In highly myopic patients undergoing cataract surgery, the decision between implanting a zero power intraocular lens (IOL) or leaving the eye aphakic (without a lens) requires careful consideration. Here’s an overview of the key factors:
## Benefits of Zero Power IOL Implantation
**Stabilization of vitreous base:** Implanting a zero or low-power IOL helps stabilize the vitreous base and reduces complications associated with posterior capsule opacification[1]. This is particularly important in extremely myopic eyes which are at higher risk for retinal detachment.
**Improved refractive predictability:** Using a zero power IOL can provide better refractive predictability compared to leaving the eye aphakic. The Haigis formula has shown to be the most accurate for calculating IOL power in highly myopic eyes requiring minus-power or zero-power IOLs[1].
**Easier future adjustments:** If refractive changes occur over time, having an IOL in place allows for easier adjustments through IOL exchange or piggyback lens implantation.
## Considerations for Aphakia
**Simplicity:** In some ultra-myopic cases with very long axial lengths (>31 mm), leaving the eye aphakic may be considered to avoid the complexities of extremely low or minus-power IOL calculations[5].
**Reduced risk of complications:** Aphakia eliminates any IOL-related complications such as decentration or rotation.
## Conclusion
For most high myopes, implanting a zero or low-power IOL is generally preferred over leaving the eye aphakic[1]. This approach offers better long-term stability, reduces the risk of retinal complications, and provides a platform for potential future adjustments. However, the decision should be made on a case-by-case basis, considering factors such as:
– Axial length
– Corneal power
– Patient expectations
– Risk of retinal complications
Careful preoperative planning, including accurate biometry and IOL power calculation using formulas optimized for high myopia (like the Haigis formula), is crucial for achieving the best outcomes in these challenging cases[1].
Citations:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2992159/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5996677/
[3] https://assileye.com/blog/implantable-contact-lenses-for-myopia/
[4] https://www.reddit.com/r/myopia/comments/14spdvb/hows_your_life_with_high_myopia/
[5] https://www.youtube.com/watch?v=LsiUO7K4iuo
[6] https://www.youtube.com/watch?v=7YQ4OlVaCCc
[7] https://www.sciencedirect.com/science/article/pii/S0886335088801482
[8] https://emedicine.medscape.com/article/1221908-overview