How to effectively correct residual ametropias

Ophthalmologists have been seeking to achieve the same quality and surgical success for high ametropia as has already been achieved for moderate ametropias. The analysis of refractive outcomes of procedures such as the Ferrara Ring implantation to correct early keratoconus, thermokeratoplasty to correct hypermetropia and corneal transplantation frequently reveals the presence of a residual ametropia that results in low or moderate visual acuity. It is our belief that the Artisan phakic intraocular lens (IOL) (Advanced Medical Optics) could go some way to adressing this issue. Hence, after mastering the surgical procedures involved for the implantation of the phakic IOL and its indication as an option for refractive surgery, we looked to assess the benefits of secondary lens implantation in the correction of residual ametropia and the impact it has on patient quality of life.

In 1986, an intrastromal corneal ring currently known as the Ferrara Ring1,2 was developed. Its main indication is to correct the changes in corneal curvature that are characteristic of keratoconus. The corneal ring keeps the corneal structure unchanged and preserves the optical zone. Additionally, it preserves positive asphericity, thus improving the visual quality by reducing halos and glares and avoiding poor night vision.