High Myopia and Cataract Surgery: Challenges, Considerations, and Outcomes

Introduction

As the prevalence of myopia continues to rise globally, ophthalmologists are increasingly encountering patients with high myopia requiring cataract surgery. This combination presents unique challenges due to the anatomical and physiological characteristics of highly myopic eyes. In this article, we'll explore the key considerations, surgical techniques, and outcomes associated with cataract surgery in patients with high myopia.

Preoperative Considerations

Proper preoperative assessment is crucial for successful outcomes in highly myopic cataract patients. Key considerations include:

• Accurate biometry: Axial length measurement is critical, as errors can lead to significant refractive surprises. Zhu et al. (2016) found that fixation stability can impact refractive outcomes in highly myopic eyes.
• IOL power calculation: Traditional formulas may be less accurate for very long eyes. Elhusseiny et al. (2022) reported that newer formulas like Barrett Universal II and Kane provide better refractive prediction for highly myopic eyes.
• Retinal examination: A thorough retinal assessment is essential due to the increased risk of retinal pathologies in high myopia.

Surgical Techniques and Intraoperative Considerations

Cataract surgery in highly myopic eyes requires special attention to several factors:

1. Capsulorrhexis: A slightly larger capsulorrhexis may be necessary due to the larger capsular bag in highly myopic eyes.
2. Phacoemulsification technique: Elhusseiny et al. (2022) recommend using chopping techniques to minimize stress on weak zonules.
3. IOL selection: Consider using a larger diameter IOL to reduce the risk of postoperative IOL decentration.
4. Anterior capsule polishing: This step can help reduce the risk of capsular contraction syndrome, which is more common in highly myopic eyes.

Postoperative Outcomes and Complications

While cataract surgery can significantly improve vision in highly myopic patients, it's important to manage expectations and be aware of potential complications:

• Visual acuity: Elhusseiny et al. (2022) reported that only 63% of myopic patients with axial length >26 mm achieve visual acuity of at least 20/40 after cataract surgery, mainly due to coexisting ocular comorbidities.
• Refractive outcomes: Highly myopic eyes tend to have greater hyperopic refractive errors postoperatively. Yokoi et al. (2013) found that eyes with axial length ≥31.00 mm had significantly higher postoperative refractive errors.
• Retinal detachment: The risk of retinal detachment is higher in highly myopic eyes after cataract surgery. Jeon et al. (2011) reported an incidence of 1.72% in highly myopic eyes compared to 0.28% in normal eyes.
• Posterior capsule opacification (PCO): Highly myopic eyes may have a higher risk of PCO development.

Quality of Life Improvements

Despite the challenges, cataract surgery can significantly improve the quality of life for highly myopic patients. Tan et al. (2022) found that vision-related quality of life improved more significantly in highly myopic patients after cataract surgery compared to normal axial length patients, with 86.7% achieving BCVA improvements of ≥0.2 logMAR units.

Conclusion

Cataract surgery in highly myopic eyes presents unique challenges but can lead to significant visual improvements and enhanced quality of life. Success depends on careful preoperative planning, appropriate surgical techniques, and diligent postoperative care. As the prevalence of high myopia continues to rise, ongoing research and technological advancements will likely further improve outcomes for this patient population.