Exploring the Latest Advancements in Refractive Eye Surgery

Introduction

Refractive surgery encompasses a range of procedures designed to correct or minimize refractive errors such as myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia. With continuous advancements in technology, the options for refractive surgery have become more diverse, offering patients further choices tailored to their specific needs.

Laser Refractive Surgery

Laser in Situ Keratomileusis (LASIK) is one of the most well-known and commonly performed refractive surgeries. It involves creating a thin flap on the cornea using a femtosecond laser or microkeratome. The underlying corneal tissue is then reshaped with an excimer laser to correct the refractive error, and the flap is repositioned. Wavefront-Guided and Topography-Guided LASIK use detailed measurements of the eye’s optical system, creating a customized treatment plan to improve visual quality. LASIK provides quick recovery and high success rates, making it a popular choice for patients with myopia, hyperopia, and astigmatism.1 Indeed, the US Patient-Reported Outcomes With Laser In Situ Keratomileusis (PROWL) Studies showed that the vast majority of patients were satisfied with their treatment.2

Photorefractive Keratectomy (PRK) is a surface ablation technique where the corneal epithelium is removed, and the underlying corneal tissue is reshaped with an excimer laser. Unlike LASIK, PRK does not involve creating a corneal flap, making it a more suitable option for patients with thinner corneas. Though recovery time is longer compared to LASIK, the visual outcomes are similar.3

Small Incision Lenticule Extraction (SMILE) is a minimally invasive procedure that uses a femtosecond laser to create a small lenticule (a thin disc of corneal tissue) within the cornea. This lenticule is then removed through a small incision, reshaping the cornea and correcting the refractive error. SMILE may offer certain benefits such as the reduction of dry eye symptoms.4

Intraocular Lenses

Refractive Lens Exchange (RLE) involves removing the natural lens and replacing it with an artificial intraocular lens (IOL). This procedure is similar to cataract surgery and is commonly used to correct myopia, hyperopia, astigmatism, and presbyopia. Modern IOL options include toric lenses, which correct astigmatism, and multifocal lenses, which create multiple focal points to provide unaided vision at near, intermediate, and far distances. Extended Depth of Focus (EDOF) lenses are designed to provide a continuous range of focus, offering excellent unaided distance and intermediate vision, with reasonable near vision.5

Phakic Intraocular Lenses (PIOLs) are advanced vision correction devices implanted in the eye while preserving the natural lens. They are primarily used for patients with high refractive errors or those who are not suitable candidates for laser eye surgery. Given its success and the evolving landscape of refractive surgery, it is anticipated that the indications for PIOLs will broaden in the future, making them a more common option for a wider range of patients. PIOLs can be implanted in either the anterior chamber (between the cornea and iris) or the posterior chamber (behind the iris). The Visian ICL (STAAR Surgical), a popular posterior chamber PIOL, is particularly renowned for its excellent visual outcomes and safety profile.6

Safety and Patient Considerations

Refractive surgery has a high success rate, but it is crucial to consider patient-specific factors such as corneal thickness, refractive error severity, and overall eye health. Preoperative evaluations, including corneal topography and wavefront analysis, are essential to determine the most suitable procedure for each patient.

Possible side effects of refractive surgery may include dry eye, glare, and halos. While most of these issues resolve over time, some patients may experience persistent symptoms. Serious complications, such as infection or ectasia (corneal weakening), are rare but can occur. It is important for patients to follow postoperative care instructions and attend all follow-up appointments to ensure optimal outcomes.

Future Directions

The field of refractive surgery continues to evolve with ongoing research and technological advancements. Future developments may include:

• Artificial Intelligence (AI) and Machine Learning: AI algorithms can enhance preoperative evaluations and improve patient selection, leading to better surgical outcomes.
• Stromal Lenticule Implantation: Lenticules removed during SMILE procedures can potentially be used to treat hyperopia or presbyopia, offering a novel approach to corneal reshaping.

Conclusion

Although refractive surgery, as discussed here, is an elective procedure, its impact on people’s lives is profound. For many, the decision to undergo refractive surgery goes beyond convenience, marking an important step toward greater independence and an enhanced quality of life. With modern, precise, and reliable techniques, refractive surgery is transformative, offering a newfound sense of freedom to individuals who have long been dependent on contact lenses or glasses.

References available on request

Written by Mr Nakul Mandal, MRCOphth, PhD, FEBO, PgDip CRS, Consultant Ophthalmic Surgeon, Blackrock Health Galway Clinic

Mr Frank Kinsella, MRCPI, FRCOphth, FWCRS, Consultant Ophthalmic Surgeon, Blackrock Health Galway Clinic

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