high refractive error, thin corneas, irregular corneal shape, or contact lens intolerance. They are commonly used for moderate to high myopia and can be configured to correct myopic astigmatism. Candidacy requires a stable prescription, adequate anterior chamber depth, healthy retina, and no active ocular disease. Contraindications include active infection, uncontrolled glaucoma, significant cataract, or insufficient space for safe lens placement.

The surgical procedure is typically performed under local anesthesia as an outpatient operation. A small corneal incision allows insertion of the ICL, which is placed behind the iris in the posterior chamber and sized to fit the eye. The eye is monitored for proper lens position and vault over the natural lens. Postoperative care includes anti-inflammatory and antibiotic drops, with follow-up visits to assess vision, lens position, and intraocular pressure.

Outcomes commonly include substantial improvement in uncorrected vision, with many patients achieving good functional acuity and refractive predictability within a fraction of a diopter. ICLs are considered reversible, as the lens can be removed or exchanged. Potential risks include cataract formation, elevated intraocular pressure, endothelial cell loss, and rare lens dislocation or pigment dispersion.