Question

What are different types of phakic IOLs and their indications?

Hint:

Phakic IOLs are ideal for patients with high refractive errors or thin corneas who are not suitable candidates for laser refractive surgery (LASIK).

Answer 1

Phakic Intraocular Lenses (IOLs) are lenses that are implanted into the eye without removing the natural lens (keeping the eye "phakic"). They are mainly used for correcting refractive errors such as myopia, hyperopia, and astigmatism in patients who are not candidates for laser refractive surgery (LASIK) or those with higher degrees of refractive error.
Types of Phakic IOLs:
1. Anterior Chamber Phakic IOLs:
- These IOLs are implanted in the anterior chamber of the eye, between the cornea and the iris.
- The most common type is the angle-supported anterior chamber IOL, which is placed in the anterior chamber angle and is supported by the angle structures.
Indications:
- Primarily used in patients with high degrees of myopia or hyperopia.
- Suitable for patients with thin corneas or large refractive errors where LASIK is not an option.
2. Posterior Chamber Phakic IOLs (e.g., Visian ICL):
- These lenses are implanted in the posterior chamber, behind the iris and in front of the natural lens.
- The implantable collamer lens (ICL) is the most common posterior chamber phakic IOL.
Indications:
- Used for high myopia or hyperopia in patients who are not suitable for LASIK.
- Suitable for patients with thicker corneas, low endothelial cell counts, or high refractive errors (up to -20 diopters or +10 diopters).
3. Torical Phakic IOLs:
- These IOLs are designed for patients with astigmatism. They are a combination of the standard anterior or posterior chamber IOLs with additional astigmatic correction built into the lens.
Indications:
- Patients with high myopic astigmatism or hyperopic astigmatism who need both astigmatic correction and refractive correction.